Lu YN, Che C, Zhen G, Chang X, Dong XQ, Wang CJ. Visible-light-enabled stereoselective synthesis of functionalized cyclohexylamine derivatives
via [4 + 2] cycloadditions.
Chem Sci 2024;
15:6507-6514. [PMID:
38699278 PMCID:
PMC11062095 DOI:
10.1039/d4sc00667d]
[Citation(s) in RCA: 0] [Impact Index Per Article: 0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2024] [Accepted: 03/26/2024] [Indexed: 05/05/2024] Open
Abstract
An unprecedented intermolecular [4 + 2] cycloaddition of benzocyclobutylamines with α-substituted vinylketones, enabled by photoredox catalysis, has been developed. The current method enables facile access to highly functionalized cyclohexylamine derivatives that were otherwise inaccessible, in moderate to good yields with excellent diastereoselectivities. This protocol has some excellent features, such as full atom economy, good functional-group compatibility, mild reaction conditions, and an overall redox-neutral process. Additionally, an asymmetric version of this cycloaddition was preliminarily investigated via the incorporation of a chiral phosphoric acid (CPA), and moderate to good enantioselectivity could be effectively realized with excellent diastereoselectivity. Synthetic applications were demonstrated via a scale-up experiment and elaborations to access amino alcohol and cyclobutene derivatives. Based on the results of control experiments, a reasonable reaction mechanism was proposed to elucidate the reaction pathway.
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