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Sugiyama Y, Yamada K, Kaneko D, Kusagawa Y, Okamura T, Sato T. Iridium-Catalyzed Reductive (3+2) Annulation of Lactams Enabling the Rapid Total Synthesis of (±)-Eburnamonine. Angew Chem Int Ed Engl 2024; 63:e202317290. [PMID: 38088513 DOI: 10.1002/anie.202317290] [Citation(s) in RCA: 1] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/14/2023] [Indexed: 12/30/2023]
Abstract
A reductive (3+2) annulation of lactams through iridium-catalyzed hydrosilylation and photoredox coupling with α-bromoacetic acid was developed. The iridium-catalyzed hydrosilylation of the lactam carbonyl group and subsequent elimination provide a transient cyclic enamine, which undergoes iridium-catalyzed photoredox coupling with α-bromoacetic acid in a one-pot process. The developed conditions show high functional-group tolerance and provide cyclic N,O-acetals containing a quaternary carbon center. The resulting N,O-acetals undergo a variety of acid-mediated nucleophilic addition reactions via iminium ions to give substituted cyclic amines. The developed sequence including reductive (3+2) annulation and acid-mediated nucleophilic addition was successfully applied to the four-step total synthesis of (±)-eburnamonine.
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Affiliation(s)
- Yasukazu Sugiyama
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Kento Yamada
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Daiki Kaneko
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Yuya Kusagawa
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Toshitaka Okamura
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
| | - Takaaki Sato
- Department of Applied Chemistry, Faculty of Science and Technology, Keio University, 3-14-1, Hiyoshi, Kohoku-ku, Yokohama, 223-8522, Japan
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Han F, Lu GS, Wu DP, Huang PQ. Iridium and B(C6F5)3 co-catalyzed chemoselective deoxygenative reduction of tertiary amides: application to the efficient synthesis and late-stage modification of pharmaceuticals. Sci China Chem 2023. [DOI: 10.1007/s11426-022-1501-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 02/15/2023]
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Wu DP, Ou W, Huang PQ. Ir-Catalyzed Chemoselective Reductive Condensation Reactions of Tertiary Amides with Active Methylene Compounds. Org Lett 2022; 24:5366-5371. [PMID: 35849542 DOI: 10.1021/acs.orglett.2c02045] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/29/2022]
Abstract
The catalytic reductive condensation reactions of tertiary amides with active methylene compounds leading to multifunctionalized non-N-containing products is described. The reactions proceed through sequential iridium-catalyzed hydrosilylation of the amides followed by acid-mediated condensation with the active methylene compounds. This scalable method is broad in scope and shows remarkable chemoselectivity for the amide group in the presence of several sensitive or even more reactive functionalities such as ester, cyano, nitro, silyl dienol ether, and ketone.
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Affiliation(s)
- Dong-Ping Wu
- Department of Chemistry, Fujian Provincial Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Wei Ou
- Department of Chemistry, Fujian Provincial Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P. R. China
| | - Pei-Qiang Huang
- Department of Chemistry, Fujian Provincial Key Laboratory of Chemical Biology, College of Chemistry and Chemical Engineering, Xiamen University, Xiamen, Fujian 361005, P. R. China
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Zhao F, Jiang F, Wang X. Deoxygenative alkylation of tertiary amides using alkyl iodides under visible light. Sci China Chem 2022. [DOI: 10.1007/s11426-022-1331-y] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 10/17/2022]
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Shi T, Wang X, Chen JH, Cao F, Yin G, Zeng YF, Wang Z. Recent Advances in the Transformations of Different Types of Stemona Alkaloids. Org Chem Front 2022. [DOI: 10.1039/d2qo00789d] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 11/21/2022]
Abstract
In recent years, researches on the total syntheses of Stemona alkaloids with different 5/7 bicyclic systems have attracted increasing attention, and the development momentum in this field has gradually changed...
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