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  Subjects -> ENGINEERING (Total: 2284 journals)
    - CHEMICAL ENGINEERING (192 journals)
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ENGINEERING (1208 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: 227)
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 Artificial Neural Systems     Open Access   (Followers: 4)
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 Human Factors/Ergonomics     Full-text available via subscription   (Followers: 25)
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: 29)
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: 11)
Applied Clay Science     Hybrid Journal   (Followers: 4)
Applied Computational Intelligence and Soft Computing     Open Access   (Followers: 12)
Applied Magnetic Resonance     Hybrid Journal   (Followers: 3)
Applied Nanoscience     Open Access   (Followers: 7)
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)
Arid Zone Journal of Engineering, Technology and Environment     Open Access   (Followers: 2)
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: 4)
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: 9)
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: 32)
Biomedical Engineering: Applications, Basis and Communications     Hybrid Journal   (Followers: 5)
Biomedical Microdevices     Hybrid Journal   (Followers: 8)
Biomedical Science and Engineering     Open Access   (Followers: 3)
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: 7)
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: 9)
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: 253)
Composites Part A : Applied Science and Manufacturing     Hybrid Journal   (Followers: 179)
Composites Part B : Engineering     Hybrid Journal   (Followers: 228)
Composites Science and Technology     Hybrid Journal   (Followers: 175)
Comptes Rendus Mécanique     Full-text available via subscription   (Followers: 2)
Computation     Open Access  
Computational Geosciences     Hybrid Journal   (Followers: 13)
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: 8)
Control Engineering Practice     Hybrid Journal   (Followers: 42)
Control Theory and Informatics     Open Access   (Followers: 7)
Corrosion Science     Hybrid Journal   (Followers: 25)
CT&F Ciencia, Tecnologia y Futuro     Open Access  

        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  [1576 journals]
  • 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
    • 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
    • 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
    • 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
  • Cycloisomerization of Oxindole-derived 1,5-enynes: A Calcium(II) catalyzed
           one-pot, solvent-free synthesis of Phenanthridinones,
           3-(cyclopentenylidene)indolin-2-ones and 3-spirocyclic indolin-2-ones
    • Authors: SRINIVASARAO YARAGORLA; Abhishek pareek, Ravikrishna Dada
      Abstract: Calcium catalyzed regioselective synthesis of oxindole derived 1,5-enynes and their cycloisomerization has been described from readily accessible 3-hydroxy-3-(alkynyl)indolin-2-ones and styrenes in one-pot, solvent free conditions. This method offers the synthesis of diversified molecules: Phenanthridinones, 3-(cyclopentenylidene) indolin-2-ones and 3-spirocyclic indolin-2-ones through a cascade cross-dehydrative-coupling/[3,3]-sigmatropic rearrangement/ carbocyclization /isomerization/oxidative-ring rearrangement/Diels-Alder cycloaddition. In addition, this method features atom and step economy, broad substrate scope with high yields.
      PubDate: 2017-07-21T05:47:19.284284-05:
      DOI: 10.1002/adsc.201700569
  • Bisphosphine-Ligated Nickel Pre-catalysts in C(sp2)-N Cross-Couplings of
           Aryl Chlorides: A Comparison of Ni(I) and Ni(II)
    • Authors: Christopher Lavoie; Robert McDonald, Erin Johnson, Mark Stradiotto
      Abstract: The influence of ancillary ligand and Ni oxidation state in the Ni-catalyzed C(sp2)-N cross-coupling of aryl chlorides is examined by use of experimental and DFT methods for the first time, focusing on (L)NiCl and (L)Ni(o-tolyl)Cl pre-catalysts (PAd-DalPhos, L1; dppf, L2). Whereas Ni(II) pre-catalysts generally out-performed Ni(I) species in our study, the viability and in some cases superiority of Ni(I) pre-catalysts in challenging aminations is established. Computational analyses support the viability of Ni(0)/Ni(II) cycles featuring rate-limiting C-N reductive elimination, as well as parallel Ni(I)/Ni(III) mechanisms involving rate-limiting C-Cl oxidative addition.
      PubDate: 2017-07-20T21:11:19.309121-05:
      DOI: 10.1002/adsc.201700672
  • Cascade One-Pot Synthesis of Indanone-Fused Cyclopentanes from the
           Reaction of Donor-Acceptor Cyclopropanes and Enynals via a Sequential
           Hydrolysis/Knoevenagel Condensation/[3+2] Cycloaddition
    • Authors: Shifa Zhu; Jiantao Zhang, Huanfeng Jiang
      Abstract: A cascade reaction of donor-acceptor cyclopropanes with enynals to construct indanone-fused cyclopentanes via a sequential hydrolysis/ Knoevenagel condensation/[3+2] cycloaddition was reported. The desired indanone-fused cyclopentanes compounds were obtained in good yields. This method featured with mild reaction conditions and broad substrate scopes, which renders this method very appealing to the chemists for the synthesis of complex molecules containing indanone-fused cyclopentanes moiety. Moreover, the products could be further converted into different functional groups through the well-known transformations.
      PubDate: 2017-07-20T21:11:15.685136-05:
      DOI: 10.1002/adsc.201700345
  • 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
  • Copper(I)-catalyzed alkyl- and arylsulfenylation of
           3,4-dihalo-2(5H)-furanones (X=Br, Cl) with sulfoxides under mild
    • Authors: Liang Cao; Shi-He Luo, Han-Qing Wu, Liu-Qing Chen, Kai Jiang, Zhi-Feng Hao, zhao-yang wang
      Abstract: An efficient copper(I)/proline sodium salt catalyzed alkyl- and arylsulfenylation of Csp2-X 3,4-dihalo-2(5H)-furanone compounds with sulfoxides is described. For inexpensive Csp2-Cl compounds, there is also a satisfactory reactivity with the moderate yields. This transformation provides a novel approach for the utilization of sulfoxides (not only DMSO) as sulfur source with mild temperature without the need for an anaerobic atmosphere. More importantly, both sulfoxide and proline sodium salt can play a dual role in this reaction.
      PubDate: 2017-07-19T05:13:18.841432-05:
      DOI: 10.1002/adsc.201700600
  • 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
    • 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
    • Authors: Yannick LANDAIS; Redouane Beniazza, Frédéric Robert, Clément Poittevin, Stéphane MASSIP, Jonathan Lusseau
      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
  • Organocascade Synthesis of Bicyclo[3.3.1]nonan-9-ones Initiated by an
           Unusual 1,6-Addition of Cyclohexanones to
    • Authors: Kwunmin Chen; De-Chih Wang, Pin-Han Huang, Wan-Wun Huang, You-Song Cheng
      Abstract: . An efficient organocatalytic cascade reaction for the synthesis of the bicyclo[3.3.1]nonan-9-one skeleton is reported. The cascade reaction proceeds smoothly between prochiral 4-substituted cyclohexanone and (E)-2-(3-arylallylidene)-indene-1,3-dione involving 1,6-/-protonation/1,4-addition sequence to construct bicyclic products that contain five stereogenic centres with good to high chemical yields and excellent diastereo- and enantioselectivity (up to> 20:1 dr and 97% ee) in the presence of a thioether linked L-prolinol-camphor-derived organocatalyst at an ambient temperature. An interesting organocatalytic three component triple cascade reaction has been performed to produce bicyclo[2.2.2]octan-2-one with a favourable chemical yield and stereoselectivity (>19:1 dr and 97% ee) starting from 1,3-indanedione, enal and cyclohexenone in the presence of a primary amine organocatalyst.Keywords: Organocatalysis, Cascade reaction, Vinylogous , Enantioselectivity, Bicycle
      PubDate: 2017-07-18T08:10:56.464637-05:
      DOI: 10.1002/adsc.201700338
  • [4 + 2] and [3 + 2] Annulation of α-Chloroaldehydes and Dithioesters:
           Synthesis of 1,4-Oxathin-2(3H)-ones and 1,3-Oxathioles
    • Authors: Tong Wang; Zhong-Hua Gao, Song Ye
      Abstract: The [4+2] and [3+2] annulations of α-chloroaldehydes with dithioesters were discovered. In the presence of N-heterocyclic carbene (NHC) catalyst, the [4+2] annulation went smoothly to afford highly substituted 1,4-oxathiin-2(3H)-ones, while the [3+2] annulation was observed to give 1,3-oxathioles in the absence of NHC.
      PubDate: 2017-07-17T21:20:47.528734-05:
      DOI: 10.1002/adsc.201700601
  • 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
    • 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
  • 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, Ru-Long Yan
      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: 2017-07-14T23:30:51.680106-05:
      DOI: 10.1002/adsc.201700634
  • 2-Iodoxybenzoic Acid Tosylates: the Alternative to Dess-Martin Periodinane
           Oxidizing Reagents
    • Authors: Mekhman Yusubov; Pavel Postnikov, Roza Yusubova, Akira Yoshimura, Gerrit Jürjens, Andreas Kirschning, Viktor 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 protocol that uses pyridine as additive. The oxidations proceed very fast 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: 2017-07-14T23:30:46.1084-05:00
      DOI: 10.1002/adsc.201700776
  • 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
      Abstract: The copper-catalyzed external-oxidant-free regioselective aminodifluoroalkylation of alkenes with readily available α-bromodifluoroacetamides is 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 Cu-catalyzed generation of difluoroalkyl radical is proposed.
      PubDate: 2017-07-13T21:26:11.893776-05:
      DOI: 10.1002/adsc.201700559
  • Selective reduction of azines to benzyl hydrazones with NaBH4 catalyzed by
           mesoporous silica supported silver nanoparticles: A catalytic route
           towards pyrazole synthesis
    • Authors: Ioannis Lykakis; Charistoudi Evangelia, Michael Kallitsakis, Ioannis Charisteidis, Kostas S. Triantafyllidis
      Abstract: The catalytic activity of supported silver nanoparticles on mesoporous silica was studied, for the selective reduction of azines into benzyl hydrazones using sodium borohydride as mild reducing agent. Different sizes of silver nanoparticles supported on mesoporous silica (Ag/HMS) were successfully prepared by two methods, i.e. wet impregnation followed by reduction with hydrogen at 350oC and in situ deposition/reduction with a mixture of amines (ethanolamine and ethylenediamine). The Ag/HMS (amines) catalyst was found to promote the selective 1,2-reduction of aryl-substituted azines, compared to the corresponding 1,4-reduction that occurs in general reduction processes. This catalytic transfer hydrogenation process found to be clear, fast and quantitative (>99% yields and selectivity) towards benzyl hydrazones synthesis under mild conditions. Of great importance is that under the present catalytic conditions reducible functional groups remain intact. Formal kinetics, support the in situ formation of silver-hydride species being responsible for the reduction process. The presence of protic polar methanol enhanced the catalytic activity of Ag/HMS. Based on the recycling studies the catalytic system Ag/HMS-NaBH4 was found to catalyze the selective reduction of azines nine times without significant loss of its activity. Finally, one-pot reaction between the in situ produced benzyl hydrazones and a series of nitrostyrenes readily provided the regioselective synthesis of 1,3,5,-subtituted pyrazoles, highlighting a useful synthetic application of the catalytic protocol.
      PubDate: 2017-07-13T21:25:55.770228-05:
      DOI: 10.1002/adsc.201700442
  • Iodine(III)-Mediated/Catalyzed Cycloisomerization–Amination Sequence of
           N-Propargyl Carboxamides
    • Authors: Yuki Okamura; Daisuke Sato, Akira Yoshimura, Viktor Zhdankin, Akio Saito
      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: 2017-07-12T20:45:58.174956-05:
      DOI: 10.1002/adsc.201700587
  • Synthesis of 1,2-Dihydrocyclobuta[b]quinoline Derivatives from
           Isocyanophenyl-Substituted Methylenecyclopropanes
    • Authors: Min Shi; Hou-Lu Liu, Yu-Chao Yuan, Yin Wei
      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 with high 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: 2017-07-11T20:46:36.510881-05:
      DOI: 10.1002/adsc.201700509
  • 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
  • Gram-scale Synthesis of β-(Hetero)arylethenesulfonyl Fluorides via a
           Pd(OAc)2(cat.)/DDQ or AgNO3 Mediated Oxidative Heck Process
    • Authors: Gao-Feng Zha; Grant Bare, Jing Leng, Zhen-peng Shang, Zhixiong Luo, Huali Qin
      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 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, demonstrated 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 acid homo-coupling byproducts. In addition, the preparation the first aryl vinylsulfonate polymer, a material with functionalizable Michael acceptor sites, from a starting arylboronic acid is described.
      PubDate: 2017-07-10T20:41:04.408281-05:
      DOI: 10.1002/adsc.201700688
  • 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
  • Iron-Mediated Oxidative C-H Alkylation of S,S-Functionalized Internal
           Olefins via C(sp2)-H/C(sp3)-H Cross-Coupling
    • Authors: Quannan Wang; Jiang Lou, Ping Wu, Kaikai Wu, Zhengkun Yu
      Abstract: Catalytic amount of FeCl3-mediated oxidative C-H alkylation of S,S-functionalized internal olefins, that is, α-oxo ketene dithioacetals and the analogs, was efficiently achieved by means of simple ethers and toluene derivatives as the coupling partners, di-tert-butyl peroxide (DTBP) as the oxidant, and DABCO·6H2O as the additive. The alkylthio functionality is essential for the internal olefinic C-H bond to undergo such alkylation with the O-adjacent C(sp3)-H bonds of ethers and benzylic C-H bonds of toluene derivatives, respectively. Tetrasubstitu-ted olefins were thus synthesized and further transformed to highly substituted pyrazoles and isoxazoles. The strategy to activate an internal olefinic C-H bond by polarizing its parent olefinic C=C bond with both the dialkylthio and an electron-withdrawing functionality was investigated. The mechanistic studies suggest a radical pathway for the C(sp2)-H/C(sp3)-H cross-coupling reactions. The present protocol provides a convenient route to tetrasubstituted olefins.
      PubDate: 2017-07-10T09:16:15.392433-05:
      DOI: 10.1002/adsc.201700654
  • Carbonyl Ylides Derived from Palladium Carbenes: The Impressive Fluorine
    • 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
  • Synthetic Applications of Vinyl Ruthenium Carbene Derived from
           Diazoalkanes and Alkynes
    • Authors: Soumen Dey; Suman De Sarkar
      Abstract: Synthetic applications of vinyl ruthenium carbene intermediate catalytically generated by the reaction between diazoalkane and alkyne have gained much attention in recent years. Latest advances in this field with respect to vinyl ruthenium carbene and its coupling partners, thus providing straightforward access to several diverse molecular scaffolds in a stereo-controlled manner, are discussed herein.
      PubDate: 2017-07-10T09:15:58.911652-05:
      DOI: 10.1002/adsc.201700622
  • Efficient Approach to Amide Bond Formation with Nitriles and Peroxides:
           One-Pot Access to Boronated β-Ketoamides
    • Authors: Babasaheb Sopan Gore; Gopal Chandru Senadi, Amol Milind Garkhedkar, Jeh-Jeng Wang
      Abstract: . An efficient, mild and practical approach for the synthesis of amides from nitriles and peroxides is reported in the presence of BF3-etherate. In this protocol, we utilized peroxides as C1 synthons for the amidation reaction. Also, we successfully prepared boron- incorporated β-ketoamides in a one-pot assembly from β-ketonitriles. A variety of functional groups were tolerated in moderate to good yields. Radical inhibition studies showed that the reaction proceeded via a non-radical pathway.
      PubDate: 2017-07-06T21:22:07.006436-05:
      DOI: 10.1002/adsc.201700532
  • Phosphine-Catalyzed Asymmetric Intermolecular Cross Rauhut-Currier
           Reaction of β-Perfluoroalkyl Substituted Enones and Vinyl Ketones
    • Authors: Junliang Zhang; Mengna Tao, Wei Zhou
      Abstract: The highly enantioselective N-acyl aminophosphine-catalyzed challenging asymmetric intermolecular cross Rauhut-Currier reaction of vinyl ketones with β-perfluoroalkyl enones is described, which provides a facile access to chiral multifunctional compounds bearing a perfluoroalkyl substituted stereocenter in good yields and ees.
      PubDate: 2017-07-04T21:49:59.302091-05:
      DOI: 10.1002/adsc.201700666
  • Corrigendum 201500290_Pàmies_Diéguez_Bäckvall ASC 2015,
           357, 1567 –1586
    • Authors: Joe 02 Richmond
      PubDate: 2017-07-03T21:27:46.032448-05:
      DOI: 10.1002/adsc.201700854
  • Metal-Free Iodosulfonylation of Internal Alkynes: Stereo-defined Access to
           Tetrasubstituted Olefins
    • Authors: ravi kumar; Vikas Dwivedi, Maddi Sridhar Reddy
      Abstract: Stereoselective E-iodosulfonylation of internal alkynes for synthesizing highly defined tetrasubstituted olefins using sodium phenyl sulfinate and iodine is achieved. Most of the alkynes explored are non-symmetrical and the regioselection is in full control. Aryl alkynes with various with-drawing groups like keto, aldehyde, ester, amide, cyano, sulfone, bromo, chloro and iodo on the other end are identified as successful precursors to yield the highly functionalized olefins. Alkynes directly tethered with heteroatoms are also found as suitable substrates.
      PubDate: 2017-07-03T02:56:10.03614-05:0
      DOI: 10.1002/adsc.201700576
  • A Copper Catalyzed Cascade Approach for the Synthesis of
           Dibenzo1,8-naphthyridine Derivatives
    • Authors: Ching-Fa Yao; Bharath kumar villuri, Ashok Konala, Veerababurao kavala, Trimurtulu Kotipalli, Chun-Wei Kuo
      Abstract: . The synthesis of some novel 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 a 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: 2017-06-30T02:52:52.366868-05:
      DOI: 10.1002/adsc.201700546
  • Stereoselective Mannich Reaction of N-(tert-Butylsulfinyl)imines with
           3-Fluorooxindoles and Fluoroacetamides
    • Authors: Xiangyu Chen; Ya Li, Jianbo Zhao, Buquan Zheng, Qi Lu, Xinfeng Ren
      Abstract: A diastereoselective Mannich reaction has been developed for the construction of stereogenic C–F units by the reaction of α-fluoro-substituted amides, including highly activated 3-fluoro-oxindoles, and simple linear fluoroacetamides with N-tert-butylsulfinylimines. This method provides a concise route to a variety of structurally diverse α-fluoro-β-amino amides containing stereogenic fluorinated carbon centers. This protocol has the benefit of using readily accessible starting materials and is operationally simple. The Mannich reactions of cyclic and linear α-fluoro-substituted amides resulted in different stereochemical outcomes, suggesting that these substrates reacted via closed and open transition states, respectively.
      PubDate: 2017-06-29T21:06:51.851053-05:
      DOI: 10.1002/adsc.201700353
  • Enantioselective hydrogenation of pyrrolo[1,2-a]pyrazines, heteroaromatics
           containing two nitrogen atoms
    • Authors: Yong-Gui Zhou; Shu-Bo Hu, Zhang-Pei Chen, Bo Song, Jie Wang
      Abstract: An enantioselective iridium-catalyzed direct hydrogenation of heteroaromatics containing two nitrogen atoms, 3-substituted pyrrolo[1,2-a]pyrazines, has been successfully achieved, providing a facile synthesis of optically active 1,2,3,4-tetrahydropyrrolo[1,2-a]pyrazines with up to 96% ee.
      PubDate: 2017-06-29T21:06:34.456859-05:
      DOI: 10.1002/adsc.201700431
  • Rhodium-Catalyzed Remote (C-8) alkylation of Quinolines with Activated and
    • Authors: Ritika Sharma; Inder Kumar, Rakesh Kumar, Upendra Sharma
      Abstract: Reported herein is a Rh(III)-catalyzed regioselctive distal C(sp2)-H bond alkylation of quinoline N-oxides using olefins as alkyl source and N-oxide as the traceless directing group. The reaction exhibits broad substrate scope with excellent selectivity for C-8 position and good yields of alkylated products. The usefulness of the developed catalytic protocol is established by synthesis of EP4 agonist. In mechanistic study, C-8 olefinated quinoline was identified as the reaction intermediate, which gets reduced to desired C-8 alkylated product in the presence of Rh(I) species (produced from Rh(III) during reaction) and formic acid. Formic acid is produced from DMF in the presence of AgBF4.
      PubDate: 2017-06-29T21:06:23.61485-05:0
      DOI: 10.1002/adsc.201700542
  • Synthesis of Tetrasubstituted α,β-Unsaturated Aldehydes via Radical
           1,4-Aryl Migration/Trifluoromethylthiolation Cascade Reaction of Aryl
           Propynyl Ethers
    • Authors: Chun-Huan Guo; Dao-Qian Chen, Si Chen, Xue-yuan Liu
      Abstract: An novel one-pot synthesis of tetrasubstituted acrylaldehydes via difunctionalization of aryl propynyl ethers has been achieved, which involves trifluoromethylthiolation process, radical 1,4-aryl migration from oxygen to carbon. The reaction shows excellent conversion of aryl propynyl ethers into SCF3-containing α,β-unsaturated aldehydes through a radical pathway.
      PubDate: 2017-06-28T21:06:33.230271-05:
      DOI: 10.1002/adsc.201700534
  • Carboxylate Salt Bridge Mediated Enamine Catalysis: Expanded Michael
           Reaction Substrate Scope and Facile Access to Antidepressant (R)-Pristiq
    • Authors: Thomas Nugent; Hussein Ali El Damrany Hussein, Shahzad Ahmed, Foad Tehrani Najafian, Ishtiaq Hussain, Tony Georgiev, Mahmoud Khalaf Aljoumhawy
      Abstract: We report broad guidance on how to catalyze enantioselective aldehyde additions to nitroalkene or maleimide Michael electrophiles in the presence of unprotected acidic spectator groups, e.g., carboxylic acids, acetamides, phenols, catechols, and maleimide NH groups. Remarkably, these L-threonine and L-serine potassium salt catalyzed reactions proceed even when the nucleophilic and electrophilic Michael partners simultaneously contain acidic spectator groups. These findings begin to address the historical non-compatibility of enantioselective catalytic reactions in the presence of acidic moieties and simultaneously encroach on the reaction capabilities normally associated with cellular environments. A carboxylate salt bridge, from the catalyst enabled enamine, to the Michael electrophile is thought to facilitate the expanded Michael substrate profile. A practical outcome of these endeavors is a new synthetic route to (R)-Pristiq, (-)-O-desmethylvenlafaxine, an antidepressant, in the highest yield known to date because no protecting groups are required.
      PubDate: 2017-06-28T21:06:27.8545-05:00
      DOI: 10.1002/adsc.201700801
  • Gold-Photoredox Cocatalyzed Tandem Oxycyclization/Coupling Sequence of
           Allenols and Diazonium Salts with Visible Light Mediation
    • Authors: Pedro Almendros; Benito Alcaide, Borja Aparicio, Carlos Lazaro-Milla, Amparo Luna, OLALLA NIETO FAZA
      Abstract: The room temperature radical cycloetherification/arylation cascade of allenols and diazonium salts has been accomplished via a combination of gold and photoredox catalysis to provide 2,3,4-trisubstituted-2,5-dihydrofurans. The functionalized oxacycle formation sequence is chemo- and regioselective for the cycloetherification and for the position that bears the aryl moiety after the cross-coupling. Mechanistic investigations revealed that this transformation proceeds through an initial oxidation of Au(I) to a phenyl Au(III) complex, which, upon coordination to the allene, catalyzes its cyclization and leads to the coupling product after a reductive elimination regenerating Au(I).
      PubDate: 2017-06-28T21:06:06.801198-05:
      DOI: 10.1002/adsc.201700598
  • Synthesis of 1-Vinyl/Aryl Benzotriazole 3-Oxides through Copper-Catalyzed
           C-N Bond Coupling Reaction
    • Authors: Wei-Min Shi; Feng-Ping Liu, Zhi-Xin Wang, Hong-Yan Bi, Cui Liang, Li-Ping Xu, Gui-Fa Su, Dong-Liang Mo
      Abstract: An efficient synthesis of 1-vinyl/aryl benzotriazole 3-oxides via the copper-promoted coupling of N-hydroxybenzotriazoles with alkenyl or aryl boronic acids is reported. This strategy features mild reaction conditions, good functional group tolerance, broad substrate scope and rapid introduction of benzotriazole N-oxides moieties into molecules. Density functional theory calculations revealed that the formation of the favored N-coupling product depends on the kinetically more favorable C−N bond formation pathway.
      PubDate: 2017-06-28T21:06:00.783759-05:
      DOI: 10.1002/adsc.201700462
  • Alternatives to Phosphinooxazoline (tBuPHOX) Ligands in the
           Metal-Catalyzed Hydrogenation of Minimally Functionalized Olefins and
           Cyclic β-Enamides
    • Authors: Maria Biosca; Marc Magre, Mercedes Coll, Oscar Pàmies, Montserrat Diéguez
      Abstract: This study presents a new series of readily accessible iridium- and rhodium-phosphite/oxazoline catalytic systems that can efficiently hydrogenate, for the first time, both minimally functionalized olefins and functionalized olefins (62 examples in total) in high enantioselectivities (ee's up to>99%) and conversions. The phosphite-oxazoline ligands, which are readily available in only two synthetic steps, derive from previous privileged (S)-4-alkyl-2-[2-(diphenylphosphino)phenyl]-2-oxazoline (PHOX) ligands by replacing the phosphine moiety by a biaryl phosphite group and/or the introduction of a methylene spacer between the oxazoline and the phenyl ring. The modular design of the ligands have given us the opportunity not only to overcome the limitations of the iridium-PHOX catalytic systems in the hydrogenation of minimally functionalized Z-olefins and 1,1-disusbtituted olefins, but also to expand their use to unfunctionalized olefins containing other challenging scaffolds (e.g., exocyclic benzofused and triaryl substituted olefins) and also to olefins with poorly coordinative groups (e.g., α,β unsaturated lactams, lactones, alkenylboronic esters, ...) with enantioselectivities typically>95% ee. Moreover, both enantiomers of the hydrogenation product could be obtained by simply changing the configuration of the biaryl phosphite moiety. Remarkably, the new catalytic systems also provided excellent enantioselectivities (up to 99% ee) in the asymmetric hydrogenation of another challenging class of olefins – the functionalized cyclic β-enamides. Again, both enantiomers of the reduced amides could be obtained by changing the metal from Ir to Rh. We also demonstrated that environmentally friendly propylene carbonate can be used with no loss of enantioselectivity. Another advantage of the new ligands over the PHOX ligands is that the best ligands are derived from the affordable (S)-phenylglycinol rather than from the expensive (S)-tert-leucinol.
      PubDate: 2017-06-28T05:56:50.148859-05:
      DOI: 10.1002/adsc.201700573
  • Cp*Rh(III)-Catalyzed Directed C-H Methylation and Arylation of Quinoline
           N-Oxides at the C-8 Position
    • Authors: Bao Wang; Chunpu Li, Hong Liu
      Abstract: Herein, we report novel Cp*Rh(III)-Catalyzed Directed C-H Methylation and Arylation of Quinoline N-Oxides at the C-8 Position. This method features good to excellent regioselectivity, diverse functional group tolerance, and mild reaction conditions. Additionally, preliminary mechanistic experiments were conducted and a possible mechanism was proposed.
      PubDate: 2017-06-22T20:52:08.383018-05:
      DOI: 10.1002/adsc.201700484
  • N-Heterocyclic Carbene-Catalyzed Umpolung of Alkynyl 1,2-Diketones
    • Authors: Xinqiang Fang; Xiangwen Kong, Guoxiang Zhang, Shuang Yang, Xiaozhi Liu
      Abstract: The umpolung of alkynyl 1,2-diketones via N-heterocyclic carbene (NHC) catalysis was achieved for the first time, allowing rapid access to a large variety of synthetically and pharmaceutically important α-pyrones under very mild conditions. A completely new NHC-catalyzed umpolung pattern involving an O-acylated allenolate as the key intermediate was proposed. Moreover, an unprecedented reaction pathway, featured by a series of group migrations and new bond formation, was postulated to demonstrate the formation of the products.
      PubDate: 2017-06-22T01:21:23.466952-05:
      DOI: 10.1002/adsc.201700700
  • Rhodium(II)/Chiral Phosphoric Acid Co-Catalyzed Enantioselective O–H
           Bond Insertion of α-Diazoesters
    • Authors: Yiliang Zhang; Yuan Yao, Li He, Yang Liu, Lei Shi
      Abstract: A rhodium(II)/chiral phosphoric acid system has been developed for the asymmetric catalytic insertion of α-diazoesters into the O–H bond of carboxylic acids to generate an array of synthetically useful α-hydroxy ester derivatives in good ee (up to 95% ee). Furthermore, the substrate scope could be successfully extended to a range of phenols and alcohols with high yield (up to 92%) and excellent enantioselectivity (up to 97%) under mild reaction conditions. Additionally, a density functional theory (DFT) study was performed to elucidate the reaction mechanism.
      PubDate: 2017-06-21T20:46:11.284992-05:
      DOI: 10.1002/adsc.201700572
  • Arylation of Azaarylmethylamines with Aryl Chlorides and a
           NiBr2/NIXANTPHOS-based Catalyst
    • Authors: Gui Gao; Yue Fu, Minyan Li, Bo Wang, Bing Zheng, Shicong Hou, Patrick J. Walsh
      Abstract: A nickel-catalyzed coupling of azaarylmethylamines with aryl chlorides has been achieved. NIXANTPHOS together with low cost NiBr2 was successfully developed and optimized to exhibit high reactivity at 2.5 mol % loading. Under optimized reaction conditions, aryl(azaaryl)methylamine products were afforded in good to excellent yields (22 examples, up to 98% yield).
      PubDate: 2017-06-20T20:51:17.341065-05:
      DOI: 10.1002/adsc.201700438
  • Copper-Catalyzed Aerobic Oxygenation of Benzylpyridine N-oxides and
           Subsequent Post-Functionalization
    • Authors: Hans Sterckx; Carlo Sambiagio, Vincent Médran-Navarrete, Bert 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 anti-histaminic drug Acrivastine via three consecutive N-oxide activated C-H functionalization processes, starting from picoline N-oxide.
      PubDate: 2017-06-20T20:50:42.436235-05:
      DOI: 10.1002/adsc.201700588
  • Metal-Free Difluoromethylthiolation, Trifluoromethylthiolation, and
    • Authors: Qiang Yan; Lvqi Jiang, Wenbin Yi, Qiran Liu, Wei Zhang
      Abstract: The inside cover picture, provided by Qiang Yan, Lvqi Jiang, Wenbin Yi, Qiran Liu, and Wei Zhang illustrates a new method for direct difluoromethylthiolation using easy-to-handle HCF2SO2Na as a reagent in the present of (EtO)2P(O)H and TMSCl. HCF2S+ generated from this system undergoes electrophilic reactions with aromatic compounds including indoles, pyrroles, and activated benzenes. This method is also applicable for trifluoromethylthiolation with CF3SO2Na and perfluoroalkylthiolation with RfSO2Na. Reaction mechanisms for the metal-free electrophilic fluoroalkylthiolation reactions are also discussed. Details of this work can be found in the full paper on pages xxxx–xxxx (Q. Yan, L. Jiang, W. Yi, Q. Liu, W. Zhang, Adv. Synth. Catal. 2017, 359, xxxx–xxxx;
      DOI : 10.1002/adsc.201700270).
      PubDate: 2017-06-20T07:22:49.808856-05:
  • Organocatalytic Heterocyclization Driven by Dynamic Kinetic Resolution:
           Enantioselective Access to Multi-heteroatomic Cyclic Structures Mediated
           by Cinchona Alkaloid-based Catalysts
    • Authors: V. Capaccio; A. Capobianco, A. Stanzione, G. Pierri, C. Tedesco, A. Di Mola, A. Massa, L. Palombi
      Abstract: A new class of multi-heteroatomic cyclic compounds containing N, S and O has been achieved in an enantioselective fashion via desymmetrization of 2-cyano-N-tosylbenzylidenimine with thiols and subsequent catalytic dynamic kinetic resolution (DKR). Both organo- and phase transfer catalysis based on cinchona alkaloids having two H-bonding coordination sites proved to be effective to furnish very good level of enantioselectivity (up to 95:5 er) in the heterocyclization of racemic N-Tosyl-protected N,S-acetals deriving from 2-formyl benzonitriles.
      PubDate: 2017-06-20T02:11:00.907215-05:
      DOI: 10.1002/adsc.201700472
  • Gold-Catalyzed Cycloisomerizations of Functionalyzed Cyclopropyl Alkynes:
           the Cases of Carboxamides and Alcohols
    • Authors: Jesús M. Fernández-García; Hugo A. Garro, Laura Fernández-García, Patricia García-García, Manuel Fernández-Rodríguez, Isabel Merino, Enrique Aguilar
      Abstract: Push-pull alkynylcyclopropane derivatives are claimed as suitable and active substrates for gold-catalyzed transformations. Thus, 2(3H)-azepinones can be readily prepared from alkynylcyclopropanecarboxamides through a nucleophilic addition/cyclopropane ring-opening cascade process and, in this manuscript, the scope and the limitations of such reaction sequence are reported. The cascade reaction is general and occurs with complete regio- and quimioselection to form the seven-membered heterocycles with the exception of primary alkyl-substituted alkynylcyclopropanecarboxamides that render 4-methoxy-6-oxo-4-enenitriles in moderate yields. Additionally, less activated alkynylcyclopropylmethanols undergo regioselective cicloisomerization at low temperature leading to oxabicyclo[4.1.0]heptanes. Notably, the cyclopropane ring opening of these adducts takes place under thermal conditions to form dihydropyranones.
      PubDate: 2017-06-19T20:45:57.237562-05:
      DOI: 10.1002/adsc.201700264
  • Synthesis of β-Keto Sulfones via Coupling of Aryl/Alkyl Halides, Sulfur
           Dioxide and Silyl Enolate through Metal-Free Photoinduced C-X Bond
    • Authors: Xinxing Gong; Yechun Ding, Xiaona Fan, Jie Wu
      Abstract: A photoinduced sulfonylative coupling of aryl/alkyl halides, DABCO·(SO2)2 (1,4-diazabicyclo[2.2.2]octane-sulfur dioxide), and silyl enolates under metal-free conditions is developed, giving rise to β-keto sulfones in good yields. This transformation proceeds smoothly at room temperature under ultraviolet irradiation with good tolerance of various functional groups. Aryl iodides/bromides and alkyl halides are all good substrates in the sulfonylative reaction. A plausible mechanism is proposed, which undergoes through a radical process under photoinduced conditions.
      PubDate: 2017-06-19T20:45:50.290292-05:
      DOI: 10.1002/adsc.201700525
  • Making Copper(0) Nanoparticles in Glycerol: a Straightforward Synthesis
           for a Multipurpose Catalyst
    • Authors: Trung Dang-Bao; Christian Pradel, Isabelle Favier, Montserrat Gómez
      Abstract: Small zero-valent copper nanoparticles (CuNPs) have been straightforward prepared from Cu(I) and Cu(II) precursors in glycerol and in the presence of polyvinylpyrrolidone as stabilizer. Thanks to the negligible vapor pressure of the solvent, these original nano-systems could be directly characterized in glycerol besides solid state, exhibiting relevantly homogeneous colloidal dispersions, also even after catalysis. CuNPs coming from the well-defined coordination complex di-μ-hydroxo-bis[(N,N,N’,N’-tetramethylethylenediamine)copper(II)] chloride ([Cu(κ2-N,N-TMEDA)(μ-OH)]2Cl2) have been highly efficient in C-C and C-heteroatom bond formation processes. This new catalytic system has proved its performance in C-N couplings and in the synthesis of differently substituted propargylamines through cross-dehydrogenative couplings, multi-component reactions such as A3 (aldehyde-alkyne-amine) and KA2 (ketone-alkyne-amine) couplings, as well in the formation of heterocycles such as benzofurans, indolizines, and quinolines under smooth conditions. No significant copper amount was detected in the extracted organic compounds from the catalytic phase by Inductively Coupled Plasma-Atomic Emission Spectroscopy (ICP-AES) analyses, proving a highly efficient immobilization of copper nanoparticles in glycerol. From a mechanistic point of view, spectroscopy data (infrared and ultraviolet-visible spectra) agree with a surface-like catalytic reactivity.
      PubDate: 2017-06-18T21:22:32.59075-05:0
      DOI: 10.1002/adsc.201700535
  • Synergistic Strategies of Cyano Migration and Photocatalysis for
           Difunctionalization of Unactivated Alkenes: Synthesis of Di- and
           Mono-Fluorinated Alkyl Nitriles
    • Authors: Rongguo Ren; Zhen Wu, Leitao Huan, Chen Zhu
      Abstract: A general protocol for the challenging cyanofluoroalkylation of unactivated alkenes is disclosed. A broad range of synthetically useful di- and mono-fluorinated alkyl nitriles are readily obtained in good yields under mild reaction conditions. The efficient combination of intramolecular cyano migration and photoredox catalysis significantly expands the field of difunctionalization of olefins.
      PubDate: 2017-06-17T16:38:09.685517-05:
      DOI: 10.1002/adsc.201700591
  • Diethyloxalate as “CO” Source for Palladium-Catalyzed
           Ethoxycarbonylation of Bromo- and Chloroarene Derivatives
    • Authors: Amandine Monrose; Helori Salembier, Till Bousquet, Sylvain Pellegrini, Lydie Pélinski
      Abstract: Palladium(II)-catalyzed ethoxycarbonylation of aryl bromides with diethyloxalate oxalate is described. Functionalized aromatic esters can be efficiently synthesized with only 0.65 mol % PdCl2(PPh3)2 catalyst under microwave irradiation and without additional ligand. This method illustrates an inexpensive and operationally simple method for the preparation of aromatic esters.
      PubDate: 2017-06-16T05:00:24.233043-05:
      DOI: 10.1002/adsc.201700307
  • Decarboxylative aminocatalytic cascade for the synthesis of
    • Authors: Anna Albrecht; Jan Bojanowski
      Abstract: A novel decarboxylative aminocatalytic strategy for the synthesis of 4,4a-dihydroxanthones is described. It was realized employing dienamine activation and utilizes readily available β,β-disubstituted enals and chromone-3-carboxylic acids as starting materials. Decarboxylation reaction is the key step of the cascade making the aminocatalyst turnover possible.
      PubDate: 2017-06-14T23:20:44.935758-05:
      DOI: 10.1002/adsc.201700400
  • Amine Activation: N-Arylamino Acid Amide Synthesis from Isothioureas and
           Amino Acids
    • Authors: Yan-Ping Zhu; Pieter Mampuys, Sergey Sergeyev, Steven Ballet, Bert U. W. Maes
      Abstract: N-arylamino acid amides have been synthesized via a novel method based on N-arylamine activation into isothioureas followed by reaction with amino acids under iron catalysis. The activated N-arylamines are easily prepared using a three-component reaction with commercial reagents, tert-butylisocyanide and S-phenyl benzenethiosulfonate. The protocol shows a broad functional group compatibility, with respect to side chain functionality of the amino acid (e. g. aliphatic and aromatic OH, (hetero)aromatic NH, amide NH, thioether), and the chiral amino acids do not undergo epimerization. The mechanism of the new amide synthesis has been studied.
      PubDate: 2017-06-14T06:27:31.459646-05:
      DOI: 10.1002/adsc.201700134
  • Modular Synthesis of Triazole-based Chiral Iodoarenes for Enantioselective
    • Authors: Christian Hempel; caecilia maichle-moessmer, Miquel Àngel Pericàs, Boris Johannes Nachtsheim
      Abstract: A new triazole-based C1-symmetric chiral iodoarene was synthesized in a highly modular route. Based on enzymatic kinetic resolution of an easy accessible propargylic alcohol both enantiomers were accessible in enantiopure form. By Huisgen-type azide-alkyne cycloaddtion a series of differently substituted iodoarenes were synthesized in high overall yields. Finally this novel iodoarene was successfully applied in the oxidative Kita cyclization of naphthol derivatives. Good yields and high ee values were obtained in the asymmetric spirocyclyzation via in situ generation of the hypervalent iodine species using mCPBA as the terminal oxidant.
      PubDate: 2017-06-13T21:21:14.2918-05:00
      DOI: 10.1002/adsc.201700246
  • Regioselective and Enantiospecific Synthesis of Dioxepines by
           CpRu-Catalyzed Condensations of Diazocarbonyls and Oxetanes
    • Authors: Leo Egger; Laure Guenee, Thomas Buergi, Jérôme Lacour
      Abstract: 1,4-Dioxepines result from the decomposition of α-diazo-β-ketoesters in the presence of oxetanes using the catalytic combination of [CpRu(CH3CN)3][BArF] and 1,10-phenanthroline. The regioselective [4+3] insertions follow a SN1-like mechanism and occur yet enantiospecifically (es 74%). The retention of configuration was ascertained by VCD and solid state analyses. Furans, products of [4+1] insertions, are only observed as traces in the above protocol. To promote their formation under CpRu catalysis, it is necessary to use a two-step process with α-halogenated alcohols as substrates.
      PubDate: 2017-06-13T21:21:12.882534-05:
      DOI: 10.1002/adsc.201700638
  • Cobalt(III)-Catalyzed Alkylation of Primary C(sp3)-H Bonds with Diazo
    • Authors: Sheng-Yi Yan; Peng-Xiang Ling, Bing-Feng Shi
      Abstract: Chelation-assisted C(sp2)–H metalation/carbenoid insertion has been well investigated. However, the analogous carbene functionalization of C(sp3)–H bonds remains a great challenge. Here we report the first Cobalt(III)-catalyzed alkylation of 8-methylquinolines with diazo compounds through primary C(sp3)–H cobaltation/carbenoid insertion. The reaction is highly efficient, scalable and tolerates a variety of functional groups. Furthermore, the unique protocol can be applied to the synthesis of azatricyclic antibiotic compounds.
      PubDate: 2017-06-13T21:21:10.017975-05:
      DOI: 10.1002/adsc.201700636
  • Enantioselective Mannich-type Reactions to Construct CF3S-containing
           Tetrasubstituted Carbon Stereocenters via Asymmetric Dual-Reagent
    • Authors: Gang Zhao; Lijun Xu, Changwu Zheng, Hongyu Wang
      Abstract: The approach to construct the tetrasubstituted carbon stereocenter bearing both a SCF3 group and a cyano group has been realized, through asymmetric organophosphine-catalyzed Mannich-type reactions. The products were obtained with high yields and moderate to high enantioselecitivities. Two diastereomers could be isolated from each reaction (25 overall examples), rendering this approach a viable opportunity for molecular diversity generation and improvement of the bioactivity of related drug candidates.
      PubDate: 2017-06-13T21:21:09.077296-05:
      DOI: 10.1002/adsc.201700321
  • α,α-Difluoro-α-(trimethylsilyl)acetamides as Versatile Reagents for the
           Preparation of Difluorinated Aldol and Mannich Adducts
    • Authors: Aurelien Honraedt; Arie Van Der Lee, Jean-Marc Campagne, Eric Leclerc
      Abstract: The very efficient addition of α,α-difluoro-α-(trimethylsilyl)acetamides to aldehydes, ketones and N-(tert-butanesulfinyl)imines is described. The reaction is promoted by a catalytic amount of TBAT and high yields, as well as very high stereoselectivities in the case of N-(tert-butanesulfinyl)imines, are achieved. The synthetic potential of this method is illustrated by the conversion of the resulting products to β-hydroxyketones, diols and β-aminoalcohols by addition of various Grignard reagents or reduction of the amide moiety.
      PubDate: 2017-06-12T21:20:33.855878-05:
      DOI: 10.1002/adsc.201700371
  • Ag-Catalyzed Atom-Economic Hydrophosphorylation of Propargyl Epoxides: An
           Access to 4-Phosphoryl 2,3-Allenols and Stereodefined 1-Phosphoryl
    • 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 Ag 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 Pd-catalyzed coupling reaction is also described.
      PubDate: 2017-06-12T21:20:31.244059-05:
      DOI: 10.1002/adsc.201700421
  • Pd(dba)2/tBuONO-Catalyzed Cyclization of o-Alkynylanilines with tBuONO:
           Synthesis and Applications of Indazole 2-oxides
    • Authors: Gopal Chandru Senadi; Ji-Qi Wang, Babasaheb Sopan Gore, Jeh-Jeng Wang
      Abstract: An efficient method for the synthesis of 1-benzy/aryl-indazole 2-oxides via a bis(dibenzylidene acetone)palladium(0) (Pd(dba)2)/tert-butyl nitrite (TBN)-catalyzed reaction of o-alkynylaniline derivatives with TBN is reported. The overall transformation involved the formation of three new bonds via N-nitrosation (N-NO), 5-exo-dig cyclization (C-N) and oxidation (C=O). The notable features were the mild reaction conditions, broad substrate scope and dual role of TBN as a NO source and redox co-catalyst. This strategy was implemented for the synthesis of indazole-3-carbaldehyde derivatives and the formal syntheses of pharmaceutically active YC-1, an anticancer agent (lonidamine), and the male contraceptive experimental drugs AF2785 and adjudin (AF-2364).
      PubDate: 2017-06-12T21:20:30.028609-05:
      DOI: 10.1002/adsc.201700456
  • 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
  • Metal–free C5-H Bromination of Quinolines for One-pot C−X
           (X=C, O, S) Bond Formations
    • Authors: You Li; Longzhi Zhu, Xin Cao, Chak-Tong Au, Renhua Qiu, Shuang-Feng Yin
      Abstract: We developed an efficient and convenient method for metal-free bromination of 8-aminoquinoline scaffolds on the C5 position that is geometrically inaccessible. And this bromination step can be followed in a one-pot manner with five kinds of C−X (X=C, O, S) cross-coupling reactions without any extra workup, such as removal of the solvent or filtration for the separation of intermediate. The reaction tolerates a wide scope of alkyl and aryl amides as well as (hetero)aryl boronic acids, generating the corresponding arylation products in good to excellent yields. Furthermore, the one-pot alkenylation, alkynylation, thiolation and phenoxylation of quinolines on the C5 position can be efficiently realized using this brominated quinoline amide molecular platform. Thus, the method shows high practical potential in industrial organic synthesis.
      PubDate: 2017-06-12T09:27:56.851614-05:
      DOI: 10.1002/adsc.201700391
  • α-Keto Thioesters as Building Blocks for Accessing
           γ-Hydroxybutenolides and Oxazoles
    • Authors: Kanchan Mal; Indrajit Das
      Abstract: α-Keto thioesters, with two electrophilic carbon centres, have been found to react differently with β-keto esters and isocyanoacetates. They undergo base induced Knoevenagel-type condensation on the keto carbonyl group with β-keto esters, followed by intramolecular cyclization and water addition leads to highly substituted γ-hydroxybutenolides. On the other hand, substituted oxazole derivatives have been obtained using isocyanoacetates via nucleophilic displacement on the thioester carbonyl followed by intramolecular cyclization. Further functionalization of the γ-hydroxybutenolides is also demonstrated via a BF3.OEt2-mediated cation-driven nucleophilic addition of terminal alkynes to access multiply substituted butenolides.
      PubDate: 2017-06-12T09:27:43.650878-05:
      DOI: 10.1002/adsc.201700329
  • Base-Promoted Tandem Reaction to Conjugate Dienone or Chromone Derivatives
           with Cyano Group: Insertion of Alkynes into C-C σ-Bonds of
    • Authors: Qiyi Yao; Lingkai Kong, Fangfang Zhang, Xianghua Tao, Yanzhong Li
      Abstract: Base-promoted insertion reactions of alkynes into C-C σ-bonds ofα-cyano ketones were established to construct highly functionalized conjugate 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, further C-O bond coupling reaction occurs to afford chromone derivatives in good to high yields. A variety of 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: 2017-06-11T21:23:50.366177-05:
      DOI: 10.1002/adsc.201700565
  • Lewis Acid-Catalyzed [4+2] Annulation between Propargylic Alcohols with
    • Authors: Ya-Ping Han; Xue-Song Li, Zhou Sun, Xin-Yu Zhu, Ming Li, Xian-Rong Song, Yong-Min Liang
      Abstract: An unprecedented Copper (II) trifluoromethanesulfonate-catalyzed [4+2] cascade annulation of propargylic alcohols with benzo[d]isoxazoles proceeds through a sequential ring opening/Meyer−Schuster rearrangement/intermolecular cyclization. This protocol, which tolerates a broad variety of functional groups, offers versatile, modular and atom-economical access to a new class of fascinating quinoline derivatives in good yields under mild conditions. The transformation could be scaled up to gram scale efficiently, thus highlighting the synthetic utility of this methodology.
      PubDate: 2017-06-11T21:15:56.115403-05:
      DOI: 10.1002/adsc.201700495
  • Interaction of gem-Difluorinated Iodides with Silyl Enol Ethers Mediated
           by Photoredox Catalysis
    • Authors: Grigory Chernov; Vitalij Levin, Vladimir Kokorekin, Marina Struchkova, Alexander D. Dilman
      Abstract: A method for the synthesis of β,β-difluorinated ketones by coupling of α,α-difluorinated iodides with silyl enol ethers is described. The reaction is performed in the presence of iridium(III) photocatalysts under the irradiation with 400 nm light emitting diodes.
      PubDate: 2017-06-09T23:20:21.695369-05:
      DOI: 10.1002/adsc.201700423
  • Enantioselective Synthesis of Chiral 3-Substituted-3-silylpropionic Esters
           via Rhodium/Bisphosphine-Thiourea-Catalyzed Asymmetric Hydrogenation
    • Authors: Zongpeng Zhang; Zhengyu Han, Guoxian Gu, Xiu-Qin Dong, Xumu Zhang
      Abstract: We successfully developed asymmetric hydrogenation of β-silyl-α,β-unsaturated esters to prepare chiral 3-substituted-3-silylpropionic ester products catalyzed by rhodium/bisphosphine-thiourea (ZhaoPhos) with excellent results (up to 97% yield,>99% ee, 1 500 TON). Moreover, our hydrogenation product can be efficiently converted to other important organic molecules, such as chiral ethyl (R)-3-hydroxy-3-phenylpropanoate, (R)-3-(dimethyl(phenyl)silyl)-3-phenylpropanoic acid.
      PubDate: 2017-06-07T21:20:37.901744-05:
      DOI: 10.1002/adsc.201700355
  • Chlorotrimethylsilane and Sodium Iodide: A Useful Combination for the
           Regioselective Deoxygenation of Arylalkyl-α-Diketones
    • Authors: Ling-Zhi Yuan; Guangkuan Zhao, Abdallah Hamze, Mouad Alami, Olivier Provot
      Abstract: An efficient regioselective deoxygenation of arylalkyl-1,2-diketones by the couple trimethylsilylchloride/sodium iodide has been reported. In all cases, the deoxygenation takes place on the carbonyl group (Cα=O) proximal to the aromatic ring in methylene chloride at room temperature in good yields, furnishing a series of variously functionalized alkylbenzylketones. A large range of functional groups were well tolerated on the ortho-, meta- and para-positions by this mild process regardless of their electronic effects, demonstrating the general character of the present methodology. The trimethylsilylchloride/sodium iodide reducing process was also successfully applied to reduce α-ketoacid and α-ketoester substrates.
      PubDate: 2017-06-07T08:20:21.995255-05:
      DOI: 10.1002/adsc.201700276
  • Copper-Catalyzed Sequential Azomethine Imine-Alkyne Cycloaddition and
           Umpolung Thiolation Reactions
    • Authors: Wanzhi Chen; Min Zhang, Feifei Wu, Huanhong Wang, Junshi Wu
      Abstract: Copper-catalyzed sequential 1,3-dipolar cycloadditions of azomethine imines and alkynes and electrophilic thiolations are described. The C-S, C-N, and C-C bonds were simultaneously formed in one pot, leading to N,N-bicyclic pyrazolidinones in good to excellent yields. The process is proposed to proceed via reaction of a cuprate pyrazolidinonate intermediate and benzenesulfonothioate.
      PubDate: 2017-06-06T03:41:49.193967-05:
      DOI: 10.1002/adsc.201700387
  • Route to O-aminosulfonates and Sulfonamides through Insertion of Sulfur
           Dioxide and Hydrogen Atom Transfer
    • Authors: Tong Liu; Danqing Zheng, Zhenhua Li, Jie Wu
      Abstract: A three-component reaction of aryldiazonium tetrafluoroborates, DABCO•(SO2)2 and hydroxylamines under catalyst-free and additive-free conditions is developed, providing aryl O-aminosulfonates in good yields. Sulfonamides could also be obtained via a one-pot process through a reaction of aryldiazonium tetrafluoroborates, DABCO·(SO2)2 and amines in the presence of N-hydroxybenzotriazole. A mechanism involved with the insertion of sulfur dioxide and hydrogen atom transfer is proposed, supported by theoretical calculations.
      PubDate: 2017-05-31T21:25:45.239637-05:
      DOI: 10.1002/adsc.201700501
  • Non-Heme Iron Catalysts with a Rigid Bis-Isoindoline Backbone and Their
           Use in Selective Aliphatic C−H Oxidation
    • Authors: Jianming Chen; Martin Lutz, Michela Milan, Miquel Costas, Matthias Otte, Bert Klein Gebbink
      Abstract: Iron complexes derived from a bis-isoindoline-bis-pyridine ligand platform based on the BPBP ligand (BPBP = N,N′-bis(2-picolyl)-2,2′-bis-pyrrolidine) have been synthesized and applied in selective aliphatic C–H oxidation with hydrogen peroxide under mild conditions. The introduction of benzene moieties on the bis-pyrrolidine backbone leads to an increased preference of tertiary over secondary C–H bond oxidation (3°/2° ratio up to 33). On the other hand, substituting the meta-position of the pyridines with bulky silyl groups affords enhanced secondary C–H oxidation selectivity and generally leads to higher product yields and mass balances.
      PubDate: 2017-05-31T21:25:44.130265-05:
      DOI: 10.1002/adsc.201700239
  • Catalytic Asymmetric [4+1] Cyclization of ortho-Quinone Methides with
    • 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-alkyl phenols 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: 2017-05-31T21:25:35.969015-05:
      DOI: 10.1002/adsc.201700487
  • Guanidinium Hydroiodide/Cumene Hydroperoxide-Mediated Intermolecular
           Oxidative Coupling Reaction of β–Ketoamides with Oxindoles
    • Authors: Takanari Kato; Koji Yasui, Minami Odagi, Kazuo Nagasawa
      Abstract: The first catalytic intermolecular oxidative cross-coupling reaction between two different carbonyl compounds was achieved by using cumene hydroperoxide as an environmentally friendly, mild oxidant in the presence of a cyclic guanidinium hydroiodide derivative as a catalyst. Cross-coupling reaction between various β-ketoamides and oxindoles took place smoothly, and the corresponding 1,4-dicarbonyl compounds were obtained in 80-99% yield.
      PubDate: 2017-05-30T21:20:32.131504-05:
      DOI: 10.1002/adsc.201700266
  • Photopromoted Entry to Benzothiophenes, Benzoselenophenes, 3H-Indoles,
           Isocoumarins, Benzosultams, and (Thio)Flavones by Gold-Catalyzed Arylative
           Heterocyclization of Alkynes
    • Authors: Pedro Almendros; Benito Alcaide, Eduardo Busto, Fernando Herrera, Carlos Lazaro-Milla, Amparo Luna
      Abstract: Visible light-promoted and gold-photoredox catalyzed reactions of heteroatom(N, S, Se, O)-tethered alkynes with arenediazonium salts selectively reacted to build vicinal diaryl-substituted 2H-benzo[e][1,2]thiazine 1,1-dioxides (benzosultams), benzoselenophenes, benzothiophenes, 4H-chromen-4-ones (flavones), 3H- indoles, 1H-isochromen-1-ones (isocoumarins), and 4H-thiochromen-4-ones (thioflavones). Moreover, the utility of functionalized 3H-indoles as precursors for further elaboration has been demonstrated with the switchable and facile preparation of 1H-indoles, 2-oxindoles, and 3-oxindolines.
      PubDate: 2017-05-30T21:20:30.072314-05:
      DOI: 10.1002/adsc.201700427
  • Salicylic Acid-Catalyzed One-Pot Hydrodeamination of Aromatic Amines by
           tert-Butyl Nitrite in Tetrahydrofuran
    • Authors: Diego Felipe-Blanco; Francisco Alonso, Jose Gonzalez-Gomez
      Abstract: A significant acceleration in the hydrodeamination of in situ formed diazonium salts (from aromatic amines) has been observed in the presence of 10-mol% salicylic acid, using tetrahydrofuran as the hydrogen donor. The reaction proceeds efficiently at 20 ºC for a wide range of substituted anilines, even at 10-mmol scale, without any other additive. The same protocol has been adapted to the selective deuterodeamination of some aromatic amines. Control experiments clearly show that aryl radicals are involved in the reaction mechanism.
      PubDate: 2017-05-29T21:20:38.845891-05:
      DOI: 10.1002/adsc.201700475
  • An Enantioselective Multicomponent Carbonyl Allylation of Aldehydes with
           Dienes and Alkynyl Bromides Enabled by Chiral Palladium Phosphate
    • Authors: Liu-zhu Gong; Hong-Cheng Shen, Pu-Sheng Wang, Zhong-Lin Tao, Zhi-Yong Han
      Abstract: An enantioselective multicomponent carbonyl allylation reaction of 1,3-butadienes, alkynyl bromides and aldehydes has been established, leading to the generation of densely functionalized homoallylic alcohols in high levels of structural diversity and stereoselectivity. The multicomponent process sequentially undergoes the oxidative addition, salt metathesis, insertion/π-allyl-Pd formation, asymmetric allylic borylation, and enantioslecitve carbonyl allylborylation, wherein the alkynyl palladium phosphate in situ generated from the chiral silver phosphate and the alkynyl palladium bromide turns out to be a key intermediate that allows the efficient stereochemical control.
      PubDate: 2017-05-29T21:20:35.371511-05:
      DOI: 10.1002/adsc.201700621
  • Regioselective Synthesis of Heteroatom-Functionalized
           Cyclobutene-triflones and Cyclobutenones
    • Authors: Pedro Almendros; Benito Alcaide, Carlos Lazaro-Milla
      Abstract: The controlled metal-free synthesis of a vast variety of heteroatom-containing cyclobutene-triflones and cyclobutenones has been developed starting from heteroatom-substituted alkynes and a pyridinium salt (a latent Tf2C=CH2 source). This powerful methodology, involving cyclization reactions allows for the selective preparation of oxygen-, nitrogen-, bromine-, chlorine-, iodine-, sulphur-, selenium-, tellurium-, phosphorus-, and silicon-functionalized cyclobutene derivatives.
      PubDate: 2017-05-29T21:20:34.07567-05:0
      DOI: 10.1002/adsc.201700492
  • A Sequential Suzuki Coupling Approach to Unsymmetrical Aryl s-Triazines
           from Cyanuric Chloride
    • Authors: Chen Wang; Jiehui Zhang, Jie Tang, Gang Zou
      Abstract: A practical approach has been developed for efficient synthesis of unsymmetrical aryl s-triazines via highly selective sequential Suzuki coupling of cyanuric chloride (2,4,6-trichlorotriazine) with aryl or vinyl boronic or diarylborinic acids catalysed by 0.1–0.5 mol% Pd(PPh3)2Cl2 under mild conditions. The second and third Suzuki couplings for unsymmetrically trisubstituted aryl s-triazines could be more practically conducted in one-pot procedure. An electron-withdrawing conjugate group at phenyl ring of arylboronic acids was unexpectedly found to completely block the coupling while steric hindrance from an ortho electron-donating substituent could be overcome.
      PubDate: 2017-05-29T04:30:34.463915-05:
      DOI: 10.1002/adsc.201700260
  • One-Pot Synthesis of Benzene and Pyridine Derivatives via Copper-Catalyzed
           Coupling Reactions
    • Authors: Jianwei Han; Xin Guo, Yafeng Liu, Yajie Fu, Rulong Yan, Baohua Chen
      Abstract: A highly efficient one-pot synthesis of polysubstituted pyridine has been achieved through copper-catalyzed oxidative sp3 C−H coupling of acetophenones with toluene derivatives. Besides, the polysubstituted benzene was obtained through copper-catalyzed coupling of acetophenones. Both of the reactions exhibited a good functional group tolerance to produce a 2,4,6-triphenylpyridine or 1,3,5-triarylbenzene in high yields. Compared with previous methods, these transformations allow a highly flexible and efficient preparation of substituted pyridines and benzenes.
      PubDate: 2017-05-29T00:55:41.512502-05:
      DOI: 10.1002/adsc.201700053
  • 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 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: 2017-05-25T21:20:33.256638-05:
      DOI: 10.1002/adsc.201700179
  • Carbonylative Tertiary Amide Synthesis from Aryl Iodides and Tertiary
           Amines via Oxidant-Free C-N Bond Cleavage Catalyzed by Palladium(II)
           Chloride in Polyethylene Glycol/Water
    • Authors: Bhalchandra Bhanage; Rajendra S Mane
      Abstract: In this work, we have described the carbonylative amides syntheses from aryl iodides and tertiary amines as an aminal source via oxidant free Csp3-N bond cleavage using in situ formation of palladium(0) nanoparticles from palladium(II) chloride in polyethylene glycol-400/water. Notably, these reactions were performed under base-free, ligand free conditions and do not require any oxidant for the C-N bond cleavage. The developed protocol offers selectively N-dealkyaltion of tertiary amines in polyethylene glycol/water solvent system. A series of symmetrical and unsymmetrical aliphatic, alicyclic, benzyl as well as aromatic tertiary amines with aryl iodides were well tolerated and affording desired products in good yields.Further, the in situ generation of palladium(0) nanoparticles in the polyethylene glycol-400 is confirmed by TEM, FEG-SEM, EDS and XRD techniques which strongly indicate that the palladium nanoparticles are highly active species and the reaction proceeds through classical palladium(0)/palladium(II) pathway. Additionally, the syntheses can be easily scaled up and the catalytic system can be recycled up to five times without loss of its catalytic activity and selectivity.
      PubDate: 2017-05-25T21:20:31.622766-05:
      DOI: 10.1002/adsc.201700317
  • Regiodivergent C5 & C8- visible light induced C-H functionalisation of
           quinolines under metal-, photosensitizer- and oxidant-free conditions
    • Authors: Percia Arockiam; Lucas Guillemard, joanna Wencel-delord
      Abstract: A general strategy towards C5 and C8 selective perfluoroalkylation of quinoline derivatives is described. This exceptionally mild radical transformation, compatible with a large panel of substrates, does not require any transition metal catalysts or oxidants. Outstandingly, visible light photoinduction using simple household bulbs, in absence of a photosensitizer, is a unique activation mode. Further importance of this reaction relays on its capacity to functionalise selectively both C5 and C8-quinoline positions. This transformation, perfectly fulfilling green-chemistry requirements, allows truly practical and straightforward access to a variety of unprecedented functionalised amino- and amidoquinolines, presenting attractive features for medicinal and agrochemical industry.
      PubDate: 2017-05-22T21:21:28.868037-05:
      DOI: 10.1002/adsc.201700471
  • Copper-Catalyzed Intermolecular Amino-Alkylation of Alkenes with
           α-Bromoalkyl Esters and Amines toward Pyrrolidin-2-ones
    • Authors: Gao-Hui Pan; Xuan-Hui Ouyang, Ming Hu, Ye-Xiang Xie, Jin-Heng Li
      Abstract: We here describe a new copper-catalyzed tandem annulation of alkenes with α-bromoalkyl esters and primary amines for producing polysubstituted pyrrolidin-2-ones. The reaction allows the formation of three new chemical bonds, one C-C bond and two C-N bonds, in a single reaction, and represents the first three-component difunctionalization of alkenes for the synthesis of pyrrolidin-2-ones involving [2+2+1] annulation.
      PubDate: 2017-05-22T21:21:19.177806-05:
      DOI: 10.1002/adsc.201700365
  • Catalytic Asymmetric [3+3] Cycloaddition of Azomethine Ylides with
           C3-Substituted 2-Indolylmethanols
    • Authors: Xiao-Xue Sun; Can Li, Ying-Ying He, Zi-Qi Zhu, Guang-Jian Mei, Feng Shi
      Abstract: The first catalytic asymmetric [3+3] cycloaddition of azomethine ylides with C3-substituted 2-indolylmethanols has been established, leading to diastereo- and enantioselective construction of a tetrahydropyrimido[1,6-a]indole framework (up to 91% yield,>95:5 dr, 98:2 er). This reaction also represents a new type of catalytic enantioselective [3+3] cycloaddition using azomethine ylides.
      PubDate: 2017-05-22T06:30:30.37819-05:0
      DOI: 10.1002/adsc.201700203
  • Calcium(II)-Catalyzed Alkenylation of N-Acyliminiums and Related Ions with
           Vinylboronic Acids
    • Authors: Chenxiao Qi; Vincent Gandon, David Lebœuf
      Abstract: Efficient C−C bond-forming reactions between N,O-acetals and vinylboronic acids were achieved via a calcium(II)-catalyzed formation of a N-acyliminium intermediate or a related ion. This strategy can give a rapid access to a wide variety of alkenyl-functionalized nitrogen-containing compounds in good to excellent yields under simple reaction conditions.
      PubDate: 2017-05-22T06:25:25.942442-05:
      DOI: 10.1002/adsc.201700214
  • Palladium-Catalyzed Regioselective Direct Arylation of Benzofurazans at C4
    • Authors: Imane Idris; Fazia Derridj, Jean-Francois Soulé, Henri Doucet
      Abstract: The palladium-catalyzed direct arylation of benzofurazans with aryl bromides to access 4-arylbenzofurazans proceeds in moderate-to-high yields using phosphine-free palladium acetate as the catalyst and potassium acetate as an inexpensive base. A wide variety of (hetero)aryl bromides, including bromopyridine and bromothiophene derivatives has been successfully employed. Palladium-catalyzed one-pot C4,C7-diarylation of benzofurazane was also described using a larger amount of aryl bromide. Moreover, the derivatization of 4-arylbenzofurazans into 4-arylquinaxolines is also reported.
      PubDate: 2017-05-22T02:55:50.208995-05:
      DOI: 10.1002/adsc.201700435
  • Copper(II)-Catalyzed Aerobic Oxidative Desulfitative 6π
           Electrocyclization: Efficient Synthesis of Diverse 4-Aminoquinolines
    • Authors: Lou Shi; Ling Pan, Yifei Li, QUN LIU
      Abstract: The C−C bond formation via C−S bond activation (disclosed in 2000) has received increasing attentions. However, stoichiometric amount of exogenous thiophilic reagents are generally required as thiolate scavengers. Herein, a new model for the synthesis of 4-aminoquinolines, Cu(II)-catalyzed aerobic oxidative desulfitative 6π cyclization of the readily available N-aryl-imino ketene N,S- acetals is described. The reaction can proceed efficiently under mild reaction conditions without any exogenous thiolate scavengers (due to the formation of disulfide as the by-product) to afford diverse 4-aminoquinolines, a privileged structure motif displaying antimalarial activity, with a wide range of functional groups at C2−C8 positions.
      PubDate: 2017-05-21T21:20:34.145623-05:
      DOI: 10.1002/adsc.201700410
  • Issue 17, U1, Kobayashi Z700155
    • Authors: Joe 02 Richmond; Hiroyuki Miyamura, Shū Kobayashi
      PubDate: 2017-05-17T20:45:32.970478-05:
      DOI: 10.1002/adsc.201700625
  • Metal-Free Synthesis of Pyrazoles from 1,3-Diarylpropenes and Hydrazines
           via Multiple Inter-/Intramolecular C-H Aminations
    • Authors: Li Tang; Minyang Ma, Qi Zhang, Huan Luo, Tao Wang, Yonghai Chai
      Abstract: A facile and metal-free access to pyrazoles from 1,3-diarylpropenes and hydrazines via multiple inter-/intramolecular C-H aminations was described. Under the neutral and mild DDQ-oxidative conditions, various di-substituted pyrazoles were synthesized in moderate to excellent yields. This method provides a pot- and step-economy strategy for the construction of pyrazoles, especially those for drug discovery.
      PubDate: 2017-05-17T20:45:31.417145-05:
      DOI: 10.1002/adsc.201700196
  • Organocatalytic Enantioselective Synthesis of Dihydropyranoindole
           Derivatives Bearing Trifluoromethylated All-Carbon-Substituted
    • Authors: Qinxin Lou; Yuyang Ding, Dengfeng Xu, Guokai Liu, Junling Zhao
      Abstract: Malononitrile and isatin-derived trifluoromethyl acrylates underwent Michael addition/cyclization reaction, a process that was catalyzed efficiently by a bifunctional squaramide catalyst to afford a range of dihydropyranoindole derivatives bearing trifluoromethylated all-carbon-substituted stereocenters in high yields (up to 99%) with excellent enantioselectivity (up to 98% ee). This transformation was also examined with ethyl cyanoacetate as a nucleophile using bifunctional thiourea as catalyst in moderate yields (up to 79%) and high enantioselectivity (up to 98% ee). One of the products has been used for the synthesis of biologically interesting triazolopyrimidine derivative.
      PubDate: 2017-05-16T20:45:45.762991-05:
      DOI: 10.1002/adsc.201700465
  • Issue 16, U1, Mandai F700057
    • Authors: Joe 02 Richmond; Koichi Mitsudo, Hiroki Mandai, Seiji Suga
      PubDate: 2017-05-16T03:35:40.010934-05:
      DOI: 10.1002/adsc.201700620
  • Issue 14, U1, Pericas F700120
    • Authors: Joe 02 Richmond; Alessandro Ferrali, Carles Rodríguez-Escrich, Fernando Bravo, Miquel A. Pericàs
      PubDate: 2017-05-14T21:20:45.286678-05:
      DOI: 10.1002/adsc.201700610
  • Enantioselective Epoxidation of Electron-Deficient Alkenes Catalyzed by
           Manganese Complexes with Chiral N4 Ligands Derived from Rigid Chiral
    • Authors: Hanmin Huang; Xiang-Ning Chen, Bao Gao, yijin Su
      Abstract: A series of tetradentate sp2N/sp3N hybrid chiral N4 ligands derived from rigid chiral diamines were synthesized, which enabled the first Mn-catalyzed enantioselective epoxidation of electron-deficient alkenes with H2O2 as an oxidant. The reaction furnishes enantiomerically pure epoxy amides, epoxy ketones as well as epoxy esters in good yields and excellent enantioselectivities (up to 99.9% ee) with lower catalyst loading. Preliminary studies on structure-activity relationship demonstrated that maintaining comparatively lower electron-donating ability of the sp3-N and relatively higher electron-donating ability of sp2-N of the N4 ligands is beneficial to getting higher activity and selectivity, thus providing us a new view to understand epoxidation with H2O2.
      PubDate: 2017-05-12T23:17:27.801923-05:
      DOI: 10.1002/adsc.201700541
  • Asymmetric [4+1] Cycloadditions of N-Thioacyl Imines and Sulfur Ylides
    • Authors: Chao Li; Kun Jiang, Tian-Yu liu, Ying-Chun Chen
      Abstract: A new asymmetric [4+1] cycloaddition reaction of N-thioacyl imines, generated in situ from α-amido sulfones, and sulfur ylides bearing a D-camphor scaffold, is reported. The enantiocontrol was significantly improved by adding catalytic amounts of (R)-1,1’-bi(2-naphthol), furnishing a spectrum of 2-alkylthio-4,5-dihydrothiazoles in modest to high yields with moderate to excellent stereoselectivity (>19:1 dr, up to 98% ee)
      PubDate: 2017-05-11T21:13:11.565259-05:
      DOI: 10.1002/adsc.201700445
  • Acyl radical Addition onto Aza-Baylis-Hillman Adducts. A Stereocontrolled
           access to 2,3,5-Trisubstituted Pyrrolidines
    • Authors: Yannick LANDAIS; Simon Grélaud, Jonathan Lusseau, Stéphane MASSIP
      Abstract: Free-radical addition of acyl radicals to chiral aza-Baylis-Hillman adducts was shown to afford the corresponding 1,4-aminoketones in good yields and good 1,2-stereocontrol. These ketones were then elaborated further using conditions varying as a function of the nature of the N-protecting group. Robust N-Ts protection thus allowed the formation, under acidic conditions, of a cyclic iminium which was reduced using bulky (Me3Si)2SiH into the corresponding 2,3,5-pyrrolidine exhibiting a trans-trans relative configuration. In contrast, under these conditions, the N-Boc protecting group was removed, leading to the formation of stable dihydropyrroles, which were then hydrogenated with PtO2, leading to 2,3,5-pyrrolidines having a trans-cis relative configuration. When additional ketone or ester groups were present on the pyrrolidine skeleton, further cyclization led to indolizidinones and pyrrolizidines in good overall yield in 4 steps and two-pot operations.
      PubDate: 2017-05-11T03:37:18.916889-05:
      DOI: 10.1002/adsc.201700362
  • Transmetalation of Alkylzirconocenes in Copper-Catalyzed Alkyl–Alkynyl
           Cross-Coupling Reactions
    • Authors: Kiran Indukuri; Olivier Riant
      Abstract: A simple copper-catalyzed alkyl-alkynyl cross-coupling strategy has been developed by the reaction between alkynyl bromides and alkylzirconocenes. The alkylzirconocenes were generated in situ via regioselective addition of Schwartz's reagent (ZrCp2HCl) on alkenes. The reaction has a broad scope, a range of functionalized bromoalkynes and alkylzirconium reagents were successfully coupled, resulting moderate to good yields of the desired internal alkynes.
      PubDate: 2017-05-11T03:36:17.245204-05:
      DOI: 10.1002/adsc.201700164
  • Metal-Free, Visible-Light-Promoted Synthesis of 3-Phosphorylated Coumarins
           via Radical C-P/C-C Bond Formation
    • Authors: Dan Liu; Jian-Qiang Chen, Xing-Zhi Wang, Peng-Fei Xu
      Abstract: A metal-free, visible-light-promoted direct difunctionlization of alkynoates was achieved under mild conditions. By employing catalytic quantities of the commercially available Eosin Y (EY) as the photocatalyst and tert-butyl-hydroperoxide (TBHP) as the oxidant, we developed the radical tandem phosphorylation/cyclization reaction to synthesize various 3-phosphorylated coumarins with high functional group tolerance, moderate to good yields and excellent regioselectivities.
      PubDate: 2017-05-09T20:55:55.371231-05:
      DOI: 10.1002/adsc.201700293
  • Catalytic Asymmetric 1,2-Difunctionalization of Indolenines with
           α-(Benzothiazol-2-ylsulfonyl) Carbonyl Compounds
    • Authors: You-Dong Shao; Dao-Juan Cheng
      Abstract: A novel catalytic asymmetric 1,2-difunctionalization reaction of indolenines with α-(benzothiazol-2-ylsulfonyl) carbonyl compounds was developed. By employing the strategy of Brønsted acid-assisted chiral phosphoric acid catalysis, the Mannich addition/Smiles rearrangement cascade occurred smoothly and provided a new family of optically active 1,2-difunctionalized 2-substituted indolines in good yields and enantioselectivities.
      PubDate: 2017-05-09T07:25:52.214092-05:
      DOI: 10.1002/adsc.201700187
  • Solid supported chiral N-picolylimidazolidinones: recyclable catalysts for
           the enantioselective, metal- and H2-free reduction of imines in batch and
           in flow mode
    • Authors: Riccardo Porta; Maurizio Benaglia, Rita Annunziata, Alessandra Puglisi, Giuseppe Celentano
      Abstract: A new class of solid supported chiral imidazolidinones organocatalysts for the catalytic reduction of imines with trichlorosilane was developed. Polystyrene proved to be a more effective support than silica in terms of both chemical and stereochemical efficiency. Even with a loading as low as 1 mol % the best performing supported catalyst showed a remarkable activity and stereocontrol ability, promoting the reduction with stereoselectivities reaching 98% e.e. and in most cases ranging between 90-95% e.e. The general scope of the methodology and the good recyclability of the immobilized catalyst were demonstrated. The polystyrene-anchored chiral catalyst was also used to prepare packed bed reactors for the continuous flow synthesis of chiral amines, that were obtained in excellent yields and enantioselectivities. By exploiting the chiral organocatalytic reactor, the in-flow stereoselective synthesis of a common, immediate precursor of rivastigmine, of the calciomimetic (R)-NPS 568 and of Acrylamide (S)-A, currently under study for the treatment of neuropathic pain, was successfully accomplished.
      PubDate: 2017-05-09T07:25:45.408399-05:
      DOI: 10.1002/adsc.201700376
  • One-pot Synthesis of Oxindoles through C−H Alkylation and Intramolecular
           Cyclization of Azobenzenes with Internal Olefins
    • Authors: Sang Hoon Han; Neeraj Kumar Mishra, Hyeim Jo, Yongguk Oh, Mijin Jeon, Saegun Kim, Woo Jung Kim, Jong Suk Lee, Hyung Sik Kim, In Su Kim
      Abstract: The rhodium(III)-catalyzed site-selective C−H alkylation of azobenzenes and internal olefins, such as maleimides, maleates and fumarates, followed by reductive intramolecular cyclization is described. A cationic rhodium catalyst in the presence of acetic acid additive in dichloroethane solvent was found to be the optimal catalytic system for the construction of ortho-alkylated azobenzenes, which smoothly underwent the intramolecular cyclization leading to the formation of C3-functionalized oxindoles in the presence of zinc powder and acetic acid. The formed oxindole scaffold could be an important asset towards the development of novel bioactive compounds.
      PubDate: 2017-05-08T04:35:15.525584-05:
      DOI: 10.1002/adsc.201700147
  • N-Heterocyclic Carbene-Catalyzed Mannich Reaction for the Synthesis of
           β-Amino Ketones: N,N-Dimethylformamide as Carbon Source
    • Authors: Anitha Alanthadka; Sankari Devi E, Tamil Selvi A, Nagarajan Subbiah, Vellaisamy Sridharan, C. Uma Maheswari
      Abstract: The efficiency of N,N-dimethylformamide (DMF) in the N-Heterocyclic carbene-catalyzed Mannich reaction for the synthesis of β-amino ketones have been demonstrated. This strategy involves oxidative coupling of aryl methyl ketones and 2-aminopyridines in presence of DMF. The reaction doesn’t require pre-functionalization of the substrates, thus making it practically applicable approach for generation of β-amino ketones. The reaction requires the use of tin(II) chloride dihydrate (SnCl2·2H2O) as Lewis acid in presence of tert-Butyl hydroperoxide (TBHP) as the oxidant. The reaction was tolerant to several aryl methyl ketones, including 2-acetylnaphthalene and acetylthiophene. Various substituted 2-aminopyridines reacts with acetophenone to give the desired β-amino ketones in good yields.
      PubDate: 2017-05-05T23:23:15.742102-05:
      DOI: 10.1002/adsc.201700125
  • Exploring Multistep Continuous Flow Hydrosilylation Reactions Catalyzed by
    • Authors: Lewis Wilkins; Joseph Howard, Stefan Burger, Louis Frentzel-Beyme, Duncan Browne, Rebecca Melen
      Abstract: Exploring the combination of continuous-flow processes with the boron Lewis acid catalyzed hydrosilylation of aldehydes and ketones has delivered a robust and generally applicable reaction protocol. Notably this approach permits ready access to high temperatures and pressures and thus allows improved reactivity of substrates that were previously recalcitrant under the traditional approach. Efforts to quench the output from the flow reactor with water showed surprising tolerance leading to the application of continuous-flow systems in a multistep imine formation/hydrosilylation processes to yield the corresponding secondary amines from their aldehyde and aniline precursors.
      PubDate: 2017-05-05T23:23:10.079287-05:
      DOI: 10.1002/adsc.201700349
  • Enantioselective Sulfa-Michael Addition of Aromatic Thiols to
    • Authors: Qi Wei; Wenduan Hou, Na Liao, Yungui Peng
      Abstract: An efficient enantioselective Michael addition of a series of aromatic thiols acting as nucleophiles for β-monosubstituted, α,β- and β,β-disubstituted nitroalkenes promoted by a multi-functional chiral catalyst has been developed. The methodology accommodates a wide variety of aryl thiols and nitroalkene substrates, and affords the 2-nitro-1-arylethyl sulfides in excellent yields (up to 99%) and enantioselectivities (up to 99% ee). This reaction could be scaled up to gram even with a dramatically reduced catalyst loading of 0.05 mol%.
      PubDate: 2017-05-03T01:35:41.523431-05:
      DOI: 10.1002/adsc.201700109
  • Metal-free Difluoromethylthiolation, Trifluoromethylthiolation, and
           Perfluoroalkylthiolation with Sodium Difluoromethanesulfinate, Sodium
           Trifluoromethanesulfinate or Sodium Perfluoroalkanesulfinate
    • Authors: Qiang Yan; Lvqi Jiang, Wenbin Yi, Qiran Liu, Wei Zhang
      Abstract: A method for direct difluoromethylthiolation of Ar-H bonds is introduced. Stable and easy-to-handle HCF2SO2Na is reduced with (EtO)2P(O)H in the presence of TMSCl to generate HCF2S+ for regioselective difluoromethylthiolation of aromatic compounds including indoles, pyrroles, and activated benzenes. This method is also applicable for trifluoromethylthiolation with CF3SO2Na and perfluoroalkylthiolation with RfSO2Na for arenes and heteroarenes. Reaction mechanisms associated with the metal-free electrophilic fluoroalkylthiolation reactions are also discussed.
      PubDate: 2017-04-28T23:37:36.807269-05:
      DOI: 10.1002/adsc.201700270
  • Formation of Phenyliodonio-Substituted Spirofurooxindole Trifluoroacetates
           from N-Substituted 3-Oxopentanediamides via Phenyliodine
           Bis(trifluoroacetate)-Mediated Oxidative Cascade Reactions
    • Authors: Bei Hu; Yang Cao, Bobo Zhang, Daisy Zhang-Negrerie, Yunfei Du
      Abstract: The reaction of N-substituted 3-oxopentanediamides with phenyliodine bis(trifluoroacetate) (PIFA) was found to give a novel class of phenyliodonio-substituted spirofurooxindole trifluoroacetates under metal-free conditions. The reaction is postulated to proceed via a cascade process involving an oxidative C—O bond formation, an oxidative C—C bond formation and a final iodination step.
      PubDate: 2017-04-28T02:51:16.437465-05:
      DOI: 10.1002/adsc.201700075
  • Iridium-Catalyzed Enantioselective Hydrogenation of Vinylsilanes
    • Authors: Aie Wang; Maurizio Bernasconi, Andreas Pfaltz
      Abstract: The front cover picture, provided by Aie Wang, Maurizio Bernasconi, and Andreas Pfaltz, illustrates the potential of chiral iridium N,P-ligand complexes as catalysts for the asymmetric hydrogenation of vinylsilanes. Wide ranges of trisubstituted and disubstituted terminal vinylsilanes bearing aryl, alkyl, carboethoxy, or hydroxymethyl substituents were converted into chiral silanes with high enantioselectivity. In addition to trimethylsilyl and dimethyl(phenyl)silyl derivatives, trialkoxysilyl- and silacyclobutyl-substituted alkenes were used as substrates. Details can be found in the communication on pages XXXX–XXXX (A. Wang, M. Bernasconi, A. Pfaltz, Adv. Synth. Catal. 2017, 359, XXXX–XXXX;
      DOI 10.1002/adsc.201700162).
      PubDate: 2017-04-26T07:25:34.664626-05:
  • Palladium-catalyzed Regioselective Allylation of Chloromethyl
           (Hetero)arenes with Allyl Pinacolborate
    • Authors: Sheng Zhang; Aziz Ullah, Yoshinori Yamamoto, Ming Bao
      Abstract: Palladium-catalyzed regioselective allylation between chloromethyl (hetero)arenes and allyl pinacolborate is reported in this work. Chloromethyl arenes smoothly reacted with allyl pinacolborate, producing para-allylated dearomatization products or para-allylated arenes in satisfactory to good yields. 2-(Chloromethyl)thiophenes and 2-(chloromethyl)furans bearing substituents on 5-positions also smoothly reacted with allyl pinacolborate, producing 5-position allylated dearomatization products in satisfactory yields.
      PubDate: 2017-04-25T23:20:50.762026-05:
      DOI: 10.1002/adsc.201700350
  • Dehydrogenation of N-Heterocycles Using Graphene Oxide as a Versatile
           Metal-free Catalyst under Air
    • Authors: Jingyu Zhang; Shiya Chen, Fangfang Chen, Wensheng Xu, Guojun Deng, Hang Gong
      Abstract: Graphene oxide (GO) has been developed as an inexpensive, environmental friendly, metal-free carbocatalyst for the dehydrogenation of N-heterocycles has been developed. Valuable compounds, such as quinoline, 3,4-dihydroisoquinoline, quinazoline, and indole derivatives, were achieved. The investigation of various oxygen-containing molecules with different conjugated systems indicated that both the oxygen-containing groups and large π-conjugated system in GO sheets are essential for this reaction.
      PubDate: 2017-04-25T23:20:49.75341-05:0
      DOI: 10.1002/adsc.201700178
  • Nickel-Catalyzed Regioselective C-H Bond mono- and bis-Nitration of Aryl
           Oxazolines with tert-Butyl Nitrite as Nitro Source
    • Authors: Li Wan; Kai Qiao, Xin Yuan, Mingwei Zheng, Bingbing Fan, Zhechen Di, Dong Zhang, Zheng Fang, Kai Guo
      Abstract: An efficient and regioselectivenickel-catalyzed remote C-H nitration of 2-aryl oxazoline amides using the non-corrosive TBN as nitro source has been developed. The protocol makes use of inexpensive nickel salts as catalysts and delivers the corresponding products in excellent yields. Notably, bis-nitration products were obtained by simply increasing the amount of tert-butyl nitrite. This reaction proceeds in air and features excellent functional group compatibility, broad substrate scope and is suitable for gram-scale synthesis.
      PubDate: 2017-04-24T21:21:06.488778-05:
      DOI: 10.1002/adsc.201700186
  • Bichromatic Photosynthesis of Coumarins by UV Filter Enabled Olefin
    • Authors: Or Eivgi; Revannath Sutar, Ofer Reany, N. Gabriel Lemcoff
      Abstract: Herein, we report on a two-step bichromatic synthesis of coumarins involving UV-A and UV-C light. The first step is a UV-A photoinduced ruthenium catalyzed cross-metathesis (CM) reaction of 2-nitrobenzyl protected 2-hydroxystyrenes with acrylates, using an external solution of 1-pyrene carboxaldehyde as a UV filter. Irradiation in the absence of the filter permanently inhibits the light activated catalyst due to photocleavage of the photolabile protecting group (PPG) and ensuing phenolate chelation to the ruthenium. The simple removal of the external filter after CM allows further photochemical reactions with UV-C light to achieve more complex architectures, such as the coumarins presented in this work.
      PubDate: 2017-04-21T23:30:43.31149-05:0
      DOI: 10.1002/adsc.201700316
  • Concise Synthesis of Spiro[indoline-3,2’-pyrrolidine] and
           1-Aza-carbazole Derivatives via Copper-Catalyzed Cyclization of Indoles
    • Authors: Peng-Fei Wang; Chao Chen, Hui Chen, Li-Shuai Han, Liu Liu, Hongbin Sun, Xiaoan Wen, Qing-Long Xu
      Abstract: A high-yielding copper-catalyzed dearomatization reaction of indole from 2-methyl indole-derived oxime acetates was realized, providing access to structurally novel spiro[indoline-3,2’-pyrrolidine] derivatives in 67-98% yields. When the C2-position of the indole was not substituted, aza-carbazole derivatives were obtained in moderate yields. This transformation provided an efficient approach to access nitrogen-containing spiroindolenine and aza-carbazole derivatives with wide substrate scope.
      PubDate: 2017-04-20T21:36:16.402295-05:
      DOI: 10.1002/adsc.201700073
  • Enantioselective Synthesis of 2-Bromomethyl Indolines via
           BINAP(S)-Catalyzed Bromoaminocyclization of Allyl Aniline
    • Authors: Jun Deng; Sheng-Nan Yu, Yin-Long Li
      Abstract: An enantioselective bromoamination of allyl aniline with N-bromosuccinimide (NBS) catalyzed by BINAP(S), BINAP monosulfide is described. This protocol could provide a range of chiral 2-bromomethyl indolines in good to excellent yields with up to 87% ee. Furthermore, the resulting chiral 2-bromomethyl indolines could be easily converted into synthetically useful chiral building blocks.
      PubDate: 2017-04-20T09:26:54.496747-05:
      DOI: 10.1002/adsc.201700106
  • Copper-Catalyzed One-pot Synthesis of Pyrimidines from Amides,
           DMF–DMA and Enamines
    • Authors: Hitesh Jalani; Wangshui Cai, hongjian Lu
      Abstract: A versatile copper catalyzed one-pot synthesis of diversely substituted pyrimidines directly from amides, N,N′-dimethylformamide dimethylacetal (DMF–DMA) and enamines has been established. The reaction involved the two C–N bonds and one C–C bond formation by formal [2+1+3] annulation approach to pyrimidines. This protocol is based on the use of readily available primary amides, DMF–DMA and enamines to install di- and tri-substituted pyrimidine structure with diverse functionality in one-pot manner, which makes this strategy to be appealing for the medicinal chemistry.
      PubDate: 2017-04-20T06:32:46.176053-05:
      DOI: 10.1002/adsc.201700234
  • Photoinduced Copper(I)-Catalyzed Cyanation of Aromatic Halides at Room
    • Authors: Kicheol Kim; Soon Hyeok Hong
      Abstract: The first photoinduced Cu(I)-catalyzed cyanation of aromatic halides at room temperature has been developed. The sp2 cyanation reaction exhibits outstanding tolerance to functional groups including primary amines and carboxylic acids, and chemoselectivity to SN2-reactive alkyl chlorides. Mechanistic investigations indicate that the reaction occurs via single-electron transfer (SET) between the aryl halide and an excited Cu(I) cyanide catalytic intermediate.
      PubDate: 2017-04-19T21:35:07.323581-05:
      DOI: 10.1002/adsc.201700213
  • Aldehydes as Carbon Radical Acceptors: Silver Nitrate-Catalyzed Cascade
           Decarboxylation and Oxidative Cyclization toward Dihydroflavonoid
    • Authors: Wen-Chao Yang; Peng Dai, Kai Luo, Yi-Gang Ji, Lei Wu
      Abstract: Silver nitrate-catalyzed cascade decarboxyl-ation and oxidative cyclization of α-oxocarboxylic acids, alkenes, and aldehydes is demonstrated for the first time. With ammonium persulfate as the oxidant, the cascade reactions afforded dihydroflavonoid derivatives as products with moderate to good yields, exhibiting a broad substrate tolerance. The radical pathway with aldehydes as the carbon radical acceptors was exemplified by control experiments.
      PubDate: 2017-04-19T21:35:01.269676-05:
      DOI: 10.1002/adsc.201601407
  • Palladium-catalyzed direct β-C-H arylation of ketones with
           arylboronic acids in water
    • Authors: Xiaoyun Hu; Xiaobo Yang, Xijie Dai
      Abstract: A palladium-catalyzed direct β-C-H arylation of ketones was developed under mild conditions in water, featuring commercially available arylboronic acids as nucleophilic aryl sources and o-iodoxybenzoic acid as the oxidant. The method provides a concise route to access β-arylated ketones. Preliminary studies indicated that direct asymmetric β-C-H arylation of ketones could be achieved by this strategy.
      PubDate: 2017-04-19T04:20:46.835237-05:
      DOI: 10.1002/adsc.201700277
  • Stereoselective Vicinal Difunctionalization of Alkynes through A
    • Authors: Yuanchao Xiang; Yuewen Li, yunyan kuang
      Abstract: Stereoselective vicinal difunctionalization of alkynes through trifluoromethylation and sulfonylation via a three-component reaction of alkynes, sodium sulfinates, and Togni reagent under catalyst- and additive-free conditions is realized. This reaction proceeds at room temperature in DMSO, providing (E)-β-trifluoromethyl vinylsulfones in moderate to good yields. The advantages of this tandem radical process include extremely mild conditions, excellent stereoselectivity, and experimentally operational ease.
      PubDate: 2017-04-18T21:20:38.336121-05:
      DOI: 10.1002/adsc.201700278
  • Hydrogen Bonding-Assisted Enhancement of the Reaction Rate and Selectivity
           in the Kinetic Resolution of d,l-1,2-Diols with Chiral Nucleophilic
    • Authors: Kazuki Fujii; Koichi Mitsudo, Hiroki Mandai, Seiji Suga
      Abstract: An extremely efficient acylative kinetic resolution of d,l-1,2-diols in the presence of only 0.5 mol% of binaphthyl-based chiral N,N-4-dimethylaminopyridine was developed (selectivity factor of up to 180). Several key experiments revealed that hydrogen bonding between the tert-alcohol unit(s) of the catalyst and the 1,2-diol unit of the substrate is critical for accelerating the rate of monoacylation and achieving high enantioselectivity. This catalytic system can be applied to a wide range of substrates involving racemic acyclic and cyclic 1,2-diols with high selectivity factors. The kinetic resolution of d,l-hydrobenzoin and trans-1,2-cyclohexanediol on a multigram scale (10 g) also proceeded with high selectivity and under moderate reaction conditions: (i) very low catalyst loading (0.1 mol%); (ii) an easily achievable low reaction temperature (0 °C); (iii) high substrate concentration (1.0 M); and (iv) short reaction time (30 min).
      PubDate: 2017-04-10T02:16:22.961945-05:
      DOI: 10.1002/adsc.201700057
  • cis-4-Alkoxydialkyl- and cis-4-Alkoxydiarylprolinol Organocatalysts: High
           Throughput Experimentation (HTE)-Based and Design of Experiments
           (DoE)-Guided Development of a Highly Enantioselective aza-Michael Addition
           of Cyclic Imides to α,β-Unsaturated Aldehydes
    • Authors: Ismael Arenas; Alessandro Ferrali, Carles Rodríguez-Escrich, Fernando Bravo, Miquel A. Pericàs
      Abstract: A diverse family (37 compounds) of cis-4-alkoxydiorganylprolinol derivatives has been prepared and evaluated in organocatalysis for the first time. The combined use of high throughput experimentation (HTE) techniques with efficient analytical methods has led to the identification of two superior catalysts for the enantioselective addition of succinimide to α,β-unsaturated aldehydes. Further optimization of the reaction conditions with design of experiments (DoE) techniques established the catalyst of choice for the considered aza-Michael reaction, the corresponding adducts (12 examples) being obtained in good yields and excellent enantioselectivities (succinimide and maleimide donors). The synthetic versatility of these Michael adducts is illustrated by a two-step sequence leading to enantiopure 1,3-amino alcohols.
      PubDate: 2017-04-06T06:22:08.809649-05:
      DOI: 10.1002/adsc.201700120
  • Application of dehydroabietic acid in palladium-catalysed enyne
    • Authors: Na Wu; Ruikun Li, Feihu Cui
      Abstract: Dehydroabietic acid (DAA) promotes palladium(0)-catalysed cyclisations of arene-tethered 1,7-enynols and 1,m-enynoates (m = 6,7) to give fused carbocyclic dienes. 6,6,6,5-tetracyclic lactones are accessible by one-pot cycloisomerisation / Diels-Alder reaction / lactonisation from 1,7-enynols. Furthermore, asymmetric counteranion-directed catalysis was developed, which afforded an indene derivative with an all-carbon quaternary stereogenic center.
      PubDate: 2017-04-05T21:21:07.375403-05:
      DOI: 10.1002/adsc.201700061
  • Palladium-Catalyzed Synthesis of Tetrasubstituted Olefins by Triple Domino
    • Authors: Kanagaraj Naveen; Savariyappan Albert Nikson, Paramasivan Thirumalai Perumal
      Abstract: An efficient, highly regio- and stereoselective protocol for the synthesis of tetrasubstituted olefins is developed by palladium(0)-catalyzed triple domino process. It involves the formation of three new C-C bonds through double carbopalladation and C-H activation across 2-bromoaryl alkynyl biaryls/heteroaryls with norbornene. This method is practically simple with broad substrate scope and tolerates a wide range of substituents. The products bearing 9H-pyrrolo[1,2-a]indole motifs reveal an intriguing solid state fluorescence properties and thus explicit a new class of aggregation induced emission (AIE) fluorophores.
      PubDate: 2017-04-04T09:26:16.390239-05:
      DOI: 10.1002/adsc.201700169
  • Iridium-Catalyzed Enantioselective Hydrogenation of Vinylsilanes
    • Authors: Aie Wang; Maurizio Bernasconi, Andreas Pfaltz
      Abstract: We have screened a diverse array of iridium complexes derived from chiral N,P ligands as catalysts for the asymmetric hydrogenation of vinylsilanes, a transformation for which generally applicable catalysts were lacking. Several catalysts emerged from this study that enabled the highly enantioselective hydrogenation of a wide range of vinylsilanes with trisubstituted or disubstituted terminal C=C bonds bearing aryl, alkyl, ethoxycarbonyl, or hydroxymethyl substituents. In addition to trimethylsilyl and dimethyl(phenyl)silyl derivatives, trialkoxysilyl- and silacyclobutyl-substituted alkenes were used as substrates.
      PubDate: 2017-03-15T07:30:37.736451-05:
      DOI: 10.1002/adsc.201700162
  • A Polystyrene-Supported Phase-Transfer Catalyst for Asymmetric Michael
           Addition of Glycine-Derived Imines to α,β-Unsaturated Ketones
    • Authors: Javier Miguélez; Hiroyuki Miyamura, Shū Kobayashi
      Abstract: A 2-oxopyrimidinium salt was immobilized onto a polystyrene-derived polymer to generate a heterogeneous catalyst that effectively promoted the asymmetric Michael addition of glycine-derived imines to α,β-unsaturated ketones. The reactions proceeded smoothly to afford the desired adducts, (S)-tert-butyl 2-[(diarylmethylidene)amino]-5-oxoalkanoates, in high yields and with high enantioselectivities (up to 92% ee). The polymer catalyst could be recovered and reused at least five times without significant loss of activity or selectivity.
      PubDate: 2017-03-13T03:36:50.620841-05:
      DOI: 10.1002/adsc.201700155
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