TMSBr-Promoted Cascade Cyclization of
ortho-Propynol Phenyl Azides for the Synthesis of 4-Bromo Quinolines and Its Applications.
Molecules 2019;
24:molecules24213999. [PMID:
31694215 PMCID:
PMC6864654 DOI:
10.3390/molecules24213999]
[Citation(s) in RCA: 4] [Impact Index Per Article: 0.8] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 09/30/2019] [Revised: 10/22/2019] [Accepted: 10/31/2019] [Indexed: 12/14/2022] Open
Abstract
Difficult-to-access 4-bromo quinolines are constructed directly from easily prepared ortho-propynol phenyl azides using TMSBr as acid-promoter. The cascade transformation performs smoothly to generate desired products in moderate to excellent yields with good functional groups compatibility. Notably, TMSBr not only acted as an acid-promoter to initiate the reaction, and also as a nucleophile. In addition, 4-bromo quinolines as key intermediates could further undergo the coupling reactions or nucleophilic reactions to provide a variety of functionalized compounds with molecular diversity at C4 position of quinolines.
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