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  Subjects -> ENGINEERING (Total: 2287 journals)
    - CHEMICAL ENGINEERING (192 journals)
    - CIVIL ENGINEERING (186 journals)
    - ELECTRICAL ENGINEERING (105 journals)
    - ENGINEERING (1206 journals)
    - ENGINEERING MECHANICS AND MATERIALS (385 journals)
    - HYDRAULIC ENGINEERING (55 journals)
    - INDUSTRIAL ENGINEERING (68 journals)
    - MECHANICAL ENGINEERING (90 journals)

ENGINEERING (1206 journals)                  1 2 3 4 5 6 7 | Last

Showing 1 - 200 of 1205 Journals sorted alphabetically
3 Biotech     Open Access   (Followers: 7)
3D Research     Hybrid Journal   (Followers: 19)
AAPG Bulletin     Hybrid Journal   (Followers: 6)
AASRI Procedia     Open Access   (Followers: 15)
Abstract and Applied Analysis     Open Access   (Followers: 3)
Aceh International Journal of Science and Technology     Open Access   (Followers: 2)
ACS Nano     Full-text available via subscription   (Followers: 235)
Acta Geotechnica     Hybrid Journal   (Followers: 7)
Acta Metallurgica Sinica (English Letters)     Hybrid Journal   (Followers: 5)
Acta Polytechnica : Journal of Advanced Engineering     Open Access   (Followers: 2)
Acta Scientiarum. Technology     Open Access   (Followers: 3)
Acta Universitatis Cibiniensis. Technical Series     Open Access  
Active and Passive Electronic Components     Open Access   (Followers: 7)
Adaptive Behavior     Hybrid Journal   (Followers: 11)
Adıyaman Üniversitesi Mühendislik Bilimleri Dergisi     Open Access  
Adsorption     Hybrid Journal   (Followers: 4)
Advanced Engineering Forum     Full-text available via subscription   (Followers: 6)
Advanced Science     Open Access   (Followers: 5)
Advanced Science Focus     Free   (Followers: 3)
Advanced Science Letters     Full-text available via subscription   (Followers: 7)
Advanced Science, Engineering and Medicine     Partially Free   (Followers: 7)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17)
Advances in Calculus of Variations     Hybrid Journal   (Followers: 2)
Advances in Catalysis     Full-text available via subscription   (Followers: 5)
Advances in Complex Systems     Hybrid Journal   (Followers: 7)
Advances in Engineering Software     Hybrid Journal   (Followers: 25)
Advances in Fuel Cells     Full-text available via subscription   (Followers: 15)
Advances in Fuzzy Systems     Open Access   (Followers: 5)
Advances in Geosciences (ADGEO)     Open Access   (Followers: 10)
Advances in Heat Transfer     Full-text available via subscription   (Followers: 21)
Advances in Magnetic and Optical Resonance     Full-text available via subscription   (Followers: 9)
Advances in Natural Sciences: Nanoscience and Nanotechnology     Open Access   (Followers: 28)
Advances in Operations Research     Open Access   (Followers: 11)
Advances in OptoElectronics     Open Access   (Followers: 5)
Advances in Physics Theories and Applications     Open Access   (Followers: 12)
Advances in Polymer Science     Hybrid Journal   (Followers: 41)
Advances in Porous Media     Full-text available via subscription   (Followers: 4)
Advances in Remote Sensing     Open Access   (Followers: 37)
Advances in Science and Research (ASR)     Open Access   (Followers: 6)
Aerobiologia     Hybrid Journal   (Followers: 1)
African Journal of Science, Technology, Innovation and Development     Hybrid Journal   (Followers: 4)
AIChE Journal     Hybrid Journal   (Followers: 30)
Ain Shams Engineering Journal     Open Access   (Followers: 5)
Akademik Platform Mühendislik ve Fen Bilimleri Dergisi     Open Access  
Alexandria Engineering Journal     Open Access   (Followers: 1)
AMB Express     Open Access   (Followers: 1)
American Journal of Applied Sciences     Open Access   (Followers: 28)
American Journal of Engineering and Applied Sciences     Open Access   (Followers: 11)
American Journal of Engineering Education     Open Access   (Followers: 9)
American Journal of Environmental Engineering     Open Access   (Followers: 16)
American Journal of Industrial and Business Management     Open Access   (Followers: 23)
Analele Universitatii Ovidius Constanta - Seria Chimie     Open Access  
Annals of Combinatorics     Hybrid Journal   (Followers: 3)
Annals of Pure and Applied Logic     Open Access   (Followers: 2)
Annals of Regional Science     Hybrid Journal   (Followers: 7)
Annals of Science     Hybrid Journal   (Followers: 7)
Applicable Algebra in Engineering, Communication and Computing     Hybrid Journal   (Followers: 2)
Applicable Analysis: An International Journal     Hybrid Journal   (Followers: 1)
Applied Catalysis A: General     Hybrid Journal   (Followers: 6)
Applied Catalysis B: Environmental     Hybrid Journal   (Followers: 15)
Applied Clay Science     Hybrid Journal   (Followers: 5)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 4)
Applied Nanoscience     Open Access   (Followers: 8)
Applied Network Science     Open Access  
Applied Numerical Mathematics     Hybrid Journal   (Followers: 5)
Applied Physics Research     Open Access   (Followers: 3)
Applied Sciences     Open Access   (Followers: 2)
Applied Spatial Analysis and Policy     Hybrid Journal   (Followers: 4)
Arabian Journal for Science and Engineering     Hybrid Journal   (Followers: 5)
Archives of Computational Methods in Engineering     Hybrid Journal   (Followers: 4)
Archives of Foundry Engineering     Open Access  
Archives of Thermodynamics     Open Access   (Followers: 7)
Arkiv för Matematik     Hybrid Journal   (Followers: 1)
ASEE Prism     Full-text available via subscription   (Followers: 3)
Asian Engineering Review     Open Access  
Asian Journal of Applied Science and Engineering     Open Access   (Followers: 1)
Asian Journal of Applied Sciences     Open Access   (Followers: 2)
Asian Journal of Biotechnology     Open Access   (Followers: 8)
Asian Journal of Control     Hybrid Journal  
Asian Journal of Current Engineering & Maths     Open Access  
Asian Journal of Technology Innovation     Hybrid Journal   (Followers: 8)
Assembly Automation     Hybrid Journal   (Followers: 2)
at - Automatisierungstechnik     Hybrid Journal   (Followers: 1)
ATZagenda     Hybrid Journal  
ATZextra worldwide     Hybrid Journal  
Australasian Physical & Engineering Sciences in Medicine     Hybrid Journal   (Followers: 1)
Australian Journal of Multi-Disciplinary Engineering     Full-text available via subscription   (Followers: 2)
Autonomous Mental Development, IEEE Transactions on     Hybrid Journal   (Followers: 8)
Avances en Ciencias e Ingeniería     Open Access  
Balkan Region Conference on Engineering and Business Education     Open Access   (Followers: 1)
Bangladesh Journal of Scientific and Industrial Research     Open Access  
Basin Research     Hybrid Journal   (Followers: 5)
Batteries     Open Access   (Followers: 4)
Bautechnik     Hybrid Journal   (Followers: 1)
Bell Labs Technical Journal     Hybrid Journal   (Followers: 23)
Beni-Suef University Journal of Basic and Applied Sciences     Open Access   (Followers: 4)
BER : Manufacturing Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Motor Trade Survey     Full-text available via subscription   (Followers: 1)
BER : Retail Sector Survey     Full-text available via subscription   (Followers: 2)
BER : Retail Survey : Full Survey     Full-text available via subscription   (Followers: 2)
BER : Survey of Business Conditions in Manufacturing : An Executive Summary     Full-text available via subscription   (Followers: 3)
BER : Survey of Business Conditions in Retail : An Executive Summary     Full-text available via subscription   (Followers: 3)
Bharatiya Vaigyanik evam Audyogik Anusandhan Patrika (BVAAP)     Open Access   (Followers: 1)
Biofuels Engineering     Open Access  
Biointerphases     Open Access   (Followers: 1)
Biomaterials Science     Full-text available via subscription   (Followers: 10)
Biomedical Engineering     Hybrid Journal   (Followers: 16)
Biomedical Engineering and Computational Biology     Open Access   (Followers: 13)
Biomedical Engineering Letters     Hybrid Journal   (Followers: 5)
Biomedical Engineering, IEEE Reviews in     Full-text available via subscription   (Followers: 17)
Biomedical Engineering, IEEE Transactions on     Hybrid Journal   (Followers: 31)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 9)
Biomedical Science and Engineering     Open Access   (Followers: 4)
Biomedizinische Technik - Biomedical Engineering     Hybrid Journal  
Biomicrofluidics     Open Access   (Followers: 4)
BioNanoMaterials     Hybrid Journal   (Followers: 2)
Biotechnology Progress     Hybrid Journal   (Followers: 39)
Boletin Cientifico Tecnico INIMET     Open Access  
Botswana Journal of Technology     Full-text available via subscription  
Boundary Value Problems     Open Access   (Followers: 1)
Brazilian Journal of Science and Technology     Open Access   (Followers: 2)
Broadcasting, IEEE Transactions on     Hybrid Journal   (Followers: 10)
Bulletin of Canadian Petroleum Geology     Full-text available via subscription   (Followers: 14)
Bulletin of Engineering Geology and the Environment     Hybrid Journal   (Followers: 3)
Bulletin of the Crimean Astrophysical Observatory     Hybrid Journal  
Cahiers, Droit, Sciences et Technologies     Open Access  
Calphad     Hybrid Journal  
Canadian Geotechnical Journal     Hybrid Journal   (Followers: 14)
Canadian Journal of Remote Sensing     Full-text available via subscription   (Followers: 41)
Case Studies in Engineering Failure Analysis     Open Access   (Followers: 8)
Case Studies in Thermal Engineering     Open Access   (Followers: 3)
Catalysis Communications     Hybrid Journal   (Followers: 6)
Catalysis Letters     Hybrid Journal   (Followers: 2)
Catalysis Reviews: Science and Engineering     Hybrid Journal   (Followers: 8)
Catalysis Science and Technology     Free   (Followers: 6)
Catalysis Surveys from Asia     Hybrid Journal   (Followers: 3)
Catalysis Today     Hybrid Journal   (Followers: 8)
CEAS Space Journal     Hybrid Journal  
Cellular and Molecular Neurobiology     Hybrid Journal   (Followers: 3)
Central European Journal of Engineering     Hybrid Journal   (Followers: 1)
CFD Letters     Open Access   (Followers: 6)
Chaos : An Interdisciplinary Journal of Nonlinear Science     Hybrid Journal   (Followers: 2)
Chaos, Solitons & Fractals     Hybrid Journal   (Followers: 3)
Chinese Journal of Catalysis     Full-text available via subscription   (Followers: 2)
Chinese Journal of Engineering     Open Access   (Followers: 2)
Chinese Science Bulletin     Open Access   (Followers: 1)
Ciencia e Ingenieria Neogranadina     Open Access  
Ciencia en su PC     Open Access   (Followers: 1)
Ciencias Holguin     Open Access   (Followers: 1)
CienciaUAT     Open Access  
Cientifica     Open Access  
CIRP Annals - Manufacturing Technology     Full-text available via subscription   (Followers: 11)
CIRP Journal of Manufacturing Science and Technology     Full-text available via subscription   (Followers: 14)
City, Culture and Society     Hybrid Journal   (Followers: 21)
Clay Minerals     Full-text available via subscription   (Followers: 10)
Clean Air Journal     Full-text available via subscription   (Followers: 2)
Coal Science and Technology     Full-text available via subscription   (Followers: 3)
Coastal Engineering     Hybrid Journal   (Followers: 11)
Coastal Engineering Journal     Hybrid Journal   (Followers: 5)
Coatings     Open Access   (Followers: 3)
Cogent Engineering     Open Access   (Followers: 2)
Cognitive Computation     Hybrid Journal   (Followers: 4)
Color Research & Application     Hybrid Journal   (Followers: 1)
COMBINATORICA     Hybrid Journal  
Combustion Theory and Modelling     Hybrid Journal   (Followers: 13)
Combustion, Explosion, and Shock Waves     Hybrid Journal   (Followers: 13)
Communications Engineer     Hybrid Journal   (Followers: 1)
Communications in Numerical Methods in Engineering     Hybrid Journal   (Followers: 2)
Components, Packaging and Manufacturing Technology, IEEE Transactions on     Hybrid Journal   (Followers: 26)
Composite Interfaces     Hybrid Journal   (Followers: 6)
Composite Structures     Hybrid Journal   (Followers: 259)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 182)
Composites Part B : Engineering     Hybrid Journal   (Followers: 236)
Composites Science and Technology     Hybrid Journal   (Followers: 216)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 14)
Computational Optimization and Applications     Hybrid Journal   (Followers: 7)
Computational Science and Discovery     Full-text available via subscription   (Followers: 2)
Computer Applications in Engineering Education     Hybrid Journal   (Followers: 6)
Computer Science and Engineering     Open Access   (Followers: 17)
Computers & Geosciences     Hybrid Journal   (Followers: 28)
Computers & Mathematics with Applications     Full-text available via subscription   (Followers: 5)
Computers and Electronics in Agriculture     Hybrid Journal   (Followers: 4)
Computers and Geotechnics     Hybrid Journal   (Followers: 10)
Computing and Visualization in Science     Hybrid Journal   (Followers: 5)
Computing in Science & Engineering     Full-text available via subscription   (Followers: 30)
Conciencia Tecnologica     Open Access  
Concurrent Engineering     Hybrid Journal   (Followers: 3)
Continuum Mechanics and Thermodynamics     Hybrid Journal   (Followers: 6)
Control and Dynamic Systems     Full-text available via subscription   (Followers: 9)
Control Engineering Practice     Hybrid Journal   (Followers: 42)
Control Theory and Informatics     Open Access   (Followers: 8)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  
CTheory     Open Access  
Current Applied Physics     Full-text available via subscription   (Followers: 4)
Current Science     Open Access   (Followers: 58)

        1 2 3 4 5 6 7 | Last

Journal Cover Advanced Synthesis & Catalysis
  [SJR: 2.729]   [H-I: 121]   [17 followers]  Follow
    
   Hybrid Journal Hybrid journal (It can contain Open Access articles)
   ISSN (Print) 1615-4150 - ISSN (Online) 1615-4169
   Published by John Wiley and Sons Homepage  [1577 journals]
  • Palladium-Catalyzed Regioselective Oxidative Annulation of Cyclohexanones
           and 2-Aminophenyl Ketones Using Molecular Oxygen as the Sole Oxidant
    • Authors: Wan-Lu Mu; Meirong Wang, Hui-Jing Li, Deng-Ming Huang, Yi-Yun Zhang, Chao-Yi Li, Ying Liu, Yan-Chao Wu
      Abstract: A facile oxidative annulation of cyclohexanones and 2-aminophenyl ketones that uses molecular oxygen as the sole oxidant is described. The reaction provides a direct approach to acridines, a structural motif for a large number of fluorescent sensors, functional materials, ligands, and pharmaceuticals. In the presence of a palladium catalyst, high regioselectivity is observed when using non-symmetric 3-substituted cyclohexanones. With the use of oxygen as the terminal redox moderator, the electron gap of the global redox condensation process is filled and the reaction efficiency is significantly promoted. This protocol possesses many advantages such as using non-hazardous oxidant and readily available starting materials, high regioselectivity, and water as the only by-product.
      PubDate: 2017-09-24T21:20:37.132654-05:
      DOI: 10.1002/adsc.201700715
       
  • Chemo- and Diastereoselective Construction of Indenopyrazolines via a
           Cascade aza-Michael/Aldol Annulation of Huisgen Zwitterions with
           2-Arylideneindane-1,3-diones
    • Authors: Yuming Li; Haikun Zhang, Rong Wei, Zhiwei Miao
      Abstract: A cascade aza-Michael/Aldol annulation of 2-arylideneindane-1,3-diones with in situ generated Huisgen zwitterions has been developed. This reaction afforded the desired products in moderate to good yields (up to 87%) with excellent chemo- and diastereoselectivity (up to 20:1). This strategy allows facile diastereoselective preparation of biologically important indenopyrazoline derivatives containing two contiguous chiral centers including a quaternary stereogenic center.
      PubDate: 2017-09-24T21:20:25.99175-05:0
      DOI: 10.1002/adsc.201701013
       
  • 4-Dimethylaminopyridine-Mediated [3+3] Cycloaddition of Aza-oxyallyl
           Cations and Nitrones
    • Authors: qianfa jia; Dongli Li, ming lang, kun zhang, Jian Wang
      Abstract: A new 4-dimethylaminopyridine (DMAP) mediated [3+3] cycloaddition of in situ generated aza-oxyallyl cations with nitrones is reported. This simple and efficient method delivers a series of new motifs in good to excellent yields under mild conditions. Furthermore, a 1.0 mmol scale reaction was performed in undiminished yield, demonstrating the practicality of this protocol for large-scale synthesis.
      PubDate: 2017-09-22T23:26:07.337557-05:
      DOI: 10.1002/adsc.201700415
       
  • Stereoselective Synthesis of 3,3’-Bisindolines by Organocatalytic
           Michael Additions of Fluorooxindole Enolates to Isatylidene Malononitriles
           in Aqueous Solution
    • Authors: Balaraman Kaluvu; Ransheng Ding, Christian Wolf
      Abstract: A highly diastereoselective organocatalytic reaction for the synthesis of fluorinated 3,3’-bisindolines exhibiting adjacent tetrasubstituted carbon stereocenters is described. A broad variety of heterochiral bisindolines was prepared in 91-99% yield using 3-fluorooxindoles and isatylidene malononitriles in the presence of catalytic amounts of triethylamine in water or aqueous solution. The reaction can be upscaled without compromising yield and diastereoselectivity and the general usefulness of this method was demonstrated with various Michael acceptors and extended to aldol and Mannich reactions.
      PubDate: 2017-09-22T23:26:02.414418-05:
      DOI: 10.1002/adsc.201701107
       
  • Copper-Catalyzed Radical Silylarylation of Ynones with Silanes: En Route
           to Silyl-Functionalized Indenones
    • Authors: Jin Xie; Zhongfei Yan, Chengjian Zhu
      Abstract: A copper-catalyzed radical silylarylation of ynones with commercially available silanes using DCP(dicumyl peroxide) as an efficient oxidant has been developed.This approach represents an efficient route to silyl-functionalized indenone derivatives in moderate to good yield. The resulting silyl-functionalized structures hold potential for further post-modification to construct complex target molecules. This protocol is distinguished by its excellent selectivity, gram scale-up ability and broad scope as well as readily available starting materials.
      PubDate: 2017-09-22T23:25:55.669318-05:
      DOI: 10.1002/adsc.201700926
       
  • Elemental Sulfur as Reaction Medium for the Synthesis of Fused Nitrogen
           Heterocycles by Oxidative Coupling between Cycloalkanones and Nitrogen
           Nucleophiles
    • Authors: Thanh Binh Nguyen; pascal retailleau
      Abstract: Molten elemental sulfur was found to be an excellent reaction medium for oxidative coupling between bis-aza nucleophiles and cycloalkanones to the fused diaza heterocycles. No extensive aromatization was observed when cyclohexanone was used. These reaction conditions tolerate a wide range of functional groups and are applicable to oxidation sensitive o-phenylenediamines.
      PubDate: 2017-09-22T23:25:44.22263-05:0
      DOI: 10.1002/adsc.201700919
       
  • Gold-catalyzed Fluorination of Alkynyl Esters and Ketones: Efficient
           Access to Fluorinated 1,3-Dicarbonyl Compounds
    • Authors: Gerald B. Hammond; Bo Xu, Xiaojun Zeng, Shiwen Liu, Zhichao Lu
      Abstract: We developed an efficient synthesis of 2-fluoro-1,3-dicarbonyl compounds using readily available alkynyl ketones or esters as starting material. The key step is the insertion of hydrogen fluoride (HF) to the gold carbene intermediate generated from cationic gold catalyzed addition of N-oxides to alkynyl ketones or esters. This method gives excellent chemical yields and regioselectivity with good functional group tolerance.
      PubDate: 2017-09-22T23:25:30.959455-05:
      DOI: 10.1002/adsc.201701179
       
  • Oxidative Phosphorylation of N-Aryl Glycine Amides via sp3 C-H
           Functionalization
    • Authors: Xiao-Dong Jia; Xiaofei Liu, Yu Shao, Yu Yuan, Yingzu Zhu, Wentao Hou, Xuewen Zhang
      Abstract: An efficient phosphorylation of various glycine amides has been developed for radical cation salt-induced C-H functionalization, producing a series of α-aminophosphonates in high yields. Different from reported approaches, trialkyl phosphite was chosen as the phosphorus nucleophile, and the scope investigation shows broad functional group tolerance and high efficiency of the oxidative phosphorylation. This method provides a new way to synthesize α-aminophosphonates.
      PubDate: 2017-09-21T21:21:01.676871-05:
      DOI: 10.1002/adsc.201700850
       
  • Asymmetric Organocatalytic Conjugate Addition of Thiocarboxylic Acids to
           In Situ-Generated ortho-Quinomethanes in Oil-Water Phases
    • Authors: Yi-Feng Wang; Mingming Chu, Cheng Zhang, Juanjuan Shao, Suosuo Qi, Biao Wang, Xiao-Hua Du, Dan-Qian Xu
      Abstract: An asymmetric conjugate addition of thiocarboxylic acids to in situ-generated ortho-quinomethanes (o-QMs) catalyzed by bifunctional squaramide catalysts has been developed. The transformation proceeds with high yields (up to 96%) and enantioselectivities (up to 96% ee) in the oil-water phases. The resulting thioester could be converted facilely into the chiral benzyl mercaptan in high yield without loss of enantioselectivity. The study also showed that the oil-water biphase contributed significantly to the efficiency of the catalytic system.
      PubDate: 2017-09-21T21:20:32.188413-05:
      DOI: 10.1002/adsc.201700825
       
  • Direct C-H Arylation as Chemoselective Single-Step Access to
           Organic-Electronics-Versatile π-Acceptor-π Type Building Blocks
    • Authors: Kuan-Ming Lu; Wei-Ming Li, Po-Yu Lin, Kuan-Ting Liu, Ching-Yuan Liu
      Abstract: Different from the traditional multi-step synthesis, a chemoselective direct C-H arylation is reported for the single-step synthesis of various useful π-acceptor-π (π-A-π) type building blocks for use in organic electronics. This well-optimized C-H heteroarylation exhibits good product yields, broad substrate scope, and high functional group compatibility. Application in the efficient synthesis of a new metal-free dye sensitizer for dye-sensitized solar cells (DSSCs) is also demonstrated.
      PubDate: 2017-09-20T21:20:42.148464-05:
      DOI: 10.1002/adsc.201700762
       
  • Dehydration-type Ti-Claisen Condensation (Carbonhomologation) of
           α-Heteroatom-substituted Acetates with Alkyl Formates: Utilization as
           Novel (Z)-Stereodefined Cross-coupling Partners and Application to Concise
           Synthesis of Strobilurin A
    • Authors: Yoo Tanabe
      Abstract: Abstract.TiCl4–Et3N or –Bu3N reagent conducted a highly (Z)-stereoselective carbon homologation (dehydration type Ti-Claisen condensation) of alkyl α-heteroatom (halo and sulfonyloxy)-substituted acetates (XCH2CO2R) with alkyl formates (HCO2R) to afford various alkyl β-alkoxy-α-halo or sulfonyloxy-substituted acrylates (24 examples; 51%–91% yield). Stereoretentive Suzuki-Miyaura, Negishi, and Sonogashira cross-couplings using the obtained methyl β-methoxy-α-halo or sulfonyloxy-substituted acrylates proceeded smoothly to produce a variety of β-alkoxy-α-substituted acrylates in moderate to high yield (35 examples; 29% – 99% yield). As a successful application, a 3-step straightforward synthesis of strobilurin A was performed utilizing the present reaction sequence (dehydration type Ti-Claisen condensation and Suzuki-Miyaura cross-coupling), wherein the geometry of the three consecutive olefins (2E,3Z,5E) was completely maintained.
      PubDate: 2017-09-19T03:40:52.223631-05:
      DOI: 10.1002/adsc.201700879
       
  • Asymmetric Hydrolytic and Aminolytic Kinetic Resolution of Racemic
           
    • Authors: Rajkumar Tak; manish kumar, Tusharkumar Menapara, Naveen Gupta, Rukhsana Kureshy, Noor-ul H. Khan, Eingathodi Suresh
      Abstract: New chiral macrocyclic Co(III) salen complexes 1-8 were synthesized and used as catalyst for asymmetric kinetic resolution of terminal epoxides and glycidyl ethers with aromatic/aliphatic amines and water as nucleophiles. This is the first occasion where a Co(III)-salen complex demonstrated its ability to catalyze AKR as well as HKR reactions. Excellent enantiomeric excess of epoxides, corresponding amino alcohols and diols (upto 99%) with quantitative yield were achieved by using the chiral Co(III) salen complexes in DCM at room temperature. This protocol was further extended for the synthesis of two important drug molecules i.e., (S)-Propranolol and (R)-Naftopidil. The catalytic system was also explored for the synthesis of chirally pure diol and chiral cyclic carbonate using carbon dioxide as a greener renewable C1 source. The catalyst was recycled upto 5 catalytic cycles with retention of enantioselectivity.
      PubDate: 2017-09-19T03:40:35.831647-05:
      DOI: 10.1002/adsc.201700788
       
  • Copper-Catalyzed Hydroamination of N-Allenylazoles: Access to
           Amino-Substituted N-Vinylazoles
    • Authors: Luca Alessandro Perego; Rémi Blieck, Julie Michel, Ilaria Ciofini, Laurence Grimaud, Marc Taillefer, Florian Monnier
      Abstract: Building on mechanistic studies, the innate capability of azoles to act as a directing group has been exploited to design an efficient and simple procedure for the hydroamination of N-allenylazoles with secondary amines. The reaction proceeds under mild conditions by copper(I) catalysis yielding the corresponding and original linear E allylic amines with total regio- and stereoselectivity. Density Functional Theory (DFT) calculations offer a mechanistic explanation of the significantly higher reactivity of N-allenyl-(1,2)-azoles compared to their 1,3-analogues as a result of the reaction-enhancing coordination of the pyridine-like nitrogen to the copper center.
      PubDate: 2017-09-18T21:40:43.240025-05:
      DOI: 10.1002/adsc.201700965
       
  • An Unexpected Domino Reaction of β-Keto Sulfones with Acetylene Ketones
           Promoted by Base: Facile Synthesis of 3(2H)-Furanones and Sulfonylbenzenes
           
    • Authors: Wei Tong; Qian-yu Li, Yanli Xu, Heng-shan Wang, Yan-yan Chen, Ying-ming Pan
      Abstract: An unexpected domino reaction of β-keto sulfones with acetylene ketones has been developed. The domino reaction of β-keto sulfones with diynones proceeded smoothly in the 30% mol K2CO3 without other additives, and afforded the novel 3(2H)-furanone derivatives. Replaced diynones with terminal alkyne ketones, the reaction regioselectivity was changed and sulfonylbenzenes were obtained via the benzannulation in good yields.
      PubDate: 2017-09-18T21:40:35.498945-05:
      DOI: 10.1002/adsc.201700830
       
  • Regioselective Epoxidations by Cytochrome P450 3A4 Using a Theobromine
           Chemical Auxiliary to Predictably Produce N-Protected β- or γ- Amino
           Epoxides
    • Authors: Vanja Polic; Kin Jack Cheong, Fabien Hammerer, Karine Auclair
      Abstract: N-Protected β- and γ-amino epoxides are useful chiral synthons. We report here that the enzyme cytochrome P450 3A4 can catalyze the formation of such compounds in a regio- and stereo-selective manner, even in the presence of multiple double bonds or aromatic substituents. To this end, the theobromine chemical auxiliary is used not only to control the selectivity of the enzyme, but also as a masked amine and to facilitate product recovery. Theobromine predictably directed epoxidation at the double bond of the fourth carbon from the theobromine group. Unlike with most catalysts, the selectivity did not depend on electronic or steric factors but rather on the position of the olefin relative to the theobromine group.
      PubDate: 2017-09-18T21:40:29.406882-05:
      DOI: 10.1002/adsc.201700637
       
  • A Deoxygenative [4 + 1] Annulation Involving N-Acyldiazenes for Efficient
           Synthesis of 2,2,5-Trisubstituted 1,3,4-Oxadiazole Derivatives
    • Authors: Rong Zhou; Ling Han, Honghui Zhang, Rongfang Liu, Ruifeng Li
      Abstract: An unprecedented highly efficient P(NMe2)3 [tris(dimethylamino)phosphine]-mediated deoxygenative [4 + 1] annulation of N-acyldiazenes with α-dicarbonyl compounds such as isatins, α-keto esters, and α-diketones is reported. The annulation reactions proceed smoothly under mild conditions to deliver a broad range of 2,2,5-trisubstituted 1,3,4-oxadiazole derivatives in moderate to excellent yields from readily available starting materials. It represents the first realization of [4 + 1] annulation mode involving N-acyldiazenes to construct five-membered heterocycles.
      PubDate: 2017-09-17T21:31:55.504283-05:
      DOI: 10.1002/adsc.201700935
       
  • Asymmetric Synthesis of Spirooxindole δ-Lactones with Vicinal Tertiary
           and Quaternary Stereocenters via Regio-, Diastereo-, and Enantioselective
           Organocatalytic Vinylogous Aldol− cyclization Cascade Reaction
    • Authors: Jeng-Liang Han; You-Da Cai, Chia-Hao Chang
      Abstract: A highly region-, diastereo-, and enantioselective organocatalytic vinylogous aldol−cyclization cascade reaction of prochiral 3-akylidene oxindoles to isatins has been achieved by using bifuctional organocatalysts. A variety of enantioenriched spirooxindole δ-lactones with vicinal tertiary and quaternary stereocenters were generated in good to excellent yields with good to high diastereoselectivities and enantioselectivities.
      PubDate: 2017-09-17T21:31:32.757548-05:
      DOI: 10.1002/adsc.201701104
       
  • A Case Study of Thiourea-Assisted Iminium Formation by Hydroxyl Anion
           Binding: Kinetic, Spectroscopic and Computational Evidences
    • Authors: Pedro Merino; Veronica Juste, Liher Prieto, Ignacio Delso, Ruben Manzano, Tomás Tejero, EFRAIM REYES, Jose L. Vicario
      Abstract: The experimental and computational study of the mechanism of the iminium-organocatalyzed formation of N-hydroxypyrrolidines from nitrones, as a case study, revealed a hitherto unknown mode of action for the Schreiner’s thiourea used as co-catalyst. The experimental data suggest that thiourea promotes the formation of the iminium ion through hydroxyl anion recognition forming a stable ion pair. Such an ion pair facilitates enolization of the nitrone through a H-bond network thus promoting the reaction with iminium ion. The computational model supports the mechanism and the catalytic cycle. This mechanistic rationale is supported by the lack of reactivity of preformed iminium ion with the nitrone in the absence of thiourea-hydroxyl complex and the observed reactivity when a complex thiourea-tetrabutylammonium hydroxide is added
      PubDate: 2017-09-17T21:31:23.315897-05:
      DOI: 10.1002/adsc.201700986
       
  • Enzymatic Synthesis of Bufadienolide O-Glycosides as Potent Antitumor
           Agents Using a Microbial Glycosyltransferase
    • Authors: Kai Li; Jin Feng, Yi Kuang, Wei Song, Meng Zhang, Shuai Ji, Xue Qiao, Min Ye
      Abstract: Bufadienolides are a class of natural cardiotonic steroids and are well known for their antitumor activities. Their clinical use has been hindered by poor water solubility. Enzymatic glycosylation is a favorable approach to improve solubility of natural products. In this work, we describe the highly efficient one-step synthesis of bufadienolide O-glucosides and O-galactosides using a microbial glycosyltransferase YjiC1, with conversion rates from 63% to 99%. A total of 24 glycosides including 17 new compounds were obtained from 14 substrates, and their structures were identified by extensive NMR and high-resolution electrospray ionization mass spectrometry (HR-ESI-MS) analyses. These products belong to five types: glycosylation at 3β-OH, 7β-OH, 3β,7β-di-OH, 11α-OH, and 12β-OH. The O-glycosides at C-7β or C-11α of bufadienolides were reported for the first time. Moreover, the 3-O-glycosides exhibited significant cytotoxic activities against A549 and MCF7 human cancer cell lines, and showed potent inhibitory activities against Na+/K+-ATPase with IC50 values from 0.05-0.76 μM. Particularly, bufalin 3-O-β-D-glucoside showed enhanced water solubility (25-fold increase from bufalin) and potent antitumor activities (30% inhibition rate, 1.4 mg/kg, ip) on A549 human lung cancer xenograft Balb/c nude mice model, and could be a promising drug candidate.
      PubDate: 2017-09-17T21:31:11.671603-05:
      DOI: 10.1002/adsc.201700777
       
  • Copper-Mediated Thiolation of Unactivated Heteroaryl C-H Bonds with
           Disulfides under Ligand- and Metal-Oxidant-Free Conditions
    • Authors: Ya Li; Yuejin Liu, Bing-Feng Shi
      Abstract: Diverse synthesis of sulfenylated heteroarenes was achieved via a copper-mediated C-H thiolation assisted by 2-(pyridin-2-yl)isopropylamine (PIP-amine) directing group. The reaction features a broad substrate scope; good functional group tolerance; ligand- and metal-oxidant-free conditions; exceptional compatibility with aliphatic disulfides; and excellent yields, providing a highly efficient approach to the biologically important sulfenylated heteroarenes.
      PubDate: 2017-09-15T23:31:50.461868-05:
      DOI: 10.1002/adsc.201700949
       
  • Palladium-catalyzed Oxa-[4+2] Annulation of para-Quinone Methides
    • Authors: Zhenbo Yuan; Rui Pan, He Zhang, Lina Liu, Aijun Lin, Hequan Yao
      Abstract: An unprecedented palladium-catalyzed oxa-[4+2] annulation of para-quinone methides with allyl carbonates bearing a nucleophilic alcohol side chain has been developed. This method provided an efficient strategy to the construction of 2-oxaspiro-cyclohexadienones via 1,6-conjugated addition-mediated allylation in moderate to good yields. Preliminary results on asymmetric derivatives promised potential in the synthesis of enantioenriched frameworks.
      PubDate: 2017-09-15T23:31:40.282932-05:
      DOI: 10.1002/adsc.201700978
       
  • Rh(II)-Catalyzed Tandem Cyclization of Aliphatic
           N-Sulfonyl-1,2,3-triazoles and Alcohols for the Synthesis of 6-Alkoxy
           Piperidin-3-ones
    • Authors: Ran Zhang; Yang Li, Arshad Ali, Jiamin Hao, Xihe Bi, Junkai Fu
      Abstract: A diastereoselective synthesis of 6-alkoxy piperidin-3-ones based on a novel Rh(II)-catalyzed tandem cyclization of aliphatic N-sulfonyl triazoles and alcohols is reported herein for the first time, which provides a facile entry into piperidinones bearing quaternary carbons at C4 or C5 position. By employing an external chiral alcohol, the asymmetric version of the reaction has been realized.
      PubDate: 2017-09-15T23:31:34.600536-05:
      DOI: 10.1002/adsc.201700882
       
  • Catalyst- and Oxidant-Free Desulfonative C-P Couplings for the Synthesis
           of Phosphine Oxides and Phosphonates
    • Authors: Wen-Jing Xiao; Hong-Mei Guo, Quan-Quan Zhou, Xuan Jiang, De-Qing Shi
      Abstract: An efficient and practical approach towards phosphine oxides and phosphonates has been successfully developed through the desulfonative coupling of various sulfones with secondary phosphine oxides and phosphites. This protocol features simple experimental procedures under mild conditions (i.e., catalyst- and oxidant-free, room temperature and open to air). By doing so, a variety of alkynyl, alkenyl and allyl phosphine oxides or phosphonates can be produced in generally good reaction efficiency and selectivity (31 examples, up to 98% yield).
      PubDate: 2017-09-15T23:31:29.921771-05:
      DOI: 10.1002/adsc.201700886
       
  • Asymmetric [3+2] Annulations to Construct 1,2-Bispirooxindoles
           Incorporating a Dihydropyrrolidine Motif
    • Authors: Qing He; Wei Du, Ying-Chun Chen
      Abstract: Constructing chiral bispirooxindoles is difficult to achieve but highly attractive owing to their many potential applications in medicinal chemistry. Here we present an asymmetric [3+2] annulation reaction of Morita-Baylis-Hillman carbonates from isatins and isatin-based N-Boc ketimines under the catalysis of the newly designed multifunctional 4-dimethylaminopyridine-type substance. The reaction shows high γ-regioselectivity, producing highly complex 1,2-bispirooxindoles incorporating a dihydropyrrolidine motif in excellent yields with moderate to outstanding stereo- selectivity (dr>19:1, up to>99% ee). This protocol has been expanded to utilize trifluoromethyl-containing ketimines, delivering complicated architectures with fused and spirocyclic frameworks in modest enantioselectivity.
      PubDate: 2017-09-14T21:37:38.1218-05:00
      DOI: 10.1002/adsc.201700849
       
  • Development of Imino-λ3-iodanes with Improved Reactivity for Metal-Free
           [2+2+1] Cycloaddition-Type Reactions
    • Authors: Takafumi Baba; Shunsuke Takahashi, Yui Kambara, Akira Yoshimura, Victor Nemykin, Viktor Zhdankin, Akio Saito
      Abstract: Directed toward the enhancement of electrophilicity of imino-λ3-iodanes, we developed (tosylimino)pentafluorophenyl-λ3-iodane, which show the superior reactivity to the commonly used (tosylimino)phenyl-λ3-iodane for our previously reported [2+2+1]-type synthesis of imidazoles.
      PubDate: 2017-09-14T21:37:30.472021-05:
      DOI: 10.1002/adsc.201700934
       
  • Organocatalytic Enantioselective Synthesis of Trifluoromethyl-Containing
           Tetra-lin Derivatives by Sequential (Hetero)Michael
           Reaction-Intramolecular Nitrone Cycloaddition
    • Authors: Fernando Rabasa Alcañiz; Javier Torres Fernández, Maria Sanchez-Rosello, Tomás Tejero, Pedro Merino, Santos Fustero, Carlos del Pozo
      Abstract: The enantioselective synthesis of tetralin derivatives bearing a trifluoromethylated all-carbon quaternary stereocenter has been accomplished through a synthetic sequence comprising an organocatalytic -functionalization of ortho-1-trifluoromethylvinyl (hetero)aromatic conjugated aldehydes followed by intramolecular nitrone 1,3-cycloaddition reaction (INCR). Both nitromethane and N-Cbz-hydroxylamine were employed as nucleophiles in the initial organocatalytic conju-gate addition step, which provided the chiral information required for the subsequent diastereoselective INCR. Although diastereoselectivity was moderate, good yields and enantioselectivities were, in general, obtained. Interestingly, an inver-sion of the selectivity in the intramolecular cycloaddition step was observed when either nitromethane or N-Cbz-hydroxylamine were employed. This outcome was studied by means of theoretical calculations, which were in agreement with the experimental results. In addition, the ring opening of the isoxazolidine moiety rendered the corresponding fluor-inated diamino alcohols in a very efficient manner
      PubDate: 2017-09-14T21:37:26.267491-05:
      DOI: 10.1002/adsc.201700975
       
  • Rhodium(III)-Catalyzed Diastereoselective Synthesis of 1-Aminoindanes via
           C−H Activation
    • Authors: Sang Hoon Han; Neeraj Kumar Mishra, Mijin Jeon, Saegun Kim, Hyung Sik Kim, Seung-Young Jung, Young Hoon Jung, Jin-Mo Ku, In Su Kim
      Abstract: The rhodium(III)-catalyzed cross-coupling reaction between N-sulfonyl aldimines and various olefins such as maleimides, fumarates, maleates, α,β-unsaturated ketones, acrylate and nitroalkenes is described. This transformation efficiently leads to the diastereoselective synthesis of pharmacologically privileged 1-aminoindane derivatives via the C−H alkylation followed by subsequent intramolecular cyclization. Notably, single diastereomers in all cases were observed, and the relative stereochemistry of products was confirmed by the X-ray crystallographic data.
      PubDate: 2017-09-14T21:37:15.660909-05:
      DOI: 10.1002/adsc.201701082
       
  • Synthesis of Spiroindolenines via Regioselective Gold(I)-Catalyzed
           Cyclizations of N-Propargyl Tryptamines
    • Authors: Valentin Magné; Angela Marinetti, Vincent Gandon, Arnaud Voituriez, Xavier Guinchard
      Abstract: N-Propargyl tryptamines bearing N-substituents such as propargyl, allyl, alkyl or benzyl groups undergo regioselective gold-catalyzed cyclizations to the corresponding spiroindolenines, while it was previously shown that N-sulfonyl-N-propargyl tryptamines lead to achiral azepino[4,5-b]indoles. An asymmetric approach to these spiroindolenines is disclosed using chiral gold complexes, leading to enantiomeric ratios up to 84/16. The spiroindolenines could be late-stage functionalized using Huisgen cyclizations, Palladium-catalyzed cross couplings or reductions. Computational studies show that the reaction evolves via different mechanistic pathways depending on the nature of the substituent at the amine.
      PubDate: 2017-09-14T21:37:00.981957-05:
      DOI: 10.1002/adsc.201700932
       
  • Recent progress in organocatalytic asymmetric domino transformations
    • Authors: Tanmoy Chanda; John Zhao
      Abstract: Sustainability in chemical synthesis is a major aspect of the current synthetic endeavor and, therefore, mimicking the biological process in the laboratory nowadays has the highest priority. Towards achieving this goal, designing organic reactions in domino mode rather than the multistep synthetic pathways and using organocatalysis instead of metal catalysis have received a lot of attentions due to the inherent advantages of these processes in terms of synthetic efficiency and sustainability. As a result, the field of asymmetric organocatalytic domino reactions has witnessed tremendous progress in recent years. This review attempts to summarize the latest developments in asymmetric organocatalyzed domino reactions since 2012, with the emphasis on the catalysts and reaction modes. Discussions on the reaction mechanisms and the applications of the developed domino reaction methods in the synthesis of biological active molecules and natural products are also included when appropriate.
      PubDate: 2017-09-14T21:36:07.958132-05:
      DOI: 10.1002/adsc.201701059
       
  • Tandem Cross Coupling Reaction of Alcohols for Sustainable Synthesis of
           β-Alkylated Secondary Alcohols and Flavan Derivatives
    • Authors: Sujan Shee; Bhaskar Paul, Dibyajyoti Panja, Bivas Chandra Roy, Kaushik Chakrabarti, Kasturi Ganguli, Ayan Das, Gourab Kanti Das, Sabuj Kundu
      Abstract: A Ru(II) NHC complex (loading down to 0.001 mol%) catalyzed cross coupling of a broad range of aromatic, aliphatic and heterocyclic alcohols is reported. This protocol also functioned efficiently under solvent-free conditions. Remarkably, this catalytic system disclosed so far the highest TON of 288000 for the cross coupling of alcohols. Notably, this methodology was successfully applied for the one-pot synthesis of a range of flavan derivatives. A detailed DFT studies and kinetic experiments were performed to understand the reaction mechanism as well as the high reactivity of this catalytic system.
      PubDate: 2017-09-14T21:31:38.09614-05:0
      DOI: 10.1002/adsc.201700722
       
  • Iron-Catalyzed C(sp3)-C(sp3) Bond Formation in
           3,4-Dihydro-1,4-benzoxazin-2-ones
    • Authors: Jie Dong; Wenjian Min, Haitao Li, Zheng-Jun Quan, Cai-Xia Yang, Congde Huo
      Abstract: A novel and convenient iron-catalyzed oxidative dehydrogenative coupling reaction of 3,4-Dihydro-1,4-benzoxazin-2-ones with malonic esters or ketones was performed under mild reaction conditions to construct alkyl–alkyl C(sp3)–C(sp3) bonds. This transformation can be catalyzed efficiently by magnetically recoverable iron nanoparticles and the catalyst can be recycled easily for 7 times without decreasing activity.
      PubDate: 2017-09-14T21:31:27.074054-05:
      DOI: 10.1002/adsc.201700816
       
  • Recent advances in C-B bond formation through a free radical pathway
    • Authors: Guobing Yan; Dayun Huang, Xiangmei Wu
      Abstract: The development of methodology for the preparation of arylboronic acids or arylboronates is of significant interest to organic chemists. Classical synthetic methods to prepare these organoboron compounds are based on the reaction of Grignard or lithium reagents with trialkyl borates. In the past few decades, the transition- metal-catalyzed borylation of aryl halides or pseudohalides, and C-H bonds of hydrocarbons has been a powerful tool for the synthesis of arylboronates in modern organic synthesis. These transformations are generally considered to proceed via organometallic intermediates generated by oxidative addition or transmetalation process from the boron reagent. Several reviews on this type of borylation catalyzed by transition-metal have been published in the literature. Interestingly, there is anovel recognition that the boron reagent can participate in free-radical coupling via the homolytic cleavage of boron–boron bond in recent years. In this review, recent advances in the new area of boron chemistry are summarized and their mechanisms are also discussed
      PubDate: 2017-09-14T21:30:59.754243-05:
      DOI: 10.1002/adsc.201701030
       
  • Base-Free Selective O-Arylation and Sequential [3,3]-Rearrangement of
           Amidoximes with Diaryliodonium Salts: Synthesis of 2-Substituted
           Benzoxazoles
    • Authors: Wei-Min Shi; Xiao-Hua Li, Cui Liang, Dong-Liang Mo
      Abstract: A variety of functionalized 2-substituted benzoxazoles can be prepared in good yields from amidoximes and diaryliodonium salts by selective O-arylation and sequential [3,3]-rearrangement under metal-free conditions. O-arylation of amidoximes was promoted by 3Å molecule sieves in the absence of a base and a sequential TFA-mediated [3,3]-rearrangement was used to synthesize 2-substituted benzoxazoles. Both of the O-aryl products and rearrangement products were compatible with a broad range of sensitive functional groups such as ester, aldehyde, nitro, vinyl, amine, and amide groups in addition to halides. A bidentate N-ligand with double benzoxazoles was prepared at gram-scale in two steps.
      PubDate: 2017-09-14T21:30:55.913247-05:
      DOI: 10.1002/adsc.201700906
       
  • Acceptorless and Base-Free Dehydrogenation of Cyanohydrin with
           (η6-Arene)halide(Bidentate Phosphine)ruthenium(II) Complex
    • Authors: Kicheol Kim; Adhitya Mangala Putra Moeljadi, Hajime Hirao, Soon Hyeok Hong
      Abstract: The front cover picture, provided by Kicheol Kim, illustrates the development of a ruthenium catalytic system for acyl cyanide synthesis via acceptorless dehydrogenation of cyanohydrins. As opposed to the thermodynamically preferred elimination of hydrogen cyanide, the dehydrogenation of cyanohydrins could be kinetically controlled with ruthenium(II) bidentate phosphine complexes. Effects of ligands and counter anions in the ruthenium catalyst were investigated to modulate catalytic activity and selectivity. Details can be found in the communication on pages ###–### (K. Kim, A. M. P. Moeljadi, H. Hirao, S. H. Hong, Adv. Synth. Catal. 2017, 359, ###–###;
      DOI : 10.1002/adsc.201700786).
      PubDate: 2017-09-14T07:40:26.075041-05:
       
  • Asymmetric Vinylogous Aldol Reaction of -ketoesters with
           3-alkylidene oxindoles
    • Authors: Krishna Kumar; Manish Kumar Jaiswal, Ravi Singh
      Abstract: An efficient enantioselective vinylogous aldol reaction of 3-alkylidene oxindoles with -ketoesters by a bifunctional cinchona alkaloid derived thiourea catalyst has been disclosed here. The simultaneous H-bond directing dual activation of vinylogous nucleophile and electrophile afforded high yield (upto 92%) while obtaining excellent stereocontrol (upto 99% ee).
      PubDate: 2017-09-14T02:45:21.414997-05:
      DOI: 10.1002/adsc.201700758
       
  • Efficient transformation of alkyl 3-nitro-5-(aryl/
           alkyl)isoxazole-4-carboxylates into 3-amino- and
           3-hydrazinyl-5-aryl/alkyl-isoxazole-4-carboxylates in aqueous solution
    • Authors: Sushobhan Mukhopadhyay; Dinesh Barak, Ilesha Avasthi, Sanjay Batra
      Abstract: An efficient protocol for transforming alkyl 3-nitro-5-(aryl/ alkyl)isoxazole-4-carboxylates into 3-amino- and 3-hydrazinyl-5-aryl/alkyl-isoxazole-4-carboxylates is described. The reaction that is carried out in aqueous acetonitrile solution generally afford the products without any chromatographic purification. Investigations with the substrate scope reveal that this protocol is compatible only when the ester group is present at the C-4 position of the isoxazole ring.
      PubDate: 2017-09-14T02:43:30.308497-05:
      DOI: 10.1002/adsc.201700881
       
  • Organocatalyzed Thia-Michael Addition and Sequential Inverse Electron
           Demanding Diels−Alder Reaction to 3-Vinyl-1,2,4-triazine Platforms
    • Authors: Clément Berthonneau; Floris Buttard, Marie-Aude Hiebel, Franck Suzenet, jean-François Brière
      Abstract: This work highlights the use of 3-vinyl-1,2,4-triazines as original thia-Michael acceptors and inverse electron demanding Diels-Alder platforms en route to new 7,8-dihydro-5H-thiopyrano[4,3-b]pyridines. The required but rather unstable propargylthiol nucleophiles were successfully generated in-situ upon an innovative DBU-catalyzed methanolysis event of the corresponding propargyl thioacetate derivatives.
      PubDate: 2017-09-14T02:35:25.262186-05:
      DOI: 10.1002/adsc.201700831
       
  • The Base-Promoted Annulation of 2-Hydrazinyl Pyridine and CO2 toward
           Triazolones
    • Authors: Xiaopeng Wu; Song Sun, Bingbing Wang, Jiang Cheng
      Abstract: A base-promoted annulation of 2-hydrazinyl pyridine and atmospheric pressure of CO2 has been developed in the presence of silane as reducing reagent, affording a series of triazolones in moderate to excellent yields. CO2 served as a carbonyl source in this transformation. Moreover, benzamidrazones also worked well under this procedure. Thus, it represents a green, sustainable and straightforward pathway to access triazolone frameworks.
      PubDate: 2017-09-14T02:26:22.749021-05:
      DOI: 10.1002/adsc.201700869
       
  • Potassium Hydroxide-Catalyzed Alkynylation of Heteroaromatic N-Oxides with
           Terminal Alkynes
    • Authors: Xiaopei Chen; Fangfang Yang, Xiuling Cui, Yangjie Wu
      Abstract: An efficient potassium hydroxide-catalyzed alkynylation of heteroaromatic N-oxides under transition-metal-free conditions with the assistance of visible-light has been developed. Various C2-alkynylheterocycles were obtained in up to 92% yield with good functional group tolerance. This new method is operational simple, highly efficient, atom economic, and environmental friendly.
      PubDate: 2017-09-14T02:12:18.670062-05:
      DOI: 10.1002/adsc.201700931
       
  • Bifunctional Phase-Transfer Catalysts Catalyzed Diastereo- and
           Enantioselective Aza-Henry Reaction of β,γ-Unsaturated Nitroalkenes With
           Amidosulfones
    • Authors: Ning Lu; Fuquan Bai, Yanhong Fang, Zhonglin Wei, Jungang Cao, Dapeng Liang, Yingjie Lin, Haifeng Duan
      Abstract: An efficient diastereo- and enantioselective aza-Henry reaction of β,γ-unsaturated nitroalkenes with N-Boc amidosulfones has been achieved by using bifunctional chiral phase-transfer catalysts bearing multiple H-bonding donors, which was derived from cinchona alkaloids. This asymmetric catalytic protocol is suitable for a wide range of substrates, and give the corresponding products in high to excellent yields (up to 99%) with excellent diastereo- and enantioselectivities (up to>99:1 dr, up to>99% ee).
      PubDate: 2017-09-14T02:08:58.296739-05:
      DOI: 10.1002/adsc.201700787
       
  • P-Stereogenic Chiral Phosphine-Palladium Complex Catalyzed
           Enantioselective Synthesis of Phosphoryl-Substituted Atropisomeric
           Vinylarenes
    • Authors: Hao Wu; Zhengxu Han, Bo Qu, Dan Wang, yongda Zhang, Yibo Xu, Nelu Grinberg, Heewon Lee, Jinghua J. Song, Frank Roschangar, Guijun Wang, Chris Senanayake
      Abstract: P-Stereogenic chiral phosphine BI-BOP is employed for the first time as ligand to promote catalytic enantioselective synthesis of phosphoryl-substituted atropisomeric vinylarenes through a palladium–carbene pathway. This strategy utilizes 10 mol% palladium(II) acetate, 20 mol% phosphine ligand as well as a variety of N-tosylhydrazones and phosphoryl-substituted aryl bromides as the reaction partners. The desired axially chiral vinylarenes were isolated with up to 80% yield and 96:4 er, and can be further converted effectively and stereoselectively into dialkylphosphoryl-substituted atropisomeric arenes through a Grignard reaction. This protocol offers a general approach to synthesize phosphine-substituted atropisomeric vinylarenes with high enantiomeric purities.
      PubDate: 2017-09-14T01:53:20.040663-05:
      DOI: 10.1002/adsc.201700837
       
  • Palladium-Catalyzed One-Pot Synthesis of C2-Quaternary Indolin-3-ones via
           1H-indole-3-sulfonates Generated in Situ from 2-Alkynyl Arylazides and
           Sulfonic Acids
    • Authors: Xiaoxiang Zhang; Ping Li, Chang Lyu, Wanxiong Yong, Jing Li, Xingyu Pan, Xinbao Zhu, Weidong Rao
      Abstract: A novel method for the synthesis of C2-quaternary indole-3-ones via palladium-catalyzed one-pot transformation of 2-alkynyl arylazides is described. The reaction produced in moderate to excellent yields under mild conditions. This novel rearrangement of 1-H-indole-3-sulfonates represents an important contribution to the application of aryl sulfonates.
      PubDate: 2017-09-12T21:28:29.608617-05:
      DOI: 10.1002/adsc.201700838
       
  • Deracemization and Stereoinversion of α-Amino Acids by L-Amino Acid
           Deaminase
    • Authors: Elena Rosini; Roberta Melis, Gianluca Molla, Davide Tessaro, Loredano Pollegioni
      Abstract: Enantiomerically pure α-amino acids are compounds of primary interest for the fine chemical, pharmaceutical, and agrochemical sectors. Amino acid oxidases are used for resolving D,L-amino acids in biocatalysis. We recently demonstrated that L-amino acid deaminase from Proteus myxofaciens (PmaLAAD) shows peculiar features for biotechnological applications, such as a high production level as soluble protein in Escherichia coli and a stable binding with the flavin cofactor. Since L-amino acid deaminases are membrane-bound enzymes, previous applications were mainly based on the use of cell-based methods. Now, taking advantage of the broad substrate specificity of PmaLAAD, a number of natural and synthetic L-amino acids were fully converted by the purified enzyme into the corresponding α-keto acids: the fastest conversion was obtained for 4-nitrophenylalanine. Analogously, starting from racemic solutions, the full resolution (ee> 99%) was also achieved. Notably, D,L-1-naphthylalanine was resolved either into the D- or the L-enantiomer by using PmaLAAD or the D-amino acid oxidase variant having a glycine at position 213, respectively, and was fully deracemized when the two enzymes were used jointly. Moreover, the complete stereoinversion of L-4-nitrophenylalanine was achieved using PmaLAAD and a small molar excess of borane tert-butylamine complex. Taken together, recombinant PmaLAAD represents a L-specific amino acid deaminase suitable for producing the pure enantiomers of several natural and synthetic amino acids or the corresponding keto acids, compounds of biotechnological or pharmaceutical relevance.
      PubDate: 2017-09-11T01:16:33.333662-05:
      DOI: 10.1002/adsc.201700806
       
  • Palladium-Catalyzed [5+1] Annulation of 2-(1-Arylvinyl) Anilines and
           α-Diazocarbonyl Compounds toward Multi-functionalized Quinolines
    • Authors: Jiawei Zhu; Weiming Hu, Song Sun, Jin-Tao Yu, Jiang Cheng
      Abstract: A palladium-catalyzed [5+1] annulation of 2-(1-arylvinyl) anilines and α-diazocarbonyl compounds has been developed, affording a series of multi-functionalized quinolines in moderate to good yields. This procedure proceeded with the sequential insertion of N-H bond to the palladium carbene, intramolecular Heck reaction and decarboxylation steps. In this reaction, alkyl 2-diazophenylacetates served as C1 building block, which represents a key compliment to diazo chemistry.
      PubDate: 2017-09-10T21:27:33.930873-05:
      DOI: 10.1002/adsc.201701069
       
  • Desymmetrization of Cyclopentenediones via Organocatalytic
           Cross-Dehydrogenative Coupling
    • Authors: Fabrizio Vetica; Stephen Bailey, Pankaj Chauhan, Mathias Turberg, Adjmal Ghaur, Gerhard Raabe, Dieter Enders
      Abstract: An enantioselective synthesis of cyclopentenediones bearing a pyrazole unit has been achieved through an organocatalytic Michael addition/oxidation process. This desymmetrization reaction led to the desired pyrazole-cyclopentenediones with high yield and good enantioselectivities. The postulated cross-dehydrogenative coupling-mechanism has been investigated via preliminary control experiments.
      PubDate: 2017-09-08T23:41:23.226992-05:
      DOI: 10.1002/adsc.201700917
       
  • Light-Driven Vitamin B12-Mediated Generation of Acyl Radicals from
           2-S-Pyridyl Thioesters
    • Authors: Michał Ociepa; Oskar Baka, Jakub Narodowiec, Dorota Gryko
      Abstract: Acyl radicals are invaluable intermediates in organic synthesis, however their generation remains challenging. Herein, we present an unprecedented light-driven, cobalt-catalysed method for generation of acyl radicals from readily available 2-S-pyridyl thioesters. The synthetic potential of this methodology was demonstrated in the Giese-type acylation of activated olefins in the presence of heptamethyl cobyrrinate. This vitamin B12 derivative proved the most efficient catalysts in the studied process. The developed method features broad substrate scope (38 examples), good functional group tolerance, and mild reaction conditions. Moreover, it is easily scalable (illustrated on 20-fold scale-up procedure), enabling its preparative use. Mechanistic studies revealed that the reaction proceeds via a radical pathway with the key steps involving the formation of acyl-vitamin B12 complex and subsequent photolysis of the Co-C bond.
      PubDate: 2017-09-08T07:42:03.634577-05:
      DOI: 10.1002/adsc.201700913
       
  • Lewis Acid Catalyzed [3+2] Cycloaddition of Donor- Acceptor Cyclopropanes
           and 1-Azadienes: Synthesis of Imine Functionalized Cyclopentanes and
           Pyrrolidine Derivatives
    • Authors: Prabal Banerjee; Kamal Verma
      Abstract: Lewis acid catalyzed formal [3+2] cycloadditions of 1-azadienes with donor acceptor cyclopropanes to synthesize varieties of imine functionalized cyclopentanes and pyrrolidine derivatives in moderate to high yield have been developed. Moreover, pharmaceutically relevant azabicyclo[3.2.1]octane, bearing two all-carbon quaternary stereogenic centers at the bridgehead positions, has been synthesized by nosyl group deprotection and intramolecular amidation of imine functionalized cyclopentane derivative.
      PubDate: 2017-09-07T21:20:50.296946-05:
      DOI: 10.1002/adsc.201700744
       
  • Base-Promoted Tandem Reaction towards Conjugated Dienone or Chromone
           Derivatives with a Cyano Group: Insertion of Alkynes into C–C σ-Bonds
           of 3-Oxopropanenitriles
    • Authors: Qiyi Yao; Lingkai Kong, Fangfang Zhang, Xianghua Tao, Yanzhong Li
      Abstract: Base-promoted insertion reactions of alkynes into the C–C σ-bonds of α-cyano ketones were established to construct highly functionalized conjugated olefins or chromone derivatives via transition metal-free tandem reactions. These reactions are initialized through the nucleophilic attack of α-cyano ketones to alkynones followed by intramolecular nucleophilic addition/ring-opening to furnish the cyano-containing alkenes. In the cases of alkynones bearing an ortho-halide-substituted aryl ring, a further C–O bond coupling reaction occurs to afford chromone derivatives in good to high yields. Various alkynones bearing alkyl or aryl substituents were compatible in the reaction. This reaction has the potential to become a general synthetic protocol for the preparation of cyano-substituted olefins and chromones due to the abundance of easily accessible starting materials possessing diverse substituent groups.
      PubDate: 2017-09-07T03:15:53.89097-05:0
      DOI: 10.1002/adsc.201700565
       
  • A Copper-Catalyzed Cascade Approach for the Synthesis of
           Dibenzo[b,f]1,8-naphthyridine Derivatives
    • Authors: Bharath Kumar Villuri; Ashok Konala, Veerababurao Kavala, Trimurtulu Kotipalli, Chun-Wei Kuo, Ching-Fa Yao
      Abstract: The synthesis of some dibenzo[b,f]-[1,8]naphthyridine derivatives in a cascade manner is reported. The reaction includes a Knovenagel condensation, the insertion of a nitrile and an alkyne into an N–H bond and an oxidation/oxidative C–C bond cleavage sequence in the presence of copper iodide. The key 1,8-naphthyridine core was constructed in a cascade manner during the course of the reaction itself which allows diverse dibenzo[b,f]-[1,8]naphthyridine derivatives to be readily prepared.
      PubDate: 2017-09-07T03:05:32.626476-05:
      DOI: 10.1002/adsc.201700546
       
  • Copper-Catalyzed Aerobic Oxygenation of Benzylpyridine N-Oxides and
           Subsequent Post-Functionalization
    • Authors: Hans Sterckx; Carlo Sambiagio, Vincent Médran-Navarrete, Bert U. W. Maes
      Abstract: A copper-catalyzed aerobic oxidation of benzylpyridine N-oxides is reported. The N-oxide moiety acts as a built-in activator for the benzylic methylene oxidation, without requirement of additives. Reaction conditions were identified which suppress undesired benzoylpyridine formation via N-deoxygenation involving intermolecular oxygen transfer. The versatility of the N-oxide group of the benzoylpyridine N-oxide reaction products for post-functionalization of the pyridine ring is demonstrated through efficient C–C, C–N, C–O and C–Cl bond forming procedures, with both nucleophiles and electrophiles. Finally, the applicability of the new synthetic methodology is demonstrated in an alternative route towards the antihistaminic drug Acrivastine via three consecutive N-oxide activated C–H functionalization processes, starting from picoline N-oxide.
      PubDate: 2017-09-06T09:36:21.199591-05:
      DOI: 10.1002/adsc.201700588
       
  • Site-Selective Rhodium(III)-Catalyzed C−H Amination of 7-Azaindoles with
           Anthranils: Synthesis and Anticancer Evaluation
    • Authors: Mijin Jeon; Jihye Park, Prasanta Dey, Yongguk Oh, Hyunjung Oh, Sangil Han, Sung Hee Um, Hyung Sik Kim, Neeraj Kumar Mishra, In Su Kim
      Abstract: The front cover picture, provided by Kim, Mishra and co-workers, illustrates the synthetic strategy for the formation of ortho-aminated N-aryl-7-azaindoles based on the rhodium(III)- or iridium(III)-catalyzed C−H functionalization using anthranils and azides. The synthesized 7-azaindoles were readily transformed into biologically relevant azaindoloacridines, azaindoloacridones, and bis-indoles. Notably, all synthetic products were evaluated for anticancer activity against human breast adenocarcinoma cells, human renal carcinoma cells, and human prostate adenocarcinoma cells. Some of 7-azaindole derivatives displayed potent cytotoxicity competitive with anticancer doxorubicin. Details can be found in the communication on pages XXXX–XXXX (M. Jeon, J. Park, P. Dey, Y. Oh, H. Oh, S. Han, S. H. Um, H. S. Kim, N. K. Mishra, I. S. Kim, Adv. Synth. Catal. 2017, 359, XXXX–XXXX;
      DOI 10.1002/adsc.201700800).
      PubDate: 2017-09-06T03:10:34.881342-05:
       
  • One-Pot Enantioselective Synthesis of ᴅ-Phenylglycines from Racemic
           Mandelic Acids, Styrenes, or Biobased ʟ-Phenylalanine via Cascade
           Biocatalysis
    • Authors: Yi Zhou; Shuke Wu, Zhi Li
      Abstract: Enantiopure ᴅ-phenylglycine and its derivatives are an important group of chiral amino acids with broad applications in pharmaceutical industry. However, the existing synthetic methods for ᴅ-phenylglycine mainly rely on toxic cyanide chemistry and multistep processes. To provide green and safe alternatives, we leveraged cascade biocatalysis for one-pot synthesis of ᴅ-phenylglycine from racemic mandelic acid, styrene, and biobased ʟ-phenylalanine, respectively. Recombinant Escherichia coli (LZ110) was engineered to coexpress four enzymes to catalyze 3-step reactions in one pot, transforming mandelic acid (210 mM) to give enantiopure ᴅ-phenylglycine in 29.5 g L−1 (195 mM) with 93% conversion. Using the same whole-cell catalyst, other 12 ᴅ-phenylglycine derivatives were also produced from the corresponding mandelic acid derivatives in high conversion (58-94%) and very high ee (93-99%). E. coli (LZ116) expressing seven enzymes was constructed for the transformation of styrene to enantiopure ᴅ-phenylglycine in 80% conversion via one-pot 6-step cascade biotransformation. 12 Substituted ᴅ-phenylglycines were also produced from the corresponding styrene derivatives in high conversion (45-90%) and very high ee (92-99%) via the same cascade reactions. A nine-enzyme-expressing E. coli (LZ143) was engineered to transform biobased ʟ-phenylalanine to enantiopure ᴅ-phenylglycine in 83% conversion via one-pot 8-step transformation. Preparative biotransformation was also demonstrated. The high-yielding synthetic methods use cheap and green reagents (ammonia, glucose, and/or oxygen), and E. coli whole-cell catalysts, thus providing green and useful alternative methods for manufacturing ᴅ-phenylglycine.
      PubDate: 2017-09-05T21:26:49.893987-05:
      DOI: 10.1002/adsc.201700956
       
  • 2-Iodoxybenzoic Acid Tosylates: the Alternative to Dess–Martin
           Periodinane Oxidizing Reagents
    • Authors: Mekhman S. Yusubov; Pavel S. Postnikov, Roza Ya. Yusubova, Akira Yoshimura, Gerrit Jürjens, Andreas Kirschning, Viktor V. Zhdankin
      Abstract: Two powerful hypervalent iodine(V) oxidants, DMP-OTs (1-tosyloxy-1,1-diacetoxy-1H-1λ5-benzo[d][1,2]iodoxol-3-one) and IBX-OTs (1-tosyloxy-1-oxo-1H-1λ5-benzo[d][1,2]iodoxol-3-one) show high reactivity in the oxidation of structurally complex primary and secondary alcohols, which are highly functionalized polyketide or terpene fragments or steroids. The yields of the corresponding carbonyl compounds are even higher for the protocol that uses pyridine as additive. The oxidations proceed very rapidly at room temperature leaving the protective groups and π-systems intact and affording the corresponding carbonyl compounds in good to excellent yields. Moreover, IBX-OTs is an efficient reagent for the oxidative dehydrogenation of steroidal alcohols to the corresponding enones.
      PubDate: 2017-09-04T07:36:01.091175-05:
      DOI: 10.1002/adsc.201700776
       
  • Preparation of Building Blocks for Iterative Suzuki-Miyaura Reactions via
           Direct Bromination of Aryl Boronic Acids: One-Pot Total Syntheses of
           Dictyoterphenyls A and B
    • Authors: Chun-Young Lee; Cheol-Hong Cheon
      Abstract: A highly efficient method for the preparation of 4-alkoxy-3-bromophenyl boronic acid N-methyliminodiacetic acid (MIDA) esters as building blocks in iterative Suzuki-Miyaura reactions from the 4-alkoxyphenylboronic acids is described using a boronic acid moiety as a blocking group in bromination reactions. With these MIDA boronates, the total syntheses of dictyoterphenyls A and B were developed in only two separate one-pot operations. Furthermore, we have developed a more practical protocol for the preparation of meta-terphenyl natural products by simply adding the second aryl halide and water to the reaction mixture via the controlled release technique.
      PubDate: 2017-09-03T21:31:56.021471-05:
      DOI: 10.1002/adsc.201700733
       
  • Efficient Heterogeneous Gold(I)-Catalyzed Direct Csp2–Csp Bond
           Functionalization of Arylalkynes Through A Nitrogenation Process to Amides
           
    • Authors: Quan Nie; Feiyan Yi, Bin Huang, Mingzhong Cai
      Abstract: The first heterogeneous gold(I)-catalyzed direct Csp2–Csp bond functionalization of arylalkynes through a nitrogenation process to amides has been achieved by using an ordered mesoporous silica (MCM-41)-immobilized phosphine gold(I) complex [MCM-41-PPh3-AuCl] as catalyst and silver carbonate (Ag2CO3) as cocatalyst with trimethylsilyl azide (TMSN3) as a nitrogen source, yielding a variety of amides in moderate to excellent yields under mild conditions. This heterogeneous phosphine gold(I) complex shows the same turnover numbers as the homogeneous chloro(triphenylphosphine)gold(I) (Ph3PAuCl) and can easily be recovered by simple filtration of the reaction solution and recycled at least eight times without significant loss of activity, providing a novel, efficient, practical and economic method for the synthesis of amides from alkynes.
      PubDate: 2017-09-03T21:20:30.128146-05:
      DOI: 10.1002/adsc.201700783
       
  • Copper-Catalyzed Cascade Cyclization of 2-Propynolphenols: Access to
           4-Phosphorylated 2H-Chromenes
    • Authors: Ren Li; Xi Chen, Xian-Rong Song, Haixin Ding, Pengyang Wang, Qiang Xiao, Yong-Min Liang
      Abstract: A novel copper-catalyzed cascade cyclization of easily prepared 2-propynolphenols with disubstituted phosphine oxide is developed to give 4-phosphorylated 2H-chromenes in moderate to excellent yields. This cascade process involves multiple bond-forming events including C−O and C−P bonds. Moreover, both tertiary and secondary propargylic alcohols with diverse functional groups showed excellent compatibilities under ligand and additive-free conditions.
      PubDate: 2017-09-01T23:25:42.385175-05:
      DOI: 10.1002/adsc.201700985
       
  • Metal-Free Annulation Cascades of 1,7-Enynes Using Di-tert-Butyl Peroxide
           as the Methyl Source towards the Synthesis of Polyheterocyclic Scaffolds
    • Authors: Fang-Lin Tan; Ming Hu, Ren-Jie Song, Jin-Heng Li
      Abstract: A new metal-free oxidative cascade methylation/cyclization of benzene-linked 1,7-enynes is described for the construction of methylated polyheterocyclic scaffolds skeletons. In this transformations, three new C-C bonds and two new rings were formed. Notably, di-tert-butyl peroxide (DTBP) acts not only a radical initiator but also an efficient methyl source.
      PubDate: 2017-08-31T21:26:04.111045-05:
      DOI: 10.1002/adsc.201700699
       
  • Selective C(sp3)–H Monoarylation Catalyzed by a Covalently Cross-linked
           Reverse Micelle-Supported Pd Catalyst
    • Authors: Caroline Hoyt; Li-Chen Lee, Jian He, Jin-Quan Yu, Christopher Jones
      Abstract: Inert C(sp3)–H activation via ligand coordination has presented promising control over catalytic properties, specifically over mono versus diarylation of protected starting materials, demonstrated by one of us utilizing homogenous catalytic species with pyridine-based ligands [Science, 2014, 343, 1216-1220]. In this work, we illustrate the performance of a solvated micelle-supported ligand as a platform for coordination with palladium for C–H arylation. The micelle-supported ligand is one of the first applications of a micelle-supported ligand for C–H arylation, and provides a tunable support for future elaboration. The use of a spatially constrained system promoted selectivity trends influenced by both the sterics and electronics of the system, differing from the homogeneous catalyst, with high yields and selectivities.
      PubDate: 2017-08-31T21:25:47.423617-05:
      DOI: 10.1002/adsc.201700707
       
  • Asymmetric Stereoablative Aryloxylation of 3-Bromooxindoles with
           Bifunctional Catalyst
    • Authors: Amol Jadhav; Aarti Manchanda, Manish Kumar Jaiswal, Ravi Singh
      Abstract: In this communication, the development of a highly enantioselective stereoablative protocol for the chemoselective aryloxylation of 3-bromooxindoles with aryl alcohols have been realized. Promoted by easily available cinchona alkaloid derivatives (C6'-OH) under air- and moisture-tolerant conditions, aryloxylation of a wide range of 3-bromooxindoles bearing a 3'-alkyl substituent proceeded in high yields and excellent enantioselectivities (up to 95% ee). The newly developed strategy expediently provided the 3-phenoxy analogue of the core of alkaloid CPC-1.
      PubDate: 2017-08-31T21:21:05.358331-05:
      DOI: 10.1002/adsc.201700693
       
  • Copper-Catalyzed Aerobic Annulation of Hydrazones: Direct Access to
           Cinnolines
    • Authors: Chunling Lan; Zhuang Tian, Xuchun Liang, Mingchun Gao, Wenting Liu, Yu An, Wencheng Fu, Guanming Jiao, Junjie Xiao, Bin Xu
      Abstract: A novel method was developed for the construction of biologically active poly-substituted cinnolines from easily accessible hydrazones in good to excellent yields. Simple copper catalyst could efficiently promote the C−N bond formation through selective C–H functionalization and dehydrogenative amination. Furthermore, the inert C−Heteroatom(O/F/N) bonds are susceptible to cleavage in high selectivity in the newly developed aerobic annulation with the present C–H bond intact.
      PubDate: 2017-08-30T21:20:48.713971-05:
      DOI: 10.1002/adsc.201700669
       
  • Organocatalytic asymmetric synthesis of six-membered carbocycle-based
           spirocompounds
    • Authors: Xin Xie; Wei Huang, Cheng Peng, Bo Han
      Abstract: Well-developed asymmetric organocatalysis has been widely incorporated in various cascade/tandem sequences, providing simple access to structurally complex target molecules in a highly stereoselective fashion, including spirocyclic compounds. Among all types of spirocyclic skeletons, one containing a six-membered carbocyclic ring is recognized as an important core framework with up to six consecutive stereogenic centers and is commonly found in many natural products, biologically active molecules and lead compounds. This review describes the asymmetric synthesis of spirocyclic compounds containing six-membered carbocycles using small organic molecules as catalysts.
      PubDate: 2017-08-29T21:20:48.990145-05:
      DOI: 10.1002/adsc.201700927
       
  • Direct Organocatalytic Multicomponent Synthesis of Enantiopure
           γ-Butyrolactones via Tandem Knoevenagel-Michael-Lactonization Sequence
    • Authors: Tushar M. Khopade; Amol D. Sonawane, Jyotsna S. Arora, Ramakrishna Bhat
      Abstract: An expedient and straightforward protocol is developed for the synthesis of highly enantiopure synthesis of γ-butyrolactones. For the first time, one pot enantioselective organocatalytic multicomponent reaction (OMCR) is explored to construct functionalized butyrolactones without the use of pre-functionalized substrates and expensive transition metals. The protocol is proved to be reproducible on a gram scale. Density functional theory (DFT) calculations strongly support the mechanism and were in close agreement with the observed high stereoselectivity.
      PubDate: 2017-08-25T23:35:50.600856-05:
      DOI: 10.1002/adsc.201701084
       
  • Mechanistic Insight into Weak-Base-Catalyzed Generation of Carbon Monoxide
           from Phenyl Formate and Its Application to Catalytic Carbonylation at Room
           Temperature without Use of External Carbon Monoxide Gas
    • Authors: Hideyuki Konishi; Mika Matsubara, Keisuke Mori, Takaki Tokiwa, Sundaram Arulmozhiraja, Yuta Yamamoto, Yoshinobu Ishikawa, Hiroshi Hashimoto, Yasuteru Shigeta, Hiroaki Tokiwa, Kei Manabe
      Abstract: . The mechanisms of weak-base-catalyzed generation of carbon monoxide (CO) and phenol from phenyl formate were investigated by experimental and theoretical methods. Kinetic studies revealed a first-order reaction in both phenyl formate and the base. The reaction was found to proceed by an E2 α-elimination pathway, which involves the abstraction of the formyl proton of phenyl formate, simultaneously generating CO and phenoxide. The reaction rate was affected by the substituents of phenyl formate, the polarity of solvents, and the basicity of bases. The mechanistic insight obtained from these studies permitted the chemical control of the rate of CO generation, which were key to the development of the external-CO-free Pd-catalyzed phenoxycarbonylation of haloarenes at room temperature. Because of the mild reaction conditions and wide substrate scope, this phenoxycarbonylation constitutes a general, safe, and practical method to synthesize arenecarboxylic acid esters.
      PubDate: 2017-08-25T23:35:33.211748-05:
      DOI: 10.1002/adsc.201700751
       
  • Metal-Free Nitration of the C(sp3)–H Bonds of 2-Oxindoles through
           Radical Coupling Reaction at Room Temperature
    • Authors: wenting wei; wenming zhu, weiwei ying, yining wang, wenhui bao, lehan gao, yunjie luo, hongze liang
      Abstract: A metal-free nitration of the C(sp3)–H bonds of 2-oxindoles with t-BuONO through radical coupling reaction at room temperature has been developed. Using t-BuONO both as a nitrating reagent and as an oxidant, to couple with the C(sp3)–H bonds of 2-oxindoles, thus forming a new C–N bond without using any other reagents. This reaction provides a green and straightforward approach to some useful 3-nitro-2-oxindoles in moderate to good yields.
      PubDate: 2017-08-24T04:37:58.701882-05:
      DOI: 10.1002/adsc.201700870
       
  • Asymmetric Intermolecular Rauhut-Currier Reactions for the Construction of
           3,3-Disubstituted Oxindoles with Quaternary Stereogenic Centres
    • Authors: Hongyu Wang; Kaiye Wang, Yunquan Man, Xiaonan Gao, Limin Yang, Yanfei Ren, Na Li, Bo Tang, Gang Zhao
      Abstract: A remote-cross-Rauhut-Currier (rcRC) reaction utilizing vinyl ketones and para-quinone methides derived from isatins was realized, which was successfully catalysed using bifunctional phosphines furnishing chiral 3,3-disubstituted oxindoles with excellent enantioselectivities and high yields. The mechanistic studies demonstrated the key role of the alkyl hydrogen of the vinyl ketones, which conceivably interacted with the para-quinone methide carbonyl group via the H-bond offering a new insight for the design of novel asymmetric reactions.
      PubDate: 2017-08-24T04:37:54.617411-05:
      DOI: 10.1002/adsc.201700649
       
  • A visible light driven, metal-free route to aromatic amides via radical
           arylation of isonitriles.
    • Authors: Marco Alberto Malacarne; Stefano Protti, Maurizio Fagnoni
      Abstract: The photochemical metal-free carboamidation of aryl radicals has been exploited for the preparation of aromatic amides, including hetero- and polyaromatic derivatives, under visible light irradiation of arylazo sulfones in the presence of isocyanides in aqueous acetonitrile. The process was useful for the smooth preparation of antidepressant Moclobemide.
      PubDate: 2017-08-24T04:37:48.738424-05:
      DOI: 10.1002/adsc.201700619
       
  • Diastereoselective Synthesis of Nine-Membered Heterocycles via the
           Cycloaddition and Sequential Rearrangement of N-Vinyl Nitrones with
           Isocyanates
    • Authors: Ning Zou; Ji-Wen Jiao, Yu Feng, Chun-Hua Chen, Cui Liang, Gui-Fa Su, Dong-Liang Mo
      Abstract: A metal-free construction of highly diastereoselective nine-membered heterocycles is described via the cycloaddition and rearrangement of N-vinyl-α,β-unsaturated ketonitrones and isocyanates. Notably, the prepared nine-membered heterocycles afforded 2,3-dihydropyrrolizines under heating conditions. Mechanistic studies showed that the nine-membered rings might undergo decarboxylation, isomerization, aza-Michael addition, and aromatization to afford 2,3-dihydropyrrolizines in a one-pot reaction.
      PubDate: 2017-08-24T04:37:38.836411-05:
      DOI: 10.1002/adsc.201700685
       
  • Organocatalytic Asymmetric Synthesis of 3,3-Disubstituted
           3,4-Dihydro-2-quinolones
    • Authors: Subhas Pan; Soumendranath Mukhopadhyay, Utpal Nath
      Abstract: The first organocatalytic asymmetric reaction employing 3,4-dihydro-2-quinolone has been developed leading to the synthesis of biologically important 3,3-disubstituted-dihydro-2-quinolones. Cinchona alkaloid derived bifunctional amino-thiourea catalysts were found to be the best catalysts. The products were obtained in high enantio- and good diastereoselectivities and also few synthetic transformations have been demonstrated.
      PubDate: 2017-08-22T03:30:21.057054-05:
      DOI: 10.1002/adsc.201700655
       
  • Transition Metal-Catalysed Intramolecular Carbenoid C-H Insertion for
           Pyrrolidine Formation by Decomposition of α-Diazoesters
    • Authors: Daniel Solé i Arjó; Arianna Amenta, Francesco Mariani, M.-Lluisa Bennasar, Israel Fernandez
      Abstract: The use of Pd-, Rh(II)- and Ru(II)-based catalysts has been explored in the transition metal-catalysed intramolecular carbenoid C–H insertion of α-diazoesters leading to pyrrolidines. Although the outcome of the reaction was highly substrate-dependent, in general, it was possible to control the chemoselectivity of the process towards pyrrolidines by adequate catalyst selection. The Pd(0)-catalysts were as efficient as [Rh(Ph3CCO2)2]2 in promoting the C(sp3)–H insertion of ortho-substituted anilines. In contrast, for anilines bearing meta- and para-substituents, the Rh(II)-catalyst provided the best chemoselectivities and reaction yields. On the other hand, [Ru(p-cymene)Cl2]2 was the most efficient catalyst for the insertion reaction of the N-benzyl-N-phenyl and N,N-dibenzyl α-diazoesters, while the C(sp3)–H insertion of the N-benzylsulfonamide substrate was only promoted by [Rh(Ph3CCO2)2]2. According to density functional theory (DFT) calculations, the mechanism involved in the Pd(0)- and Ru(II)-catalysed C(sp3)–H insertions differs considerably from that typically proposed for the Rh(II)-catalysed transformation. Whereas the Pd(0)-catalysed reaction involves a Pd-mediated 1,5-H migration from the C(sp3)–H bond to the carbenoid carbon atom leading to the formal oxidation of the transition metal, a Ru(II)-promoted Mannich type reaction involving a zwitterionic intermediate seems to be operative in the Ru(II)-catalysed transformation.
      PubDate: 2017-08-19T00:10:26.684849-05:
      DOI: 10.1002/adsc.201700840
       
  • Intermolecular tandem addition/esterification reaction of alkenes with
           malonates leading to γ-lactones mediated by molecular iodine under
           visible light irradiation
    • Authors: Saki Maejima; Eiji Yamaguchi, Akichika Itoh
      Abstract: The iodine-mediated intermolecular C–C bond-forming/esterification reaction of various alkenes including α-olefins with malonates under irradiation using a compact fluorescent lamp has been developed to synthesize γ-lactones in moderate-to-excellent yields. The method developed in this research shows broad substrate scope and moderate diastereoselectivity and constructs valuable polyfunctionalized γ-lactones. Furthermore, developed methodology was comprehensively studied by performing several control experiments, radical trapping, and radical clock experiments. These experiments showed that the sequential iodination by an iodine radical is triggered for the following C–C bond-forming reaction.
      PubDate: 2017-08-17T21:20:35.512351-05:
      DOI: 10.1002/adsc.201700809
       
  • Rhodium-Catalyzed Synthesis of Multiaryl-substituted Naphthols via a
           Removable Directing group
    • Authors: Lianhui Wang; Yunliang Yu, Mengqi Yang, Changsheng Kuai, Dingding Cai, Jinfeng Yu, Xiuling Cui
      Abstract: Arene homologation employing internal alkynes as coupling partners and 2-pyridyloxyl as directing group through dual C−H bond functionalization was accomplished using (pentamethylcyclopentadienyl)- rhodium(III) chloride dimer as a pre-catalyst. This protocol proved tolerant of synthetically valuable functional groups, and provided an expeditious access to highly congested naphthalene derivatives in moderate to good yields. Furthermore, the pyridyl moiety could be removed to furnish the versatile (OH)-free naphthols.
      PubDate: 2017-08-17T09:21:07.862777-05:
      DOI: 10.1002/adsc.201700726
       
  • Nitrile as a Versatile Directing Group for C(sp2)−H
           Functionalizations
    • Authors: Yuanyuan Ping; Liping Wang, Qiuping Ding, Yiyuan Peng
      Abstract: The one-step direct regioselective functionaliztion of inert C(sp2)-H bonds is an efficient and sustainable methodology for the synthesis of a variety of useful natural products and pharmaceutical intermediates. A range of functional groups have been widely used as directing group for various regioselective transformations. Among these, the weakly coordinating nitrile group has attracted much attention because it is a transformable, easily installed and readily removed directing group, which can be easily converted into a number of different functional groups, such as carboxyl, carbamoyl, aminomethyl, carbonyl, and heterocyclic functionalities. This review describes recent advances in nitrile-directed C-H functionalizations catalyzed by Pd(II), Ru(II), Rh(III) and Ir(I) catalysts. The review is divided into sections related to ortho-, meta-, and para-C-H bond functionalizations, which are subdivided according to reaction type (olefination, arylation, halogenation, hydroxylation and acetoxylation).
      PubDate: 2017-08-17T09:20:57.033531-05:
      DOI: 10.1002/adsc.201700684
       
  • Lipase-Initiated Tandem Biginelli Reactions via In Situ-Formed
           Acetaldehydes in One Pot: Discovery of Single-Ring Deep Blue Luminogens
    • Authors: Xiao-Qi Yu; Wei Zhang, Na Wang, Zeng-Jie Yang, Yan-Rong Li, Yuan Yu, Xue-Mei Pu
      Abstract: A facile approach for synthesis of 3,4-dihydropyrimidin-2(1H)-ones was developed by a tandem multi-component reaction (MCR) in one pot. This approach involves two steps, lipase-catalyzed in situ generation of acetaldehyde and the Biginelli reaction in turns. Several control experiments were performed using acetaldehydes directly to explore the possible mechanism of this procedure. Moreover, owing to the distinct modularity and highly efficient features of the MCR, it assembles libraries ofstructurally diverse products (yields up to 98% under the optimized conditions in this paper) and provided an exceptional synthesis tool for the discovery of the minimal deep-blue luminogen in the solid state, namely, a single ring.
      PubDate: 2017-08-17T09:20:37.490282-05:
      DOI: 10.1002/adsc.201700599
       
  • Palladium-Catalyzed Regioselective Synthesis of 1,2-Fused-indole
           Diazepines via [5+2] Annulation of o-Indolo Anilines with Alkynes
    • Authors: Chung-Ming Sun
      Abstract: An efficient and regioselective Pd(II)-catalyzed [5+2] annulation of unprotected o-indolo anilines with internal alkynes under microwave irradiation has been explored. The diverse imine-containing 1,2-fused indole [1,7-a] diazepines are constructed in moderate to excellent yields. The mechanistic pathway shows pivalic acid and molecular oxygen to play crucial roles for the regeneration of highly active electrophilic Pd-species in the catalytic cycle.
      PubDate: 2017-08-17T04:31:24.94153-05:0
      DOI: 10.1002/adsc.201700741
       
  • Palladium-Catalyzed Synthesis of N-Cyclohexyl Anilines from Phenols with
           Hydrazine or Hydroxylamine via N-N/O Cleavage
    • Authors: Jiang-Sheng Li; Zihang Qiu, Chao-Jun Li
      Abstract: Direct access to amines from biomass-based phenols via deoxygenative transformation remains greatly challenging in organic synthesis. Herein, we present a palladium-catalyzed deoxygenative amination of phenols (and their benzyl ether) with hydrazine as nitrogen source. The hydroxylamine/formic acid can be a substitute for hydrazine in some cases. This deoxyamination features the involvement of a complex C-O bond and N-N/O bond-cleavage process and allows for the construction of N-substituted cyclohexyl anilines from an array of phenols by finely controlling the reaction conditions in moderate to good yields.
      PubDate: 2017-08-16T21:22:25.474549-05:
      DOI: 10.1002/adsc.201700712
       
  • Corrigendum 201601317, Wenbing Yin, ASC 2017, 359, 995-1006
    • Authors: Joe 02 Richmond; Peng Zhang, Yinglu Cui, Kai Li, Xue Qiao, Ying-Tao Zhang, Shu-Ming Li, Russell J. Cox, Bian Wu, Min Ye, Wen-Bing Yin
      PubDate: 2017-08-16T21:22:13.425719-05:
      DOI: 10.1002/adsc.201701070
       
  • Traceless Directing Group Assisted Cobalt-Catalyzed C-H Carbonylation of
           Benzylamines
    • Authors: Fei Ling; Chongren Ai, Yaping Lv, Weihui Zhong
      Abstract: The first example of cobalt-catalyzed C(sp2)-H carbonylation of benzylamines using a traceless directing group is reported, which was successfully applied to the synthesis of N-unprotected iso-indolinones through direct C−H/N−H bonds activation. This protocol tolerates a variety of functional groups and provides a facile and efficient method for the formal synthesis of (+)-garenoxacin.
      PubDate: 2017-08-15T21:21:37.491569-05:
      DOI: 10.1002/adsc.201700780
       
  • Copper-Catalyzed Acyloxycyanation of Alkynes with Acetonitrile:
           Regioselective Construction of Cyclic Acrylonitriles by 6-endo or 5-exo
           Cyclization
    • Authors: Yamin Zhu; Zengming Shen
      Abstract: An efficient difunctionalization of alkynes by tandem iodolactonization and copper-catalyzed cyanation using acetonitrile as a cyanating reagent is reported for the first time. This approach can afford cyano-containing isocoumarin- or phthalide- derivatives in good yields by careful choice of the carboxylate nucleophiles and electrophilic iodine sources. Thus, an acyloxycyanation strategy can be achieved in good yields and high regioselectivity of either 6-endo or 5-exo cyclization products.
      PubDate: 2017-08-14T21:21:20.944376-05:
      DOI: 10.1002/adsc.201700577
       
  • A Cooperative Ternary Catalysis System for Asymmetric Lactonizations of
           α-Ketoesters
    • Authors: Karl Scheidt; Kathleen Murauski, Daniel Walden, Paul Cheong
      Abstract: A general and enantioselective N-heterocyclic carbene (NHC)-catalyzed lactonization of simple enals and α-ketoesters has been discovered using a new ternary cooperative catalytic system. The highly selective annulation was achieved by using a combination of a chiral NHC, a hydrogen-bond donor, and a metal salt, facilitating self-assembly of the reactive partners. A proposed model for this new mode of NHC chiral relay catalysis is supported by experimental and computational mechanistic studies.
      PubDate: 2017-08-14T21:21:08.787674-05:
      DOI: 10.1002/adsc.201701015
       
  • Asymmetric Bioreduction of β-Activated Vinylphosphonate Derivatives
           Using Ene-Reductases
    • Authors: Ignacy Janicki; Piotr Kielbasinski, Nikolaus G. Turrini, Kurt Faber, Mélanie Hall
      Abstract: A series of functionalized α-chiral phosphonates were obtained by enzymatic reduction of corresponding β-activated vinylphosphonate derivatives employing several ene-reductases of the Old Yellow Enzyme family as biocatalysts. The insufficient activation of the phosphonate group alone was compensated by introduction of an electron-withdrawing group at the β-position, which resulted in high levels of conversion (up to>99%). All active enzymes consistently furnished (R)-configurated products with exquisite stereoselectivity, thereby providing a stereocomplementary approach to current asymmetric hydrogenation protocols on similar compounds. Preparative-scale synthesis performed in aqueous buffer using formate/formate dehydrogenase for recycling of the nicotinamide cofactor granted access to β-keto-, cyano- and ester phosphonates from the (E)-isomers of α,β-unsaturated phosphonates in up to 72% isolated yield and>99% ee.
      PubDate: 2017-08-13T21:21:27.395878-05:
      DOI: 10.1002/adsc.201700716
       
  • Site-Selective Rhodium(III)-Catalyzed C−H Amination of 7-Azaindoles with
           Anthranils: Synthesis and Anticancer Evaluation
    • Authors: Mijin Jeon; Jihye Park, Prasanta Dey, Yongguk Oh, Hyunjung Oh, Sangil Han, Sung Hee Um, Hyung Sik Kim, Neeraj Kumar Mishra, In Su Kim
      Abstract: The site-selective C–H amination reaction of 7-azaindoles with various benzisoxazoles as amination surrogates under cationic rhodium(III) catalysis is described. This transformation efficiently provides a range of ortho-aminated N-aryl-7-azaindoles with excellent site-selectivity and functional group compatibility. The formed ortho-aminated 7-azaindoles were readily transformed into biologically relevant heterocycles such as azaindoloacridine, azaindoloacridone, and bis-indole compounds. Moreover, the synthetic derivatives were tested for in vitro anticancer activity against human breast adenocarcinoma cells (MCF-7), human renal carcinoma cells (786-O), and human prostate adenocarcinoma cells (DU145). Notably, some synthetic compounds were found to display most potent anticancer activity, compared to that of anticancer doxorubicin as a positive control.
      PubDate: 2017-08-13T21:21:24.158519-05:
      DOI: 10.1002/adsc.201700800
       
  • Silver-Catalyzed [3+2] Cycloaddition of Azomethine Ylides with Isocyanides
           for Imidazole Synthesis
    • Authors: Zhongyan Hu; Jinhuan Dong, Xianxiu Xu
      Abstract: A silver-catalyzed aerobic oxidative [3+2] cycloaddition of azomethine ylides with aryl or heteroaryl isocyanides was developed. The reaction represents a novel protocol for the efficient and practical synthesis of 1,2-diaryl imidazoles bearing a broad range of substitution in good to excellent yields under mild conditions. The practicability of this cycloaddition was shown by a gram-scale synthesis and double cycloaddition for the construction of highly conjugated polyarylimidazole systems.
      PubDate: 2017-08-13T21:21:18.251773-05:
      DOI: 10.1002/adsc.201700447
       
  • Intramolecular Hydroamidation of ortho-Vinyl Benzamides Promoted by
           Potassium tert-Butoxide/N,N-Dimethylformamide
    • Authors: zhenyu chen; Liang-yu Wu, Hai-sheng Fang, Ting Zhang, Zhi-feng Mao, Yong Zou, Xue-jing Zhang, Ming Yan
      Abstract: An intramolecular hydroamidation of ortho-vinyl benzamides had been developed. The reaction was promoted efficiently by potassium tert-butoxide and N,N-dimethylformamide without the need for strong oxidants or transition-metal catalysts. A series of dihydroisoquinolinones and 3-benzylisoindolinones were prepared in good to excellent yields. The new method is operationally simple, scalable, and tolerant of various functional groups.
      PubDate: 2017-08-13T21:21:10.41521-05:0
      DOI: 10.1002/adsc.201700369
       
  • Metal-Free Carboxy-Group Arylation Using Iodosoarenes by Generation of
           Reactive Diaryliodonium(III) Coupling Intermediates
    • Authors: Toshifumi Dohi; Daichi Koseki, Kohei Sumida, Kana Okada, Serina Mizuno, Asami Kato, Koji Morimoto, Yasuyuki Kita
      Abstract: The metal-free arylative coupling of carboxylic acids using iodosoarenes without the use of a catalyst and base, which is applicable to even a highly-polar molecule bearing multiple alcohol groups, is reported. The in situ preparation of the reactive diaryliodonium(III) carboxylates is the important key to this approach, and the introduction of the trimethoxybenzene auxiliary enables both the smooth salt formations and the selective aryl transfer events during the couplings.
      PubDate: 2017-08-11T23:30:44.502203-05:
      DOI: 10.1002/adsc.201700843
       
  • Palladium-Catalyzed Isocyanide Insertion with Allylic Esters: Synthesis of
           N-(But-2-enoyl)-N-(tert-butyl)benzamide Derivatives via Intramolecular
           Acyl Transfer Termination
    • Authors: Si Chen; Wan-Xu Wei, Jia Wang, Yu Xia, Yi Shen, Xin-Xing Wu, Huanwang Jing, Yong-Min Liang
      Abstract: A novel and unprecedented intramolecular acyl transfer reaction via the palladium-catalyzed insertion of isocyanide has been established. Isocyanides were inserted into C-O bond under mild conditions, using the readily available allyl ester as the starting materials. In addition, the intramolecular acyl transfer from the ester group oxygen atom to the isocyanide nitrogen atom afforded imide derivatives in moderate to excellent yields. Additionally, this transformation was validated as having operationally simple conditions and excellent functional group compatibility.
      PubDate: 2017-08-11T23:30:28.993898-05:
      DOI: 10.1002/adsc.201700765
       
  • Enantioselective Synthesis of Chiral Imidazolidine Derivatives by
           Asymmetric Ag/Xing-Phos -Catalyzed Homo-1,3-Polar [3+2] Cycloaddition of
           Azomethine Ylides
    • Authors: Bo Yu; Xing-Feng Bai, Ji-Yuan Lv, Yang Yuan, jian cao, Zhan-Jiang Zheng, Zheng Xu, yuming cui, Ke-Fang Yang, Li-Wen Xu
      Abstract: Enantioselective synthesis of chiral heterocycle derivatives is an important and challenging topic in the field of synthetic chemistry. In this work, the first stereocontrolled dimerization-type homo-1,3-polar [3+2] cycloaddition reaction of glycine aldimino esters for creating new heterocycles bearing multiple stereogenic centers has been developed through the chiral phosphine ligand –involved silver catalysis. A variety of chiral imidazolidines could be obtained with high yields and good diastereoselectivities as well as excellent enantioselectivities by employing Xing-Phos as chiral P-ligand.
      PubDate: 2017-08-11T23:25:47.13791-05:0
      DOI: 10.1002/adsc.201700732
       
  • Palladium-Catalyzed Cross-Coupling of Alkynyl Carboxylic Acids with
           Isocyanides: Solvent-Controlled Selective Synthesis of 5-Iminofuranones
           and 5-Iminopyrrolones
    • Authors: Huanfeng Jiang; Weigao Hu, Zun Li, Jiawei Li, Wanqing Wu, Hai-Yang Liu
      Abstract: A novel palladium-catalyzed cyclization of alkynyl carboxylic acids with isocyanides has been successfully developed herein. The corresponding 5-iminofuranone or 5-iminopyrrolone derivatives were constructed in moderate to good yields which were well controlled by the solvents. These reactions proceed under simple and mild reaction conditions with high efficiency, and feature a wide substrate scope, readily available starting materials and easy operation.
      PubDate: 2017-08-11T23:25:31.430816-05:
      DOI: 10.1002/adsc.201700533
       
  • Iodine Triggered Aerobic Oxysulfonylation of Styrenes
    • Authors: Khokan Chowdhuri; Tapas Achar, Prasenjit Mal
      Abstract: An iodine triggered dioxygen activation in oxysulfonylation reaction of unactivated olefins using sulfonyl hydrazides and iodine catalyst is reported here. In one pot, near quantitative synthesis of β-hydroxysulfones were achieved at 70 ºC, within 7 h, in acetonitrile and under aerobic condition. A plausible mechanism is established by radical trapping and 18O labelling experiments for the operationally simple, efficient and economically viable transformation. The direct activation of aerial oxygen under metal free and mild condition is anticipated for the oxysulfonylation of olefins.
      PubDate: 2017-08-10T21:26:28.60582-05:0
      DOI: 10.1002/adsc.201700772
       
  • The Synthesis of Chiral α-Aryl α-Hydroxy Carboxylic Acids via RuPHOX-Ru
           Catalyzed Asymmetric Hydrogenation
    • Authors: Huan Guo; Jing Li, Delong Liu, Wanbin Zhang
      Abstract: A ruthenocenyl phosphino-oxazoline-ruthenium complex (RuPHOX-Ru) catalyzed asymmetric hydrogenation of α-aryl keto acids has been successfully developed, affording the corresponding chiral α-aryl α-hydroxy carboxylic acids in high yields and with up to 97% ee. The reaction could be performed on a gram scale with a relatively low catalyst loading (up to 5000 S/C) and the resulting products can be transformed to several chiral building blocks, biologically active compounds and chiral drugs.
      PubDate: 2017-08-09T21:21:16.144224-05:
      DOI: 10.1002/adsc.201700846
       
  • Synthesis of Fluorinated Benzo[a]quinolizidines via Visible Light-induced
           Tandem Substitution of Two Fluorine Atoms in a CF3 Group
    • Authors: Haoguo Chen; Tiebo Xiao, Linyong Li, Devireddy Anand, Yuwei He, Lei Zhou
      Abstract: An efficient method for the construction of fluorinated benzo[a]quinolizidines from α-trifluoromethyl alkenes and dihydroisoquinoline acetic acids using visible light photocatalysis was developed. The reaction was accomplished through a decarboxylative/defluorinative cross-coupling, followed by an intramolecular defluorinative C-H functionalization in one-pot. Diversified fluorinated benzo[a]quinolizidines, which are less accessible by other methods, were obtained in good yields with high diastereoselectivity.
      PubDate: 2017-08-09T21:21:03.855305-05:
      DOI: 10.1002/adsc.201700852
       
  • Copper-Catalyzed Decarboxylative Alkylation of Terminal Alkynes
    • Authors: Changqing Ye; Yajun Li, Hongli Bao
      Abstract: A copper-catalyzed decarboxylative alkylation of terminal alkynes under mild reaction conditions has been reported. Various general alkyl carboxylic acids were applied as the alkyl source for the formation of C(sp3)-C(sp) bond. A range of terminal alkynes including aryl alkynes and alkyl alkynes delivered the alkylated internal alkynes with good to high performances. Mechanism studies suggested that this reaction involves a free radical pathway.
      PubDate: 2017-08-08T21:21:31.008791-05:
      DOI: 10.1002/adsc.201700798
       
  • Construction of Pyridazine Analogues via Rhodium-mediated C-H Activation
    • Authors: Chao Yang; Feifei Song, Jiean Chen, Yong Huang
      Abstract: Herein a rhodium (III)-mediated catalysis was demon-strated for approaching the structurally divergent N,N-bicyclic pyridazine analogues. The pyrazolidinone moiety was used to direct the ortho C-H activation and this led to a general synthesis of benzopyridazine analogues with satisfactory yields. The crucial effect of the base was illustrated in the sequential dehydration process. For mechanistic insight, control experiments were performed for illustration of the catalytic circle. Gram scale synthesis and several practical transformations were conducted for further applications.
      PubDate: 2017-08-08T21:21:27.448451-05:
      DOI: 10.1002/adsc.201700905
       
  • Chiral Magnesium(Ⅱ) Complex-Catalyzed Enantioselective Desymmetrization
           of meso-Aziridines with Pyrazoles
    • Authors: Xiangqiang Li; Jing Guo, Lili Lin, Haipeng Hu, Fenzhen Chang, Xiaohua Liu, Xiaoming Feng
      Abstract: A highly enantioselective catalytic protocol for the desymmetrization of meso-aziridines via ring-opening with pyrazoles is reported using an N,N'-dioxide-Mg(OTf)2 complex as the catalyst. The corresponding syn-α-pyrazole-substituted amines were obtained in good yields and enantioselectivities (up to 99% yield and 94% ee) under mild reaction conditions. Moreover, a remarkably high asymmetric amplification was observed in the catalytic system.
      PubDate: 2017-08-07T21:26:10.185095-05:
      DOI: 10.1002/adsc.201700888
       
  • Double Carbonylation Using Glyoxal (HCOCOH): A Practical Copper-Promoted
           Synthesis of Isatins from Primary and Secondary Anilines
    • Authors: Suzie Hui Chin Kuan; Wei Sun, Lu Wang, Chungu Xia, Meng Guan Tay, Chao Liu
      Abstract: A novel double carbonylation process has been demonstrated with easily available HCOCOH (glyoxal) as the double carbonylation reagent. Simple CuCl2·2H2O (copper(II) chloride dihydrate) was used as the oxidant for this transformation. Under optimized reaction conditions, various primary and secondary anilines were double-carbonylated to afford their corresponding isatins (26 examples, up to 80% yields).
      PubDate: 2017-08-07T21:21:26.410499-05:
      DOI: 10.1002/adsc.201700583
       
  • Ruthenium on carbon catalysed carbon-carbon cleavage of aryl alkyl ketones
           and aliphatic aldehydes in aqueous media
    • Authors: Tomohiro Hattori; Hiroki Okami, Tomohiro Ichikawa, Shigeki Mori, Yoshinari Sawama, Yasunari Monguchi, Hironao Sajiki
      Abstract: A new ruthenium on carbon-catalysed carbon–carbon (C–C) cleavage reaction of aryl alkyl ketone derivatives in water in the presence of CaO under atmospheric oxygen conditions has been developed. Corresponding benzoic acid derivatives were produced from various aryl alkyl ketones in excellent yields. CaO acts as an adsorbent of CO and CO2 to maintain a sufficient concentration of oxygen around the catalyst required for effective progress of the reaction. It was also revealed that aliphatic aldehydes were generated from the alkyl moiety of aryl alkyl ketones over the course of the reaction. The aliphatic aldehyde derivatives undergo either an oxidation to the corresponding aliphatic carboxylic acids or a further continuous C-C cleavage reaction to form aliphatic aldehydes with loss of one carbon along with the formation of CO and CO2.
      PubDate: 2017-08-07T21:21:20.150254-05:
      DOI: 10.1002/adsc.201700774
       
  • Silver-Catalyzed Double Hydrocarbonation of 2-Trifluorometh-
           yl-1,3-Conjugated Enynes with 1,3-Dicarbonyl Compounds: Synthesis of
           Ring-Trifluoromethylated Cyclopentene
    • Authors: Junliang Zhang; Yu Zeng, Chaoqian Huang, Peiyun Ni, Lu Liu, Yuanjing Xiao
      Abstract: An unexpected atom-economic tandem intermolecular hydrocarbonation and intramolecular hydrocarbonation (double hydrocarbonation sequence) of 2-trifluoromethyl-1,3-conjugated enynes with 1,3-dicarbonyl compounds leading to ring-trifluoromethylated cyclo-pentene frameworks by combination use of AgNO3 as a catalyst and Et3N as a base was developed. Enynes possessing electron-withdrawing aryl groups on the alkyne moiety are general good candidates for present transformation.
      PubDate: 2017-08-07T21:21:14.773468-05:
      DOI: 10.1002/adsc.201700752
       
  • Regioselective Synthesis of Selenide Ethers through Decarboxylative
           Coupling Reaction
    • Authors: Fei-Hu Cui; Jing Chen, Shi-Xia Su, Yanli Xu, Heng-shan Wang, Ying-ming Pan
      Abstract: An efficient and selective approach to the synthesis of selenide ethers containing one or two geminal C-Se bonds from readily available diselenides and phenylacetic acids was developed. Compounds containing one C-Se bond were prepared by employing air as the oxidant under metal-free conditions, whereas compounds having two geminal C-Se bonds were formed via the FeCl3/O2/Cs2CO3 system. Moreover, 1,2-diphenyldisulfane also could be smoothly converted into the corresponding sulfur ether product under the standard reaction conditions.
      PubDate: 2017-08-07T21:20:53.124143-05:
      DOI: 10.1002/adsc.201700676
       
  • Acceptorless and Base-free Dehydrogenation of Cyanohydrin with
           (η6-Arene)halide(bidentate phosphine)ruthenium(II) Complex
    • Authors: Kicheol Kim; Adhyitya Moeljadi, Hajime Hirao, Soon Hyeok Hong
      Abstract: Ruthenium-catalyzed dehydrogenation of cyanohydrins under acceptorless and base-free conditions was demonstrated for the first time in the synthesis of acyl cyanide. As opposed to the thermodynamically preferred elimination of hydrogen cyanide, the dehydrogenation of cyanohydrins could be kinetically controlled with ruthenium (II) bidentate phosphine complexes. The effects of the arene, phosphine ligands and counter anions were investigated in regard to catalytic activity and selectivity. Selective dehydrogenation can occur via β-hydride elimination with the experimentally observed [(alkoxide)Ru] complex.
      PubDate: 2017-08-07T21:20:47.575519-05:
      DOI: 10.1002/adsc.201700786
       
  • Synthesis of Fused Heterocycles via One-pot Oxidative O-Arylation,
           Pd-Catalyzed C(sp3)-H Arylation
    • Authors: Fenglin Hong; Nannan Lu, Beili Lu, Jiajia Cheng
      Abstract: An efficient and user-friendly synthesis of 7H-chromeno[3,2-c]quinolines has been developed via a one-pot oxidative O-arylation, Pd-catalyzed C(sp3)-H arylation of readily available arylols and trivalent aryliodine reagents. A variety of valuable and complex fused heterocycles were quickly assembled in high isolated yields with broad substrate scopes.
      PubDate: 2017-08-07T21:20:42.872922-05:
      DOI: 10.1002/adsc.201700761
       
  • Two-step Synthesis of Polysubstituted 6-Nitroindoles under Flow Chemical
           and Microwaves conditions
    • Authors: Alessandro Palmieri; Serena Gabrielli, Roberto Ballini, Susanna Sampaolesi
      Abstract: A new simple and efficient synthesis of 6-nitroindoles, starting from N-carboxylalkyl pyrrole-2-carboxaldehydes and protected β-nitro ketones, has been developed. The method involves two distinct domino processes, respectively performed under flow chemical conditions and microwaves irradiations. 6-Nitroindoles were produce from good to excellent overall yields.
      PubDate: 2017-08-06T21:30:19.771929-05:
      DOI: 10.1002/adsc.201700790
       
  • Catalytic Efficient Nazarov Reaction of Unactivated Aryl Vinyl Ketones via
           a Bidentate Diiron Lewis Acid Activation Strategy
    • Authors: Xin Zhou; Yukun Zhao, Yang Cao, Lirong He
      Abstract: A catalytic highly efficient Nazarov reaction of unactivated aryl vinyl ketones has been accomplished by employing aryl boric acid/Fe(OTf)3. Significant progress was obtained in utilizing an extremely broad substrate scope, giving indanones in high yields with high regioselectivities and diastereoselectivities. The mechanistic investigation supports a bidentate diiron Lewis acid catalysis, and the strong double electrophilic activation of aryl vinyl ketones via simultaneous coordination plays a key role in achieving a high reaction efficiency.
      PubDate: 2017-08-05T00:06:30.811673-05:
      DOI: 10.1002/adsc.201700820
       
  • Synthesis of polycyclic dihydroindoles by selective decompo-sition of
           bis(1,2,3-triazoles) mediated by Rh-catalysis
    • Authors: sampad Jana; Robby Vroemans, Wim Dehaen
      Abstract: We report the selective decomposition of bis(1,2,3-triazoles) by Rh(II)-catalysis. The bis(1,2,3-triazoles) undergo an intramolecular transannulation reaction via an azavinylcarbene intermediate, resulting in the formation of polycyclicdihydroindoles containg a fused triazole ring.
      PubDate: 2017-08-03T21:07:03.427621-05:
      DOI: 10.1002/adsc.201700756
       
  • Rhodium(III)-Catalyzed Tandem C‒H Olefination and Oxidative Cyclization
           of Aromatic Acids with Acrylates for the Synthesis of
           (E)-3-Ylidenephthalides
    • Authors: Wen-jing Han; Fan Pu, Juan Fan, Zhong-Wen Liu, Xian-Ying Shi
      Abstract: Intermolecular tandem C–H olefination/C–O cyclization has been achieved via a rhodium (III)-catalyzed C–H activation of carboxylic acids with acrylates. This strategy provides the direct and efficient construction of biologically relevant (E)-3-ylidenephthalide scaffolds with satisfactory to good yields, and is characterized by stoichiometric reactants, exclusive stereoselectivity, commercially available substrates, mild atmospheric conditions, and short reaction time (less than 2 h).
      PubDate: 2017-08-03T21:06:44.611186-05:
      DOI: 10.1002/adsc.201700603
       
  • Gram-scale synthesis of amines bearing gem-difluorocyclopropane moiety
    • Authors: Pavel Nosik; Andrii Gerasov, Rodion Boiko, Eduard Rusanov, Sergey Ryabukhin, Oleksandr Grygorenko, Dmitriy Volocnyuk
      Abstract: Synthesis of monocyclic, spirocyclic and fused bicyclic secondary amines bearing gem-difluorocyclo-propane moiety via difluorocyclopropanation of unsaturated N-Boc derivatives using CF3SiMe3–NaI system is described. Relative order of the substrate reactivity is established. It is shown that for the reactive alkenes, the standard reaction conditions can be used, whereas for the substrates with low reactivity, slow addition of the Ruppert–Prakash reagent is necessary.
      PubDate: 2017-08-01T21:01:23.129949-05:
      DOI: 10.1002/adsc.201700857
       
  • Synthesis of 1,2-Dihydrocyclobuta[b]quinoline Derivatives from
           Isocyanophenyl-Substituted Methylenecyclopropanes
    • Authors: Hou-Lu Liu; Yu-Chao Yuan, Yin Wei, Min Shi
      Abstract: A new protocol to synthesize 1,2-dihydrocyclobuta[b]quinoline derivatives from isocyanophenyl-substituted methylenecyclopropanes via a formal insertion of isocyanide carbon into a C−C bond has been developed. The reaction proceeds smoothly in the presence of silver carbonate (5 mol%) upon heating in a highly atom economic manner and exhibits broad substrate scope, giving the desired products in moderate to excellent yields. Furthermore, several transformations of the obtained products have been also demonstrated.
      PubDate: 2017-08-01T06:07:13.040172-05:
      DOI: 10.1002/adsc.201700509
       
  • Expeditious Synthesis of Enantioenriched Tetrahydropyrans via
           Chemoselective C–N bond Cleavage of Aza-Oxa-Bicyclo[3.2.1]Octanes
    • Authors: Cecilia Sasso D'Elia; Sébastien Goudedranche, Thierry CONSTANTIEUX, Marco Bella, Damien Bonne, Jean RODRIGUEZ
      Abstract: A rapid synthesis of enantioenriched 2,3,4-trisubstituted tetrahydropyrans in good yields and stereoselectivities is reported. The first step is a domino organocatalytic reaction between ambident electrophilic and 1,4-bis-nucleophilic 1,2-ketoamides and 1,3-bis-electrophilic enals, leading to aza-oxa-bicyclo[3.2.1]octane. Then, the TiCl4/Et3SiH system ensures a chemoselective cleavage of the C–N bond and affords the desired trisubstituted tetrahydrofuran in good yield and with conservation of the precursors optical purity. This final synthetic operation includes two consecutive oxocarbenium ion formation and reductions.
      PubDate: 2017-07-31T21:21:37.438101-05:
      DOI: 10.1002/adsc.201700735
       
  • N2-Selective Autocatalytic Ditriazolylation Reactions of Cyclopropenones
           and Tropone with N1-sulfonyl-1,2,3-triazoles
    • Authors: Long-Hai Li; Yu Jiang, Jian Hao, Yin Wei, Min Shi
      Abstract: N2-selective autocatalytic ditriazolylation reactions of cyclopropenones and tropone with N1-sulfonyl-1,2,3-triazoles were reported for the first time. In contrast to previous methods for preparing N2-substituted bis(1,2,3-triazolyl) compounds, the reaction achieved ditriazolylation in one step under simple and user-friendly conditions with a wide range of substrate scope. A plausible mechanism has been proposed relying on preliminary mechanistic investigations.
      PubDate: 2017-07-31T21:21:04.613105-05:
      DOI: 10.1002/adsc.201700936
       
  • Gold-catalyzed [4+2]- and [3+3]-Annulations of Ynamides with 1-Yn-3-ols to
           Access Six-Membered Carbo- and Oxacycles via Three Distinct Cyclizations
    • Authors: Rai-Shung Liu; Sovan Sundar Giri
      Abstract: Abstract. Three distinct strategies for catalytic annulations between ynamides and 1-yn-3-ols are described; resulting carbo- and heterocycles were produced efficiently in one-pot operations using a gold catalyst. The chemoselectivities of these annulations are controlled by variations of the substituents of ynamides and 1-yn-3-ols. This reaction sequence involves initial alkoxylations of ynamides, followed by Claisen rearrangement of propargylic enol ethers, and ended with 6-endo-trig cyclizations of 1-allenyl-5-amide intermediates. Among these cascade annulations, the cyclizations of 5-allenyl-1-amides to yield 5,6-dihydro-2-pyranones and 6-alkylenecyclohex-2-ene-1-carboxamides are unprecedented in the literature.
      PubDate: 2017-07-29T00:02:12.015745-05:
      DOI: 10.1002/adsc.201700784
       
  • Synthesis of Cyclic Sulfoximines from Sulfoximines
           and 3-Diazoindolin-2-imines
    • Authors: Gi Hoon Ko; Jeong-Yu Son, Hyunseok Kim, Chanyoung Maeng, Yonghyeon Baek, Boram Seo, Kyusik Um, Phil Ho Lee
      Abstract: A Rh-catalyzed cyclization reaction of sulfoximines with 3-diazoindolin-2-imines is described. This protocol provided a wide range of cyclic sulfoximines in moderate to excellent yields together with the release of molecular nitrogen and p-toluenesulfonamide. The present method involved the N−H/C−H activation of S-aryl sulfoximines and has the advantages of a broad substrate scope.
      PubDate: 2017-07-27T20:56:55.946649-05:
      DOI: 10.1002/adsc.201700764
       
  • A Biocatalytic One-Pot Approach for the Preparation of Lignin Oligomers
           Using an Oxidase/Peroxidase Cascade Enzyme System
    • Authors: Mohamed Habib; Peter Deuss, Nikola Loncar, Milos Trajkovic, Marco Fraaije
      Abstract: Synthetic lignin was prepared biocatalytically in a one-pot two-step reaction using an oxidase/peroxidase cascade enzyme system. Using eugenol in combination with eugenol oxidase and a peroxidase, lignin-like material was produced. The cascade reaction takes advantage of the ability of the oxidase to produce coniferyl alcohol and hydrogen peroxide from eugenol and molecular oxygen. The hydrogen peroxide is used by the peroxidase for the for-mation of crosslinks that typify lignin. As eugenol oxidase has a broad substrate acceptance profile, also 4-allylphenol (chavicol) and 4-allyl-2,6-dimethoxyphenol could be used as precursors of the synthetic lignin. As a result, all three naturally occurring monolignols could be prepared and incorporated in the synthetic lignin. The reaction was optimized in order to achieve the highest possible yield of insoluble lignin oligomers and scaled up to 1 gram. Analysis of the water-insoluble product by gel permeation chromatography revealed the formation of relatively small lignin oligomers (~1000 dalton). By using two-dimensional heteronuclear single quantum coherence nuclear magnetic resonance spectroscopy and gas chromatography-mass spectrometry analyses it could be demonstrated that the material contained α-O-4/β-O-4, β-O-4, β-β, β-5 linkages and dibenzodioxocin units. All these features indicate that the biocatalytically produced material closely resembles natural lignin. While 54% of eugenol was converted into water-insoluble oligomers, the remaining substrate was converted into water soluble dimers and tetramers which are important lignin model compounds. Therefore, the presented method represents a valuable and facile biocatalytic approach for the preparation of lignin-like material and potentially valuable chemicals.
      PubDate: 2017-07-27T20:56:19.107383-05:
      DOI: 10.1002/adsc.201700650
       
  • Catalytic Asymmetric Epoxidation of Electron-Deficient Enynes Promoted by
           Chiral N,N'-Dioxide-Scandium(III) Complex
    • Authors: Hang Zhang; Qian Yao, Lili Lin, Chaoran Xu, Xiaohua Liu, Xiaoming Feng
      Abstract: An asymmetric epoxidation of electron-deficient enynes with environmentally benign aqueous hydrogen peroxide as oxidant has been accomplished by developing a chiral N,N'-dioxide-Scandium(III) complex catalytic system. In the presence of 0.5-2 mol% catalyst, a variety of trisubstituted alkynyl oxiranes were obtained in high yields (up to 97%) with excellent ee values (up to 99%). Furthermore, control experiments provide a fundamental insight into the reaction mechanism.
      PubDate: 2017-07-26T21:26:09.166312-05:
      DOI: 10.1002/adsc.201700555
       
  • Regiodivergent Conjugate Addition Controlled by Rhodium(I) and
           Palladium(II) Catalysts: A Combined Computational and Experimental Study
    • Authors: Mu-Hyun Baik; Hoimin Jung, Ansoo Kim, Jin Kim, Hyunwoo Kim
      Abstract: A new divergent catalytic method for the 1,4- and 1,6-selective conjugate additions of arylboronic acids to α,β,γ,δ-unsaturated imino esters mediated by two different transition metal systems was developed. The Rh-complex carrying briphos, a new bicyclic, bridgehead phosphoramidite ligand, showed excellent regioselectivity towards 1,4-addition with product ratios of>50:1, whereas the Pd(OPiv)2 catalyst reversed the regiochemistry to afford the 1,6-product with mild levels of selectivity of ~1:7. Both theoretical and experimental studies were utilized to understand the catalytic systems and to elucidate the molecular level mechanism leading to the selective reactions. Since Rh(I) and Pd(II) are both d8-complexes, their electronic structures and binding behaviors can be compared. Our calculations suggest that the outcome of the catalysis in the Rh(I) system is under kinetic control, where the migratory insertion of the alkene is the step that determines the regiochemistry. When the Pd(II) catalyst is used, the regiochemistry is under thermodynamic control where the relative stability of the η3-π-allyl- over the η3-aza-π-allyl-intermediate dictates the selectivity at the 1,6-migratory insertion step.
      PubDate: 2017-07-25T21:26:28.776908-05:
      DOI: 10.1002/adsc.201700628
       
  • Synthesis of Allenamides and Structurally Related Compounds by a
           Gold-Catalyzed Hydride Shift Process
    • Authors: Fabien Gagosz; Qing Zhao
      Abstract: A new procedure for the synthesis of allenamides and structurally related compounds is reported. Under gold catalysis, a series of ynamides possessing a benzyloxy group at the propargylic position were efficiently converted into the corresponding allenamides following a 1,5 hydride shift process. The scope of the reaction was shown to be extremely broad allowing the formation of γ-mono or γ-disubstituted allenes possessing various functional groups. Notably, and in contrast to previously reported methods, not only N-allenyl sulfonamido but also urea, phosphonamido and the rarely studied phthalimido, pyrrolo, indolo and carbazolo derivatives could be readily and efficiently accessed.
      PubDate: 2017-07-25T21:26:20.390104-05:
      DOI: 10.1002/adsc.201700615
       
  • Synthesis of Dihydrophosphaisocoumarins through a Palladium-Catalyzed
           Oxidative Cyclization of Arylphosphonic Acid Monoethyl Esters with
           1,3-Dienes
    • Authors: Jeong-Yu Son; Hyunseok Kim, Woo Hyung Jeon, Yonghyeon Baek, Boram Seo, Kyusik Um, Kooyeon Lee, Phil Ho Lee
      Abstract: An efficient synthetic method for the selective preparation of dihydrophosphaisocoumarins and their derivatives was developed through a Pd-catalyzed oxidative cyclization reaction of a wide range of arylphosphonic acid monoethyl esters with activated and unactivated 1,3-dienes, including 1-aryl-substituted 1,3-dienes and 1-alkyl-substituted 1,3-dienes, thus opening a new avenue for the synthesis of phosphaheterocyclic compounds.
      PubDate: 2017-07-25T21:25:57.991166-05:
      DOI: 10.1002/adsc.201700742
       
  • Base-Promoted [3+2]-Annulation of Oxime Esters and Aldehydes for Rapid
           Isoxazoline Formation
    • Authors: Huawen Huang; Feifei Li, Zhenhua Xu, Jinhui Cai, Xiaochen Ji, Guojun Deng
      Abstract: A base-promoted [3+2]-annulation of ketoxime esters and aldehydes is disclosed for the facile and rapid synthesis of 3,5-disubstituted and 3,4,5-trisubstituted isoxazolines. The key to our success is the pivalate leaving group of oxime substrates, combined with cesium carbonate as promoter. This chemistry allows the assembly of a vast array of isoxazoline derivatives under simple base conditions in a method complementary to the classic isoxazoline formation via [3+2]-dipolar cycloaddition of nitrile oxides and olefins. It also represents a new reaction pattern involving electrophilic amination/N–O bond substitution.
      PubDate: 2017-07-25T21:25:44.470981-05:
      DOI: 10.1002/adsc.201700730
       
  • Metal-Free Activation of DMF by Dioxygen: A Cascade
           Multiple-Bond-Formation Reaction to Synthesize 3-Acylindoles from
           2-Alkenylanilines
    • Authors: Jun Deng; Ji-Bo Wang, Yin-Long Li
      Abstract: A cascade C-N, C-C and C-O multiple-bond-formation reaction to synthesize 3-acylindoles from 2-alkenylanilines with DMF (N,N-dimethylformamide) as a one-carbon synthon is described. This approach employed dioxygen as a terminal oxidant and oxygen donor, generally provided the 3-acylindoles in moderate to good yields. Moreover, the mechanistic investigation unambiguously revealed that the 2-carbon of 3-acylindole was derived from the N-methyl group of DMF.
      PubDate: 2017-07-22T00:15:48.320662-05:
      DOI: 10.1002/adsc.201700584
       
  • Tunable Dimerization and Trimerization of β-Alkynyl Ketones via Silver
           Catalysis for Accessing Spiro and Dispiro Compounds Containing
           1H-Isochromene
    • Authors: Bo Jiang; Dan Wang, Shuai Liu, Xin-Chan Lan, Armando Paniagua, Wen-Juan Hao, Guigen Li, Shu-Jiang Tu
      Abstract: New silver-catalyzed tunable dimerization and trimerization of β-alkynyl ketones have been established, enabling multiple C-C bond-forming events to selectively access skeletally diverse spiro isochromenes with generally good yields. The silver-enabled bicycloaddition of β-alkynyl ketones with water offered hydroxylated spiro isochromenes. Without water, spiro isochromenes with methylene moiety were obtained through catalytic 6-endo-dig oxo-cyclization/[4+2] cycloaddition cascades by using pyridine as additives whereas employment of 1,1‘-binaphthyl-2,2‘-diyl hydrogen phosphate (BiNPO4H) as a Brønsted acid catalyst rendered the unprecedented dispiro trimerization products through double C(sp3)-H functionalization.
      PubDate: 2017-07-22T00:15:41.005673-05:
      DOI: 10.1002/adsc.201700543
       
  • Phosphine Catalyzed [3+2] or [4+2] Cycloaddition/SN2 Substitution Domino
           Reaction of ortho-Amino Trifluoroacetophenone Derivatives with
           Hex-3-yn-2-one: Preparation of Functionalized 1-Benzazepine Compounds
    • Authors: Min Shi; Yao-Liang Sun, Yin Wei
      Abstract: In this paper, we disclosed a novel strategy for the phosphine catalyzed cycloaddition/SN2 substitution domino reaction, giving functionalized O-bridged benzoazepine and benzoxazepine derivatives in moderate to good yields. Changing the N-H protecting group of ortho-amino trifluoroacetophenone derivatives gave different bridged-ring products in one step.
      PubDate: 2017-07-22T00:15:31.535056-05:
      DOI: 10.1002/adsc.201700778
       
  • Ruthenium-Catalyzed Oxidative Formal Aza-Diels−Alder Reactions:
           Enantioselective Synthesis of Benzo[a]quinolizine-2-ones
    • Authors: Yuan Yao; Hai-Jie Zhu, Fang Li, Cheng-Feng Zhu, Yun-Fei Luo, Xiang Wu, Eric Kantchev
      Abstract: A method for preparation of thermodynamic (4R,11bS)-benzo[a]quinolizine-2-one derivatives in good enantio- and diastereoselectivity by a one-pot oxidative formal aza-Diels−Alder reaction of 1,2,3,4-tetrahydroisoquinolines and α,β-unsaturated ketones is described. The reaction proceeds via tandem Ru-catalyzed amine dehydrogenation using TBHP as the oxidant and a chiral thiourea-catalyzed formal aza-[4+2] cycloaddition, providing a step-economical strategy for synthesis of valuable heterocyclic products.
      PubDate: 2017-07-22T00:15:26.770663-05:
      DOI: 10.1002/adsc.201700738
       
  • Diversity-Oriented Synthesis of oxacyclic spirooxindole derivatives
           through ring-closing enyne metathesis and intramolecular Pauson−Khand (2
           + 2 + 1) cyclization of oxindole enynes
    • Authors: Gowravaram Sabitha; Satheeshkumar Reddy Kandimalla
      Abstract: An efficient approach for a reagent-based Diversity-Oriented Synthesis (DOS) of novel fused spiro-oxindole scaffolds have been reported from oxindole enynes. The reaction involves a metal-catalyzed C-3 allylation/vinylation/homoallylation of N-substituted isatins gives rise to corresponding alcohols that can be converted into required enynes, further transformed to a diverse complex molecular scaffolds via subsequent Ruthenium catalyzed ring-closing enyne metathesis (RCEYM), or Cobalt catalyzed intramolecular Pauson−Khand (2 + 2 + 1) cyclization reaction (IPKR). This strategy provided a facile approach to various spirooxindole-vinyl dihydropyrans/tetrahydrooxepines and spirocyclic fused cyclopentenones in good to excellent yields.
      PubDate: 2017-07-22T00:10:23.933827-05:
      DOI: 10.1002/adsc.201700511
       
  • Diastereoselective One-step Synthesis of
           2-Keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN) Analogues as
           Templates for the Development of Influenza Drugs
    • Authors: Pedro Laborda; Su-Yan Wang, Ai-Min Lu, Meng He, Xu-Chu Duan, Ying-Juan Qian, Yong-Sam Jung, Li Liu, Josef Voglmeir
      Abstract: Novel sialic acid scaffolds have great significance in the development of influenza neuraminidase inhibitors. Here the enzymatic synthesis of a wide range of 2-keto-3-deoxy-D-glycero-D-galacto-nononic acid (KDN) analogues via aldol addition of pyruvate to D-mannose, D-glucose, D-galactose, 2-deoxy-D-glucose, D-arabinose, L-arabinose and L-rhamnose using a previously unstudied N-acetylneuraminic acid (Neu5Ac) aldolase derived from the bacterium Dyadobacter fermentas was exemplified. Several of the synthesized KDN analogues showed comparable or better inhibitory activity than unstudied Neu5Ac against the mutated influenza neuraminidases (A/California/04/2009 and A/Anhui/1/2005), which both show resistance to Neu5Ac-based neuraminidase inhibitors, demonstrating that these compounds are promising templates for the development of anti-influenza drugs.
      PubDate: 2017-07-20T21:11:04.740455-05:
      DOI: 10.1002/adsc.201700678
       
  • Synthesis of a Class of Fused δ-Sultone Heterocycles via DBU-Catalyzed
           Direct Annulative SuFEx Click of Ethenesulfonyl Fluorides and Pyrazolones
           or 1,3-Dicarbonyl Compounds
    • Authors: Xing Chen; Gao-Feng Zha, Grant Bare, Jing Leng, Shi-Meng Wang, Huali Qin
      Abstract: (E)-2-(hetero)arylethenesulfonyl fluorides and (E,E)-1,3-dienylsulfonyl fluorides are bis-electrophiles and rare members of the sulfonyl fluoride family with limited information being known of their reactivity and synthetic utility. The direct annulation reaction of these 2-substituted ethenesulfonyl fluorides with medicinally important enolizable pyrazolones and 1,3-dicarbonyl compounds utilizing catalytic DBU in DCM under mild conditions leads to over 50 structurally diverse δ-sultone fused heterocycles with a pyrazolone ring or a cyclic enone, respectively, in good to excellent yield. The double bond at the 1-position adjacent to the sulfonyl fluoride group in 1,3-dienylsulfonyl fluoride is the chemoselective site of reactivity but is less reactive than the double bond of arylethenesulfonyl fluoride. High turnover and robustness of construction for these fused heterocycles, including the novel fused pyrazolone δ-sultone heterocycle series, may make compounds like these attractive to drug discovery, development and material science.
      PubDate: 2017-07-20T00:10:17.34782-05:0
      DOI: 10.1002/adsc.201700887
       
  • Transition-Metal-Free Oxidative Cross-Coupling C(sp2)-C(sp3) Bond
           
    • Authors: Yunfei Du; Longyang Dian, Daisy Zhang-Negrerie
      Abstract: A novel transition-metal-free regioselective C3-alkylation of coumarins was realized under mild reaction conditions. Various coumarins and tertiary amines smoothly underwent the direct C(sp2)-C(sp3) bond formation in the presence of n-Bu4NI as the catalyst and t-BuOOH as the oxidant.
      PubDate: 2017-07-18T21:30:43.673584-05:
      DOI: 10.1002/adsc.201700521
       
  • Selective Synthesis of Silacycles by Borane-Catalyzed Domino
           Hydrosilylation of Proximal Unsaturated Bonds: Tunable Approach to
           1,n-Diols
    • Authors: Kwangmin Shin; Seewon Joung, Youyoung Kim, Sukbok Chang
      Abstract: Tris(pentafluorophenyl)boron-catalyzed domino hydrosilylation of substrates carrying unsaturated functionalities in proximal arrangement is presented to produce silacycles. Excellent levels of efficiency and selectivity were achieved in the cyclization by the deliberate choice of the hydrosilane reagents. The key to facile cyclic hydrosilylation is the reactivity enhancement in the second intramolecular hydrosilylation by proximity effect. Not only dienes but also enones, enynes, ynones and enimines readily afford the corresponding medium-sized silacycles under convenient and mild conditions. The cyclization proceeds with acceptable diastereo-selectivity mainly controlled by the conformational bias, thereby inducing additional stereogenic centers. The silacycles obtained from this reaction were converted to 1,n-diols or 1,n-amino alcohols upon oxidation, thus rendering the present cyclization a powerful tool for accessing synthetically valuable building blocks.
      PubDate: 2017-07-18T21:30:30.7134-05:00
      DOI: 10.1002/adsc.201700698
       
  • A Unified Strategy Toward 5-, 6-, and 7-Membered Nitrogen Heterocycles
           Through Free Radical then Metal-Mediated Functionalization of
           Ene-carbamates
    • Authors: Yannick LANDAIS; Redouane Beniazza, Frédéric Robert, Clément Poittevin, Stéphane MASSIP, Jonathan Lusseau
      Abstract: Abstract. Free-radical carbo-alkenylation of N-aryl, N-benzyl, and N-phenethyl-ene-carbamates with a disulfone provides vinylsulfones which may then be functionalized and engaged in Heck-type coupling to furnish highly substituted 5-, 6- and 7-membered nitrogen heterocycles. Grignard-mediated cyclization starting from the same substrates further allowed a nucleophilic cascade process, affording a straightforward access to hydrocarbazoles, which may be regarded as potent intermediates for the synthesis of alkaloids of the aspidosperma family.
      PubDate: 2017-07-18T08:16:01.028654-05:
      DOI: 10.1002/adsc.201700485
       
  • A General and Practical Approach for Synthesis of 1,2,4-Trioxanes
           Catalyzed by Silica-Ferric Chloride
    • Authors: Mo Zhang; Yi Han, Jia-Liang Niu, Zhan-Hui Zhang
      Abstract: An efficient and practical synthetic method has been developed for the facile synthesis of 1,2,4-trioxanes by the condensation of -hydroperoxy alcohols and carbonyl compounds in the presence of a catalytic amount of silica-supported FeCl3 (FeCl3/SiO2) at room temperature. The method has the benefits of operational simplicity, high yields and potentially large-scale application. Moreover, the catalyst can be readily recovered by simple filtration and reused up to five times with almost maintained its catalytic activity.
      PubDate: 2017-07-17T21:20:39.698753-05:
      DOI: 10.1002/adsc.201700671
       
  • Copper(I)-Catalyzed Synthesis of 4,5-Dihydropyrazolo[1,5-a]pyrimidines via
           Cascade Transformation of N-Propargylic Sulfonylhydrazones with Sulfonyl
           Azides
    • Authors: Zong-Cang Ding; Xiao-Ming An, Jia-Hao Zeng, Zhao-Ning Tang, Zhuang-Ping Zhan
      Abstract: A rapid and effective approach to 4-tosyl-4,5-dihydropyrazolo[1,5-a]pyrimidines via copper-catalyzed one-pot cascade transformation of N-propargylic sulfonylhydrazones with sulfonyl azides under mild conditions has been developed. This process relies on the copper-catalyzed azide-alkyne cycloaddition (CuAAC) and intramolecular [4+2] cycloaddition of α,β-unsaturated hydrazone with the in situ generated ketenimine intermediate, affording the useful bicyclization products with high efficiency.
      PubDate: 2017-07-14T23:31:02.599934-05:
      DOI: 10.1002/adsc.201700635
       
  • Secondary Phosphine Oxide Preligand for Palladium-Catalyzed C–H
           (Hetero)Arylations: Efficient Access to Pybox Ligands
    • Authors: Debasish Ghorai; Valentin Müller, Helena Keil, Dietmar Stalke, Giuseppe Zanoni, Boryslav A. Tkachenko, Peter Schreiner, Lutz Ackermann
      Abstract: C‒H arylations of oxazolines were accomplished with a well-defined palladium catalyst derived from a secondary bisdiamantyl phosphine oxide. The single-component secondary phosphine oxide (SPO)-palladium complex enabled C‒H activations with aryl bromides and challenging aryl chlorides in the absence of directing groups, setting the stage for the step-economical synthesis of pybox ligands under racemization-free reaction conditions.
      PubDate: 2017-07-11T20:46:29.781358-05:
      DOI: 10.1002/adsc.201700663
       
  • Combining Sanford Arylations on Benzodiazepines with the Nuisance Effect
    • Authors: Raysa Khan; Sarote Boonseng, Paul Kemmitt, Robert Felix, Hazel Cox, Simon Coles, Graham Tizzard, Gareth Williams, Olivia Simmonds, Jessica Harvey-Cox, John Atack, John Spencer
      Abstract: 5-Phenyl-1,3-dihydro-2H-1,4-benzodiazepin-2-ones react under palladium- and visible light photoredox catalysis, in refluxing methanol, with aryldiazonium salts to afford the respective 5-(2-arylphenyl) analogues. With 2- or 4-fluorobenzenediazonium derivatives, both fluoroaryl- and methoxyaryl- products were obtained, the latter resulting from a SNAr on the fluorobenzenediazonium salt (“nuisance effect”). A computational DFT analysis of the Pd-catalysed and the Pd/Ru-photocalysed mechanism for the functionalization of benzodiazepine indicated that in the presence of the photocatalyst the reaction proceeds via a low-energy SET pathway avoiding the high-energy oxidative addition step in the Pd-only catalysed reaction pathway.
      PubDate: 2017-07-11T20:46:23.895754-05:
      DOI: 10.1002/adsc.201700626
       
  • Yttrium-Benzyl Complexes Bearing Chiral Iminophosphonamide Ligands:
           Synthesis and Application in Catalytic Asymmetric Amine-Silane
           Dehydrocoupling Reactions
    • Authors: Nan Li; Bing-Tao Guan
      Abstract: A series of novel iminophosphonamide ligands with chiral diamine moieties were designed and synthesized. Yttrium- benzyl compounds bearing these chiral iminophosphonamide ligands showed high reactivity and selectivity on the first catalytic asymmetric cross-dehydrogenative coupling of amines with prochiral silanes under mild conditions. A stable boron derivative of silylamines was synthesized and up to 23% ee value was determined by chiral HPLC analysis. Employing this catalyst system, catalytic kinetic resolution of an axially chiral silane and further in situ allylation were achieved in good yields and enantioselectivity.
      PubDate: 2017-07-10T20:40:40.33614-05:0
      DOI: 10.1002/adsc.201700327
       
  • Carbonyl Ylides Derived from Palladium Carbenes: The Impressive Fluorine
           Effect
    • Authors: Huanfeng Jiang; Chuanle Zhu, Rui Zhu, Pengquan Chen, Fulin Chen, Wanqing Wu
      Abstract: The first example for the generation of carbonyl ylides from palladium carbenes is reported. Systematic investigation of the substituents attached to the carbonyl group indicates that the employment of trifluoromethyl group as the substituent is very critical for the success of this transformation. The remarkable fluorine effect on thereactivity is very impressive, which allows to the construction of various trifluoromethylated oxiranes in high yields and diastereoselectivities.
      PubDate: 2017-07-10T09:16:06.97508-05:0
      DOI: 10.1002/adsc.201700336
       
  • Silver-Catalyzed Atom-Economic Hydrophosphorylation of Propargyl Epoxides:
           An Access to 4-Phosphoryl 2,3-Allenols and Stereodefined 1-Phosphoryl
           1,3-Dienes
    • Authors: Ruwei Shen; Jianlin Yang, Ming Zhang, Li-Biao Han
      Abstract: The highly regioselective nucleophilic ring opening of propargyl epoxides by P(O)H compounds based on a silver catalyst is reported. A variety of P(O)H compounds including H-phosphonates, H-phosphinates and diarylphosphine oxides can be used to produce 4-phosphoryl 2,3-allenols under mild conditions. The stereoselective synthesis of 1-phosphoryl 1,3-butadienes from 4-phosphoryl 2,3-allenols and organoboronic acids via a palladium-catalyzed coupling reaction is also described.
      PubDate: 2017-07-05T06:30:26.15644-05:0
      DOI: 10.1002/adsc.201700421
       
  • Tunable Triazole-Phosphine-Copper Catalysts for the Synthesis of
           2-Aryl-1H-benzo[d]imidazoles from Benzyl Alcohols and Diamines by
           Acceptorless Dehydrogenation and Borrowing Hydrogen Reactions
    • Authors: Zhaojun Xu; Duo-Sheng Wang, Xiaoli Yu, Yongchun Yang, Dawei Wang
      Abstract: Triazole-phosphine-copper complexes (TAP−Cu) have been synthesized and applied as tunable and efficient catalysts for the selective synthesis of fluoro-substituted 2-aryl-1H-benzo[d]imidazole and 1-benzyl-2-aryl-1H-benzo[d]imidazole derivatives from simple alcohols in only one step. TAP−Cu exhibited excellent and tunable catalytic activity for both dehydrogenation and borrowing hydrogen reactions with more than 80 examples being demonstrated for the first time. It was observed that the ligand played a critical role in catalyst activity. Mechanistic studies and deuterium labeling experiments indicated that the reactions proceeded by an initial and reversible alcohol dehydrogenation resulting in a copper hydride intermediate. This was also supported by the direct observation of a diagnostic copper hydride signal by solid-state infrared spectroscopy. The TAP−Cu-H complex showed absorptions at 912 cm−1 that could be assigned to copper−hydride stretches. Furthermore, the direct trapping of an intermediate bisimine was also successfully performed.
      PubDate: 2017-06-19T06:16:48.395644-05:
      DOI: 10.1002/adsc.201700179
       
  • Catalytic Asymmetric [4+1] Cyclization of ortho-Quinone Methides with
           3-Chlorooxindoles
    • Authors: Xiao-Li Jiang; Si-Jia Liu, Yu-Qi Gu, Guang-Jian Mei, Feng Shi
      Abstract: In this work, we established catalytic asymmetric [4+1] cyclization of ortho-quinone methides (o-QMs) with 3-chlorooxindoles and a catalytic asymmetric domino oxidation/[4+1] cyclization reaction of 2-alkylphenols with 3-chlorooxindoles, which constructed a spirooxindole-based 2,3-dihydrobenzofuran scaffold in good yield (up to 97%), with excellent diastereoselectivity (up to>95:5 dr) and high enantioselectivity (up to 99% ee). This work is not only the first highly enantioselective [4+1] cyclization of o-QMs but has also realized the first catalytic asymmetric domino [4+1] cyclization of o-QMs. In addition, both of the reactions provide efficient stereoselective methods for constructing spirooxindole-based 2,3-dihydrobenzofuran scaffolds with optical purity.
      PubDate: 2017-06-19T06:10:31.923612-05:
      DOI: 10.1002/adsc.201700487
       
  • Suzuki-Miyaura Cross-Coupling Reactions of Tetrahydroxanthones and
           4-Chromanone Lactones to Heteromeric Biaryls
    • Authors: Larissa Geiger; Martin Nieger, Stefan Bräse
      Abstract: We report on a Suzuki-Miyaura cross-coupling study of a tetrahydroxanthone model system with different boronic acids, pinacolato borons and halides to heteromeric biaryls. We transferred these reaction conditions to the Suzuki-Miyaura cross-coupling reactions of 4-chromanone lactones. We thereby obtained complex building blocks offering a convenient starting point for further transformations towards various natural products with the tetrahydroxanthone structural motif.
      PubDate: 2017-06-12T21:20:25.767189-05:
      DOI: 10.1002/adsc.201700497
       
  • Front Cover Picture: Gram-Scale Synthesis of Amines Bearing a
           gem-Difluorocyclopropane Moiety (Adv. Synth. Catal. 18/2017)
    • Authors: Pavel S. Nosik; Andrii O. Gerasov, Rodion O. Boiko, Eduard Rusanov, Sergey V. Ryabukhin, Oleksandr O. Grygorenko, Dmitriy M. Volochnyuk
      Pages: 3077 - 3077
      Abstract: The front cover image, provided by Pavel Nosik, Andriy Gerasov, Sergey Ryabukhin, Oleksandr Grygorenko, and Dmitriy Volochnyuk illustrates the synthesis of secondary amines bearing a gem-difluorocyclopropane moiety via reaction of unsaturated N-Boc derivatives with the CF3SiMe3−NaI system. For the reactive alkenes, the standard reaction conditions can be used, whereas for those substrates with low reactivity, slow addition of the Ruppert-Prakash reagent is necessary. (Background artwork by Web Design Studio “ZORELiT”). Details can be found in the full paper on pages 3126–3136 (P. S. Nosik, A. O. Gerasov, R. O. Boiko, E. Rusanov, S. V. Ryabukhin, O. O. Grygorenko, D. M. Volochnyuk, Adv. Synth. Catal. 2017, 359, 3126–3136;
      DOI : 10.1002/adsc.201700857).
      PubDate: 2017-09-18T04:10:19.252932-05:
       
  • Cover Picture: Secondary Phosphine Oxide Preligands for
           Palladium-Catalyzed C–H (Hetero)Arylations: Efficient Access to Pybox
           Ligands (Adv. Synth. Catal. 18/2017)
    • Authors: Debasish Ghorai; Valentin Müller, Helena Keil, Dietmar Stalke, Giuseppe Zanoni, Boryslav A. Tkachenko, Peter R. Schreiner, Lutz Ackermann
      Pages: 3078 - 3078
      Abstract: The inside cover picture, provided by Lutz Ackermann and co-workers, demonstrates the design of the novel palladium complex derived from a secondary bisdiamantyl phosphine oxide preligand that enables the facile activation of challenging C−H bonds of oxazolines without the need of directing groups. The user-friendly palladium catalyst also proved effective for synthetically useful heterocyclic electrophiles, which sets the stage for the step-economical synthesis of pybox ligands under racemization-free reaction conditions. Details of this study can be found in the full paper on pages 3137–3141 (D. Ghorai, V. Müller, H. Keil, D. Stalke, G. Zanoni, B. A. Tkachenko, P. R. Schreiner, L. Ackermann, Adv. Synth. Catal. 2017, 359, 3137–3141;
      DOI : 10.1002/adsc.201700663).
      PubDate: 2017-09-18T04:10:15.822408-05:
       
  • Copper-Catalyzed Aminodifluoroalkylation of Alkenes with
           α-Bromodifluoroacetamides: Synthesis of 3,3-Difluoropyrrolidin-2-ones
    • Authors: Yunhe Lv; Weiya Pu, Qingqing Wang, Qian Chen, Jiejie Niu, Qian Zhang
      Pages: 3114 - 3119
      Abstract: Copper-catalyzed external-oxidant-free regioselective aminodifluoroalkylation of alkenes with readily available α-bromodifluoroacetamides was realized. This reaction exhibits good functional group tolerance with respect to alkenes and α-bromodifluoroacetamides in affording 3,3-difluoropyrrolidin-2-ones. A mechanism involving copper-catalyzed generation of a difluoroalkyl radical is proposed.
      PubDate: 2017-07-26T06:15:41.937079-05:
      DOI: 10.1002/adsc.201700559
       
  • Gram-Scale Synthesis of β-(Hetero)arylethenesulfonyl Fluorides via a
           
    • Authors: Gao-Feng Zha; Grant A. L. Bare, Jing Leng, Zhen-Peng Shang, Zhixiong Luo, Hua-Li Qin
      Pages: 3237 - 3242
      Abstract: A practical oxidative Heck reaction between organoboronic acids and ethenesulfonyl fluoride (ESF) is developed. Aryl- and heteroaryl-boronic acids react efficiently and stereoselectively with ESF in the presence of a catalytic amount of Pd(OAc)2 and 2,3-dichloro-5,6-dicyano-p-benzoquinone (DDQ) or AgNO3 in AcOH to afford the corresponding E-isomer of β-arylethenesulfonyl fluoride products. The utility of this reaction is exemplified by an expanded scope of 47 examples including N-, O-, and S-containing heteroaromatics, demonstrating chemoselectivity over aryliodides, and gram-scale operation without the requirement for strict anhydrous or oxygen-free conditions. Furthermore, this procedure discriminates against the formation of arylboronic acids homo-coupling byproducts. In addition, the preparation of the first aryl vinylsulfonate polymer, a material with functionalizable Michael acceptor sites, from a starting arylboronic acid is described.
      PubDate: 2017-07-25T06:25:28.554847-05:
      DOI: 10.1002/adsc.201700688
       
  • Iodine(III)-Mediated/Catalyzed Cycloisomerization–Amination Sequence of
           N-Propargyl Carboxamides
    • Authors: Yuki Okamura; Daisuke Sato, Akira Yoshimura, Viktor V. Zhdankin, Akio Saito
      Pages: 3243 - 3247
      Abstract: (Diacetoxyiodo)benzene or iodine(III) catalyst, in situ generated from iodobenzene precatalyst with Oxone, promotes the cycloisomerization–amination sequence of N-propargyl carboxamides with bis(sulfonyl)imides under mild conditions, thereby leading to the direct formation of oxazoles bearing nitrogen functional groups.
      PubDate: 2017-07-27T04:37:05.547841-05:
      DOI: 10.1002/adsc.201700587
       
  • TBAI/K2S2O8 Initiated Radical Cyclization to Synthesize β- Arylsulfonyl
           Naphthalenes from Homopropargylic Alcohols and Sulfonyl Hydrazides
    • Authors: Xiaodong Yang; Lianbiao Zhao, Bingxiang Yuan, Zhenjie Qi, Rulong Yan
      Pages: 3248 - 3253
      Abstract: A metal-free radical addition method for the synthesis of β-arylsulfonyl naphthalenes with homopropargylic alcohols and sulfonyl hydrazides has been developed. In this reaction, sulfonyl hydrazide is employed as the source of sulfonyl radical to produce the desired sulfone directly. There is the first example for homopropargylic alcohol through direct intramolecular addition of vinyl radical to arenes with sulfonyl radical, which is initiated by the TBAI/K2S2O8 reaction system and generates the desired products in moderate yields.
      PubDate: 2017-08-01T06:07:33.852157-05:
      DOI: 10.1002/adsc.201700634
       
 
 
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