Gopal B, Singh PR, Kumar M, Goswami A. Synthesis of Indole-Fused Dihydrothiopyrano Scaffolds
via (3 + 3)-Annulations of Donor-Acceptor Cyclopropanes with Indoline-2-Thiones.
J Org Chem 2023;
88:132-142. [PMID:
36524970 DOI:
10.1021/acs.joc.2c01990]
[Citation(s) in RCA: 4] [Impact Index Per Article: 4.0] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/23/2022]
Abstract
A new methodology for the synthesis of N-haloindole-fused dihydrothiopyrano derivatives via (3 + 3)-annulation of donor-acceptor cyclopropanes (DACs) with indoline-2-thiones in the presence of Sc(OTf)3 as a Lewis acid catalyst has been developed. This protocol provides a variety of indole-fused dihydrothiopyrano molecules in good to excellent yields, which architecturally resemble other indole-fused tricyclic molecules having potential medicinal value. In addition, we have described a detailed reaction mechanism and transformation of the furnished product into N-fused thiazino indole molecule.
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