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Publisher: John Wiley and Sons   (Total: 1583 journals)

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Showing 1 - 200 of 1583 Journals sorted alphabetically
Abacus     Hybrid Journal   (Followers: 12, SJR: 0.48, h-index: 22)
About Campus     Hybrid Journal   (Followers: 5)
Academic Emergency Medicine     Hybrid Journal   (Followers: 54, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 44, SJR: 0.547, h-index: 30)
ACEP NOW     Free  
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 50, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 142, SJR: 0.101, h-index: 9)
Acta Geologica Sinica (English Edition)     Hybrid Journal   (Followers: 3, SJR: 0.552, h-index: 41)
Acta Neurologica Scandinavica     Hybrid Journal   (Followers: 5, SJR: 1.203, h-index: 74)
Acta Obstetricia et Gynecologica Scandinavica     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 81)
Acta Ophthalmologica     Hybrid Journal   (Followers: 5, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 54, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 7, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 35, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 5, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 2)
Addiction     Hybrid Journal   (Followers: 31, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 11, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 24, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 25, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 49, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 13, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 251, SJR: 9.021, h-index: 345)
Advanced Materials Interfaces     Hybrid Journal   (Followers: 6, SJR: 1.177, h-index: 10)
Advanced Optical Materials     Hybrid Journal   (Followers: 5, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 4)
Advanced Synthesis & Catalysis     Hybrid Journal   (Followers: 17, SJR: 2.729, h-index: 121)
Advances in Polymer Technology     Hybrid Journal   (Followers: 13, SJR: 0.344, h-index: 31)
Africa Confidential     Hybrid Journal   (Followers: 19)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 12)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 9)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 14, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 9, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 6, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 14, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 44, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 29, SJR: 1.122, h-index: 120)
Alcoholism and Drug Abuse Weekly     Hybrid Journal   (Followers: 7)
Alcoholism Clinical and Experimental Research     Hybrid Journal   (Followers: 7, SJR: 1.416, h-index: 125)
Alimentary Pharmacology & Therapeutics     Hybrid Journal   (Followers: 34, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 49, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 128, SJR: 0.951, h-index: 61)
American Business Law J.     Hybrid Journal   (Followers: 24, SJR: 0.205, h-index: 17)
American Ethnologist     Hybrid Journal   (Followers: 90, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 28, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 31, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 12, SJR: 1.018, h-index: 58)
American J. of Industrial Medicine     Hybrid Journal   (Followers: 16, SJR: 0.993, h-index: 85)
American J. of Medical Genetics Part A     Hybrid Journal   (Followers: 15, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 3, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 5, SJR: 2.315, h-index: 79)
American J. of Orthopsychiatry     Hybrid Journal   (Followers: 4, SJR: 0.756, h-index: 69)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 36, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 249, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 15, SJR: 1.197, h-index: 63)
American J. of Reproductive Immunology     Hybrid Journal   (Followers: 3, SJR: 1.347, h-index: 75)
American J. of Transplantation     Hybrid Journal   (Followers: 15, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 116, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 11, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 16)
Anatomia, Histologia, Embryologia: J. of Veterinary Medicine Series C     Hybrid Journal   (Followers: 3, SJR: 0.295, h-index: 27)
Anatomical Sciences Education     Hybrid Journal   (Followers: 1, SJR: 0.633, h-index: 24)
Andrologia     Hybrid Journal   (Followers: 2, SJR: 0.528, h-index: 45)
Andrology     Hybrid Journal   (Followers: 2, SJR: 0.979, h-index: 14)
Angewandte Chemie     Hybrid Journal   (Followers: 155)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 211, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 34, SJR: 1.576, h-index: 62)
Animal Genetics     Hybrid Journal   (Followers: 8, SJR: 0.957, h-index: 67)
Animal Science J.     Hybrid Journal   (Followers: 6, SJR: 0.569, h-index: 24)
Annalen der Physik     Hybrid Journal   (Followers: 5, SJR: 1.46, h-index: 40)
Annals of Anthropological Practice     Partially Free   (Followers: 2, SJR: 0.187, h-index: 5)
Annals of Applied Biology     Hybrid Journal   (Followers: 8, SJR: 0.816, h-index: 56)
Annals of Clinical and Translational Neurology     Open Access   (Followers: 1)
Annals of Human Genetics     Hybrid Journal   (Followers: 9, SJR: 1.191, h-index: 67)
Annals of Neurology     Hybrid Journal   (Followers: 43, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 2, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 9, SJR: 0.336, h-index: 23)
Annals of the New York Academy of Sciences     Hybrid Journal   (Followers: 5, SJR: 2.389, h-index: 189)
Annual Bulletin of Historical Literature     Hybrid Journal   (Followers: 12)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 24, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 16, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 14)
Anthropology of Consciousness     Hybrid Journal   (Followers: 11, SJR: 0.172, h-index: 5)
Anthropology of Work Review     Hybrid Journal   (Followers: 11, SJR: 0.256, h-index: 5)
Anthropology Today     Hybrid Journal   (Followers: 93, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 44, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 6, SJR: 0.432, h-index: 59)
Anzeiger für Schädlingskunde     Hybrid Journal   (Followers: 1)
Apmis     Hybrid Journal   (Followers: 1, SJR: 0.855, h-index: 73)
Applied Cognitive Psychology     Hybrid Journal   (Followers: 67, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 138, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 48, SJR: 0.868, h-index: 13)
Applied Stochastic Models in Business and Industry     Hybrid Journal   (Followers: 5, SJR: 0.613, h-index: 24)
Aquaculture Nutrition     Hybrid Journal   (Followers: 13, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 31, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 34, SJR: 1.047, h-index: 57)
Arabian Archaeology and Epigraphy     Hybrid Journal   (Followers: 11, SJR: 0.453, h-index: 11)
Archaeological Prospection     Hybrid Journal   (Followers: 12, SJR: 0.922, h-index: 21)
Archaeology in Oceania     Hybrid Journal   (Followers: 13, SJR: 0.745, h-index: 18)
Archaeometry     Hybrid Journal   (Followers: 27, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 14, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 25, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 4, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 4)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 12, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 215, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 49, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 28, SJR: 2.256, h-index: 114)
Artificial Organs     Hybrid Journal   (Followers: 1, SJR: 0.872, h-index: 60)
ASHE Higher Education Reports     Hybrid Journal   (Followers: 14)
Asia & the Pacific Policy Studies     Open Access   (Followers: 14)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 312, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 7, SJR: 0.345, h-index: 20)
Asia-pacific J. of Clinical Oncology     Hybrid Journal   (Followers: 6, SJR: 0.554, h-index: 14)
Asia-Pacific J. of Financial Studies     Hybrid Journal   (SJR: 0.241, h-index: 7)
Asia-Pacific Psychiatry     Hybrid Journal   (Followers: 3, SJR: 0.377, h-index: 7)
Asian Economic J.     Hybrid Journal   (Followers: 8, SJR: 0.234, h-index: 21)
Asian Economic Policy Review     Hybrid Journal   (Followers: 3, SJR: 0.196, h-index: 12)
Asian J. of Control     Hybrid Journal   (SJR: 0.862, h-index: 34)
Asian J. of Endoscopic Surgery     Hybrid Journal   (SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 4, SJR: 1.443, h-index: 19)
Asian J. of Social Psychology     Hybrid Journal   (Followers: 5, SJR: 0.665, h-index: 37)
Asian Politics and Policy     Hybrid Journal   (Followers: 13, SJR: 0.207, h-index: 7)
Asian Social Work and Policy Review     Hybrid Journal   (Followers: 5, SJR: 0.318, h-index: 5)
Asian-pacific Economic Literature     Hybrid Journal   (Followers: 5, SJR: 0.168, h-index: 15)
Assessment Update     Hybrid Journal   (Followers: 4)
Astronomische Nachrichten     Hybrid Journal   (Followers: 2, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 12, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 10, SJR: 0.524, h-index: 28)
Australasian J. of Dermatology     Hybrid Journal   (Followers: 8, SJR: 0.714, h-index: 40)
Australasian J. On Ageing     Hybrid Journal   (Followers: 7, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 13, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 4, SJR: 0.709, h-index: 14)
Australian and New Zealand J. of Family Therapy (ANZJFT)     Hybrid Journal   (Followers: 3, SJR: 0.382, h-index: 12)
Australian and New Zealand J. of Obstetrics and Gynaecology     Hybrid Journal   (Followers: 43, SJR: 0.814, h-index: 49)
Australian and New Zealand J. of Public Health     Hybrid Journal   (Followers: 11, SJR: 0.82, h-index: 62)
Australian Dental J.     Hybrid Journal   (Followers: 6, SJR: 0.482, h-index: 46)
Australian Economic History Review     Hybrid Journal   (Followers: 4, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 22, SJR: 0.23, h-index: 9)
Australian Economic Review     Hybrid Journal   (Followers: 6, SJR: 0.357, h-index: 21)
Australian Endodontic J.     Hybrid Journal   (Followers: 3, SJR: 0.513, h-index: 24)
Australian J. of Agricultural and Resource Economics     Hybrid Journal   (Followers: 3, SJR: 0.765, h-index: 36)
Australian J. of Grape and Wine Research     Hybrid Journal   (Followers: 5, SJR: 0.879, h-index: 56)
Australian J. of Politics & History     Hybrid Journal   (Followers: 13, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 17, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 385, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 4, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 66, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 11, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 19, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 31, SJR: 2.126, h-index: 39)
Autonomic & Autacoid Pharmacology     Hybrid Journal   (SJR: 0.371, h-index: 29)
Banks in Insurance Report     Hybrid Journal   (Followers: 1)
Basic & Clinical Pharmacology & Toxicology     Hybrid Journal   (Followers: 10, SJR: 0.539, h-index: 70)
Basic and Applied Pathology     Open Access   (Followers: 2, SJR: 0.113, h-index: 4)
Basin Research     Hybrid Journal   (Followers: 3, SJR: 1.54, h-index: 60)
Bauphysik     Hybrid Journal   (Followers: 2, SJR: 0.194, h-index: 5)
Bauregelliste A, Bauregelliste B Und Liste C     Hybrid Journal  
Bautechnik     Hybrid Journal   (Followers: 1, SJR: 0.321, h-index: 11)
Behavioral Interventions     Hybrid Journal   (Followers: 8, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 23, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 9, SJR: 0.11, h-index: 5)
Beton- und Stahlbetonbau     Hybrid Journal   (Followers: 2, SJR: 0.493, h-index: 14)
Biochemistry and Molecular Biology Education     Hybrid Journal   (Followers: 6, SJR: 0.311, h-index: 26)
Bioelectromagnetics     Hybrid Journal   (Followers: 1, SJR: 0.568, h-index: 64)
Bioengineering & Translational Medicine     Open Access  
BioEssays     Hybrid Journal   (Followers: 10, SJR: 3.104, h-index: 155)
Bioethics     Hybrid Journal   (Followers: 14, SJR: 0.686, h-index: 39)
Biofuels, Bioproducts and Biorefining     Hybrid Journal   (Followers: 1, SJR: 1.725, h-index: 56)
Biological J. of the Linnean Society     Hybrid Journal   (Followers: 14, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 3, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 42, SJR: 0.12, h-index: 1)
Biology of the Cell     Full-text available via subscription   (Followers: 9, SJR: 1.812, h-index: 69)
Biomedical Chromatography     Hybrid Journal   (Followers: 6, SJR: 0.572, h-index: 49)
Biometrical J.     Hybrid Journal   (Followers: 5, SJR: 0.784, h-index: 44)
Biometrics     Hybrid Journal   (Followers: 36, SJR: 1.906, h-index: 96)
Biopharmaceutics and Drug Disposition     Hybrid Journal   (Followers: 10, SJR: 0.715, h-index: 44)
Biopolymers     Hybrid Journal   (Followers: 18, SJR: 1.199, h-index: 104)
Biotechnology and Applied Biochemistry     Hybrid Journal   (Followers: 45, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 137, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 13, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 18, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 10, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 34, SJR: 0.763, h-index: 64)
Birth Defects Research Part A : Clinical and Molecular Teratology     Hybrid Journal   (Followers: 2, SJR: 0.727, h-index: 77)
Birth Defects Research Part B: Developmental and Reproductive Toxicology     Hybrid Journal   (Followers: 5, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)

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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  [1583 journals]
  • 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
       
  • Cobalt-Porphyrin-Catalyzed Intramolecular Buchner Reaction and Arene
           Cyclopropanation of in situ Generated Alkyl Diazomethanes
    • Authors: Haixu Wang; Cong-Ying Zhou, Chi-Ming Che
      Abstract: The inside cover picture, provided by Haixu Wang, Cong-Ying Zhou, and Chi-Ming Che, illustrates the cobalt-catalyzed conversion of N-tosylhydrazones to cycloheptatriene fused pyrrolidines and cyclopropane fused pyrrolidines. With Co(II)-porphyrin as catalyst, alkyl diazomethanes generated in situ from N-tosylhydrazones underwent intramolecular Buchner reaction and arene cyclopropanation in highly chemo- and regio-selective manner. The obtained cyclopropane fused pyrrolidines can be readily converted to other nitrogen heterocycles with potential synthetic and biological interests. Details of this work can be found in the communication on pages XXXX–XXXX (H. Wang, C.-Y. Zhou, C.-M. Che, Adv. Synth. Catal. 2017, 359, XXXX–XXXX;
      DOI : 10.1002/adsc.201700205).
      PubDate: 2017-06-22T08:25:51.696532-05:
       
  • 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
           Perfluoroalkylthiolation
    • 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
           Dissociation
    • 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
           dihydroxanthones
    • 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
           Spirocyclizations
    • 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
           Compounds
    • 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
           Catalysis
    • 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
           1,3-Dienes
    • Authors: Ruwei Shen; Jianlin Yang, Ming Zhang, Li-Biao Han
      Abstract: The highly regioselective nucleophilic ring opening of propargyl epoxides by P(O)H compounds based on a 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
           3-Oxopropanenitriles
    • 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
           Benzo[d]isoxazoles
    • 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
           3-Chlorooxindoles
    • Authors: Xiao-Li Jiang; Si-Jia Liu, Yu-Qi Gu, Guang-Jian Mei, Feng Shi
      Abstract: In this work, we established catalytic asymmetric [4+1] cyclization of ortho-quinone methides (o-QMs) with 3-chlorooxindoles and a catalytic asymmetric domino oxidation/[4+1] cyclization reaction of 2-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
       
  • Site-Directed Mutagenesis Studies on the Toluene Dioxygenase Enzymatic
           System: Role of Phenylalanine 366, Threonine 365 and Isoleucine 324 in the
           Chemo-, Regio-, and Stereoselectivity
    • Authors: María Agustina Vila; Diego Umpiérrez, Nicolás Veiga, Gustavo Seoane, Ignacio Carrera, Sonia Rodríguez Giordano
      Abstract: Toluene Dioxygenase (TDO) enzymatic complex has been widely used as a biocatalyst for the regio- and enantioselective preparation of cis-cyclohexadienediols, which are very important starting materials for organic synthesis. However, the lack of regio- and stereodiversity of the dioxygenation process by TDO and related dioxygenases constitutes a clear drawback when planning the use of these diols in synthetic schemes. In this work, we developed three TDO mutants in residues phenylalanine 366, threonine 365 and isoleucine 324, with the aim to alter the chemo-, regio- and stereoselectivity of the biotransformation of arenes. While no changes in the regioselectivity of the process were observed, dramatic variations in the chemo- and enantioselectivity were found for mutants I324F, T365N and F366 V in a substrate-dependent manner.
      PubDate: 2017-05-29T04:30:29.055303-05:
      DOI: 10.1002/adsc.201700444
       
  • 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
       
  • Regio- and Stereoselective Oxidation of Styrene Derivatives to Aryl Acids
           via One-Pot Cascade Biotransformations
    • Authors: Shuke Wu; Yi Zhou, Daniel Seet, Zhi Li
      Abstract: Green and selective oxidation methods are highly desired in chemical synthesis and manufacturing. In this paper, we developed a biocatalytic method for regio- and stereoselective oxidation of styrene derivatives into arylacetic and (S)-2-arylpropionic acids via one-pot epoxidation-isomerization-oxidation. This was done via the engineering of Escherichia coli (StyABC-EcALDH) coexpressing styrene monooxygenase (SMO), styrene oxide isomerase (SOI) and aldehyde dehydrogenase (EcALDH) as an active and easily available whole-cell catalyst. Regioselective oxidation of styrene and 11 substituted styrenes using the E. coli cells was performed in a one-pot setup, producing 12 phenylacetic acids in both high conversion and high yield. Engineering of E. coli (StyABC-ADH9v1) coexpressing SMO, SOI and ADH9v1 (a mutated alcohol dehydrogenase) led to biocatalysts capable of regio- and stereoselective oxidation of α-methylstyrene derivatives to the corresponding chiral acids. One-pot asymmetric synthesis of 4 (S)-2-arylpropionic acids was achieved in good conversion and excellent ee with the E. coli cells. This is a new type of asymmetric alkene oxidation to give chiral acids with no chemical counterpart thus far. The cascade bio-oxidation operates in mild conditions, uses molecular oxygen, exhibits very high regio- and enantioselectivity, and gives high conversion, thus providing a green and efficient method for the synthesis of arylacetic acids and (S)-2-arylpropionic acids directly from easily available styrenes.
      PubDate: 2017-05-26T23:25:40.59193-05:0
      DOI: 10.1002/adsc.201700416
       
  • Transketolase - Aldolase Symbiosis for the Stereoselective Preparation of
           Aldoses and Ketoses of Biological Interest
    • Authors: Christine Guérard-Hélaine; Maxime De Sousa Lopes Moreira, Nadia Touisni, Laurence Hecquet, Marielle Lemaire, Virgil Hélaine
      Abstract: Transketolase (TK) was used as biocatalyst to produce useful aldoses as aldolase electrophiles to prepare monosaccharides of biological interest. Unconventionally, TK was implemented in a synthetic pathway, as in metabolism, ie without using a specially designed nucleophile such as hydroxypyruvate to shift the equilibrium. Unusually, formaldehyde was taken as the general TK acceptor substrate to generate aldehydes. Here was demonstrated that this method can be generalized: the substrates and the aldolase were successfully varied, coupled with other enzymes in a one-pot one-step green cascade reaction process involving four enzymes with atom economy. In addition, new assays were developed for both monitoring the progress of the reactions and assessing the purity of the synthesized products.
      PubDate: 2017-05-26T23:25:39.348807-05:
      DOI: 10.1002/adsc.201700209
       
  • 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
       
  • Nicotinamide Adenine Dinucleotide-Dependent Redox-Neutral Convergent
           Cascade for Lactonizations with Type II Flavin-Containing Monooxygenase
    • Authors: Lei Huang; Elvira Romero, Anna K. Ressmann, Florian Rudroff, Frank Hollmann, Marco W. Fraaije, Selin Kara
      Abstract: A nicotinamide adenine dinucleotide (NADH)-dependent redox-neutral convergent cascade composed of a recently discovered type II flavin-containing monooxygenase (FMO−E) and horse liver alcohol dehydrogenase (HLADH) has been established. Two model reaction cascades were analyzed for the synthesis of γ-butyrolactone and chiral bicyclic lactones. In the former cascade, all substrates were converted into one single product γ-butyrolactone with high atom efficiency. More than 130 mM γ-butyrolactone were obtained when applying 100 mM cyclobutanone and 50 mM 1,4-butanediol in this cascade. In the second cascade where bicyclo[4.2.0]octan-7-one and cis-1,2-cyclohexanedimethanol were coupled, the ketone substrate was converted to the corresponding normal lactone with an ee value of 89–74% (3aS, 7aS) by FMO−E alone and the abnormal lactone with an ee value of>99% (3aR, 7aS) was formed by both HLADH and FMO−E.
      PubDate: 2017-05-22T06:20:34.089109-05:
      DOI: 10.1002/adsc.201700401
       
  • Palladium-Catalyzed Regioselective Direct Arylation of Benzofurazans at C4
           Position
    • 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
           Stereocenters
    • 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
           Diamines
    • 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
       
  • 2-Keto-3-Deoxy-L-Rhamnonate Aldolase (YfaU) as Catalyst in Aldol Additions
           of Pyruvate to Amino Aldehyde Derivatives
    • Authors: Karel Hernandez; Ariadna Gómez, Jesús Joglar, Jordi Bujons, Teodor Parella, Pere Clapés
      Abstract: . 4-Hydroxy-2-ketoacid derivatives are versatile building blocks for the synthesis of amino acids, hydroxy carboxylic acids and chiral aldehydes. Pyruvate aldolases are privileged catalysts for a straightforward access to this class of ketoacid compounds. In this work, a Class II pyruvate aldolase from Escherichia coli K-12, 2-keto-3-deoxy-L-rhamnonate aldolase (YfaU), was evaluated for the synthesis of amino acid derivatives of proline, pipecolic acid, and pyrrolizidine-3-carboxylic acid. The aldol addition of pyruvate to N-protected amino aldehydes was the key enzymatic aldol addition step followed by catalytic intramolecular reductive amination. The corresponding N-Cbz-amino-4-hydroxy-2-ketoacid (Cbz=benzyloxycarbonyl) precursors were obtained in 51%-95% isolated yields and enantioselectivity ratios from 26:74 to 95:5, with chiral -substituted N-Cbz-amino aldehydes. (S)-N-Cbz-amino aldehydes gave aldol adducts with preferentially (R)-configuration at the newly formed stereocenter, whereas the contrary is true for (R)-N-Cbz-amino aldehydes. Addition reactions to achiral amino aldehydes rendered racemic aldol adducts. Molecular models of the pre-reaction ternary complexes YfaU-pyruvate enolate-acceptor aldehyde were constructed to explain the observed stereochemical outcome of the reactions. Catalytic reductive amination of the aldol adducts yielded 4-hydroxy-2-pipecolic acid, and unprecedented C5 substituted 4-hydroxy proline and pyrrolizidine-3-carboxylic acid derivatives.
      PubDate: 2017-05-11T03:36:24.083334-05:
      DOI: 10.1002/adsc.201700360
       
  • 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
       
  • BIO Issue 12, 2017, U2 Z700314 Nuijens
    • Authors: Joe 02 Richmond; Ana Toplak, Peter J. L. M. Quaedflieg, Hans Ippel, Gaston J. J. Richelle, Tilman M. Hackeng, Jan H. van Maarseveen, Timo Nuijens
      PubDate: 2017-05-09T07:50:20.913397-05:
      DOI: 10.1002/adsc.201700590
       
  • Issue 12, U1, A700356 Grogan
    • Authors: Joe 02 Richmond; Juan Mangas-Sanchez, Nicholas J. Turner, Gideon Grogan
      PubDate: 2017-05-09T07:25:54.164218-05:
      DOI: 10.1002/adsc.201700540
       
  • 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
       
  • Mutagenesis-Independent, Stabilization of Class B Flavin Monooxygenases in
           Operation
    • Authors: Leticia Goncalves; Daniel Kracher, Sofia Milker, Florian Rudroff, Michael J Fink, Roland Ludwig, Andreas Bommarius, Marko Mihovilovic
      Abstract: This paper describes the stabilization of flavin-dependent monooxygenases under reaction conditions, using an engineered formulation of additives (the natural cofactors NADPH and FAD, and superoxide dismutase and catalase as catalytic antioxidants). This way, a 103–104 fold increase of the half-life was reached without resource-intensive directed evolution or structure-dependent protein engineering methods. The stabilized enzymes are highly valued for their synthetic potential in biotechnology and medicinal chemistry (enantioselective sulfur, nitrogen and Baeyer-Villiger oxidations; oxidative human metabolism), but widespread application was so far hindered by their notorious fragility. Our technology immediately enables their use, does not require structural knowledge of the biocatalyst, and creates a strong basis for the targeted development of improved variants by mutagenesis.
      PubDate: 2017-05-08T21:21:42.262742-05:
      DOI: 10.1002/adsc.201700585
       
  • Development of a unique heterogeneous palladium catalyst for
           Suzuki–Miyaura reaction using (hetero)aryl chlorides and chemoselective
           hydrogenation
    • Authors: Tomohiro Ichikawa; Moeko Netsu, Masahiro Mizuno, Tomoteru Mizusaki, Yukio Takagi, Yoshinari Sawama, Yasunari Monguchi, Hironao Sajiki
      Abstract: A unique heterogeneous palladium catalyst (7% Pd/WA30) supported on an anion exchange resin, which contains N,N-dimethylaminoalkyl functionalities on the polymer backbone, was developed. 7% Pd/WA30 could smoothly catalyze Suzuki–Miyaura reaction of even less reactive heteroaryl chlorides and heteroaryl boronic acids to afford various (hetero)biaryls due to the electron-donating effect of the tert-amines on WA30 to Pd species. It was also applicable as a chemoselective hydrogenation catalyst, showing inactivity for the hydorogenolysis of tert-butyldimethylsilyl (TBS) ethers, alkyl benzyl ethers, and benzyl alcohols. The tert-amines on WA30 acted as moderate catalyst poisons for Pd, resulting in chemoselective hydrogenation. 7% Pd/WA30 was reused for at least five times without any loss of the hydrogenation catalytic activity.
      PubDate: 2017-05-08T21:21:38.601713-05:
      DOI: 10.1002/adsc.201700156
       
  • 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
       
  • Synthesis of Nitrogen-Containing Heterocycles and Cyclopentenone
           Derivatives via Phosphine-Catalyzed Michael Addition/Intramolecular Wittig
           Reaction
    • Authors: Nidal Saleh; Florent Blanchard, Arnaud Voituriez
      Abstract: The phosphine-catalyzed Michael addition/intramolecular Wittig reaction between dialkyl acetylenedicarboxylate and amino-carbaldehyde or amino-ester derivatives has been developped. This reaction can be rendered catalytic in phosphine by the in situ chemoselective reduction of the phosphine oxide with silane. This methodology enables rapid access to a variety of nitrogen-containing heterocycles, which are present in numerous natural products and/or bioactive compounds. Either classical heating or microwave conditions give access to the desired products in good yields (15 examples, 60-99% yields). This catalytic methodology is further applicable to the synthesis of enantioenriched 1H-pyrrole derivatives, with the use of chiral phosphines. Finally, we successfully extended the reaction to the synthesis of polysubstituted cyclopentenone, starting from butane-2,3-dione as substrate.
      PubDate: 2017-05-05T23:23:14.199497-05:
      DOI: 10.1002/adsc.201700313
       
  • Organocatalyzed Deracemisation of Δ2-Pyrrolin-4-ones
    • Authors: Sebastijan Ričko; Anže Meden, Anže Ivančič, Andrej Perdih, Bogdan Štefane, Jurij Svete, Uroš Grošelj
      Abstract: Racemic pyrrolin-4-ones, accessible from α-amino acids, undergo asymmetric stereoselective organocatalyzed 1,4-additions to trans-β-nitrostyrenes (up to 98% ee; dr up to 97:3). In a series of typical organocatalysts, the best performance was achieved using (+)-camphor-1,3-diamine-derived bifunctional organocatalysts. A broad substrate scope and some follow-up modifications have been demonstrated.
      PubDate: 2017-05-05T23:23:12.674988-05:
      DOI: 10.1002/adsc.201700539
       
  • Exploring Multistep Continuous Flow Hydrosilylation Reactions Catalyzed by
           Tris(pentafluorophenyl)borane
    • 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
       
  • Synthesis of Aryldihalomethanes by Denitrogenative Dihalogenation of
           Benzaldehyde Hydrazones
    • Authors: Zhensheng Zhao; Kaivalya G. Kulkarni, Graham K. Murphy
      Abstract: We report a denitrogenative dihalogenation reaction of phenyldiazomethanes in which the hypervalent iodine reagents PhICl2 and TolIF2 act as surrogates for elemental chlorine and fluorine. Halogen transfer from iodane to aryldiazomethane is described, as is a tandem oxidative dihalogenation reaction between iodane and hydrazone. This is the first use of non-α-stabilized diazo compounds in this reaction, which provided an efficient synthesis of aryldifluoromethane (ArCHF2) and aryldichloromethane (ArCHCl2) derivatives.
      PubDate: 2017-05-04T01:30:29.94663-05:0
      DOI: 10.1002/adsc.201700393
       
  • Hypervalent Iodine-Promoted Aromatization of Exocyclic β-Enaminones for
           the Synthesis of meta-N,N-Diarylaminophenols
    • Authors: Dhananjay Bhattacherjee; Vandna Thakur, Arun K. Shil, Pralay Das
      Abstract: A metal- and additive-free milder cascade approach for the synthesis of meta-N,N-diarylaminophenols (DAAP) starting from exocyclic β-enaminones has been developed. The feasibility of the process is rationalized by the suitable molecular geometry of β-enaminones for tandem N-arylative α-iodination and aromatization under milder basic conditions. Furthermore, the developed strategy has been extended to the synthesis of meta-N-benzyl-N-arylaminophenols (BAAP). 4-Ethylpropionyl-2-cyclohexenone has been explored to give 7-diarylaminochroman-2-one (DAAC) by employing a similar one-pot approach. The plausible mechanistic steps were deduced based upon isolation of a stable intermediate and structural identification through X-ray crystallographic analysis.
      PubDate: 2017-05-04T01:30:26.7599-05:00
      DOI: 10.1002/adsc.201700004
       
  • Two-Step Enzymatic Synthesis of
           β-D-N-Acetylgalactosamine-(14)-D-N-Acetylglucosamine (LacdiNAc)
           Chitooligomers for Deciphering Galectin Binding Behavior
    • Authors: Dominic Laaf; Pavla Bojarová, Barbora Mikulová, Helena Pelantova, Vladimir Kren, Lothar Elling
      Abstract: A two-step synthesis of engineered variants of Talaromyces flavus β-N-acetylhexosaminidase (TfHexY470N) and human β4-galactosyltransferase (β4GalTY284L) yielded complex glycans comprising a chitooligomeric spacer (β1,4GlcNAc)n=0-3 terminated with a β4-linked β-D-GalNAc-(14)-D-GlcNAc (LacdiNAc) epitope. These compounds are novel inhibitors of human galectin 3 (Gal 3), a widely spread animal lectin with important physiological functions in cellular communication. The multivalent presentation of glycan oligomers was accomplished by chemical conjugation of glycans to lysine residues of bovine serum albumin (BSA). Binding studies of Gal-3 to immobilized BSA neo-glycoconjugates revealed the beneficial influence of the chitooligomeric spacer for the ligand-lectin affinity. We conclude that the use of the (β1,4GlcNAc)n=0-3 spacer is a perfect nature-like solution for the presentation of elaborated Gal-3 glycan epitopes that surpasses the performance of commonly used synthetic spacers.
      PubDate: 2017-05-03T21:20:39.122719-05:
      DOI: 10.1002/adsc.201700331
       
  • Methylidene Group in Phosphonic Acid Analogue of Phenylalanine Reverses
           the Enantiopreference of Binding to Phenylalanine Ammonia-Lyases
    • Authors: Zsófia Bata; Renzhe Quian, Alexander Roller, Jeannie Horak, László Csaba Bencze, Csaba Paizs, Friedrich Hammerschmidt, Beáta G. Vértessy, László Poppe
      Abstract: Aromatic amino acid ammonia-lyases and aromatic amino acid 2,3-aminomutases contain the post-translationally formed prosthetic 3,5-dihydro-4-methylidene-5H-imidazol-5-one (MIO) group. MIO-enzymes catalyze the stereoselective synthesis of α- or β-amino acid enantiomers, making these chemical processes environmentally friendly and affordable. Characterization of novel inhibitors enables structural understanding of enzyme mechanism and recognize promising herbicide candidates as well. The present study found, that both enantiomers of the aminophosphonic acid analogue of the natural substrate phenylalanine and a novel derivative bearing a methylidene at the β-position inhibited phenylalanine ammonia-lyases (PAL), representing MIO enzymes. X-ray methods unambiguously determined the absolute configuration of all tested enantiomers during their synthesis. Enzyme kinetic measurements revealed the enantiomer of the methylidene substituted substrate analogue being mirror image relation to the natural L-phenylalanine as the strongest inhibitor. Isothermal titration calorimetry (ITC) confirmed the binding constants and provided a detailed analysis of the thermodynamic driving forces of ligand binding. Molecular docking suggested that binding of the (R)- and (S)-enantiomers is possible by a mirror image packing.
      PubDate: 2017-05-03T21:20:34.286978-05:
      DOI: 10.1002/adsc.201700428
       
  • 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
       
  • Cobalt-Porphyrin-Catalyzed Intramolecular Buchner Reaction and Arene
           Cyclopropanation of In Situ Generated Alkyl Diazomethanes
    • Authors: Haixu Wang; Cong-Ying Zhou, Chi-Ming Che
      Abstract: Cobalt(II)-porphyrin catalyzed intramolecular Buchner reaction and arene cyclopropanation of alkyl diazomethanes in situ generated from N-tosylhydrazones to give a range of bicyclic cycloheptatriene fused pyrrolidines and tetracyclic cyclopropane fused pyrrolidines in good to high yields and with high chemo- and regio-selectivity. The obtained cyclopropane fused pyrrolidines can be readily converted to other N-heterocycles with potential synthetic and biological interests.
      PubDate: 2017-04-28T23:37:23.371198-05:
      DOI: 10.1002/adsc.201700205
       
  • Iodine(III)-Promoted Ring Contractive Cyanation of Exocyclic β-Enaminones
           for the Synthesis of Cyanocyclopentanones
    • Authors: Dhananjay Bhattacherjee; Vandna Thakur, Saurabh Sharma, Sandeep Kumar, Richa Bharti, C. Bal Reddy, Pralay Das
      Abstract: A highly efficient hypervalent iodine-promoted regiocontrolled ring contractive cyanation (RCC) reaction of exocyclic β-enaminones for the synthesis of cyanocyclopentanone (CCP) was demonstrated at ambient temperature with a wide substrate scope. The methodology offers a facile technique to construct an amino carbonitrile-containing quaternary stereocenter at the α-position of cyclopentanone in good yields. The sequence of substrate addition that can facilitate the reaction to follow different pathways (free radical/non-radical) to afford the same final product was critically investigated.
      PubDate: 2017-04-28T02:51:21.643414-05:
      DOI: 10.1002/adsc.201601208
       
  • 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
       
  • Intermolecular Halogenation/Esterification of Alkenes with
           N–Halosuccinimide and Acetic Acid Catalyzed by DABCO
    • Authors: Laura S. Pimenta; Elena Gusevskaya, Eduardo Alberto
      Abstract: DABCO (1,4-diazabicyclo[2.2.2]octane) is a suitable Lewis base that acts as an organocatalyst in the activation of N–chlorosuccinimide (NCS) towards chlorination of alkenes. The chloriranium ion formed from NCS and the alkene, can be intermolecularly opened by a nucleophile, such as acetic acid, to produce highly functionalized trans-chloroesters in high yields. The protocol is also applied to the synthesis of chlorohydrins and chloroethers using water or methanol as nucleophiles instead of acetic acid. Brominated analogs can also be synthesized from alkenes and N–bromosuccinimide (NBS) in the presence of various basic catalysts. However, the reaction pattern seems to be remarkably different. The catalytic performance of bases in the bromoesterification of alkenes was found to be strongly affected by their Brønsted-basicity, suggesting that acetyl hypobromite, formed in situ from NBS and acetic acid, acts as a real brominating agent in these systems.
      PubDate: 2017-04-26T21:20:41.454427-05:
      DOI: 10.1002/adsc.201700117
       
  • Organocatalytic enantioselective synthesis of 1,4-dihydropyridines
    • Authors: Fernando Auria-Luna; Eugenia Marqués-López, Raquel Herrera
      Abstract: This review aims to bring light upon a very interesting group of compounds, the 1,4-dihydropyridines (1,4-DHPs). These structures are well-known pharmacophores, used for many years to treat cardiovascular diseases because of their activity as calcium channel blockers. In addition, their potential as drugs to treat other affections has been recently exposed. The racemic synthesis of 1,4-DHPs has been well studied, while the asymmetric approaches are mainly based on the use of chiral auxiliaries or chiral resolutions. However, there are scarce examples regarding enantioselective organocatalytic methods. Herein, we will summarize the existing examples in this field of research.
      PubDate: 2017-04-26T21:20:34.415043-05:
      DOI: 10.1002/adsc.201700300
       
  • 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
       
  • Omniligase-1: A Powerful Tool for Peptide Head-to-Tail Cyclization
    • Authors: Marcel Schmidt; Ana Toplak, Peter Quaedflieg, Hans Ippel, Gaston J.J. Richelle, Tilman M. Hackeng, Jan H. van Maarseveen, Timo Nuijens
      Abstract: Strategies for the efficient synthesis of peptide macrocycles have been a long-standing goal. In this paper, we demonstrate the use of the peptide ligase termed omniligase-1 as a versatile and broadly applicable enzymatic tool for peptide cyclization. Several head-to-tail (multi)cyclic peptides have been synthesized, including the cyclotide MCoTI-II. Cyclization and oxidative folding of the cyclotide MCoTI-II was efficiently performed in a one-pot reaction on 1 gram scale. The native cyclotide was isolated and the correct disulfide bonding pattern was confirmed by NMR structure determination. Furthermore, compatibility of chemo-enzymatic peptide synthesis (CEPS) using omniligase-1 with methods such as chemical ligation of peptides onto scaffolds (CLIPS) and was successfully demonstrated by synthesizing a kinase-inhibitor derived tricyclic peptide. Our studies indicate that the minimal ring size for omniligase-1 mediated cyclization is 11 amino acids, whereas the cyclization of peptides longer than 12 amino acids proceeds with remarkable efficiency. In addition, several macrocycles containing non-peptidic backbones (e.g. polyethylene glycol), isopeptide bonds (amino acid side-chain attachment) as well as D-amino acids could be efficiently cyclized.
      PubDate: 2017-04-21T23:36:14.088307-05:
      DOI: 10.1002/adsc.201700314
       
  • Bichromatic Photosynthesis of Coumarins by UV Filter Enabled Olefin
           Metathesis
    • 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
       
  • Chemo- and Stereoselective Cytochrome P450-BM3 Catalyzed Sulfoxidation of
           1-Thiochroman-4-ones Enabled by Directed Evolution
    • Authors: Jian-bo Wang; Adriana Ilie, Manfred Reetz
      Abstract: Directed evolution utilizing an unconventional approach to saturation mutagenesis has been applied to cytochrome P450-BM3 as a catalyst in the asymmetric sulfoxidation of 1-thiochroman-4-one and two derivatives thereof with complete chemoselectivity as well as (S)- and (R)-selectivity on an optional basis. Whereas wildtype P450-BM3 shows in the case of the parent compound poor enantioselectivity in slight favor of the (S)-sulfoxide (er = 75 : 25), (S)-selectivity was enhanced to er = 93 : 7, while reversal of enantioselectivity favoring the (R)-sulfoxide was also achieved (er = 7 : 93). Two derivatives of the parent substrate underwent similar stereoselective sulfoxidation reactions. Sulfoxides of this type are of potential pharmaceutical interest. This biocatalytic approach nicely complements synthetic methods.
      PubDate: 2017-04-21T23:30:35.059827-05:
      DOI: 10.1002/adsc.201700414
       
  • Synthesis and Cytotoxic Evaluation of N-Aroylureas through
           Rhodium(III)-Catalyzed C−H Functionalization of Indolines with
           Isocyanates
    • Authors: Taejoo Jeong; Suk Hun Lee, Neeraj Kumar Mishra, Umasankar De, Jihye Park, Prasanta Dey, Jong Hwan Kwak, Young Hoon Jung, Hyung Sik Kim, In Su Kim
      Abstract: The rhodium(III)-catalyzed C−H amidation and subsequent C−N bond formation reaction of indolines with aryl and alkyl isocyanates at room temperature are reported. These transformations allow the generation of N-aroylurea functionality at the C7-position of indolines, which is known as a crucial scaffold found in biologically active molecules. In addition, the synthesis of pyrroloindolidione derivatives is also described through sequential C6-amidation reaction and intramolecular cyclization of C7-amidated indolines. All synthesized products were evaluated for in vitro cytotoxic effect against human prostate adenocarcinoma cells (DU145), human breast cancer cells (MCF-7), and triple negative human breast cancer cells (MDA-MB-231), respectively. Notably, compounds 4d and 4e with linear alkyl side chains were found to be highly cytotoxic, which is comparable to that of anticancer doxorubicin and cisplatin as positive controls.
      PubDate: 2017-04-21T05:30:51.780498-05:
      DOI: 10.1002/adsc.201700311
       
  • 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
       
  • Combining Cu-Catalyzed Hydroboration with Pd-Catalyzed Suzuki Coupling for
           the One-pot Synthesis of Arylallylamines under Micellar Conditions
    • Authors: Pedro Horn; Roger Braun, Victória Isoppo, Jessie da Costa, Diogo Lüdtke, Angélica Moro
      Abstract: Herein we report the one-pot dual-metal catalytic synthesis of arylallylamines, by combination of a Cu-catalyzed hydroboration with a Pd-catalyzed Suzuki arylation, using a broad range of aryl halides. Importantly, the reaction sequence was entirely performed in water, in the presence of small amounts of SPGS-550M, without the need of solvent switch or addition of organic co-solvents, rendering it operationally simple and environmentally benign. The usefulness of this methodology was highlighted in a short synthesis of the pharmaceutically important compound naftifine.
      PubDate: 2017-04-20T06:32:52.015358-05:
      DOI: 10.1002/adsc.201700094
       
  • 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
           Temperature
    • 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
           Derivatives
    • 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
       
  • Pd/P-doped Porous Organic Polymer as Recyclable Chemoselective and Highly
           Efficient Hydrogenation Catalysts under Ambient Conditions
    • Authors: Zong-Cang Ding; Cun-Yao Li, Jun-Jia Chen, Jia-Hao Zeng, Hai-Tao Tang, Yun-Jie Ding, zhuang-ping zhan
      Abstract: A new type of phosphorus-doped porous organic polymer (POP) has been readily synthesized through Heck reaction, which could be used not only as a support but also a ligand for Pd nanoparticles. The dual-functional material supported Pd nanocatalyst was used for highly efficient and chemoselective hydrogenation of varieties of nitroarenes and α,β-unsaturated compounds, as well as the synthesis of indoles from 2-nitrophenylacetonitrile under 1 atm H2 in green solvents at room temperature. No obvious aggregation and loss of catalytic activity of the new nanocatalyst were observed after 10 times in the reaction.
      PubDate: 2017-04-19T21:34:48.809021-05:
      DOI: 10.1002/adsc.201700374
       
  • 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
       
  • NAD(P)H-Dependent Dehydrogenases for the Asymmetric Reductive Amination of
           Ketones: Structure, Mechanism, Evolution and Application
    • Authors: Mahima Sharma; Juan Mangas-Sanchez, Gideon Grogan
      Abstract: . Asymmetric reductive aminations are some of the most important reactions in the preparation of active pharmaceuticals, as chiral amines feature in many of the world’s most important drugs. Although many enzymes have been applied to the synthesis of chiral amines, the development of reductive amination reactions that use enzymes is attractive, as it would permit the one-step transformation of readily available prochiral ketones into chiral amines of high optical purity. However, as most natural 'reductive aminase' activities operate on keto acids, and many are able to use only ammonia as the amine donor, there is considerable scope for the engineering of natural enzymes for the reductive amination of ketones, and also for the preparation of secondary amines using alkylamines as donors. This review summarises research into the development of NAD(P)H-dependent dehydrogenases for the reductive amination of ketones, including amino acid dehydrogenases (AADHs), natural amine dehydrogenases (AmDHs), opine dehydrogenases (OpDHs) and imine reductases (IREDs). In each case knowledge of the structure and mechanism of the enzyme class is suumarised, with a further description of the engineering of those enzymes for the reductive amination of ketones towards primary and also secondary amine products.
      PubDate: 2017-04-19T03:04:04.669848-05:
      DOI: 10.1002/adsc.201700356
       
  • 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
       
  • Direct Olefination of Fluorinated Quinoxalines via Cross-Dehydrogenative
           Coupling Reactions: A New NIR Probe for Mitochondria
    • Authors: Zeyuan Zhang; yiwen Zheng, Zuobang Sun, Zhen Dai, Ziqiang Tang, Jiangshang Ma, Chen Ma
      Abstract: A large library 5,8-distyrylquinoxaline fluorophores were obtained in good-to-excellent yields via the palladium-catalyzed oxidative C-H/C-H cross-coupling of electron-deficient fluorinated quinoxalines with electron-rich styrenes. The resulting fluorophores, named Qu-Fluors, exhibit tunable color emissions with quantum yields up to 83% and large Stokes shifts up to 6236 cm−1 in CH2Cl2. The bioimaging performance of Qu-Fluors is shown to have potential as NIR fluorescent probes for Mitochondria.
      PubDate: 2017-04-18T01:21:10.262675-05:
      DOI: 10.1002/adsc.201700237
       
  • Iridium-Catalyzed Intramolecular C-H Silylation of Silicon-Tethered Arene
           and Hydrosilane: Facile and Catalytic Synthesis of Cyclic Siloxanes
    • Authors: Yan Lin; Ke-Zhi Jiang, jian cao, Zhan-Jiang Zheng, Zheng Xu, yuming cui, Li-Wen Xu
      Abstract: Catalytic C-H silylation is an increasingly important topic in the field of organosilicon chemistry and homogenous catalysis as well as organic synthesis, but its synthesis and transformation is usually challenging and often incompatibility with some functional groups. In this manuscript, a new type of silanol-directed intramolecular dehydrogenative silylation under iridium catalysis has been developed. The described silylative cyclization had good functional group compatibility, providing a general and efficient route to unsymmetric cyclic siloxanes with multiple potentially modifiable silicon atoms in high site-selectivities. The resulting organosilicon compounds exhibited diverse synthetic applications owing to their unique structures.
      PubDate: 2017-04-13T21:25:38.326421-05:
      DOI: 10.1002/adsc.201700160
       
  • Metal Substitution Modulates the Reactivity and Extends the Reaction Scope
           of Myoglobin Carbene Transfer Catalysts
    • Authors: Rudi Fasan; Gopeekrishnan Sreenilayam, Eric Moore, Viktoria Steck
      Abstract: Engineered myoglobins have recently emerged as promising scaffolds for catalyzing carbene-mediated transformations. In this work, we investigated the effect of altering the metal center and its first-sphere coordination environment on the carbene transfer reactivity of myoglobin. To this end, we first established an efficient protocol for the recombinant expression of myoglobin variants incorporating metalloporphyrins with non-native metals, including second- and third-row transition metals (ruthenium, rhodium, iridium). Characterization of the cofactor-substituted Mb variants across three different carbene transfer reactions (cyclopropanation, N‒H insertion, S‒H insertion) revealed a major influence of the nature of metal center, its oxidation state and first-sphere coordination environment on the catalytic activity, stereoselectivity, and/or oxygen tolerance of these artificial metalloenzymes. In addition, myoglobin variants incorporating manganese- or cobalt-porphyrins were found capable of catalyzing an intermolecular carbene C‒H insertion reaction involving phthalan and ethyl alpha-diazoacetate, a reaction not supported by iron-based myoglobins and previously accessed only using iridium-based (bio)catalysts. These studies demonstrate how modification of the metalloporphyrin cofactor environment provides a viable and promising strategy to enhance the catalytic properties and extend the reaction scope of myoglobin-based carbene transfer catalysts.
      PubDate: 2017-04-12T22:18:43.513358-05:
      DOI: 10.1002/adsc.201700202
       
  • Nickel-Catalyzed Sulfonylation of C(sp2)–H Bonds with Sodium
           Sulfinates
    • Authors: Shuang-Liang Liu; Xue-Hong Li, Shu-Sheng Zhang, Sheng-Kai Hou, Guang-Chao Yang, Jun-Fang Gong
      Abstract: The first Ni-catalyzed ortho-sulfonylation of C(sp2)–H bonds with sodium sulfinates directed by (pyridin-2-yl)isopropylamine (PIP-amine) is described. This strategy exhibits a broad substrate scope and good functional group tolerance with high monosulfonylation selectivity. Besides arenes and heteroarenes, the reaction can also be extended to alkenes, providing diverse diaryl and alkyl-aryl sulfones in high yields. Furthermore, a plausible Ni(I)/Ni(III) mechanism is outlined based on our experimental results and related precedents.
      PubDate: 2017-04-10T21:24:52.777198-05:
      DOI: 10.1002/adsc.201700290
       
  • Organocatalysis and Biocatalysis Hand in Hand: Combining Catalysts in
           One-pot Procedures
    • Authors: Fabricio bisogno; Martín Guillermo López-Vidal, Gonzalo de Gonzalo
      Abstract: Nature has developed multi-step processes catalysed by several catalysts working concurrently, thus improving reaction efficiency. The quest for novel and improved catalytic systems has led to the development of biocatalytic and later to organocatalytic procedures as very valuable tools in asymmetric synthesis while using mild reaction conditions in absence of metal catalysts. As a timeless challenge, chemists are facing the need for process designs in which different sort of catalysts can operate successfully in one-pot concurrent fashion.Likewise, such designs bring about the best of each catalyst and, in certain cases, enable to improve problematic issues, such as reactivity, selectivity, solubility, inhibition, etc. Specifically, to combine these two types of catalysts in one-pot, achieving high yields and selectivity, is a fascinating edge of catalysis. This review covers representative advances in this field, in particular those in which biocatalysts and organocatalysts are employed either in sequential reactions or in simultaneous processes.
      PubDate: 2017-04-06T21:20:34.322555-05:
      DOI: 10.1002/adsc.201700158
       
  • Application of dehydroabietic acid in palladium-catalysed enyne
           cycloisomerisation
    • 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
           Process
    • 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
       
  • Exploring the Catalytic Promiscuity of Phenolic Acid Decarboxylases:
           Asymmetric, 1,6-Conjugate Addition of Nucleophiles Across 4-Hydroxystyrene
           
    • Authors: Stefan Payer; Xiang Sheng, Hannah Pollak, Christiane Wuensch, Georg Steinkellner, Fahmi Himo, Silvia Glueck, Kurt Faber
      Abstract: . The catalytic promiscuity of a ferulic acid decarboxylase from Enterobacter sp. (FDC_Es) and phenolic acid decarboxylases (PADs) for the asymmetric conjugate addition of water across the C=C bond of hydroxystyrenes was extended to N-, C- and S-nucleophiles methoxyamine, cyanide and propanethiol to furnish the corresponding addition products in up to 91% e.e.The products obtained from the biotransformation employing the most suitable enzyme / nucleophile pairs were isolated and characterized after optimizing the reaction conditions. Finally, a mechanistic rationale supported by quantum mechanical calculations for the highly (S)-selective addition of cyanide is proposed.
      PubDate: 2017-04-03T21:21:49.464084-05:
      DOI: 10.1002/adsc.201700247
       
  • 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 optimal catalytic system for the construction of ortho-alkylated azobenzenes, which smoothly underwent the intramolecular cyclization leading to the formation of C3-functionalized oxindole using zinc powder and acetic acid. The formed oxindolic scaffold can be an important asset towards the development of novel bioactive compounds.
      PubDate: 2017-04-02T21:21:20.61402-05:0
      DOI: 10.1002/adsc.201700147
       
  • One-pot Three-component Synthesis of Alkyl/Arylthioether-Substituted
           Imidazo[1,2-α]pyridine Derivatives via C(sp2)-H Functionalization
    • Authors: Wenhui Zhu; Yingcai Ding, Zhaogang Bian, Ping Xie, Baojun Xu, Qiujie Tang, Wei Wu, Aihua Zhou
      Abstract: Sulfenylation is an important transformation to generate C-S bonds in organic synthesis. Here, two three-component synthetic protocols were developed for using imidazo[1,2-α]pyridine,inorganic, odorless S8 and alcohols or arylboronic acid as reactants to make alkyl/aryl-S-substituted imidazo[1,2-α]pyridine derivatives via C(sp2)-H functionalization. The reactions proceeded with high efficiency and broad functional group tolerance, affording regioselective products in good yields.
      PubDate: 2017-04-02T21:21:13.061797-05:
      DOI: 10.1002/adsc.201601431
       
  • Visible-Light Photocatalytic Bicyclization of 1,7-Enynes toward
           Functionalized Sulfone-Containing Benzo[a]fluoren-5-ones
    • Authors: Bo Jiang; Min-Hua Huang, Yi-Long Zhu, Wen-Juan Hao, Ai-Fang Wang, De-Cai Wang, Feng Liu, Ping Wei, Shu-Jiang Tu
      Abstract: A new visible-light photocatalytic arylsulfonylation and bicyclizations of C(sp3)-tethered 1,7-enynes with sulfinic acids has been developed, delivering functionalized sulfone-containing benzo[a]fluoren-5-ones with generally good yields. This Eosin Y-catalyzed approach makes use of visible light as a safe and eco-friendly energy source to drive cascade cyclization reactions, resulting in continuous multiple bond-forming events including C−S and C−C bonds to efficiently construct polycyclic-linked alkyl arylsulfone.
      PubDate: 2017-04-01T04:25:23.573728-05:
      DOI: 10.1002/adsc.201700124
       
  • Incorporation of Carbon Dioxide into Carbamate Directing Groups:
           Palladium-Catalyzed meta-C–H Olefination and Acetoxylation of Aniline
           Derivatives
    • Authors: Long Yang; Lei Fu, Gang Li
      Abstract: Carbon dioxide (CO2), a readily available, nontoxic, and inexpensive greenhouse gas, is an ideal reagent for carbamate synthesis. For the first time, CO2 has been efficiently incorporated into a novel nitrile-containing directing group (DG) for meta-C–H activation of anilines under mild conditions. Thus, a variety of aniline derivatives were meta-olefinated with palladium(II) acetate. meta-C–H acetoxylation was also feasible and the carbamate DG could be easily removed under basic conditions. The practicality of substrate preparation, functional group tolerance, and versatility of this method make it a valuable addition to meta-C–H functionalization of anilines.
      PubDate: 2017-03-31T23:25:39.741368-05:
      DOI: 10.1002/adsc.201700261
       
  • Lewis Acid-Catalyzed C(sp3)-C(sp3) Bond Forming Cyclization Reactions for
           Synthesis of Tetrahydroprotoberberine Derivatives
    • Authors: Jianjun Li; Cong Qin, Yang Yu, Huaqiang Fan, Yiwei Fu, Hao Li, Wei Wang
      Abstract: An efficient Lewis acid-catalyzed C(sp3)-C(sp3) bond forming annulation reaction has been developed. This strategy serves as a new method for the facile synthesis of tetrahydro-5H-isoquinolino[2,1-g][1,6]naphthyridine derivatives. A wide range of 2-methylquinoline-3-carbaldehydes and 1,2,3,4-tetrahydroisoquinolines can be applied for this process to afford structurally diverse tetrahydroprotoberberine derivatives in excellent yields.
      PubDate: 2017-03-25T01:05:34.412644-05:
      DOI: 10.1002/adsc.201601423
       
 
 
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