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Rong N, Zhou A, Liang M, Wang SG, Yin Q. Asymmetric Hydrogenation of Racemic 2-Substituted Indoles via Dynamic Kinetic Resolution: An Easy Access to Chiral Indolines Bearing Vicinal Stereogenic Centers. J Am Chem Soc 2024; 146:5081-5087. [PMID: 38358355 DOI: 10.1021/jacs.4c00298] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/16/2024]
Abstract
The asymmetric hydrogenation (AH) of N-unprotected indoles is a straightforward, yet challenging method to access biologically interesting NH chiral indolines. This method has for years been limited to 2/3-monosubstituted or 2,3-disubstituted indoles, which produce chiral indolines bearing endocyclic chiral centers. Herein, we have reported an innovative Pd-catalyzed AH of racemic α-alkyl or aryl-substituted indole-2-acetates using an acid-assisted dynamic kinetic resolution (DKR) process, affording a range of structurally fascinating chiral indolines that contain exocyclic stereocenters with excellent yields, diastereoselectivities, and enantioselectivities. Mechanistic studies support that the DKR process relies on a rapid interconversion of each enantiomer of racemic substrates, leveraged by an acid-promoted isomerization between the aromatic indole and nonaromatic exocyclic enamine intermediate. The reaction can be performed on a gram scale, and the products can be derivatized into non-natural β-amino acids via facile debenzylation and amino alcohol upon reduction.
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Affiliation(s)
- Nianxin Rong
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Ao Zhou
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
- Southern University of Science and Technology, Shenzhen, 518055, China
| | - Mingrong Liang
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Shou-Guo Wang
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
| | - Qin Yin
- Shenzhen Institute of Advanced Technology, Chinese Academy of Sciences, Shenzhen 518055, China
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Zhou Y, Guo S, Huang Q, Lang Q, Chen GQ, Zhang X. Facile access to chiral γ-butyrolactones via rhodium-catalysed asymmetric hydrogenation of γ-butenolides and γ-hydroxybutenolides. Chem Sci 2023; 14:4888-4892. [PMID: 37181773 PMCID: PMC10171041 DOI: 10.1039/d3sc00491k] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/30/2023] [Accepted: 03/13/2023] [Indexed: 05/16/2023] Open
Abstract
The highly efficient Rh/ZhaoPhos-catalysed asymmetric hydrogenation of γ-butenolides and γ-hydroxybutenolides was successfully developed. This protocol provides an efficient and practical approach to the synthesis of various chiral γ-butyrolactones, which are synthetically valuable building blocks of diverse natural products and therapeutic substances, with excellent results (up to >99% conversion and 99% ee). Further follow-up transformations have been revealed to accomplish creative and efficient synthetic routes for several enantiomerically enriched drugs via this catalytic methodology.
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Affiliation(s)
- Yuxuan Zhou
- Shenzhen Grubbs Institute, Department of Chemistry, and Medi-Pingshan, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
| | - Siyuan Guo
- Shenzhen Grubbs Institute, Department of Chemistry, and Medi-Pingshan, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
| | - Qiyuan Huang
- Shenzhen Grubbs Institute, Department of Chemistry, and Medi-Pingshan, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
| | - Qiwei Lang
- Shenzhen Grubbs Institute, Department of Chemistry, and Medi-Pingshan, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
| | - Gen-Qiang Chen
- Shenzhen Grubbs Institute, Department of Chemistry, and Medi-Pingshan, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
| | - Xumu Zhang
- Shenzhen Grubbs Institute, Department of Chemistry, and Medi-Pingshan, Southern University of Science and Technology Shenzhen 518000 People's Republic of China
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Xiao F, Liao P, Lu X, Wang J, Dong XQ, Wang CJ. Iridium-Catalyzed Asymmetric Cascade Allylation/Lactonization of Indole Esters: Access to Chiral Tricyclic Oxazinoindolones. Org Lett 2022; 24:8592-8597. [DOI: 10.1021/acs.orglett.2c03100] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/18/2022]
Affiliation(s)
- Fan Xiao
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P.R. China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 230021, P.R. China
| | - Peiqin Liao
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Xiaoguang Lu
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Jin Wang
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Xiu-Qin Dong
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P.R. China
| | - Chun-Jiang Wang
- Engineering Research Center of Organosilicon Compounds & Materials, Ministry of Education, College of Chemistry and Molecular Sciences, Wuhan University, Wuhan, Hubei 430072, P.R. China
- State Key Laboratory of Organometallic Chemistry, Shanghai Institute of Organic Chemistry, Shanghai, 230021, P.R. China
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Wang F, Chen Y, Yu P, Chen GQ, Zhang X. Asymmetric Hydrogenation of Oximes Synergistically Assisted by Lewis and Brønsted Acids. J Am Chem Soc 2022; 144:17763-17768. [PMID: 36166275 DOI: 10.1021/jacs.2c07506] [Citation(s) in RCA: 1] [Impact Index Per Article: 0.5] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/17/2022]
Abstract
Due to their low reactivity, difficult enantiocontrol, and proneness to N-O bond cleavage, the catalytic asymmetric hydrogenation of oximes to hydroxylamines has remained a significant challenge. Herein, a Lewis and Brønsted acid cooperation strategy was established for the asymmetric hydrogenation of oximes, providing the corresponding hydroxylamines with up to 95% yield and up to 96% ee. Addition of Lewis and Brønsted acid was crucial to obtain high conversion and enantioselectivity. Mechanistic investigations indicates that the thiourea fragment of the ligand, Lewis acid (In(OTf)3 or Zn(OAc)2), as well as the Brønsted acid (l-CSA) played vital roles in the control of reactivity and enantioselectivity of the reaction. In addition, the synthetic elaboration of this transformation was demonstrated by gram scale experiment with retention of the yield and enantioselectivity.
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Affiliation(s)
- Fangyuan Wang
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Yu Chen
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Peiyuan Yu
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Gen-Qiang Chen
- Academy for Advanced Interdisciplinary Studies, Southern University of Science and Technology, Shenzhen, 518000, China
| | - Xumu Zhang
- Department of Chemistry and Shenzhen Grubbs Institute, Southern University of Science and Technology, Shenzhen, 518000, China
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