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Publisher: John Wiley and Sons   (Total: 1589 journals)

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Showing 1 - 200 of 1589 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: 65, SJR: 1.385, h-index: 91)
Accounting & Finance     Hybrid Journal   (Followers: 48, SJR: 0.547, h-index: 30)
ACEP NOW     Free   (Followers: 1)
Acta Anaesthesiologica Scandinavica     Hybrid Journal   (Followers: 53, SJR: 1.02, h-index: 88)
Acta Archaeologica     Hybrid Journal   (Followers: 168, 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: 6, SJR: 0.112, h-index: 1)
Acta Paediatrica     Hybrid Journal   (Followers: 56, SJR: 0.794, h-index: 88)
Acta Physiologica     Hybrid Journal   (Followers: 6, SJR: 1.69, h-index: 88)
Acta Polymerica     Hybrid Journal   (Followers: 9)
Acta Psychiatrica Scandinavica     Hybrid Journal   (Followers: 37, SJR: 2.518, h-index: 113)
Acta Zoologica     Hybrid Journal   (Followers: 7, SJR: 0.459, h-index: 29)
Acute Medicine & Surgery     Hybrid Journal   (Followers: 5)
Addiction     Hybrid Journal   (Followers: 36, SJR: 2.086, h-index: 143)
Addiction Biology     Hybrid Journal   (Followers: 14, SJR: 2.091, h-index: 57)
Adultspan J.     Hybrid Journal   (SJR: 0.127, h-index: 4)
Advanced Energy Materials     Hybrid Journal   (Followers: 26, SJR: 6.411, h-index: 86)
Advanced Engineering Materials     Hybrid Journal   (Followers: 26, SJR: 0.81, h-index: 81)
Advanced Functional Materials     Hybrid Journal   (Followers: 51, SJR: 5.21, h-index: 203)
Advanced Healthcare Materials     Hybrid Journal   (Followers: 14, SJR: 0.232, h-index: 7)
Advanced Materials     Hybrid Journal   (Followers: 295, 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: 7, SJR: 2.488, h-index: 21)
Advanced Science     Open Access   (Followers: 5)
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: 21)
Africa Research Bulletin: Economic, Financial and Technical Series     Hybrid Journal   (Followers: 13)
Africa Research Bulletin: Political, Social and Cultural Series     Hybrid Journal   (Followers: 11)
African Development Review     Hybrid Journal   (Followers: 33, SJR: 0.275, h-index: 17)
African J. of Ecology     Hybrid Journal   (Followers: 16, SJR: 0.477, h-index: 39)
Aggressive Behavior     Hybrid Journal   (Followers: 15, SJR: 1.391, h-index: 66)
Aging Cell     Open Access   (Followers: 11, SJR: 4.374, h-index: 95)
Agribusiness : an Intl. J.     Hybrid Journal   (Followers: 3, SJR: 0.627, h-index: 14)
Agricultural and Forest Entomology     Hybrid Journal   (Followers: 16, SJR: 0.925, h-index: 43)
Agricultural Economics     Hybrid Journal   (Followers: 45, SJR: 1.099, h-index: 51)
AIChE J.     Hybrid Journal   (Followers: 32, 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: 33, SJR: 2.833, h-index: 138)
Alimentary Pharmacology & Therapeutics Symposium Series     Hybrid Journal   (Followers: 3)
Allergy     Hybrid Journal   (Followers: 51, SJR: 3.048, h-index: 129)
Alternatives to the High Cost of Litigation     Hybrid Journal   (Followers: 3)
American Anthropologist     Hybrid Journal   (Followers: 152, 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: 93, SJR: 2.325, h-index: 51)
American J. of Economics and Sociology     Hybrid Journal   (Followers: 29, SJR: 0.211, h-index: 26)
American J. of Hematology     Hybrid Journal   (Followers: 35, SJR: 1.761, h-index: 77)
American J. of Human Biology     Hybrid Journal   (Followers: 13, 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: 16, SJR: 1.115, h-index: 61)
American J. of Medical Genetics Part B: Neuropsychiatric Genetics     Hybrid Journal   (Followers: 4, SJR: 1.771, h-index: 107)
American J. of Medical Genetics Part C: Seminars in Medical Genetics     Partially Free   (Followers: 6, SJR: 2.315, h-index: 79)
American J. of Physical Anthropology     Hybrid Journal   (Followers: 37, SJR: 1.41, h-index: 88)
American J. of Political Science     Hybrid Journal   (Followers: 290, SJR: 5.101, h-index: 114)
American J. of Primatology     Hybrid Journal   (Followers: 16, 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: 18, SJR: 2.792, h-index: 140)
American J. on Addictions     Hybrid Journal   (Followers: 9, SJR: 0.843, h-index: 57)
Anaesthesia     Hybrid Journal   (Followers: 138, SJR: 1.404, h-index: 88)
Analyses of Social Issues and Public Policy     Hybrid Journal   (Followers: 9, SJR: 0.397, h-index: 18)
Analytic Philosophy     Hybrid Journal   (Followers: 20)
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: 179)
Angewandte Chemie Intl. Edition     Hybrid Journal   (Followers: 229, SJR: 6.229, h-index: 397)
Animal Conservation     Hybrid Journal   (Followers: 41, 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: 7, 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: 48, SJR: 5.584, h-index: 241)
Annals of Noninvasive Electrocardiology     Hybrid Journal   (Followers: 1, SJR: 0.531, h-index: 38)
Annals of Public and Cooperative Economics     Hybrid Journal   (Followers: 8, 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: 13)
Annual Review of Information Science and Technology     Hybrid Journal   (Followers: 14)
Anthropology & Education Quarterly     Hybrid Journal   (Followers: 25, SJR: 0.72, h-index: 31)
Anthropology & Humanism     Hybrid Journal   (Followers: 17, SJR: 0.137, h-index: 3)
Anthropology News     Hybrid Journal   (Followers: 15)
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: 91, SJR: 0.545, h-index: 15)
Antipode     Hybrid Journal   (Followers: 50, SJR: 2.212, h-index: 69)
Anz J. of Surgery     Hybrid Journal   (Followers: 8, 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: 70, SJR: 0.754, h-index: 69)
Applied Organometallic Chemistry     Hybrid Journal   (Followers: 7, SJR: 0.632, h-index: 58)
Applied Psychology     Hybrid Journal   (Followers: 209, SJR: 1.023, h-index: 64)
Applied Psychology: Health and Well-Being     Hybrid Journal   (Followers: 50, 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: 14, SJR: 1.025, h-index: 55)
Aquaculture Research     Hybrid Journal   (Followers: 32, SJR: 0.807, h-index: 60)
Aquatic Conservation Marine and Freshwater Ecosystems     Hybrid Journal   (Followers: 36, 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: 29, SJR: 0.809, h-index: 48)
Archeological Papers of The American Anthropological Association     Hybrid Journal   (Followers: 15, SJR: 0.156, h-index: 2)
Architectural Design     Hybrid Journal   (Followers: 26, SJR: 0.261, h-index: 9)
Archiv der Pharmazie     Hybrid Journal   (Followers: 3, SJR: 0.628, h-index: 43)
Archives of Drug Information     Hybrid Journal   (Followers: 5)
Archives of Insect Biochemistry and Physiology     Hybrid Journal   (SJR: 0.768, h-index: 54)
Area     Hybrid Journal   (Followers: 13, SJR: 0.938, h-index: 57)
Art History     Hybrid Journal   (Followers: 274, SJR: 0.153, h-index: 13)
Arthritis & Rheumatology     Hybrid Journal   (Followers: 54, SJR: 1.984, h-index: 20)
Arthritis Care & Research     Hybrid Journal   (Followers: 27, 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: 15)
Asia & the Pacific Policy Studies     Open Access   (Followers: 16)
Asia Pacific J. of Human Resources     Hybrid Journal   (Followers: 326, SJR: 0.494, h-index: 19)
Asia Pacific Viewpoint     Hybrid Journal   (Followers: 1, SJR: 0.616, h-index: 26)
Asia-Pacific J. of Chemical Engineering     Hybrid Journal   (Followers: 8, 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: 4, 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: 4, 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   (Followers: 1, SJR: 0.394, h-index: 7)
Asian J. of Organic Chemistry     Hybrid Journal   (Followers: 6, 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: 12, 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: 3, SJR: 0.701, h-index: 40)
Atmospheric Science Letters     Open Access   (Followers: 29, SJR: 1.332, h-index: 27)
Austral Ecology     Hybrid Journal   (Followers: 15, SJR: 1.095, h-index: 66)
Austral Entomology     Hybrid Journal   (Followers: 9, 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: 6, SJR: 0.39, h-index: 22)
Australian & New Zealand J. of Statistics     Hybrid Journal   (Followers: 14, SJR: 0.275, h-index: 28)
Australian Accounting Review     Hybrid Journal   (Followers: 3, 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: 47, 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: 6, SJR: 0.171, h-index: 12)
Australian Economic Papers     Hybrid Journal   (Followers: 31, 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: 15, SJR: 0.203, h-index: 14)
Australian J. of Psychology     Hybrid Journal   (Followers: 18, SJR: 0.384, h-index: 30)
Australian J. of Public Administration     Hybrid Journal   (Followers: 419, SJR: 0.418, h-index: 29)
Australian J. of Rural Health     Hybrid Journal   (Followers: 5, SJR: 0.43, h-index: 34)
Australian Occupational Therapy J.     Hybrid Journal   (Followers: 72, SJR: 0.59, h-index: 29)
Australian Psychologist     Hybrid Journal   (Followers: 12, SJR: 0.331, h-index: 31)
Australian Veterinary J.     Hybrid Journal   (Followers: 23, SJR: 0.459, h-index: 45)
Autism Research     Hybrid Journal   (Followers: 36, 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: 11, 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: 5, 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: 9, SJR: 0.297, h-index: 23)
Behavioral Sciences & the Law     Hybrid Journal   (Followers: 24, SJR: 0.736, h-index: 57)
Berichte Zur Wissenschaftsgeschichte     Hybrid Journal   (Followers: 10, 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: 16, SJR: 1.172, h-index: 90)
Biological Reviews     Hybrid Journal   (Followers: 5, SJR: 6.469, h-index: 114)
Biologie in Unserer Zeit (Biuz)     Hybrid Journal   (Followers: 41, 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: 37, 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: 44, SJR: 0.415, h-index: 55)
Biotechnology and Bioengineering     Hybrid Journal   (Followers: 152, SJR: 1.633, h-index: 146)
Biotechnology J.     Hybrid Journal   (Followers: 14, SJR: 1.185, h-index: 51)
Biotechnology Progress     Hybrid Journal   (Followers: 39, SJR: 0.736, h-index: 101)
Biotropica     Hybrid Journal   (Followers: 20, SJR: 1.374, h-index: 71)
Bipolar Disorders     Hybrid Journal   (Followers: 9, SJR: 2.592, h-index: 100)
Birth     Hybrid Journal   (Followers: 38, 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: 7, SJR: 0.468, h-index: 47)
Birth Defects Research Part C : Embryo Today : Reviews     Hybrid Journal   (SJR: 1.513, h-index: 55)
BJOG : An Intl. J. of Obstetrics and Gynaecology     Partially Free   (Followers: 247, SJR: 2.083, h-index: 125)

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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  [1589 journals]
  • Visible Light Activated Radical Denitrative Benzoylation of
           β-Nitrostyrenes: A Photocatalytic Approach to Chalcones
    • Authors: Shubhangi Tripathi; Ritu Kapoor, Lal Dhar Yadav
      Abstract: A metal-free, convenient photocatalytic approach to chalcones from β-nitrostyrenes and benzaldehydes via a radical denitrative benzoylation pathway is reported. The salient features of the protocol include the utilization of visible light as an inexpensive and ecosustainable energy source, N-hydroxyphthalimide (NHPI) as a reusable organophotocatalyst and acetonitrile as an acceptable green solvent to afford chalcones in excellent yields at room temperature in a one-pot procedure. Notably, this is the first application of β-nitrostyrenes as readily available substrates for chalcone synthesis and the first example of photocatalysis in this field.
      PubDate: 2018-01-19T01:00:52.516656-05:
      DOI: 10.1002/adsc.201701559
       
  • I2-Triggered Reductive Generation of N-Centered Iminyl Radicals: An
           Isatin-to-Quinoline Strategy for the Introduction of Primary Amides
    • Authors: Qinghe Gao; Zhao-Min Liu, Yakun Wang, Xia Wu, Jixia Zhang, Anxin Wu
      Abstract: An efficient and alternative isatin-to-quinoline strategy illustrates the metal-like behavior of molecular iodine in the N-O reduction of ketoxime acetates. This process involves N-O/C-N bond cleavages and C-C/C-N bond formation to furnish pharmacologically significant quinoline-4-carboxamide derivatives. In this process, metal catalysts and extra oxidants are unnecessary. Mechanistic studies confirm the crucial role of molecular iodine in the iminyl radical generation process, in that molecular iodine can catalyze single-electron reduction coupling reactions in a manner similar to transition metals.
      PubDate: 2018-01-19T01:00:49.161099-05:
      DOI: 10.1002/adsc.201701610
       
  • Carboxyl-Directed Conjugate Addition of C‒H Bonds to α,ß-Unsaturated
           Ketones in Air and Water
    • Authors: Wen-jing Han; Fan Pu, Chao-Jun Li, Zhong-Wen Liu, Juan Fan, Xian-Ying Shi
      Abstract: A simple ruthenium-catalyzed conjugate addition of C‒H bonds to α,ß-unsaturated ketones directed by a removable carboxyl group was developed as an effective protocol to synthesize ortho-alkylated benzoic acids in a greener manner. Without any additives, satisfactory to excellent yields of the targeted products were achieved in neat water, and the process characterizes in mild reaction conditions (in air and water), simple operations, and broad substrate scope. Noteworthy features of this method include mild reaction conditions (in air and water), operational simplicity and broad substrate scope. The versatility and utility of the addition products were demonstrated through further transformation into commonly inaccessible but highly useful motifs of meta-substituted alkylbenzenes and 3-substituted isochromanones.
      PubDate: 2018-01-19T01:00:45.023258-05:
      DOI: 10.1002/adsc.201701468
       
  • Conversion of Primary Amines to Symmetrical Secondary and Tertiary Amines
           using a Co-Rh Heterobimetallic Nanocatalyst
    • Authors: Hyunho Chung; Seulgi Han, Ji Hoon Park, Young Keun Chung
      Abstract: Symmetrical tertiary amines have been efficiently realized from amine and secondary amines via deaminated homocoupling with heterogeneous bimetallic Co2Rh2/C as catalyst (molar ratio Co:Rh = 2:2). Unsymmetric secondary anilines were produced from the reaction of anilines with symmetric tertiary amines. The Co2Rh2/C catalyst exhibited very high catalytic activity towards a wide range of amines and could be conveniently recycled ten times without considerable leaching.
      PubDate: 2018-01-19T01:00:39.263516-05:
      DOI: 10.1002/adsc.201701522
       
  • Evaluating Gold and Selenium Chemistry for Selective Transformations of
           Lignin Model Compounds
    • Authors: Leandro Andrade; Wagner Santos, Kevin Dias, Leidaiany Santos, Camila Kisukuri, Thenner Rodrigues, Rafael Geonmonond, Pedro Camargo
      Abstract: Applications of gold and selenium chemistry are reported as novel approaches to promote lignin depolymerization into more valuable chemicals via selective oxidation reactions (alcohol oxidations and Baeyer-Villiger reactions). In this study, we proposed two different oxidative methodologies using Au/SiO2 and phenylseleninic acid resin (PAR) as stable and reusable catalysts to promote selective transformations of the β-O-4 linkage of lignin model compounds. After evaluating the catalytic systems under batch conditions, they were both applied in a packed-bed reactor for continuous flow operations. By using Au/SiO2 as a catalyst under flow conditions, ketones were efficiently obtained (up to 86% conv) from the oxidation of alcohols with a residence time (tR) of 30 min. In the case of Baeyer-Villiger oxidations catalyzed by phenylseleninic acid resin, the corresponding esters were obtained in up to 91% conv (tR = 30 min). Both systems efficiently catalyzed the conversion of the lignin model compounds.
      PubDate: 2018-01-18T01:25:47.860713-05:
      DOI: 10.1002/adsc.201701207
       
  • Chemoselective Flow Hydrogenation Approaches to Diversify the Cytotoxic
           Tetrahydroepoxyisoindole Carboxamide Scaffold
    • Authors: Lawson Spare; David Harman, Janice Aldrich-Wright, Thanh Nguyen, Christopher Gordon
      Abstract: Abstract: An Intramolecular Diels-Alder cycloaddition reaction between a furan diene and an alkynic dienophile was performed within a flow hydrogenator fitted with an inert titanium column at 150 °C, no H2, under 100 bar pressure. A single column pass (tR = 1.6 min) afforded ≈ 55% conversion to the tetrahydroepoxyisoindole carboxamide scaffold with a product turnover of ≈ 0.035 g/h, a 95% improvement over batch procedures. The cycloaddition protocol is performed in water and ethanol, does not require catalysts or other additives. Quantitative hydrogenation of the resulting dual π-bonds within the oxabicyclo system was effected with either a 10% Pd/Al2O3 or 10% Pd/CaCO3 catalyst at 20 °C, 20 bar, with full H2 whereas utilisation of a Raney Ni catalyst under these conditions resulted in a quantitative mono-olefin reduction of the C4-C5 double-bond. With regard to di-olefin reduction, a degree of stereoselectivity was observed with the aforementioned palladium-based catalysts yielding exclusive formation of (R) configuration at C7 while utilisation of a 5% Pt/C (sulfided) catalyst at temperatures below 60 °C promoted the formation of the (S)-isomer at C7. Hence this work further highlights that flow-hydrogenation provides unprecedented convenience for establishing robust protocols to effect chemoselective transformations.
      PubDate: 2018-01-18T01:25:34.787615-05:
      DOI: 10.1002/adsc.201701471
       
  • Recovery and Recycling of Chiral Iridium(N,P Ligand) Catalysts from
           Hydrogenation Reactions
    • Authors: Andreas Pfaltz; Marc-André Müller, Stefan Gruber
      Abstract: Despite the high efficiency and broad scope of chiral iridium(N,P ligand) complexes as catalysts for asymmetric hydrogenation, the problem of catalyst recovery and recycling has so far attracted little attention. We have found that at the end of a hydrogenation reaction, iridium(N,P ligand) catalysts form dimeric Ir(III) dihydride complexes, which can be converted back to the original precatalysts by addition of COD. Based on these findings, a practically simple protocol for catalyst recovery was devised. The recovered complexes showed essentially the same reactivity and enantioselectivity as the original catalysts. Especially large-scale applications and hydrogenations of less reactive substrates that require high catalyst loadings will benefit from this protocol that allows recovery and reuse of expensive iridium complexes.
      PubDate: 2018-01-17T01:26:26.827181-05:
      DOI: 10.1002/adsc.201701591
       
  • Pd-tBuONO Cocatalyzed Aerobic Indole Synthesis
    • Authors: Xiao-Shan Ning; Xin Liang, Kang-Fei Hu, Chuan-Zhi Yao, Jian-Ping Qu, Yan-Biao Kang
      Abstract: A Pd-tBuONO co-catalyzed scalable and practical synthesis of indoles with molecular oxygen as terminal oxidant is developed. Either terminal or internal 2-vinylanilines could be smoothly converted to desired indoles under one general condition. This method has been evaluated in the large scale synthesis of indomethacin and a potential anti-breast cancer drug candidate 1.
      PubDate: 2018-01-17T01:25:47.077127-05:
      DOI: 10.1002/adsc.201701512
       
  • Direct Synthesis of Primary Anilines via Nickel-mediated
           C(sp2)-H Aminations
    • Authors: Lin Yu; Xiang Cheng, Da Liu, Liang Hu, Yongqi Yu, Hang Huang, Ze Tan, Qingwen Gui
      Abstract: An efficient and mild protocol for the direct conversion of arene C–H bonds to C–NH2 without the need for extra deprotection step has been established, and to the best of our knowledge, this is the first time that the synthesis of primary anilines via nickel-mediated C(sp2)-H activations has been reported. This approach utilizes 8-aminoquinoline as the directing group and sodium azide, a cheap and commercially available material, as the nitrogen source. In addition, the reaction is highly selective, affording the mono- ortho-aminated benzamides only. The reaction tolerates a broad range of substrates with diverse functional groups and the corresponding ortho-aminated benzamides were efficiently synthesized in 41-82% yields.
      PubDate: 2018-01-17T01:25:30.852289-05:
      DOI: 10.1002/adsc.201701371
       
  • Iridium-catalyzed Asymmetric Hydrogenation of Polycyclic Heteroaromatics,
           Pyrrolo/Indolo[1,2-a]quinoxalines and Phenanthridines
    • Authors: Shu-Bo Hu; Xiao-Yong Zhai, Hong-Qiang Shen, Yong-Gui Zhou
      Abstract: Owing to the reversible dehydrogenative rearomatization of hydrogenation product and poisoning effect of nitrogen atom, asymmetric hydrogenation of polycyclic nitrogen-containing heteroaromatics is still a great challenge. Herein, through in situ protection of hydrogenation products with acetic anhydride to inhibit rearomatization and poisoning effect, a novel iridium-catalyzed enantioselective hydrogenation of polycyclic nitrogen-containing heteroaromatics, pyrrolo/indolo[1,2-a]- quinoxalines and phenanthridines, has been successfully developed, providing a facile access to chiral dihydro- pyrrolo/indolo[1,2-a]quinoxalines and dihydrophenanthri- dines with up to 98% ee.
      PubDate: 2018-01-16T01:20:49.547328-05:
      DOI: 10.1002/adsc.201701450
       
  • One-pot Synthesis of Alkynylated Coumarins via Rhodium-Catalyzed
           Annulation of Aryl Thiocarbamates with 1,3-Diynes or Terminal Alkynes
    • Authors: Yuan Gao; Fenfen Zeng, Xudong Sun, Minfeng Zeng, Zhen Yang, Xianqiang Huang, Guodong Shen, Yongsheng Tan, Ruokun Feng, Chenze Qi
      Abstract: A convenient and selective synthesis of alkynylated coumarins from various aryl thiocarbamates and 1,3-diynes or terminal alkynes via rhodium-catalyzed C-H bond activation has been developed. In this transformation, both symmetrical and asymmetrical 1,3-diynes could be applicable, obtaining various 3-alkynylated coumarins in moderate to excellent yields. When R1 is aryl group, the resulting compounds were found to exhibit intense fluorescence in the range of 412-443 nm with quantum yield of up to 0.57 in CH2Cl2. Moreover, the internal alkynes were readily converted to 1,2-dione, olefins, alkanes, and bisheterocycles under certain conditions.
      PubDate: 2018-01-16T01:20:41.431079-05:
      DOI: 10.1002/adsc.201701388
       
  • Palladium-Catalyzed Regioselective Three-Component Cascade Bisthiolation
           of Terminal Alkynes
    • Authors: Huanfeng Jiang; Jianxiao Li, Can Li, Lu Ouyang, Chunsheng Li, Shaorong Yang, Wanqing Wu
      Abstract: An efficient and novel NHC(N-heterocyclic carbene)-palladium-catalyzed three-component cascade bisthiolation of terminal alkynes, K2S (potassium sulfide) and diaryliodonium salts for the assembly of functionalized (Z)-1,2-bis(arylthio)alkene derivatives has been accomplished for the first time. This unique observation features a broad substrate scope, excellent functional-group tolerance, and high regioselectivity. Especially, an arylthiolate anion from diaryliodonium salts and potassium sulfide was proposed as the key intermediate in the catalytic cycle.
      PubDate: 2018-01-16T01:20:28.867225-05:
      DOI: 10.1002/adsc.201701417
       
  • Direct Synthesis of Sulfinamides by the Copper-Catalyzed Electrophilic
           Amidation of Sulfenate Anions
    • Authors: Junliang Zhang; Qiang Dai
      Abstract: A method for the construction of sulfinamides via the copper-catalyzed electrophilic amination of sulfenate anions using N-benzoyloxyamines as the amination reagents. This procedure featured with the capture of in-situ generated sulfenate anions from β-sulfinyl esters under mild conditions, which provides an efficient strategy for the synthesis of diverse sulfinamides in moderate to good yields.
      PubDate: 2018-01-14T21:50:57.174886-05:
      DOI: 10.1002/adsc.201701510
       
  • Inexpensive Ruthenium NNS-Complexes as efficient ester hydrogenation
           catalyst with high C=O vs. C=C selectivities
    • Authors: Bernhard Stadler; Pim Puylaert, Justus Diekamp, Richard van Heck, Yuting Fan, Anke Spannenberg, Sandra Hinze, Johannes de Vries
      Abstract: Ru(NNS)(PPh3)Cl2 (NNS = 2-(methylthio)-N-(pyridin-2-yl-methyl)ethan-1-amine) was employed in the hydrogenation of α,β-unsaturated esters, reaching selectivities for the allylic alcohol up to 95% in the hydrogenation of iso-butyl¬cinnamate. In addition, several ester substrates were hydrogenated with catalyst loadings as low as 0.05 mol%. Surprisingly, selectivity of the hydrogenation of the C=O vs the C=C bonds strongly depends on the solvent.
      PubDate: 2018-01-13T01:25:33.283102-05:
      DOI: 10.1002/adsc.201701607
       
  • Photoinduced N-methylation and N-sulfonylation of azobenzenes with DMSO
           under mild reaction conditions
    • Authors: Ning Xu; Yan Zhang, Wei Chen, Pinhua Li, Lei Wang
      Abstract: A photoinduced N-methylation and N-sulfonylation of azobenzenes with dimethyl sulfoxide (DMSO) was developed in the absence of an external photosensitizer under mild conditions. The reactions underwent smoothly to generate the corresponding products in high yields through a radical addition using the starting material azobenzene as a photosensitizer. This strategy features simple operation, easily available starting materials and DMSO acting as both methylating and sulfonylating agent.
      PubDate: 2018-01-13T01:25:27.701105-05:
      DOI: 10.1002/adsc.201701548
       
  • An efficient and practical method for the enantioselective synthesis of
           tertiary trifluoromethyl carbinols.
    • Authors: Lorenzo G. Borrego; Rocío Recio, Manuel Alcarranza, Inmaculada Fernández, Noureddine Khiar
      Abstract: An efficient sulfinamide/olefin based chiral ligand, MetSulfolefin, has been developed for the enantioselective rhodium-catalysed addition of aryl-boronic acids to trifluoromethyl ketones. This shelf stable ligand is insensitive to air, oxygen and moisture, and it is obtained in only two high yielding steps from cheap commercially available (R)-tert-butanesulfinamide. The new ligand tolerates the use of hindered boronic acids and leads to the formation of a series of chiral trifluoromethyl-substituted tertiary carbinols in high yields and excellent enantioselectivities (up to>99% ee).
      PubDate: 2018-01-12T00:21:04.356577-05:
      DOI: 10.1002/adsc.201701212
       
  • Chelation-promoted efficient C−H/N−H cross dehydrogenative coupling
           between picolinamides and simple ethers under copper catalysis
    • Authors: Qiang Yue; Zhen Xiao, Zhengkun Kuang, Zhengding Su, Qian Zhang, Dong Li
      Abstract: A highly efficient copper-catalyzed C−H/N−H cross dehydrogenative coupling between picolinamides and simple ethers was developed. The reaction was promoted by the chelation assistance of removable picolinyl group and exhibited excellent TON and TOF number. This method was applicable to both N−aryl and alkyl picolinamides as well as various cyclic and acyclic ethers with good functional group compatibility. It also possessed the merit of air and moisture tolerance and easy operation.
      PubDate: 2018-01-11T05:25:40.788431-05:
      DOI: 10.1002/adsc.201701508
       
  • A Heteroarylamine Library: Indium-Catalyzed Nucleophilic Aromatic
           Substitution of Alkoxyheteroarenes with Amines
    • Authors: Kyohei Yonekura; Yasuhiro Yoshimura, Mizuri Akehi, Teruhisa Tsuchimoto
      Abstract: Under indium Lewis acid catalysis, electron-rich five-membered heteroaryl electrophiles fused with/without a benzene ring were found to couple with amines to produce heteroarylamines with broad structural diversity. The heteroarylamine formation proceeds through the cleavage of a heteroaryl–OMe bond by the nucleophilic attack of the amine based on the nucleophilic aromatic substitution (SNAr). In contrast to the corresponding traditional SNAr amination, the present SNAr-based heteroaryl amination can be performed without relying on both heteroaryl electrophiles with electron-withdrawing groups and nucleophilicity-enhanced metal amides. High compatibility towards the functional groups such as NO2, Br, I, CF3, CN, CO2Et, pyridyl, thiazolyl, C=C, and OH groups was observed, thus showing the practicality and reliability of this method. Mechanistic studies indicated that a carbon–indium bond is likely to be formed on the heteroaryl ring during the process.
      PubDate: 2018-01-11T05:25:32.427223-05:
      DOI: 10.1002/adsc.201701452
       
  • Visible-Light-Promoted Decarboxylative Giese Reactions of α-Aryl
           Ethenylphosphonates and the Application in the Synthesis of Fosmidomycin
           Analogue
    • Authors: Ting Guo; Li Zhang, Yewen Fang, Xiaoping Jin, Yan Li, Ruifeng Li, Xie Li, Wu Cen, Xiaobo Liu, Zongming Tian
      Abstract: An unprecedented approach for the synthesis of α-aryl alkylphosphonates based on visible-light photocatalytic Giese reaction of α-aryl vinylphosphonates with aliphatic carboxylic acids has been successfully developed. This protocol tolerates a wide range of functional groups and shows broad substrate scope with regard to both the carboxylic acid and vinylphosphonate components. With sequential Giese/hydrolysis reactions as the strategy, the oxo-phosphonates could be easily accessible. The synthetic application of the hydroformylation reaction was demonstrated by the synthesis of the intermediate of α-phenyl substituted fosmidomycin analogue. Furthermore, the competitive decarboxylative alkylation of vinylphosphonate and acrylate was also investigated.
      PubDate: 2018-01-11T05:25:26.260146-05:
      DOI: 10.1002/adsc.201701285
       
  • Water-Mediated One-pot Three-Component Synthesis of Hydrazinyl-Thiazoles
           Catalyzed by Copper Oxide Nanoparticles Dispersed on Titanium Dioxide
           Support: A Green Catalytic Process
    • Authors: Trivikram Reddy Gundala; Kumar Godugu, Nallagondu Chinna Gangi Reddy
      Abstract: The present work describes the catalytic activity of copper oxide nanoparticles dispersed on titanium dioxide in water for one-pot synthesis of a library of hydrazinyl-thiazoles via a three-component reaction of various aldehydes/ketones with thiosemicarbazide and different phenacyl bromides. The structure of the synthesized compound, (E)-4-(4-bromophenyl)-2-(2-(4-methoxybenzylidene) hydrazinyl)thiazole is confirmed by single crystal X-ray diffraction studies. The catalyst prepared by a molten-salt method is characterized by X-ray diffraction, field emission scanning electron microscopy, transmission electron microscopy, energy dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, Auger electron spectroscopy and electron spin resonance spectroscopy. The noteworthy advantages of this method include its broad substrate scope, clean reaction profile, short reaction times and high yields at low catalyst loading. Further, the product does not require any chromatographic purification and the method has the potential for large-scale applications in pharmaceutical industries. In addition, the developed catalyst can be recovered and reused for 5 times without significant loss of activity. Mechanistic studies suggest that the reaction begins with the activation of the carbonyl group of both aldehyde/ketone and phenacyl bromide by copper oxide nanoparticles supported on titanium dioxide in water. These studies reveal that the reaction proceeds via the formation of thiosemicarbazone intermediate.
      PubDate: 2018-01-06T00:31:14.701737-05:
      DOI: 10.1002/adsc.201701063
       
  • Rhodium(III)-Catalyzed Selective Direct Olefination of Imidazoles
    • Authors: Lijin Xu; Haoqiang Zhao, Jianbin Xu, Changjun Chen, Xin Xu, Yixiao Pan, Zongyao Zhang, Huanrong Li
      Abstract: Rhodium(III)-catalyzed chelation-assisted highly regio- and stereoselective direct olefination of imidazoles with olefins has been developed. A broad range of C2-substituted N-(2-pyrimidyl)imidazoles underwent smooth C5-olefination with both activated and unactivated olefins to furnish the corresponding products in good to excellent yields with high tolerance of functional groups on both coupling partners in the presence of a cationic rhodium(III) catalyst. The combination of a catalytic amount of Cu(OAc)2 (copper(II) acetate) and O2 (oxygen) serves as the terminal oxidant. This protocol strongly relies on the use of 2-substituted imidazoles as the substrates, and the presence of readily installable and removable pyrimidyl directing group was found to be critical for catalysis. Mechanistic studies suggest the involvement of a five-membered rhodacycle as the key intermediate in the catalytic cycle. The method can also be extended to the coupling reaction of benzimidazoles with olefins
      PubDate: 2018-01-06T00:30:48.470942-05:
      DOI: 10.1002/adsc.201701515
       
  • Cobalt(III)–Catalyzed C–H Activation: A Secondary Amide Directed
           Decarboxylative Functionalization of Alkynyl Carboxylic Acids Wherein
           Amide NH–group Remains Unreactive
    • Authors: Nachimuthu Muniraj; Kandikere Prabhu
      Abstract: A Co(III)-catalyzed C-H activation reaction for ortho-alkenylation of benzamides (aryl/heteroaryl) and C2-alkenylation of indole derivatives have been developed using alkynyl carboxylic acid as an alkene source. A high regioselectivity has been achieved in the formation of disubstituted alkenes, and the possible cyclic products were not observed. This efficient alkenylation shows a broad range of substrate scope with a good functional group tolerance. The application of the methodology has been showcased by transforming an alkenylated amide to a 3-hydroxy isoindolinone derivative.
      PubDate: 2018-01-04T00:50:38.690975-05:
      DOI: 10.1002/adsc.201701406
       
  • Synthesis of 7-Azaindole Amidated Derivatives: An Efficient Usage of Acyl
           Azides as the Nitrogen Source
    • Authors: Lin Dong; Wei-Huan Li, Chao Li
      Abstract: The dual behaviour of acyl azides in transition-metal-catalyzed direct C−H amidation is investigated. Variously substituted acyl azides reacted smoothly with 7-azaindoles providing a diversity of C−C or C−N amidated 7-azaindole derivatives. This amidation reaction shows an excellent controllability, which is believed to be dependent on catalyst system.
      PubDate: 2018-01-03T07:10:47.742957-05:
      DOI: 10.1002/adsc.201701336
       
  • Metal-Free Azidation of α-Hydroxy Esters and α-Hydroxy Ketones
           Using Azidotrimethylsilane
    • Authors: Xiao-Ping Yin; Lei Zhu, Jian Zhou
      Abstract: We herein report a commercially available perchloric acid catalyst capable of catalyzing the azidation of α-hydroxy esters, α-hydroxy ketones and taddols using azidotrimethylsilane in dichloromethane at room temperature. Various substituted tertiary alcohols are well tolerated in this reaction. Cα-tetrasubstituted α-amino acid derivatives were prepared by one-pot sequential azidation and hydrogenation procedure. The advantage of this newly developed method includes operational simplicity, ready availability of catalyst, scale-up ability, and also good funcational group compatibility.
      PubDate: 2018-01-03T07:10:42.39563-05:0
      DOI: 10.1002/adsc.201701345
       
  • Regioselective C-7 Nitration of 8-Aminoquinoline Amides Using tert-Butyl
           Nitrite
    • Authors: Alakananda Hajra; Susmita Mondal, Sadhanendu Samanta
      Abstract: Regioselective C-7 nitration of 8-aminoquinoline amide has been achieved using tert-butyl nitrite under metal-free conditions at ambient temperature. The protocol is applicable to various aryl, heteroaryl as well as aliphatic carboxamides, and exhibits high functional group compatibility. The present method provides selective mononitrated quinoline derivatives. Experimental results suggest that the reaction likely proceeds through a radical pathway.
      PubDate: 2018-01-03T07:06:34.399061-05:
      DOI: 10.1002/adsc.201701555
       
  • Regioselective Synthesis of Angular Isocoumarinoselenazoles: A
           Benzoselenazole Directed Site Specific Ruthenium-catalyzed C(sp2)-H
           Functionalization
    • Authors: SANDIP DHOLE; Jen-Yu Liao, Sunil Kumar Dhull, Deepak Salunke, Chung-Ming Sun
      Abstract: Synthesis of new angular isocoumarinoselenazoles is described which involves the construction of 2-amino benzoselenazoles, their regioselective C2 N-alkylation and alkyne insertion. An expeditious and metal-free synthesis of 2-aminobenzoselenazoles by the reaction of methyl 3-amino-4-fluorobenzoate and isoselenocyanates was achieved. Further N-alkylation of 2-aminobenzoselenazoles resulted the formation of two regioisomers with differential reactivity towards alkyne insertion. The regioselective construction of α-pyrone ring on the benzo[1,3-d]selenazole skeleton was achieved via ruthenium (II)-catalyzed oxidative annulation. It is clear that the selenazole nitrogen plays an important role for the observed selectivity.
      PubDate: 2018-01-02T07:20:59.718459-05:
      DOI: 10.1002/adsc.201701256
       
  • Rhodium-Catalyzed Regioselective Ortho C-H Olefination of 2-Arylindoles
           via NH-Indole-Directed C-H Bond Cleavage
    • Authors: Qingshuai Han; Xiemin Guo, Ziyuan Tang, Lv Su, Zizhu Yao, Xiaofeng Zhang, Shen Lin, ShengChang Xiang, Qiufeng Huang
      Abstract: In the past decades, C-H oxidative olefination of indole at C-2, C-3, C-4 and C-7 positions was well addressed. We report here a rhodium-catalyzed NH-indole-directed ortho C-H bond olefination of 2-arylindoles. This cross-dehydrogenative-coupling proved to be broad in substrate scope, tolerating a variety of functional groups. The synthesis of 6H-isoindolo[2,1-α]indoles via rhodium-catalyzed ortho C-H olefination and subsequent intramolecular aza-Michael reaction of 2-arylindoles was also demonstrated.
      PubDate: 2017-12-31T22:50:31.696642-05:
      DOI: 10.1002/adsc.201701381
       
  • Direct Reductive Amination of Carbonyl Compounds Catalyzed by a Moisture
           Tolerant Tin(IV) Lewis Acid
    • Authors: Joshua Sapsford; Daniel Scott, Nathan Allcock, Matthew J. Fuchter, Christopher Tighe, Andrew Ashley
      Abstract: Despite the ever-broadening applications of main-group ‘frustrated Lewis pair’ (FLP) chemistry to both new and established reactions, their typical intolerance of water, especially at elevated temperatures (> 100°C), represents a key barrier to their mainstream adoption. Herein we report that FLPs based on the Lewis acid iPr3SnOTf are moisture tolerant in the presence of moderately strong nitrogenous bases, even under high temperature regimes, allowing them to operate as simple and effective catalysts for the reductive amination of organic carbonyls, including for challenging bulky amine and carbonyl substrate partners.
      PubDate: 2017-12-28T01:58:53.024744-05:
      DOI: 10.1002/adsc.201701418
       
  • Rh-Catalyzed Annulation of ortho- C-H Bonds of 2-Arylimidazoles with
           1,4,2-Dioxazol-5-ones toward 5-Arylimidazo[1,2-c]quinazolines
    • Authors: Xiaopeng Wu; Song Sun, Shengbo Xu, Jiang Cheng
      Abstract: A Rh-catalyzed unique and direct approach for constructing a series of 5-arylimidazo[1,2-c]quinazolines in moderate to excellent yields from simple and readily available 2-arylimidazoles and 3-phenyl-1,4,2-dioxazol-5-ones was described. This procedure proceeds with sequential ortho- C-H bond amidation and cyclization, which represents a facile and straightforward pathway to access such frameworks.
      PubDate: 2017-12-28T00:25:28.50152-05:0
      DOI: 10.1002/adsc.201701331
       
  • Copper-Catalyzed Stereoselective Defluorinative Borylation and Silylation
           of gem-Difluoroalkenes
    • Authors: Dong-Hang Tan; E Lin, Wei-Wei Ji, Yao-Fu Zeng, Wen-Xin Fan, Qingjiang Li, Hui Gao, Honggen Wang
      Abstract: The copper-catalyzed stereoselective defluorinative borylation and silylation of gem-difluoroalkenes was developed. The protocol led to the exclusive formation of Z type monofluoroalkenyl borons and silanes in generally good efficiency with broad substrate scope. The products formed could be readily transformed to other F-containing molecules by taking advantage of the versatile reactivities of C-B and C-Si bonds. Experimental and theoretical mechanistic studies were conducted which support an olefin insertion/syn-planar β-F elimination pathway.
      PubDate: 2017-12-26T23:55:56.022928-05:
      DOI: 10.1002/adsc.201701497
       
  • Visible Light-Induced Synthetic Approach for Selenylative Spirocyclization
           of N-Aryl Alkynamides with Molecular Oxygen as Oxidant
    • Authors: Harekrishna Sahoo; Anup Mandal, Suman Dana, Mahiuddin Baidya
      Abstract: A visible light-induced (blue LED) radical cascade has been devised to effect selenylative spirocyclization of N-aryl alkynamides at room temperature under oxygen atmosphere and without the aid of external photocatalyst. The protocol is operationally simple, scalable, and offers clean synthesis of 3-selenospiro[4,5]trienones in high yields (up to 92%). A novel spiro-ring-opening strategy has also been accomplished to access fully substituted acryl amides.
      PubDate: 2017-12-26T23:50:34.118388-05:
      DOI: 10.1002/adsc.201701410
       
  • Organocatalytic Synthesis of Oxazolines and Dihydrooxazines from
           Allyl-Amides: Bypassing the Inherent Regioselectivity of the Cyclization
    • Authors: Alexis Theodorou; Ierasia Triandafillidi, Christoforos Kokotos
      Abstract: A selective and efficient methodology for the construction of either oxazolines or dihydrooxazines from the corresponding allyl-amides is reported. Bypassing the inherent selectivity of the cyclization and depending on the substitution pattern of the substrate, a selective epoxidation-cyclization was developed leading to either the five-membered or the six-membered ring, upon simple and complementary reaction conditions. The cyclization products were obtained in good to excellent yields and high selectivities.
      PubDate: 2017-12-25T23:26:47.378734-05:
      DOI: 10.1002/adsc.201701386
       
  • Construction of Vicinal Tetrasubstituted Stereogenic Centers via a
           Mannich-Type Organocatalyzed Addition of Δ2-Pyrrolin-4-ones to Isatine
           Imines
    • Authors: Sebastijan Ričko; Anže Meden, Luka Ciber, Bogdan Štefane, Franc Pozgan, Jurij Svete, Uroš Grošelj
      Abstract: Racemic Δ2-pyrrolin-4-ones (i.e. 4-pyrrolones), easily available in two steps from N-protected α-amino acids, undergo organocatalysed asymmetric Mannich-type addition to isatin-derived ketimines to furnish the non-racemic oxindole–Δ2-pyrrolin-4-one adducts, stereoselectively (up to 96% ee, dr ≥15:1). The oxindole–pyrrolone products feature vicinal tetrasubstituted carbon stereocenters. The developed protocol has a broad substrate scope and tolerates diverse substituents at position C-5 in 4-pyrrolones and at positions N-1 and C-5/7 in isatin-imines.
      PubDate: 2017-12-25T23:26:43.631255-05:
      DOI: 10.1002/adsc.201701384
       
  • Diastereoselective Electrophilic Trifluoromethylthiolation of Chiral
           Oxazolidinones: Access to Enantiopure α-SCF3 Alcohols
    • Authors: Hélène Chachignon; Evgenii Kondrashov, Dominique Cahard
      Abstract: Lithium imide enolates featuring Evans’ chiral oxazolidinone auxiliary were involved in diastereoselective α-trifluoromethylthiolation with electrophilic SCF3 donors. Diastereopure products were isolated and converted to enantiopure α-SCF3 alcohols without racemisation.
      PubDate: 2017-12-25T23:26:24.515093-05:
      DOI: 10.1002/adsc.201701474
       
  • Palladium-catalyzed Selective Amination of Aryl(haloaryl)amines with
           9H-Carbazole Derivatives
    • Authors: Yuhki Otsuka; tetsuya yamamoto, Takanori Miyazaki, Tetsu Yamakawa
      Abstract: Palladium-catalyzed amination of aryl(haloaryl)amines with 9H-carbazole derivatives was investigated. In the amination of (4-bromophenyl)phenylamine with 9H-carbazole by the use of Pd2(dba)3/PtBu3/NaOtBu catalyst, the main product was desired 9-[4-(phenylamino)phenyl]-9H-carbazole in 60% yield with conversion of (4-bromophenyl)phenylamine>99%, and the concomitant formation of 9-[4-[phenyl[4-(phenylamino)phenyl]amino]phenyl]-9H-carbazole (15% yield), which is the consecutive by-product, was observed. When XPhos was used instead of PtBu3, the desired product was provided in 81% yield and the consecutive by-product was suppressed to 7.7%. The yield of the desired product reached 98% by the use of tBu-XPhos. Such excellent yields of the desired product were also obtained with other 2-di- tert-butyl- or 2-di(1-adamantyl)phosphino-1,1’-biaryls. Various 9-(arylamino)aryl-9H-carbazoles could be synthesized from aryl(haloaryl)amines and 9H-carbazole derivatives in high yields by the use of tBu-XPhos. The amination of 4-bromotoluene with a mixture of diphenylamine and 9H-carbazole gave only 9-o-tolyl-9H-carbazole with tBu-XPhos, while the use of PtBu3 or XPhos afforded the mixture of 9-o-tolyl-9H-carbazole and diphenyl(o-tolyl)amine, indicating that Pd2(dba)3/tBu-XPhos/NaOtBu catalyst high selectively favors 9H-carbazole over diphenylamine as an amination substrate.
      PubDate: 2017-12-25T23:20:55.526251-05:
      DOI: 10.1002/adsc.201701356
       
  • Pyrroline Synthesis via Visible-Light-Promoted Hydroimination of
           Unactivated Alkenes with N,N'-Dimethylpropyleneurea as H-Donor
    • Authors: Sai-Hu Cai; Ding-Xing Wang, Lu Ye, Ze-Yao Liu, Chao Feng, Teck-Peng Loh
      Abstract: Synthesis of 3,4-pyrroline derivatives via visible-light-induced hydro/oxyimination of unactivated olefins is reported. In the presence of the photoredox catalyst fac-Ir(ppy)3, the key iminyl radical intermediate can be readily generated from O-acyl oximes, and undergoes intramolecular cyclization and H-abstraction from solvent or is trapped by TEMPO to give the corresponding hydro/oxyimination product, respectively. Mechanistic investigations indicate that N,N'-dimethylpropylene urea (DMPU) works as both reducing agent for catalyst regeneration and H-donor for product formation in this process.
      PubDate: 2017-12-25T23:20:52.314094-05:
      DOI: 10.1002/adsc.201700937
       
  • Enantioselective Conjugate Addition of 2-Acylimidazoles with Nitroalkenes
           Promoted by Chiral-at-Metal Rhodium(III) Complexes
    • Authors: Ganesh Kumar Thota; Gui-Jun Sun, Tao Deng, Yi Li, Qiang Kang
      Abstract: An enantioselective conjugate addition of 2-acyl imidazoles with nitro-alkenes catalyzed by chiral-at-metal Rh(III) complex under mild reaction conditions was developed, affording versatile γ-nitro-ketone skeletons in good yields with excellent enantioselectivities (up to>99% ee).
      PubDate: 2017-12-25T23:20:43.059074-05:
      DOI: 10.1002/adsc.201701377
       
  • N-Arylated Sulfoximines as Cross-Coupling Building Blocks
    • Authors: Anne-Katrin Bachon; Anne-Dorothee Steinkamp, Carsten Bolm
      Abstract: The application of borylated N-aryl sulfoximines as newly designed synthetic building blocks in Suzuki-type cross coupling reactions offers rapid access to a wide range of N-biaryl derivatives with potential relevance for medicinal chemistry and crop protection in good to excellent yields (up to 98%).
      PubDate: 2017-12-24T22:50:51.752603-05:
      DOI: 10.1002/adsc.201701394
       
  • Mild Ring Contractions of Cyclobutanols to Cyclopropyl Ketones via
           Hypervalent Iodine Oxidation
    • Authors: Yan Sun; Xin Huang, Xiaojin Li, Fan Luo, Lei Zhang, Mengyuan Chen, Shiya Zheng, Bo Peng
      Abstract: An iodine-mediated oxidative ring contraction of cyclobutanols has been developed. The reaction allows the synthesis of a wide range of aryl cyclopropyl ketones under mild and eco-friendly conditions. A variety of functional groups including aromatic or alkyl halides, ethers, esters, ketones, alkenes, and even aldehydes are nicely tolerated in the reaction. This is in contrast with traditional synthetic approaches for which poor functional group tolerance is often a problem. The practicality of the method is also highlighted by the tunability of iodine oxidation system. Specifically, combining the iodine(III) reagent with an appropriate base allows the reaction to accommodate a range of challenging electron-rich arene substrates. The facile scalability of this reaction is also exhibited herein.
      PubDate: 2017-12-24T22:50:42.567932-05:
      DOI: 10.1002/adsc.201701237
       
  • Base-Promoted Tandem Cyclization for the Synthesis of Benzonitriles by
           C–C Bond Construction
    • Authors: Cheng-Zhi Zhu; Yin Wei, Min Shi
      Abstract: A facile synthesis of benzonitriles via base-promoted tandem cyclization reaction of α,β-unsaturated enones having electron-withdrawing group (EWG) and 2-acyl-acrylonitriles has been developed. This new synthetic method to access benzonitriles is suitable for a wide range of substrates. A plausible reaction mechanism has been proposed on the basis of previous literature and our own investigations.
      PubDate: 2017-12-24T22:50:30.574107-05:
      DOI: 10.1002/adsc.201701329
       
  • Oxidative Catalytic Spiroketalization Leading to Diastereoselective
           Spiro[benzofuran-2,1'-isochromene]s
    • Authors: Jiang-Kai Qiu; Wen-Juan Hao, Guigen Li, Bo Jiang
      Abstract: A new one-pot, two-step Ag-catalyzed spiroketalization of the in-situ generated quinone imine ketals (QIKs) with β-alkynyl ketones has been established, enabling multiple C−O and C−C bond-forming reactions to access densely functionalized spiro[benzofuran-2,1'-isochromene] derivatives with generally good yields. The use of β-alkynyl ketones bearing alkyl and aryl groups located at α-position of the carbonyl group could lead to highly diastereoselective spiro[chromane-2,1’-isochromene] derivatives. The reaction features broad substrate scope, mild oxidative catalytic conditions and excellent diastereoselectivity.
      PubDate: 2017-12-24T22:50:26.426157-05:
      DOI: 10.1002/adsc.201701149
       
  • Synthesis of 2-(alpha,alpha,alpha-Trifluoromethyl)-dibenzopyranones with
           Rhodium(III)-catalyzed Formal anti-Michael Addition as Key Step
    • Authors: Ling Pan; Jinhuan Dong, Di Xie, Yifei Li, QUN LIU
      Abstract: A novel rhodium(III)-catalyzed synthesis of 2-(alpha,alpha,alpha-trifluoromethyl)-dibenzopyranones from easily available 4-(alpha,alpha,alpha-trifluoromethyl)-p-quinols and N-methoxyarylamides is described. Rhodium(III)-catalyzed formal anti-Michael addition was proposed to be a crucial step in this [3 + 3] annulation with N-methoxyarylamides as effective 1,3-dipoles, providing a concise and efficient approach for the construction of alpha,alpha,alpha-trifluoromethyl-containing dibenzopyranones under mild reaction conditions.
      PubDate: 2017-12-24T21:56:31.976452-05:
      DOI: 10.1002/adsc.201701511
       
  • Efficient Synthesis of Amines by Iron-Catalyzed C=N Transfer Hydrogenation
           and C=O Reductive Amination
    • Authors: Umberto Piarulli; Sofia Vailati-Facchini, Mattia Cettolin, Xishan Bai, Giuseppe Casamassima, Luca Pignataro, Cesare Gennari
      Abstract: Here we report the catalytic transfer hydrogenation (CTH) of non-activated imines promoted by a Fe-catalyst in the absence of Lewis acid co-catalysts. Use of the (cyclopentadienone)iron complex 1, which is much more active than the classical ‘Knölker complex’ 2, allowed to reduce a number of N-aryl and N-alkyl imines in very good yields using iPrOH as hydrogen source. The reaction proceeds with relatively low catalyst loading (0.5-2 mol%) and, remarkably, its scope includes also ketimines, whose reduction with a Fe-complex as the only catalyst has little precedents. Based on this methodology, we developed a one-pot CTH protocol for the reductive amination of aldehydes/ketones, which provides access to secondary amines in high yield without the need to isolate imine intermediates.
      PubDate: 2017-12-17T22:45:23.699208-05:
      DOI: 10.1002/adsc.201701316
       
  • Synthesis of Sulfonated 5-Aminopyrazoles by I2/Benzoyl Peroxide-Mediated
           Tandem Reaction
    • Authors: Dongping Cheng; tianpeng chen, xiaoliang xu, jizhong yan
      Abstract: The tandem reaction of 3-morpholinoacrylonitrile with sulfonyl hydrazides mediated by I2/benzoyl peroxide (BPO) is reported, which offers an efficient approach for the synthesis of sulfonated 5-aminopyrazoles. It can bear a large scope of the substrates, and be used for the synthesis of aromatic, heteroaromatic and aliphatic sulfonated 5-aminopyrazoles.
      PubDate: 2017-12-16T02:05:09.672167-05:
      DOI: 10.1002/adsc.201701201
       
  • Nondirecting Group sp3 C−H Activation for Synthesis of Bibenzyls via
           Homo-coupling as Catalyzed by Reduced Graphene Oxide Supported PtPd@Pt
           Porous Nanospheres
    • Authors: Zheng-Jun Wang; Jing-Jing Lv, Rong-Nan Yi, Min Xiao, Jiu-Ju Feng, Zhiwu Liang, Ai-Jun Wang, Xinhua Xu
      Abstract: The use of heterogeneous bimetallic Pd-based nanocatalyst for directing the inactivated sp3 C−H coupling has been scarcely explored. This work reported the formation of symmetrical C−C bonds from the inactivated sp3 C−H bonds catalyzed by employing reduced graphene oxide supported PtPd@Pt porous nanospheres. The reaction of sp3 C−H activation proceeded under mild conditions without any solvent, ligand or directing group. It is a higher atom-, step- and cost-effectiveness strategy for developing heterogeneous catalysts in the synthesis of bibenzyls with various functional groups (e.g. aryl, alkyl, methoxyl, halogen, ester, and pyridyl).
      PubDate: 2017-12-16T01:22:03.839496-05:
      DOI: 10.1002/adsc.201701389
       
  • Synthesis of Chiral Sulfonyl Lactones via Copper-Catalyzed Asymmetric
           Radical Reaction of DABCO·(SO2)
    • Authors: Yang Wang; Lingling Deng, Jie Zhou, Xiaochen Wang, Haibo Mei, Jianlin Han, Yi Pan
      Abstract: In the present work, an asymmetric copper-catalyzed radical multi-component cascade reaction of an unsaturated carboxylic acid, aryldiazonium tetrafluoroborate, and DABCO·(SO2)2 (DABSO) has been developed for the enantioselective synthesis of sulfonyl lactones. In this reaction, this SO2 surrogate, DABSO was applied for the first time in the construction of chiral compounds. This multiple-step asymmetric radical reaction was carried out under mild conditions and tolerated a wide range of substrates, resulting in the corresponding sulfonyl lactones with up to 95% chemical yields and 88% ee. The current reaction enriches the research contents of DABSO, and provides a new and efficient strategy to chiral functionalized lactones bearing quarternary stereogenic center.
      PubDate: 2017-12-16T00:46:49.212861-05:
      DOI: 10.1002/adsc.201701532
       
  • Substituted Hantzsch Esters as Versatile Radical Reservoirs in Photoredox
           Reactions
    • Authors: Fangjun Gu; Wenhao Huang, Xu Liu, Wen-Xin Chen, Xu Cheng
      Abstract: Abstract. Substituted Hantzsch esters can act as radical reservoirs in photoredox reactions, steadily releasing a carbon radical and a hydrogen atom radical in the absence of an additional electron acceptor. We propose that radical release by substituted Hantzsch esters occurs via a mechanism involving an internal redox cycle. Cinnamidecinnamides, styrenes, a,b-unsaturated acids, and diarylethenes could be alkylated smoothly with these reagents.
      PubDate: 2017-12-15T03:48:57.557641-05:
      DOI: 10.1002/adsc.201701348
       
  • Transition-Metal-Free Regioselective Alkylation of Quinoline N-Oxides via
           Oxidative Alkyl Migration and C-C Bond Cleavage of tert-/sec- Alcohols
    • Authors: Subhash Ghosh; Chiranjit Sen
      Abstract: An unprecedented C2-alkylation of quinoline N-oxide derivatives via C-C bond activation of tert- and sec-alkyl alcohol is described using hypervalent iodine (III) reagent PhI(OAc)2 (PIDA). This regioselective alkylation using mild hypervalent iodine reagents is more practical, operationally simple and transition metal free. The reaction proceeds efficiently with a broad range of substrates including quinoline, isoquinoline, and pyridine N-oxides using a variety of tert-/sec- alcohols. From experimental outcome, we also propose a rationalized mechanism, mediated by PIDA.
      PubDate: 2017-12-14T01:35:32.991294-05:
      DOI: 10.1002/adsc.201701330
       
  • Pd/Mn Bimetallic Relay Catalysis for Aerobic Aldoxime Dehydration to
           Nitriles
    • Authors: Dongliang Zhang; Yaping Huang, Erlei Zhang, Rong Yi, Chao Chen, Lei Yu, Qing XU
      Abstract: A Pd/Mn bimetal system was found to be an effective catalyst for dehydration of aldoximes to the useful nitriles under mild aerobic conditions. Different to the known metal-catalyzed aldoxime dehydration reactions, this reaction very possibly proceeded via an alternative mechanism of Pd/Mn bimetal relay catalysis involving a Mn-catalyzed aerobic oxidation of aldoximes to nitrile oxides by air and a Pd-catalyzed oxygen transfer from the nitrile oxides to the solvent acetonitrile. This method tolerates a variety of substrates including sterically bulky ones and also the natural product derivative.
      PubDate: 2017-12-13T02:39:42.046675-05:
      DOI: 10.1002/adsc.201701154
       
  • Design of C3-Alkenyl-Substituted 2-Indolylmethanols for Catalytic
           Asymmetric Interrupted Nazarov-Type Cyclization
    • Authors: Cong-Shuai Wang; Jia-Le Wu, Can Li, Lin-Zhi Li, Guang-Jian Mei, Feng Shi
      Abstract: The C3-alkenyl-substituted 2-indolylmethanols have been designed as a new class of substrates for catalytic asymmetric interrupted Nazarov-type cyclizations. In the presence of chiral phosphoric acid as a mild chiral Brønsted acid, the interrupted Nazarov-type cyclization of C3-alkenyl-substituted 2-indolylmethanols with nucleophiles occurred smoothly to construct cyclopenta[b]indole frameworks in generally excellent diastereo- and enantioselectivities (up to>95:5 dr,>99% ee).
      PubDate: 2017-12-13T02:38:57.006431-05:
      DOI: 10.1002/adsc.201701521
       
  • Catalytic Enantioselective Povarov Reactions of
           Ferrocenecarbaldehyde-Derived Imines – Brønsted Acid Catalysis at
           Parts-Per-Million Level Loading
    • Authors: Dragana Stevanovic; Giulio Bertuzzi, Andrea Mazzanti, Mariafrancesca Fochi, Luca Bernardi
      Abstract: Despite the broad interest in ferrocene containing compounds, ferrocenyl substrates have been employed in catalytic asymmetric settings only sporadically. Herein, catalytic asymmetric Povarov reactions with ferrocenecarbaldehyde-derived N-aryl imines are presented. This study demonstrates that the stereoelectronic properties of ferrocenyl imines do not preclude their engagement in enantioselective phosphoric acid catalysis: cycloadducts derived from benzyl N-vinylcarbamate were obtained in good yields and nearly enantiopure form using 0.1 mol% of a standard Brønsted acid catalyst. Furthermore, it is shown that specific optimisation with some substrates allowed to lower the catalyst loading up to 10-20 parts-per-million, an unprecedented value for phosphoric acid catalysts. Such low loading protocol could be applied to a preparative scale reaction, and to imines derived from arylaldehydes.
      PubDate: 2017-12-12T03:20:29.542558-05:
      DOI: 10.1002/adsc.201701484
       
  • Oxidant-Mediated Nitrogenation and Recyclization of
           Imidazo[1,2-a]pyridines with Sodium Azide: Synthesis of
           4H-Pyrido[1,2-a][1,3,5]triazin-4-ones
    • Authors: Gangjian Cao; Zhengkai Chen, Jinyu Song, Jianfeng Xu, Maozhong Miao, Hongjun Ren
      Abstract: An expeditious and straightforward approach for the synthesis of 4H-pyrido[1,2-a][1,3,5]triazin-4-ones starting from readily available imidazo[1,2-a]pyridines and sodium azide has been presented under aerobic oxidative conditions. The reaction proceeded well with the promotion of potassium persulfate/potassium permanganate with good functional group tolerance. A wide range of biologically valuable 4H-pyrido[1,2-a][1,3,5]triazin-4-one scaffolds were assembled by this methodology. The gram-scale reaction was also achieved. A cascade nitrogenation and oxidative recyclization sequence could be involved in the reaction.
      PubDate: 2017-12-11T00:45:29.973744-05:
      DOI: 10.1002/adsc.201701480
       
  • Asymmetric Amination of α-Chiral Aliphatic Aldehydes via Dynamic Kinetic
           Resolution to Access Stereocomplementary Brivaracetam and Pregabalin
           Precursors
    • Authors: Christine Fuchs; Judith Farnberger, Georg Steinkellner, Johann Sattler, Mathias Pickl, Robert Simon, Ferdinand Zepeck, Karl Gruber, Wolfgang Kroutil
      Abstract: Over the last decades biocatalysis has emerged as an indispensable and versatile tool for the asymmetric synthesis of active pharmaceutical ingredients (APIs). In this context, especially transaminases (TAs) have been successfully used for the preparation of numerous α-chiral, optically pure amines, serving as important building blocks for APIs. Here we elaborate on the development of transaminases recognizing the α-chiral centre adjacent to an aldehyde moiety with aliphatic residues, opening up concepts for novel synthetic routes to the antiepileptic drugs Brivaracetam and Pregabalin.The transformation proceeded via dynamic kinetic resolution (DKR) based on the bio-induced racemisation of the aldehyde enantiomers, enabling the amination of the racemic substrates with quantitative conversions. Medium, substrate as well as enzyme engineering gave access to both (R)- and (S)-enantiomers of the amine precursors of the stereocomplementary drugs in high optical purity, representing a short route to mentioned APIs.
      PubDate: 2017-12-10T22:22:20.402038-05:
      DOI: 10.1002/adsc.201701449
       
  • An efficient synthesis of 6-oxa-spiro[3.4]octan-1-one derivates through
           3-diazochroman-4-one and alkene
    • Authors: Meiling Xiao; Fuming Zhang, Zhe Du, Bao-chun Ma
      Abstract: Abstract: Spiro[2, 2-dimethyl-benzofuran, bicycle [4.2.0]octane]-7’-one with fused and spiro cyclic oxygen-containing rigid skeleton structure is obtained via Wolff rearrangement and cycloaddition with good yields. Then spiro[2, 2-dimethyl-benzofuran, hexahydro-isobenzofuran-2’-one] is synthesized by further Baeyer-Villiger oxidation. These two kinds of products have a special fused and spirocyclic oxygen-containing rigid skeleton structure and are reported by our group.
      PubDate: 2017-12-10T22:22:12.246305-05:
      DOI: 10.1002/adsc.201701197
       
  • Application of Homophthalic Anhydrides as 2C Building Blocks in Catalytic
           Asymmetric Cyclizations of ortho-Quinone Methides: Diastereo- and
           Enantioselective Construction of Dihydrocoumarin Frameworks
    • Authors: Ting Zhang; Chun Ma, Jia-Yu Zhou, Guang-Jian Mei, Feng Shi
      Abstract: A catalytic asymmetric [4+2] cyclization of ortho-quinone methides with homophthalic anhydrides in the presence of chiral squaramide-tertiary amine has been established. This method provides dihydrocoumarin frameworks in excellent diastereoselectivities (all>95:5 dr) and high enantioselectivities (81%-98% ee). This reaction represents the first application of homophthalic anhydrides as 2C building blocks in catalytic asymmetric cyclizations. In addition, this approach not only provides a useful method for constructing enantioenriched dihydrocoumarin frameworks but also advances the chemistry of catalytic asymmetric cyclizations of ortho-quinone methides.
      PubDate: 2017-12-10T22:21:57.019003-05:
      DOI: 10.1002/adsc.201701333
       
  • Conversion of γ- and δ-Keto Esters into Optically Active Lactams.
           Transaminases in Cascade Processes
    • Authors: Ángela Mourelle-Insua; Luiz Arthur Zampieri, Iván Lavandera, Vicente Gotor-Fernández
      Abstract: A one-pot two-step enzymatic strategy has been designed for the production of optically active gamma- and delta-lactams in aqueous medium under mild conditions. The approach is based on the biotransamination of ethyl or methyl keto esters bearing different alkyl or aryl substitution patterns at alpha-position to the ketone functionality. In this manner, the keto esters were transformed into the corresponding amino esters with excellent conversions, which underwent spontaneous cyclisation in the reaction medium without addition of external reagents. Depending on the transaminase selectivity, both lactam enantiomers can be obtained, so initial enzyme screenings were performed using commercially available and made in house enzymes. Reaction conditions were optimised focusing on the substrate concentration, temperature and ratio of amine donor vs acceptor. Thus, ten gamma- and delta-lactams were obtained in good to high isolated yields (70-90%) and excellent selectivities (94-99%) after one or two days at 30 or 45 ºC.
      PubDate: 2017-12-10T22:21:46.370064-05:
      DOI: 10.1002/adsc.201701304
       
  • Merging Gold Catalysis and Brønsted Acid Catalysis for the Synthesis of
           Tetrahydrobenzo[b][1,8]naphthyridines
    • Authors: Ruxia Yi; Xincheng Li, Boshun Wan
      Abstract: A gold(I)/Brønsted acid-catalyzed cyclization of 2-azidobenzaldehydes with 3-aza-1,6-enynes has been developed for the synthesis of tetrahydrobenzo[b][1,8]naphthyridine derivatives. This protocol enabled the modular synthesis of tetracyclic heterocycles in one operation with water and nitrogen gas as the byproducts.
      PubDate: 2017-12-10T22:21:17.889577-05:
      DOI: 10.1002/adsc.201701323
       
  • Hypervalent Iodine-Mediated Alkene Functionalization: Oxazoline and
           Thiazoline Synthesis via Inter-/Intramolecular Aminohydroxylation and
           Thioamination
    • Authors: Hyeonho Jeon; Da Rong Kim, Ji Hoon Lee, Jaeyoung Song, Won Seok Lee, Dong Wook Kang, Soosung Kang, Seok Beom Lee, Sungwook Choi, Ki Bum Hong
      Abstract: A metal-free oxidative difunctionalization of N-allylamides and N-allylthioamides has been developed. This system features the use of a hypervalent iodine oxidant with electron-deficient amines to access 5-amino-oxazoline and thiazoline scaffolds under mild conditions. Notably, various electron-deficient amines were systematically evaluated and we verified the reaction profile was originated from an attached (benzene)sulfonyl group.
      PubDate: 2017-12-09T06:01:02.249039-05:
      DOI: 10.1002/adsc.201701087
       
  • One-Pot Synthesis of 2,3,5-Trisubstituted Thiophenes through
           Three-Component Assembly of Arylacetaldehydes, Elemental Sulfur, and
           1,3-Dicarbonyls
    • Authors: Huawen Huang; Zilong Wang, Zhonghua Qu, Fuhong Xiao, Guojun Deng
      Abstract: The three-component reaction for the synthesis of 2-arylthiophenes has been developed. Easily available arylacetaldehydes, 1,3-dicarbonyls, and elemental sulfur were directly assembled through cascade condensation/ annulation under base conditions. The present protocol provides a facile entry to 2,3,5-trisubstituted thiophenes in moderate to excellent yields with good functional group tolerance.
      PubDate: 2017-12-08T04:26:34.503252-05:
      DOI: 10.1002/adsc.201701332
       
  • Visible-Light-Promoted Alkylation of Indoles with Tertiary Amines by the
           Oxidation of a sp3 C-H Bond
    • Authors: Xuan Ding; Chun-Lin Dong, Zhi Guan, Yan-Hong He
      Abstract: A visible-light driven reaction for the synthesis of 3-arylmethyl indole derivatives using tertiary amines and indoles was first reported. Corresponding products were obtained with yields of up to 70%, and various functional groups on the indoles were well tolerated when Rose Bengal was used as a photosensitizer and air was used as a green oxidant under mild reaction conditions.
      PubDate: 2017-12-08T04:25:53.273989-05:
      DOI: 10.1002/adsc.201701131
       
  • Brønsted Acid-Mediated Formal [3+3] Annulation Between Propargylic
           Alcohols and 1,3-Diketones
    • Authors: Ya-Ping Han; Xue-Song Li, Xin-Yu Zhu, Zhou Sun, Ming Li, Yu-Zhao Wang, Yong-Min Liang
      Abstract: A Brønsted acid-mediated formal [3+3] cascade annulation of propargylic alcohols with 1,3-diketones proceeds through a sequential Meyer−Schuster rearrangement/1,2-addition. This protocol, which has a wide scope and is conducted under an ambient atmosphere, enables access to a broad array of valuable chromenone derivatives related to many natural products in satisfactory yields under mild conditions. This method could be scaled up to the gram scale, which highlights the latent applicability of this transformation.
      PubDate: 2017-12-08T03:49:57.711931-05:
      DOI: 10.1002/adsc.201701296
       
  • Synthesis of Sulfonated Benzo[d][1,3]oxazines by Merging Photoredox
           Catalysis and Insertion of Sulfur Dioxide
    • Authors: Tong Liu; Danqing Zheng, Zhenhua Li, Jie Wu
      Abstract: A photocatalytic reaction of N-(2-vinylphenyl)amides, DABCO•(SO2)2 and aryldiazonium tetrafluoroborates for the synthesis of 4-((arylsulfonyl)methyl)-4H-benzo[d][1,3]oxazines under mild conditions is reported. This synthetic approach is enabled by merging photoredox catalysis and insertion of sulfur dioxide via radical process. The specific role of photoredox catalysis in this transformation is supported by mechanistic investigation and theoretical calculations.
      PubDate: 2017-12-08T03:49:27.455819-05:
      DOI: 10.1002/adsc.201701187
       
  • Merging Brønsted Acid and Hydrogen-Bonding Catalysis: Metal-Free
           Dearomatization of Phenols via ipso-Friedel-Crafts Alkylation to Produce
           Functionalized Spirolactams
    • Authors: Shingo Harada; Irene Kwok, Hiroki Nakayama, Ayaka Kanda, Tetsuhiro Nemoto
      Abstract: Intramolecular dearomative cyclization of phenols with α-diazoamide units for synthesizing functionalized spirolactams was developed by merging Brønsted acid and hydrogen-bonding catalysis as an advantageous alternative to transition metal catalysis. This metal carbenoid-free strategy enables high chemoselectivity by suppressing potentially competing C–H insertion reactions and a Büchner reaction. Preliminary mechanistic studies were performed to elucidate the positive effect of the combined use of the catalysts, and extension to an asymmetric reaction was achieved.
      PubDate: 2017-12-08T03:47:26.641542-05:
      DOI: 10.1002/adsc.201701287
       
  • Ruthenium(II)-NNN-Pincer-Complex-Catalyzed Reactions Between Various
           Alcohols and Amines for Sustainable C-N and C-C Bond Formation
    • Authors: Milan Maji; Kaushik Chakrabarti, Bhaskar Paul, Bivas Chandra Roy, Sabuj Kundu
      Abstract: An air and moisture stable 2-hydroxypyridine based bifunctional ruthenium NNN-pincer complex catalyzed efficient (TON = 42840) N-alkylation of amines under mild conditions is described. Surprisingly, with cyclic secondary amines this methodology selectively produced only amides. Notably, N-methylation of several amines was achieved using methanol as a green methylating agent. Furthermore, with lower catalyst loading (0.2 mol%) and shorter reaction time (6 h) numerous substituted quinolines were synthesized from 2-aminobenzyl alcohols and secondary alcohols. The effectiveness of this protocol was further extended by successfully synthesizing 2-alkylaminoquinolines in one-pot fashion from amino alcohol, aliphatic nitriles and alcohols. Gram scale synthesis of various compounds was also investigated to demonstrate the synthetic applicability of this methodology.
      PubDate: 2017-12-07T00:36:23.719254-05:
      DOI: 10.1002/adsc.201701117
       
  • Iridium-Catalyzed Dynamic Kinetic Stereoselective Allylic Etherification
           of Achmatowicz Rearrangement Products
    • Authors: Zhongpeng Zhu; Haoyuan Wang, CHRISTOPHER SIMMONS, Po-Sen Tseng, Xiang Qiu, Yu Zhang, XIYAN DUAN, Jing-Kui Yang, Weiping Tang
      Abstract: We recently developed a novel Ir-catalyzed dynamic kinetic isomerization reaction for Achmatowicz rearrangement products. In this update, we show that products derived from the Achmatowicz rearrangement can also undergo Ir-catalyzed dynamic kinetic allylic etherification in the presence of an appropriate ligand and additive to afford useful intermediates for the synthesis of carbohydrates. The addition of triphenyl phosphite ligand shuts down the isomerization pathway and promotes the allylic etherification pathway. The addition of diphenyl phosphate improved the diastereoselectivity for the addition reaction. Interestingly, opposite diastereoselectivity was observed for sterically demanding alcohol nucleophiles compared to less sterically demanding alcohol nucleophiles. The method was also applied to the synthesis of several 2,3-dideoxypyranosides.
      PubDate: 2017-12-07T00:36:02.119387-05:
      DOI: 10.1002/adsc.201700950
       
  • An Allene Approach to Tetrahydrofuran-Fused Bicyclo[2.2.2]oct-2-enes
    • Authors: Shihua Song; Chunling Fu, Xin Huang, Shengming Ma
      Abstract: An efficient access to tetrahydrofuran-fused bicyclo[2.2.2]oct-2-enes via palladium-catalyzed cyclization of oxygen-tethered 2,7-alkadiynylic carbonates with 2-(buta-2,3-dienyl)malononitrile has been developed. Perfect chiral induction was observed when a substituent was introduced to the propargylic position affording the optically active polycyclic products of both enantiomers. Control experiments showed that the oxygen tether of 2,7-alkadiynylic carbonates and the two cyano groups in allene 2a are indispensible for this transformation.
      PubDate: 2017-12-06T08:36:45.662185-05:
      DOI: 10.1002/adsc.201701407
       
  • Iridium/Chiral Diene-Catalyzed Enantioselective (3 + 2) Annulation of
           Aromatic Ketimines with 1,3-Enynes via C–H Activation
    • Authors: Midori Nagamoto; Kana Sakamoto, Takahiro Nishimura
      Abstract: An Ir/chiral diene complex efficiently catalyzed enantioselective (3 + 2) annulation between 1,3-enynes and cyclic N-acyl ketimines generated in situ from 3-aryl-3-hydroxyisoindoin-1-ones. The reaction gave the corresponding aminoindane derivatives in high yields with high regio-, diastereo-, and enantioselectivity.
      PubDate: 2017-12-06T08:36:22.600433-05:
      DOI: 10.1002/adsc.201701378
       
  • Naphthalenediimide - a unique motif in macrocyclic and interlocked
           supramolecular structures
    • Authors: Andreea Diac; Mihaela Matache, Ion Grosu, Niculina Hadade
      Abstract: This review describes a survey through the macrocyclic and interlocked structures containing 1,4,5,8-naphthalendiimide residues from a synthetic point of view as well as the structural particularities that dictate the main applications in supramolecular, biological and materials chemistry. The paper is organised in comprehensive description of macrocycles, cyclophanes, catenanes, rotaxanes and metallamacrocycles along with other types of supramolecular interlocked architectures. For each category, we present the synthetic approach, the structural investigation of their properties and the developed applications as semiconductors, energy storage devices, photovoltaics, artificial photosystems, sensors, catalysts or molecular machines.
      PubDate: 2017-12-05T22:06:29.123971-05:
      DOI: 10.1002/adsc.201701362
       
  • Synthesis and reactivity of 1,1-diborylalkanes towards C-C bond formation
           and related mechanisms
    • Authors: Elena Fernández; Nuria Miralles, Ricardo J Maza
      Abstract: Gem-diborylalkanes have emerged as efficient reagents for synthesizing organoboron compounds through selective C-C bond-forming reactions. Activation of the 1,1-diborylalkanes, generate carbanions with enhanced stability that are able to react with a series of electrophiles, carbonyl compounds , imines and epoxides to promote the new C-C bond. These new set of reactions become general for a wide range of substrates and they can be understood by alternative mechanisms that justify the potential use of these reagents. The formation of the C-C-B bond can be afforded with chemo- diastereo- and enantioselectivity, because the nucleophilc α-boryl or α-diboryl carbanions attack in a stereoselective manner, by means of the catalyst involved. The synthesis of gem-diborylalkanes has also been launched by innovative methods and facilitates the access to multiborylated reagents with different substituents and properties.
      PubDate: 2017-12-05T22:06:24.692721-05:
      DOI: 10.1002/adsc.201701390
       
  • Hydration and Intramolecular Cyclization of Homopropargyl Sulfonamide
           Derivatives Catalyzed by AgSbF6: Synthesis of Structurally Diverse
           2,3-Dihydro-1H-Pyrroles
    • Authors: Xiuling Yu; Zhonglin Guo, Hongjian Song, Yuxiu Liu, qingmin wang
      Abstract: An efficient and simple approach for the synthesis of a range of functionalized of 2,3-dihydro-1H-pyrroles has been developed. The transformation consists of two sequential steps: (i) silver catalyzed hydration of homopropargyl sulfonamides and (ii) intramolecular cyclization. The methodology accommodates a wide range of substrates, and can be applied to the formal synthesis of (S)-nicotine.
      PubDate: 2017-12-05T22:06:20.342401-05:
      DOI: 10.1002/adsc.201701121
       
  • Highly Substituted Cyclohexenes via Phosphine-Catalyzed [4 + 2] Annulation
           of Electron-deficient Dienes and Vinyl Ketones
    • Authors: Junliang Zhang; Peng Chen, Junyou Zhang
      Abstract: A highly efficient phosphine-catalyzed [4+2] annulation of electron-deficient diene and alkyl vinyl ketone was developed for the first time, which provides an easy access to functionalized cyclohexenes. This method has the advantages of mild reaction conditions, widely functional group tolerance, high yields and transition metal free.
      PubDate: 2017-12-04T02:51:15.795766-05:
      DOI: 10.1002/adsc.201701168
       
  • Rapid, operationally simple, and metal-free NBS mediated one-pot synthesis
           of 1,2-naphthoquinone from 2-naphthol
    • Authors: Jaeuk Sim; Hyeju Jo, Mayavan Viji, Minho Choi, Jin-Ah Jung, Heesoon Lee, Jae Kyung Jung
      Abstract: A metal-free, one-pot synthesis of 1,2-naphthoquinone was accomplished from 2-naphthol by utilizing economically cheap NBS under open air conditions. Initial formation of 1,1-dibromonaphthalen-2-one and subsequent transformation afforded the 1,2-naphthoquinone. This oxidation was completed within 30 min and had broad substrate scope. Moreover, this system tolerated heterocyclic systems and was also applicable to 1,3-dicarbonyl systems. This practical approach with short reaction times, a simple workup, and insensitivity to moisture could override the usage of expensive and hazardous oxidizing and metal reagents.
      PubDate: 2017-12-02T00:35:40.658689-05:
      DOI: 10.1002/adsc.201701312
       
  • An Atropos Chiral Biphenyl Bisphosphine Ligand Bearing Only
           2,2’-Substituents and Its Application in Rh-Catalyzed Asymmetric
           Hydrogenation
    • Authors: Jia Jia; Zheng Ling, Zhenfeng Zhang, Ken Tamura, Ilya Gridnev, Tsuneo Imamoto, Wanbin Zhang
      Abstract: An atropos chiral biphenyl bisphosphine ligand bearing only 2,2’-substituents was rationally designed and easily synthesized utilizing a bulky chiral t-butylmethylphosphino block. Computational results showed a large difference in the free energies between the two diastereomers (7.8 kcal/mol) and attainable rotational energy barriers from one diastereomer to another (27.7 kcal/mol and reverse 19.9 kcal/mol). This ligand avoids the time-consuming optical resolution generally needed for the preparation of axially chiral ligands and shows high reactivity and enantioselectivity in Rh-catalyzed asymmetric hydrogenations.
      PubDate: 2017-11-27T22:15:54.496334-05:
      DOI: 10.1002/adsc.201701281
       
  • Recent Developments in the [5+2] Cycloaddition
    • Authors: Hélène Pellissier
      Abstract: The [5+2] cycloaddition allows the synthesis of a diversity of complex highly functionalized seven-membered products in a single step. These cycloadducts can be further readily synthetically manipulated to be applied in the synthesis of a number of complex natural products and important biologically active products containing seven-membered rings. In addition to the common and highly efficient [5+2] cycloadditions of (oxido)pyrylium and (oxido)pyridinium ions with various -systems, providing an easy access to a wide range of novel heterocyclic seven-membered rings exhibiting an oxygen or nitrogen bridge, the metal-catalyzed [5+2] cycloadditions still attract a great attention and have become one of the most popular ways of constructing seven-membered compounds. Among the most important reactions are metal-catalyzed (hetero)-[5+2] cycloadditions of vinyl-substituted three-membered rings, rhodium-catalyzed [5+2] cycloadditions of 3-acyloxy-1,4-enynes, and metal-catalyzed [5+2] cycloadditions of ortho-vinylphenols and ortho-vinyl/arylanilines.
      PubDate: 2017-11-27T22:15:35.70985-05:0
      DOI: 10.1002/adsc.201701379
       
  • (E)-3-(Alkoxycarbonyl-2-Alkyliden)-2-Oxindoles: Multidentate
           Pronucleophiles for the Organocatalytic, Vinylogous Michael Addition to
           Nitroolefins
    • Authors: Claudio Curti; Lucia Battistini, Andrea Sartori, Gloria Rassu, Giorgio Pelosi, Marco Lombardo, Franca Zanardi
      Abstract: We introduce 3-(alkoxycarbonyl-2-alkyliden)-2-oxindoles as pronucleophilic donors in the direct, vinylogous Michael addition to nitroolefins orchestrated by a chiral, bifunctional cinchona-thiourea organocatalyst. This reaction displays excellent levels of γ-site-, diastereo- and enantioselectivity delivering valuable enantioenriched functionalized oxindoles. Of note, the C-γ enolization of these pronucleophiles by the organocatalyst generates a multidentate, captodative dienolate that delivers vinylogous adducts with an unprecedented Z-selectivity through a peculiar interaction with the catalyst and the nitroolefin. The optimized procedure is operatively simple: the reaction is conducted in air, at room temperature, with low catalyst loading (up to 1 mol%). The synthetic versatility of these Michael adducts is demonstrated by several transformations leading to a valuable quaternary oxindolyl proline analogue and a chiral spirocyclic furoindolone structure. Finally, a mechanistic rationale and a suitable transition state accounting for the observed selectivities are proposed, which are supported by DFT calculations.
      PubDate: 2017-11-27T02:18:11.086984-05:
      DOI: 10.1002/adsc.201701164
       
  • Chiral Phosphoric Acid Catalyzed Enantioselective Friedel-Crafts Reaction
           of N-Protected 4-Aminoindoles with β,γ-Unsaturated α-Ketimino Esters
    • Authors: Yuyang Ding; Dengfeng Xu, Shanshui Meng, Albert S. C. Chan, Yang Li, Junling Zhao
      Abstract: Through a hydrogen bonding guided substrate modification strategy, we have developed a chiral phosphoric acid catalyzed highly enantioselective Friedel-Crafts reaction of N-protected 4-aminoindoles with β,γ-unsaturated α-ketimino esters. The mechanism and origins of the enantioselectivity of this process are indentified using DFT calculations. Both the experimental and calculation results indicated that the NH moiety on the indole C4 position is essential for the stereocontrol of the reaction. To further examine the potential usefulness of this method, gram scale synthesis and derivatizations of one of the products were also carried out.
      PubDate: 2017-11-26T22:21:08.01679-05:0
      DOI: 10.1002/adsc.201701354
       
  • Hydrogenation of Carbonyl Derivatives Catalysed by Manganese Complexes
           Bearing Bidentate Pyridinyl-Phosphine Ligands
    • Authors: Duo WEI; Antoine Bruneau-Voisine, Téo Chauvin, Vincent Dorcet, Thierry Roisnel, Dmitry Valyaev, Noël Lugan, Jean-Baptiste Sortais
      Abstract: Manganese(I) catalysts incorporating readily available bidentate 2-aminopyridinyl-phosphine ligands achieve a high efficiency in the hydrogenation of carbonyl compounds, significantly better than parent ones based on more elaborated and expensive tridentate 2,6-(diaminopyridinyl)-diphosphine ligands. The reaction proceeds with low catalyst loading (0.5 mol%) under mild conditions (50 °C) with yields up to 96%.
      PubDate: 2017-11-26T22:21:01.095235-05:
      DOI: 10.1002/adsc.201701115
       
  • Ligand-free Iron(II)-catalyzed N-Alkylation of Hindered Secondary
           Arylamines with Non-activated Secondary and Primary Alcohols via a
           Carbocationic Pathway
    • Authors: Onkar S. Nayal; Maheshwar S. Thakur, Manoranjan Kumar, Neeraj Kumar, Sushil Maurya
      Abstract: Secondary benzylic alcohols represent a challenging class of substrates for N-alkylation of amines. Herein, we described an iron(II)-catalyzed eco-friendly protocol for N-alkylation of secondary arylamines with secondary benzyl alcohols through a carbocationic pathway instead of known borrowing hydrogen transfer (BHT) approach. Transiently generated carbocations, produced from alcohols via self-condensation, were coupled with arylamines to provide highly functionalized amine products. The scope of this methodology involves N-alkylation of primary, secondary and heterocyclic amines with primary/secondary benzylic, allylic and heterocyclic alcohols, which are common key structures in numerous pharmaceuticals drugs. The method can also be easily adopted for the amination of various natural products.
      PubDate: 2017-11-26T22:20:40.677157-05:
      DOI: 10.1002/adsc.201701183
       
  • BF3•OEt2-Promoted Annulation for Substituted 2-Arylpyridines as Potent
           UV Filters and Antibacterial Agents
    • Authors: Sabera Sultana; Shizuka Mei Bautista Maezono, Muhammad Saeed Akhtar, Jae-Jin Shim, Young-Jung Wee, Sung Hong Kim, Yong Rok Lee
      Abstract: A simple and efficient BF3∙OEt2 mediated methodology for the construction of diverse 2-phenylpyridines bearing benzophenone moieties from readily available 3-formylchromones and phenylacetylenes in wet acetonitrile was developed. The nitrogen source for the pyridine construction was derived from acetonitrile. This one-pot protocol proceeds via [3+2+1] annulation through cascade nucleophilic addition, hydrolysis, Michael-type addition, ring opening, and elimination reactions. The synthesized compounds may have applications as UV filters and exhibit potent antibacterial activities.
      PubDate: 2017-11-23T22:03:01.923356-05:
      DOI: 10.1002/adsc.201701137
       
  • Organocatalytic Enantioselective Functionalization of Hydroxyquinolines
           through an aza-Friedel-Crafts Alkylation with Isatin-derived Ketimines
    • Authors: Carlos Vila; Alejandra Rendón-Patiño, Marc Montesinos-Magraner, Gonzalo Blay, M. Carmen Muñoz, José Pedro
      Abstract: A highly enantioselective addition of hydroxyquinolines to isatin-derived ketimines has been realized using a quinine-derived thiourea organocatalyst. The reaction affords chiral 3-amino-2-oxindoles bearing a quinoline moiety with a quaternary stereocenter in high yields (up to 98%) and excellent enantioselectivities (up to 99%). Moreover, we can extend this methodology for the enantioselective functionalization of 5-hydroxyisoquinoline. This methodology represents, to the best of our knowledge, the first enantioselective addition of hydroxyquinolines to imines.
      PubDate: 2017-11-23T22:02:56.30525-05:0
      DOI: 10.1002/adsc.201701217
       
  • Distal Functional Group Migration for Visible-light Induced
           Carbo-difluoroalkylation/ monofluoroalkylation of Unactivated Alkenes
    • Authors: Chen Zhu; Jiajia Yu, Dongping Wang, Yan Xu, Zhen Wu
      Abstract: A general and practical protocol for elusive carbo-difluoroalkylation/ monofluoroalkylation of unactivated alkenes based on the distal functional group migration is described. A portfolio of functional groups including heteroaryl, imino, formyl, and alkynyl groups showcase the migratory aptitude. In combination with visible-light photocatalysis, a broad range of di- and mono-fluorinated alkyl ketones are readily obtained in synthetically useful yields under mild reaction conditions.
      PubDate: 2017-11-23T22:02:32.340828-05:
      DOI: 10.1002/adsc.201701229
       
  • Metal-free Thiolation of Imidazopyridines with Functionalized Haloalkanes
           Using Elemental Sulfur
    • Authors: Jun-Rong Zhang; Ling-Zhi Zhan, Liang Wei, Yun-Yun Ning, Xiao-Lin Zhong, Jing-Xiong Lai, Li Xu, Ri-Yuan Tang
      Abstract: The assembly of two functional molecules via a sulfur-linking atom allows for access to a diverse array of thioether-containing compounds. Herein, we disclose a metal-free thiolation of imidazopyridines with a variety of functionalized haloalkanes using elemental sulfur.
      PubDate: 2017-11-19T21:51:14.39531-05:0
      DOI: 10.1002/adsc.201701190
       
  • Copper-Catalyzed Dehydrative Cyclization of 1-(2-Hydroxyphenyl)-propargyl
           Alcohols with P(O)H Compounds for the Synthesis of 2-Phosphorylmethyl
           Benzofurans
    • Authors: Ming Zhang; Jianlin Yang, Qing XU, Chao Dong, Li-Biao Han, Ruwei Shen
      Abstract: A Cu(MeCN)4BF4-catalyzed dehydrative reaction of 1-(2-hydroxyphenyl)propargyl alcohols with diarylphosphine oxides has been developed to provide an efficient synthesis of phosphorylated benzofurans in good to high yields. In the presence of a catalytic amount of an organic base, a variety of H-phosphonates and H-phosphinates can also be employed as good substrates to produce the corresponding products in moderate yields. The reaction has significant economical and ecological advantages since the formation of a new Csp3−P bond and the benzofuran framwork could both be achieved using an inexpensive copper catalyst with water produced as the sole byproduct. The synthetic transformations of the product have also been demonstrated.
      PubDate: 2017-11-18T00:31:18.615318-05:
      DOI: 10.1002/adsc.201701368
       
  • Microwave-Assisted Synthesis of Benzimidazole-Linked Indoline and Indole
           Hybrids from C-2-Linked o-Amino Benzyl Benzimidazoles
    • Authors: Yun-Ta Lee; Fengyu Chiu, Indrajeet Barve, Chung-Ming Sun
      Abstract: An efficient and novel synthesis of benzimidazole-linked indoline hybrids via an unconventional Pictet-Spengler type condensation of C-2 linked o-aminobenzyl benzimidazole with aldehydes and ketones under microwave irradiation is explored. The key condensation step consists of acid catalyzed imine generation followed by intramolecular C-C bond formation through unique reactivity of benzimidazole moiety. The scope of this method is further extended to synthesize tetracyclic pyrrolo indole benzoimidazole carboxylates through 2-carboxyaldehydes.
      PubDate: 2017-11-18T00:31:09.329285-05:
      DOI: 10.1002/adsc.201701140
       
  • Intermolecular Rhodium(II)-Catalyzed Allylic C(sp3)-H Amination of Cyclic
           Enamides
    • Authors: Isabelle Gillaizeau; Philippe Dauban, Gregory jestin, Romain Rey-Rodriguez, pascal retailleau, Benjamin Darses
      Abstract: The intermolecular Rh(II)-catalyzed C(sp3)–H amination of enamides gives access to new 4-aminopiperidine derivatives that are useful building blocks in medicinal chemistry. This efficient transformation proceeds at room temperature with complete regio- and chemoselectivity in favor of the allylic C(sp3)–H bond, and has a broad functional group tolerance. In addition, the matched combination of the chiral Rh2(S-nta)4 (nta = (S)-N-1,8-naphthoylalanine) with an optically pure (S)-sulfonimidamide allows isolation of allylic amines with excellent stereocontrol.
      PubDate: 2017-11-18T00:30:53.311861-05:
      DOI: 10.1002/adsc.201701188
       
  • Synthesis of Fused-Pyrazines via Palladium-Catalyzed Double Benzyl
           Isocyanide Insertion and Cross-Dehydrogenative Coupling
    • Authors: Gopal Chandru Senadi; Bing-Chun Guo, Yu-Ching Chang, Wan-Ping Hu, Jeh-Jeng Wang
      Abstract: A palladium-catalyzed cascade reaction has been realized for the synthesis of 5H-pyrrolo[2,3-b]pyrazines and 5H-pyrazino[2,3-b]indoles with benzyl isocyanide by choosing o-pivaloyloximes or o-iodoanilines as a suitable substrate. The key steps involved are (i) oxidative addition of palladium through N-O or C-I cleavage; (ii) migratory double isocyanide insertion; and (iii) cross-dehydrogenative coupling. Notable features are good functional group tolerance, formation of three C-C and one C-N bonds.
      PubDate: 2017-11-14T21:55:54.991938-05:
      DOI: 10.1002/adsc.201701202
       
  • Synthesis of Carbazoles from 2-Iodobiphenyls by Palladium-Catalyzed C–H
           Activation and Amination with Diaziridinone
    • Authors: Changdong Shao; Bo Zhou, Zhuo Wu, Xiaoming Ji, Yanghui Zhang
      Abstract: A facile and efficient approach has been developed for the synthesis of carbazoles from 2-iodobiphenyls and diaziridinone under palladium catalysis. A wide range of carbazoles were synthesized in good to excellent yields, and indole derivatives were obtained by using styrenes as the substrate. The palladacycles obtained from 2-iodobiphenyls acted as the key intermediate, and the reaction should proceed via a tandem Pd-catalyzed C–H activation/dual C–N bond formation sequence.
      PubDate: 2017-11-13T21:50:32.845008-05:
      DOI: 10.1002/adsc.201701039
       
  • Lewis Acid Catalyzed Reductive Amination of Aldehydes and Ketones with
           N,N-Dimethylformamide as Dimethyl Amino Source, Reductant and Solvent
    • Authors: Luo Yang; Jie Lin, Wang Zhou, Da-You Ma
      Abstract: A practical zinc acetate dihydrate catalyzed reductive amination of various carbonyl compounds with DMF as Me2N source, reductant and solvent is developed. This reaction shows broad substrate scope, good functionality tolerance, avoids pressure-proof reactor and column chromatograph isolation with up to 98 % yield, to make it an attractive method for the preparation of N,N-dimethyl tertiary amines.
      PubDate: 2017-11-13T21:50:28.01627-05:0
      DOI: 10.1002/adsc.201701221
       
  • Asymmetric Vinylogous Mannich-Type Addition of alfa,alfa-Dicyanoalkenes to
           alfa-Fluoroalkyl Sulfinyl Imines
    • Authors: Alvaro Sanz-Vidal; Javier Torres Fernández, Vadim Soloshonok, Yi Zhu, Jianlin Han, Santos Fustero, Carlos del Pozo
      Abstract: Abstract. The asymmetric vinylogous Mannich reaction (AVMR) of alfa,alfa-dicyanoalkenes with alfa-fluoroalkyl sulfinyl imines has been successfully accomplished. This transformation is unprecedented with fluorinated imines at the same time as the use of dicyanoalkenes in AVMR has been scarcely reported. Several fluorinated sulfinyl imines are compatible with the process, which gaves access to a family of chiral fluorinated amines with excellent level of stereocontrol. Interestingly, the selectivity found in our protocol is reverse to that encountered in analogous AVMR previously reported. Additionally, the synthetic applicability of the addition products has been exemplified with several transformations showing the particular reactivity of the dicyanoalkene moiety of these alfa-fluorinated amines.
      PubDate: 2017-11-12T21:56:31.560744-05:
      DOI: 10.1002/adsc.201701284
       
  • Synthesis of Cyclobutene-Fused Eight-Membered Carbocycles through
           Gold-Catalyzed Intramolecular Enyne [2+2] Cycloaddition
    • Authors: Tomohiro Iwai; Masahiro Ueno, Hiori Okochi, Masaya Sawamura
      Abstract: Cationic gold(I) complexes with hollow-shaped triethynylphosphine ligands efficiently catalyzed intramolecular [2+2] cycloaddition of 1,9-enynes to afford cyclobutene-fused eight-membered carbocycles that were difficult to synthesize by other catalytic systems. Various 1,9-enynes with carbon linkers with or without a fused ring underwent efficient [2+2] cycloaddition with 5 mol% of the Au catalyst bearing the triarylmethyl-end-capped triethynylphosphine in CH2Cl2 at rt in the presence of MS 4A as an additive. More challenging 1,9-enyne substrates with fully saturated acyclic carbon linkers underwent eight-membered ring formation at 60 °C in ClCH2CH2Cl in the absence of MS 4A, forming monocyclic 1,3-dienes as major products.
      PubDate: 2017-11-12T21:50:41.977-05:00
      DOI: 10.1002/adsc.201701193
       
  • Direct ortho-Acyloxylation of Arenes and Alkenes by Cobalt Catalysis
    • Authors: Cong Lin; Zhengkai Chen, Zhanxiang Liu, Yuhong Zhang
      Abstract: An efficient protocol of cobalt-catalyzed acyloxylation of arenes and alkenes with the assistance of 8-aminoquinolyl auxiliary is reported. In this transformation, benzoic acids, alkenyl acids, and aliphatic acids could be readily involved to afford structurally diverse esters. It is worth noting that the Ag2SO4 oxidant is renewable and the directing group could be removed and recycled. The strategy represents the first successful example of transition-metal-catalyzed acyloxylation of alkenyl carboxamides C(sp2)-H bonds with carboxylic acids.
      PubDate: 2017-11-11T07:21:03.515403-05:
      DOI: 10.1002/adsc.201701144
       
  • Enantioselective Oxy-Heck-Matsuda Arylations: Expeditious Synthesis of
           Dihydrobenzofuran Systems and Total Synthesis of the Neolignan
           (-)-Conocarpan
    • Authors: Carlos Roque Correia; Allan Ribeiro, Ellen Polo, Nelson Martins
      Abstract: This work discloses the first examples of an effective enantioselective oxy-Heck-Matsuda reaction using a variety of styrenic olefins to generate chiral dihydrobenzofurans. The reaction proceeds in moderate to good yields, with high trans diastereoselectivity (up to 20:1) in enantioselectivities up to 90:10 using the N,N-ligand pyrimidine-bisoxazoline (PyriBox) L7. The oxy-Heck-Matsuda reactions are carried out under mild conditions and rather low catalyst loading. The feasibility and practicality of the process is demonstrated by a concise total synthesis of the neolignan (-)-conocarpan. X-ray diffraction of an advanced brominated intermediate in route to (-)-conocarpan has allowed unequivocal assignment of the absolute stereochemistry of the oxy-Heck-Matsuda aryl dihydrobenzofuran adducts. A rationale for the mechanism operating in these enantioselective oxy-Heck-Matsuda reactions is also presented.
      PubDate: 2017-11-11T07:20:53.508013-05:
      DOI: 10.1002/adsc.201701278
       
  • Use of Nucleoside Phosphorylases for the Preparation of Purine and
           Pyrimidine 2′-Deoxynucleosides
    • Authors: Mikhail S. Drenichev; Cyril S. Alexeev, Nikolay N. Kurochkin, Sergey Mikhailov
      Abstract: Enzymatic transglycosylation - a transfer of the carbohydrate moiety from one heterocyclic base to another - is being actively developed and applied for the synthesis of practically important nucleosides. This reaction is catalyzed by nucleoside phosphorylases (NPs), which are responsible for reversible phosphorolysis of nucleosides to yield the corresponding heterocyclic bases and monosaccharide 1-phosphates. We found that 7-methyl-2′-deoxyguanosine (7-Me-dGuo) is an efficient and novel donor of the 2-deoxyribose moiety in the enzymatic transglycosylation for the synthesis of purine and pyrimidine 2'-deoxyribonucleosides in excellent yields. Unlike 7-methylguanosine, its 2ʹ-deoxy derivative is dramatically less stable. Fortunately, we have found that 7-methyl-2′-deoxyguanosine hydroiodide may be stored for 24 h in Тris-HCl buffer (pH 7.5) at room temperature without significant decomposition.In order to optimize the reagent ratio, a series of analytical transglycosylation reactions were conducted at ambient temperature. According to HPLC analysis of transglycosylation reactions, the product 5-ethyl-2′-deoxyuridine (5-Et-dUrd) was obtained in high yield (84-93%) by using a small excess (1.5 and 2.0 equiv.) of 7-Me-dGuo over 5-ethyluracil (5-Et-Ura) and 0.5 equiv. of inorganic phosphate. Thymidine is a less effective precursor of α-D-2-deoxyribofuranose-1-phosphate (dRib-1p) compared to 7-Me-dGuo.We synthesized 2'-deoxyuridine, 5-Et-dUrd, 2'-deoxyadenosine and 2'-deoxyinosine on a semi-preparative scale using the optimized reagents ratio (1.5:1:0.5) in high yield.Unlike other transglycosylation reactions, the synthesis of 2-chloro-2'-deoxyadenosine was performed in heterogeneous medium because of the poor solubility of initial 2-chloro-6-aminopurine. Nevertheless, this nucleoside was prepared in good yield. The developed enzymatic procedure for the preparation of 2'-deoxynucleosides may compete with the known chemical approaches.
      PubDate: 2017-11-08T21:56:15.267729-05:
      DOI: 10.1002/adsc.201701005
       
  • One-pot Domino Synthesis of Diarylalkynes/1,4-Diaryl-1,3-diynes by
           [9,9-Dimethyl-4,5-bis(diphenylphosphino)xanthene]Copper(I)
           
    • Authors: Shaozhong Qiu; Caiyang Zhang, Rui Qiu, Guodong Yin, Jinkun Huang
      Abstract: Abstract. The low loading combination of complex [9,9-dimethyl-4,5-bis(diphenylphosphino)xanthene]copper (I) iodide and simple ligand-free palladium (II) acetate was found efficient for the domino synthesis of diarylalkynes by the reaction of aryl halides with trimethylsilylethynylene or bis(trimethylsilyl)acetylene in a single-step procedure. The unsymmetrical diarylalkynes can be obtained through a one-pot two-step approach. The reactions of aryl bromides with 1,4-bis(trimethylsilyl)butadiyne also furnished the corresponding 1,4-diaryl-1,3-diynes in a similar fashion. This route to diarylalkynes and 1,4-diaryl-1,3-diynes is complementary to previously reported synthetic procedures.
      PubDate: 2017-11-07T21:55:53.651652-05:
      DOI: 10.1002/adsc.201701128
       
  • Computationally-led Ligand Modification using Interplay between Theory and
           Experiments: Highly Active Chiral Rhodium Catalyst Controlled by
           Electronic Effects and CH–π Interactions
    • Authors: Toshinobu Korenaga; Ryo Sasaki, Toshihide Takemoto, Toshihisa Yasuda, Masahito Watanabe
      Abstract: A novel chiral ligand for the rhodium-catalyzed asymmetric 1,4-addition of arylboronic acid to a coumarin substrate that could markedly reduce catalyst loading was developed using interplay between theoretical and experimental approaches. Evaluation of the transition states for insertion and for hydrolysis of intermediate complexes (which were emphasized in response to the experimental results) using DFT calculations at the B97D/6-31G(d) with the LANL2DZ basis set for rhodium revealed that: a) the electron-poor nature of the ligands; and b) CH–π interactions between the ligand and coumarin substrates played significant roles in both acceleration of insertion and inhibition of ArB(OH)2 decomposition (protodeboronation). The computationally-designed novel ligand, incorporating above information, decreased the catalyst loading up to 0.025 mol% (S/C = 4,000), which is less than one one-hundredth relative to past catalyst loadings of typically 3 mol%, with almost complete enantioselectivity. Furthermore, the gram-scale synthesis of the urological drug, (R)-Tolterodine (L)-tartrate, was demonstrated without the need of intermediary purification.
      PubDate: 2017-11-06T21:51:00.334305-05:
      DOI: 10.1002/adsc.201701191
       
  • Lewis basicity of water for a selective monodehalogenation of
           α,α-dihaloketones to α-haloketones and mechanistic study
    • Authors: Beeraiah Baire; Santu Sadhukhan
      Abstract: Abstract. The Lewis base character of the greenest reagent water has been explored over its nucleophilic property for an organic transformation. Utilizing this concept, a new strategy for the highly controlled and selective mono-dehalogenation of -dihaloketones has been discovered and reported in this manuscript. Extending this concept, first direct conversion of propargylic acetates to corresponding -iodoketones via -dihaloketones has also been efficiently achieved under metal free conditions. During the later process, water has been concurrently employed as a nucleophile and a Lewis base. Employing this type of dual reactivity of water may be for the first time in the context of organic synthesis. Control experiments supported the involvement of the enoalte as an intermediate during the monodehalogneation process.
      PubDate: 2017-11-01T21:55:47.250145-05:
      DOI: 10.1002/adsc.201701233
       
  • Organocatalytic Enantioselective Friedel-Crafts Alkylation/Lactonization
           Reaction of Hydroxyindoles with Methylene Oxindoles
    • Authors: Mengjie Xiao; Dengfeng Xu, Weihong Liang, Wenyu Wu, Albert S. C. Chan, Junling Zhao
      Abstract: The indole benzene ring functionalization was achieved using an organocatalytic enantioselective Friedel-Crafts alkylation/lactonization reaction of hydroxyindoles with a variety of substituted methylene oxindoles. This reaction was applicable to indoles with the hydroxy group substituted at the different positions of the benzene ring, and the corresponding pyrrolodihydrocoumarins were obtained in moderate to high yields (37-99%) with high stereoselectivities (up to 99% ee and>20:1 dr) in most cases. A scale-up reaction and derivation of the representative products were also carried out to investigate the usefulness of this protocol.
      PubDate: 2017-10-27T23:40:53.845474-05:
      DOI: 10.1002/adsc.201701089
       
  • Front Cover Picture: Asymmetric Construction of Spiropyrazolone Skeletons
           via Amine-Catalyzed [3+3] Annulation (Adv. Synth. Catal. 2/2018)
    • Authors: Hai-Jun Leng; Qing-Zhu Li, Rong Zeng, Qing-Song Dai, Hong-Ping Zhu, Yue Liu, Wei Huang, Bo Han, Jun-Long Li
      Pages: 193 - 193
      Abstract: The front cover picture, provided by Jun-Long Li, Bo Han and co-workers, illustrates an efficient asymmetric synthesis of structurally and stereochemically complex spiropyrazolones from simple, readily available starting materials. This approach is atom-economic, environmentally benign and compatible with many functional groups. It supports gram-scale production and diversity-oriented synthesis. This work is dedicated to Chengdu University on the occasion of its 40th anniversary. Details of this work can be found in the communication on pages 229–234 (H.-J. Leng, Q.-Z. Li, R. Zeng, Q.-S. Dai, H.-P. Zhu, Y. Liu, W. Huang, B. Han, J.-L. Li, Adv. Synth. Catal. 2018, 360, 229–234;
      DOI : 10.1002/adsc.201701035).
      PubDate: 2017-11-27T07:50:57.921282-05:
       
  • Organocatalytic Asymmetric Synthesis of Six-Membered Carbocycle-Based
           Spiro Compounds
    • Authors: Xin Xie; Wei Huang, Cheng Peng, Bo Han
      Pages: 194 - 228
      Abstract: Well-developed asymmetric organocatalysis has been widely incorporated in various cascade/tandem sequences, providing a simple access to structurally complex target molecules in a highly stereoselective fashion, including spirocyclic compounds. Among all types of spirocyclic skeletons, those containing a six-membered carbocyclic ring are recognized as an important core framework with up to six consecutive stereogenic centers and this motif is commonly found in many natural products, biologically active molecules and lead compounds. This review describes the asymmetric synthesis of spirocyclic compounds containing six-membered carbocycles using small organic molecules as catalysts.
      PubDate: 2017-11-16T09:21:45.20484-05:0
      DOI: 10.1002/adsc.201700927
       
  • Asymmetric Construction of Spiropyrazolone Skeletons via Amine-Catalyzed
           [3+3] Annulation
    • Authors: Hai-Jun Leng; Qing-Zhu Li, Rong Zeng, Qing-Song Dai, Hong-Ping Zhu, Yue Liu, Wei Huang, Bo Han, Jun-Long Li
      Pages: 229 - 234
      Abstract: Here we report a secondary amine-catalyzed, highly enantioselective [3+3] cyclization reaction of α-alkylidene pyrazolinones and α,β-unsaturated aldehydes, which facilely delivers a variety of enantioenriched spiropyrazolones showing structural and stereochemical complexity. The reaction uses an iminium ion activation strategy to activate both the β- and ipso-positions of the enals as dielectrophilic sites. A broad range of substrates are compatible with this mild reaction system.
      PubDate: 2017-10-27T04:28:43.673504-05:
      DOI: 10.1002/adsc.201701035
       
  • Palladium-Catalyzed Cross-Coupling/Annulation Cascade for Synthesis of
           9-Hydroxy and 9-Aminofluorenes.
    • Authors: Benjamin François; Luc Szczubelek, Fabienne Berrée, Thierry Roisnel, Bertrand Carboni
      Pages: 235 - 241
      Abstract: 9-Hydroxyfluorenes are easily synthesized via a tandem Suzuki/phenolic aldolisation sequence. This process was extended to 9-aminofluorenes by simply adding various amines as third partners. X-ray structures and NMR studies confirmed the presence of intermolecular O−H ⋅ ⋅ ⋅ N hydrogen bonding.
      PubDate: 2017-11-08T06:50:40.959235-05:
      DOI: 10.1002/adsc.201701146
       
  • Ester Synthesis in Water: Mycobacterium smegmatis Acyl Transferase for
           Kinetic Resolutions
    • Authors: Nicolas de Leeuw; Guzman Torrelo, Carolin Bisterfeld, Verena Resch, Luuk Mestrom, Emanuele Straulino, Laura van der Weel, Ulf Hanefeld
      Pages: 242 - 249
      Abstract: The acyl transferase from Mycobacterium smegmatis (MsAcT) catalyses transesterification reactions in aqueous media because of its hydrophobic active site. Aliphatic cyanohydrin and alkyne esters can be synthesised in water with excellent and strikingly opposite enantioselectivity [(R);E>37 and (S);E>100, respectively]. When using this enzyme, the undesired hydrolysis of the acyl donor is an important factor to take into account. Finally, the choice of acyl donor can significantly influence the obtained enantiomeric excesses.
      PubDate: 2017-11-08T06:50:29.763804-05:
      DOI: 10.1002/adsc.201701282
       
  • Iodobenzene Dichloride/Zinc Chloride-Mediated Synthesis of
           N-Alkoxyindole-3-carbonitriles from 3-Alkoxyimino-2-arylalkylnitriles via
           Intramolecular Heterocyclization
    • Authors: Zhongxiang Yun; Ran Cheng, Jiyun Sun, Daisy Zhang-Negrerie, Yunfei Du
      Pages: 250 - 254
      Abstract: A series of N-alkoxyindole-3-carbonitriles were synthesized, under mild conditions, via intramolecular heterocyclization of the readily available 3-alkoxyimino-2-arylalkylnitriles mediated by iodobenzene dichloride/zinc chloride. The mechanism of the reaction proposes the formation of a key intermediate of nitrenium cation from a chlorination and dechlorination process facilitated by the hypervalent iodine reagent and Lewis acid respectively.
      PubDate: 2017-11-08T01:35:26.641043-05:
      DOI: 10.1002/adsc.201701111
       
  • Cobalt-Catalyzed Diastereoselective [4+2] Annulation of Phosphinamides
           with Heterobicyclic Alkenes at Room Temperature
    • Authors: Rajender Nallagonda; Neetipalli Thrimurtulu, Chandra M. R. Volla
      Pages: 255 - 260
      Abstract: Cobalt-catalyzed sp2 C−H bond functionalization of diarylphosphinamides with heterobicyclic alkenes was demonstrated at room temperature employing commercially available cobalt(II)-salts. The effectiveness of this strategy was illustrated with the reaction of various 8-aminoquinoline derived phosphinic amides and 7-oxa/azabenzonorbornadienes. The reaction conditions exhibited excellent functional group tolerance and high diastereoselectivities. Furthermore, extension of this approach to the preparation of polyaryl cyclic phosphinamides was achieved through the dehydrative ring opening/aromatization sequence.
      PubDate: 2017-11-06T06:08:51.216446-05:
      DOI: 10.1002/adsc.201701162
       
  • FeCl3–Catalyzed Cascade Reactions of Cyclic Amines with
           2-Oxo-2-arylacetic Acids toward Furan-2(5H)-one Fused N,O-Bicyclic
           Compounds
    • Authors: Xiaonan Shi; Yan He, Xinying Zhang, Xuesen Fan
      Pages: 261 - 266
      Abstract: A novel and efficient synthesis of furan-2(5H)-one fused N,O-containing bicyclic compounds via the cascade reactions of N-aryl substituted cyclic amines with 2-oxo-2-arylacetic acids is presented. Mechanistically, the formation of the title compounds is initiated by the in situ formation of a cyclic enamine intermediate via FeCl3/di-tert-butyl peroxide (TBP)/oxygen (O2)-promoted C(sp3)−H dehydrogenation of saturated cyclic amine. Nucleophilic addition of the cyclic enamine intermediate onto 2-oxo-2-arylacetic acid followed by cyclization and dehydration gives the bicyclic heterocycle products. This intermolecular oxidative annulation constitutes an extension of tertiary amine-based Mannich-type β-functionalization leading to a series of N,O-bycyclic compounds in good yields with ease.
      PubDate: 2017-11-06T06:07:16.315831-05:
      DOI: 10.1002/adsc.201701053
       
  • Visible light induced Trifluoromethyl Migration: Easy Access to
           α-Trifluoromethylated Ketones from Enol Triflates
    • Authors: Shuyang Liu; Jiyang Jie, Jipan Yu, Xiaobo Yang
      Pages: 267 - 271
      Abstract: Herein, we reported a novel method to synthesize α-trifluoromethylated ketones from enol triflates. Involving a cascade sulfur dioxide extrusion and a CF3 (trifluoromethyl) radical addition process, this reaction proceeds at room temperature and is driven by visible light irradiation. This protocol bears good functional group compatibility, which can generate the desired products in good to excellent yields even in gram scale. It is hoped that this approach to generate CF3 radicals from enol triflates can be used in other radical-involved reactions.
      PubDate: 2017-11-06T06:07:00.979472-05:
      DOI: 10.1002/adsc.201701051
       
  • Selective Oxidative Coupling Reaction of Isocyanides Using Peroxide as
           Switchable Alkylating and Alkoxylating Reagent
    • Authors: Xinglu Zhang; Zhiqiang Liu, Yu Gao, Feng Li, Yaming Tian, Chunju Li, Xueshun Jia, Jian Li
      Pages: 272 - 277
      Abstract: A switchable oxidative coupling reaction of isocyanide and peroxide has been disclosed. In the presence of iron catalyst, the coupling reaction affords N-arylacetamides in good yields. By simply replacing the iron with copper catalyst, another different coupling reaction takes place in which peroxide can serve as alkoxylating source. This protocol represents a new fundamental coupling of two basic chemicals involving C−C and C−O bond-forming process. The unusual reactivity of an isocyano group in a radical reaction acting formally as an amidoyl synthon has also been well established. The experiment outcome reveals that aromatic isocyanides are particularly compatible reaction partners in present coupling reaction, whereas no desired products are observed when aliphatic isocyanides are used.
      PubDate: 2017-11-06T06:02:04.058323-05:
      DOI: 10.1002/adsc.201700953
       
  • Metal-Free One-Pot Synthesis of (Tetrahydro)Quinolines through
           Three-Component Assembly of Arenediazonium Salts, Nitriles, and Styrenes
    • Authors: So Won Youn; Huen Ji Yoo, Eun Mi Lee, Seo Young Lee
      Pages: 278 - 283
      Abstract: A highly efficient and convenient metal-free, one-pot synthesis of diversely substituted (tetrahydro)quinolines has been achieved through a three-component assembly reaction of arenediazonium salts, nitriles, and styrenes. In sharp contrast to the prior works with the same reagent blend, the formation of N-arylnitrilium intermediates from arenediazonium salts and nitriles was followed by reaction with styrenes, leading to 3,4-dihydroquinolinium salts as a common intermediate. These could be further transformed to quinolines and tetrahydroquinolines depending on the reaction conditions. The advantages of this protocol include its simplicity, metal-free and mild conditions, readily available starting materials, and good functional group tolerance.
      PubDate: 2017-12-12T03:11:28.150694-05:
      DOI: 10.1002/adsc.201701451
       
  • Nickel-Catalyzed Denitrogenative Annulation of
           1,2,3-Benzotriazin-4-(3H)-ones with Benzynes for Construction of
           Phenanthridinone Scaffolds
    • Authors: Vijaykumar H. Thorat; Nitinkumar Satyadev Upadhyay, Masahiro Murakami, Chien-Hong Cheng
      Pages: 284 - 289
      Abstract: The synthesis of phenanthridinones via denitrogenative annulation of 1,2,3-benzotriazin-4-(3H)-ones with arynes catalysed by Ni(0)/dppm was successfully developed. A variety of phenanthridinones were prepared in good to excellent yields. Based on this method, nature product, N-methylcrinasidine, was synthesized.
      PubDate: 2017-12-12T03:10:02.915909-05:
      DOI: 10.1002/adsc.201701143
       
  • Synthesis of Diverse Nitrogen Heterocycles via Palladium-Catalyzed Tandem
           Azide–Isocyanide Cross-Coupling/Cyclization: Mechanistic Insight using
           Experimental and Theoretical Studies
    • Authors: Arshad J. Ansari; Ramdas S. Pathare, Antim K. Maurya, Vijai K. Agnihotri, Shahnawaz Khan, Tapta Kanchan Roy, Devesh M. Sawant, Ram T. Pardasani
      Pages: 290 - 297
      Abstract: A rapid and elegant tandem azide–isocyanide cross-coupling/cyclization protocol has been developed based on a nitrene transfer reaction. The palladium-catalyzed ligand-free methodology led to the synthesis of three different heterocyclic scaffolds with excellent atom/step/redox economy. Studies based on first-principles-based quantum calculations and control experiments unraveled a concerted process of nitrene transfer reaction on isocyanides, ruling out the metallaaziridine intermediate reported earlier. This finding could pave the way for novel applications of nitrene transfer reactions to generate bioactive heterocycles.
      PubDate: 2017-11-30T08:41:55.228014-05:
      DOI: 10.1002/adsc.201700928
       
  • One-Pot Synthesis of N-Alkyl Benzotriazoles via a Brønsted Acid-Catalyzed
           Three-Component Reaction
    • Authors: Xiangdong Wang; Chunqi Jia, Yadong Feng, Lianhui Wang, Xiuling Cui
      Pages: 374 - 378
      Abstract: A novel three-component condensation reaction of benzotriazoles, aldehydes and tertiary anilines efficiently catalyzed by readily available organic acid p-toluenesulfonic acid (PTSA) has been developed. A series of N-alkyl benzotriazoles were synthesized in up to 97% yield for 21 examples starting from anilines, benzotriazoles and formaldehyde. This strategy features a simple system, atom economy, environmental friendliness, high efficiency, excellent regioselectivity, good functional group tolerance, easily available starting materials, and cheap catalyst. The mechanistic studies indicated that aza quinone methide was probably involved as an intermediate in this transformation.
      PubDate: 2017-11-09T12:40:34.395506-05:
      DOI: 10.1002/adsc.201700873
       
  • Iridium(III)-Catalyzed Regiocontrolled Direct Amidation of Isoquinolones
           and Pyridones
    • Authors: Debapratim Das; Rajarshi Samanta
      Pages: 379 - 384
      Abstract: Iridium(III)-catalyzed highly regiocontrolled C3/C8 amidation of isoquinolones and C6 amidation of 2-pyridones has been successfully accomplished with various azides. The optimized method is operationally simple with a broad substrate scope. The protocol has been found to be scalable.
      PubDate: 2017-12-12T03:16:58.710942-05:
      DOI: 10.1002/adsc.201701244
       
 
 
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