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Mathada BS, Yernale NG. Current Advances in Transition Metal-Free Access to Indoles. A Review. ORG PREP PROCED INT 2023. [DOI: 10.1080/00304948.2022.2151810] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/24/2023]
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Kou S, Huo J, Wang Y, Sun S, Xue F, Mao J, Zhang J, Chen L, Walsh PJ. Synthesis of Indoles via Domino Reactions of 2-Methoxytoluene and Nitriles. J Org Chem 2022; 88:5147-5152. [PMID: 36520533 DOI: 10.1021/acs.joc.2c02128] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
2-Arylindoles are privileged structures widely present in biologically active molecules. New sustainable synthetic routes toward their synthesis are, therefore, in high demand. Herein, a mixed base-promoted benzylic C-H deprotonation of commercially available ortho-anisoles, addition of the resulting anion to benzonitriles, and SNAr to displace the methoxy group provide indoles. A diverse array of 2-arylindoles is prepared with good yields (>30 examples, yields up to 99%) without added transition metal catalysts.
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Affiliation(s)
- Song Kou
- College of Plant Protection, Hebei Agricultural University, Baoding 071001, P. R. China
| | - Jingqian Huo
- College of Plant Protection, Hebei Agricultural University, Baoding 071001, P. R. China
| | - Ying Wang
- College of Plant Protection, Hebei Agricultural University, Baoding 071001, P. R. China
| | - Susu Sun
- College of Plant Protection, Hebei Agricultural University, Baoding 071001, P. R. China
| | - Fei Xue
- Institute of Material Physics & Chemistry, College of Science, Nanjing Forestry University, Nanjing 210037, P. R. China
| | - Jianyou Mao
- Institute of Advanced Synthesis, School of Chemistry and Molecular Engineering, Nanjing Tech University, 30 South Puzhu Road, Nanjing 211816, P. R. China
| | - Jinlin Zhang
- College of Plant Protection, Hebei Agricultural University, Baoding 071001, P. R. China
| | - Lai Chen
- College of Plant Protection, Hebei Agricultural University, Baoding 071001, P. R. China
| | - Patrick J. Walsh
- Roy and Diana Vagelos Laboratories, Department of Chemistry, University of Pennsylvania, Philadelphia, Pennsylvania 19104-6323, United States
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Wang B, Ren H, Cao HJ, Lu C, Yan H. A switchable redox annulation of 2-nitroarylethanols affording N-heterocycles: photoexcited nitro as a multifunctional handle. Chem Sci 2022; 13:11074-11082. [PMID: 36320483 PMCID: PMC9516892 DOI: 10.1039/d2sc03590a] [Citation(s) in RCA: 5] [Impact Index Per Article: 2.5] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 06/27/2022] [Accepted: 08/15/2022] [Indexed: 09/09/2023] Open
Abstract
The efficient transformation of nitroaromatics to functional molecules such as N-heterocycles has been an attractive and significant topic in synthesis chemistry. Herein, a photoexcited nitro-induced strategy for switchable annulations of 2-nitroarylethanols was developed to construct N-heterocycles including indoles, N-hydroxyl oxindoles and N-H oxindoles. The metal- and photocatalyst-free reaction proceeds through intramolecular redox C-N coupling of branched hydroxyalkyl and nitro units, which is initiated by a double hydrogen atom abstraction (d-HAA) process. The key to the switchable reaction outcomes is the mediation of a diboron reagent by its favorable oxy-transfer reactivity to in situ generated nitroso species. The utility of this protocol was well demonstrated by broad substrate scope, excellent yields, functional group tolerance and wide applications. Finally, detailed mechanistic studies were performed, and kinetic isotope effect (KIE) experiments indicate that the homolysis of the C-H bond is involved in the rate-determining step.
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Affiliation(s)
- Bin Wang
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Hongyuan Ren
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Hou-Ji Cao
- School of Chemistry and Chemical Engineering, Henan Normal University XinXiang Henan 453007 China
| | - Changsheng Lu
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
| | - Hong Yan
- State Key Laboratory of Coordination Chemistry, Jiangsu Key Laboratory of Advanced Organic Materials, School of Chemistry and Chemical Engineering, Nanjing University Nanjing 210023 China
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Yee KY, Leung MP, Tse MH, Choy PY, Kwong FY. Palladium‐Catalyzed Direct C‐H Olefination of Polyfluoroarenes with Alkenyl Tosylates. Eur J Inorg Chem 2022. [DOI: 10.1002/ejic.202200288] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/06/2022]
Affiliation(s)
- Ka Yee Yee
- The Chinese University of Hong Kong Department of Chemistry HONG KONG
| | - Man Pan Leung
- The Chinese University of Hong Kong Department of Chemistry HONG KONG
| | - Man Ho Tse
- The Chinese University of Hong Kong Department of Chemistry HONG KONG
| | - Pui Ying Choy
- The Chinese University of Hong Kong Department of Chemistry HONG KONG
| | - Fuk Yee Kwong
- The Chinese University of Hong Kong Department of Chemistry G56, Science CentreThe Chinese University of Hong KongShatin, N.T. 852 Hong Kong HONG KONG
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Exploitation the unique acidity of novel cerium-tungstate catalysts in the preparation of indole derivatives under eco-friendly acid catalyzed Fischer indole reaction protocol. ARAB J CHEM 2022. [DOI: 10.1016/j.arabjc.2021.103670] [Citation(s) in RCA: 3] [Impact Index Per Article: 1.5] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/26/2022] Open
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Nandy A, Sekar G. KO tBu-Promoted Halogen-Bond-Assisted Intramolecular C-S Cross-Coupling of o-Iodothioanilides for the Synthesis of 2-Substituted Benzothiazoles. J Org Chem 2021; 86:15825-15834. [PMID: 34644084 DOI: 10.1021/acs.joc.1c02023] [Citation(s) in RCA: 6] [Impact Index Per Article: 2.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 01/09/2023]
Abstract
An efficacious and mild KOtBu-promoted intramolecular C-S cross-coupling of ortho-iodothioanilides in conjunction with a catalytic quantity of phenanthroline as an additive has been described for the convenient synthesis of 2-substituted benzothiazoles. The methodology is suitable for attaining a wide variety of 2-alkyl- and 2-aryl-substituted benzothiazoles. Single-crystal XRD, DFT calculations, NMR, and UV studies suggest that halogen bonds between the units of ortho-iodothioanilides may assist in the electron transfer process.
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Affiliation(s)
- Anuradha Nandy
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600 036, India
| | - Govindasamy Sekar
- Department of Chemistry, Indian Institute of Technology Madras, Chennai, Tamil Nadu 600 036, India
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Mathada BS, Yernale NG, Basha JN, Badiger J. An insight into the advanced synthetic recipes to access ubiquitous indole heterocycles. Tetrahedron Lett 2021. [DOI: 10.1016/j.tetlet.2021.153458] [Citation(s) in RCA: 13] [Impact Index Per Article: 4.3] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/07/2023]
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