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Cong X, Zhuo Q, Hao N, Mishra A, Nishiura M, Hou Z. Divergent Synthesis of Multi-Substituted Aminotetralins via [4+2] Annulation of Aldimines with Alkenes by Rare-Earth-Catalyzed Benzylic C(sp 3 )-H Activation. Angew Chem Int Ed Engl 2024; 63:e202318203. [PMID: 38226440 DOI: 10.1002/anie.202318203] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Grants] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 11/28/2023] [Revised: 01/12/2024] [Accepted: 01/15/2024] [Indexed: 01/17/2024]
Abstract
The search for efficient and selective methods for the divergent synthesis of multi-substituted aminotetralins is of much interest and importance. We report herein for the first time the diastereoselective [4+2] annulation of 2-methyl aromatic aldimines with alkenes via benzylic C(sp3 )-H activation by half-sandwich rare-earth catalysts, which constitutes an efficient route for the divergent synthesis of both trans and cis diastereoisomers of multi-substituted 1-aminotetralin derivatives from readily accessible aldimines and alkenes. The use of a scandium catalyst bearing a sterically demanding cyclopentadienyl ligand such as C5 Me4 SiMe3 or C5 Me5 exclusively afforded the trans-selective annulation products in the reaction of aldimines with styrenes and aliphatic alkenes. In contrast, the analogous yttrium catalyst, whose metal ion size is larger than that of scandium, yielded the cis-selective annulation products. This protocol features 100 % atom-efficiency, excellent diastereoselectivity, broad substrate scope, and good functional group compatibility. The reaction mechanisms have been elucidated by kinetic isotope effect (KIE) experiments and the isolation and transformations of some key reaction intermediates.
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Affiliation(s)
- Xuefeng Cong
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Qingde Zhuo
- Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Na Hao
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Aniket Mishra
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Masayoshi Nishiura
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
| | - Zhaomin Hou
- Advanced Catalysis Research Group, RIKEN Center for Sustainable Resource Science, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
- Organometallic Chemistry Laboratory, RIKEN Cluster for Pioneering Research, 2-1 Hirosawa, Wako, Saitama 351-0198, Japan
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Foad M, Elboray E, Dardeer H, Kobayashi Y, Furuta T, Hamada S, Dohi T, Aly M. 1,3-Dipolar Cycloaddition of 3-Chromonyl-Substituted Glycine Imino Esters with Arylidenes and in situ Diastereodivergent via Retrocycloaddition. Chem Asian J 2023; 18:e202300215. [PMID: 37010444 DOI: 10.1002/asia.202300215] [Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Journal Information] [Subscribe] [Scholar Register] [Received: 03/13/2023] [Revised: 04/01/2023] [Accepted: 04/03/2023] [Indexed: 04/04/2023]
Abstract
1,3-Dipolar cycloaddition through in situ generation of azomethine ylide provides a straightforward and critically important sustainable approach for access to diverse pyrrolidine chemical space. Herein, we developed a metal-free AcOH-activated 1,3-dipolar cycloaddition protocol that permits the synthesis of uncommon pyrrolidine cycloadducts with excellent diastereoselectivity. The challenging substrates of 3-formylchromone, glycine ester.HCl and arylidene dipolarophile were reacted in the presence of AcONa, which played a dual role as a base and AcOH source, to deliver firstly endo-cycloadduct. Under prolonged reaction time at room temperature or heating; the endo-adduct underwent diastereodivergent via a sequence of retro-cycloaddition, stereomutation of the generated syn-dipole into anti-dipole and recycloaddition; to furnish the scarcely known exo'-cycloadduct with high diastereodivergency. The reaction worked well with a broad range of substrates and the stereochemistry of the obtained cycloadducts was determined without ambiguity using NMR- and X-ray analysis. Experimental and theoretical DFT calculation studies were performed to support the proposed reaction mechanism and elucidate the key role of AcOH in the process which seems more beneficial than other transition metal-catalyzed processes.
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Affiliation(s)
- Mohammed Foad
- South Valley University Faculty of Science, Chemistry, EGYPT
| | - Elghareeb Elboray
- Ritsumeikan Daigaku - Biwako Kusatsu Campus, College of Pharmaceutical sciences, 1-1-1 Nojihigashi, Kusatsu City, 525-8577, Shiga, JAPAN
| | - Hemat Dardeer
- South Valley University Faculty of Science, Chemistry, EGYPT
| | - Yusuke Kobayashi
- Kyoto Pharmaceutical University: Kyoto Yakka Daigaku, Chemistry, JAPAN
| | - Takumi Furuta
- Kyoto Pharmaceutical University: Kyoto Yakka Daigaku, Chemistry, JAPAN
| | - Shohei Hamada
- Kyoto Pharmaceutical University: Kyoto Yakka Daigaku, Chemistry, JAPAN
| | - Toshifumi Dohi
- Ritsumeikan University College of Pharmaceutical Sciences: Ritsumeikan Daigaku Yakugakubu Daigakuin Yakugaku Kenkyuka, Chemistry, JAPAN
| | - Moustafa Aly
- South Valley University Faculty of Science, Chemistry, EGYPT
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Ren X, Guo Q, Chen J, Xie H, Xu Q, Lu Z. Visible-Light Promoted Distereodivergent Intramolecular Oxyamidation of Alkenes. Chemistry 2016; 22:18695-18699. [PMID: 27770547 DOI: 10.1002/chem.201603977] [Citation(s) in RCA: 33] [Impact Index Per Article: 4.1] [Reference Citation Analysis] [What about the content of this article? (0)] [Affiliation(s)] [Abstract] [Key Words] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Received: 08/21/2016] [Indexed: 12/23/2022]
Abstract
The visible-light-promoted diastereodivergent intramolecular oxyamination of alkenes is described to construct oxazolindinones, pyrrolidinones and imidazolidones via mild generation of primary amidyl radicals from functionalized hydroxylamines. A unique phenomenon of highly diastereoselective ring-opening of aziridines controlled by electron sacrifices was observed. Highly diastereoselective amino alcohols derivatives were obtained efficiently through this protocol in gram scales. The mechanistic studies suggested the isolatable anti-aziridine intermediates were generated quickly from primary amidyl radicals and the diastereoselectivities were controlled by pKa values of the electron sacrifices.
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Affiliation(s)
- Xiang Ren
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310058, P. R. China
| | - Qihang Guo
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310058, P. R. China
| | - Jianhui Chen
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310058, P. R. China.,College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, P. R. China
| | - Hujun Xie
- Department of Applied Chemistry, Zhejiang Gongshang University, Hangzhou, Zhejiang, 310018, P. R. China
| | - Qing Xu
- College of Chemistry and Materials Engineering, Wenzhou University, Wenzhou, 325035, P. R. China
| | - Zhan Lu
- Department of Chemistry, Zhejiang University, Hangzhou, Zhejiang, 310058, P. R. China
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