Choi A, Morley RM, Coldham I. Synthesis of pyrrolo[1,2-
a]quinolines by formal 1,3-dipolar cycloaddition reactions of quinolinium salts.
Beilstein J Org Chem 2019;
15:1480-1484. [PMID:
31354865 PMCID:
PMC6633155 DOI:
10.3762/bjoc.15.149]
[Citation(s) in RCA: 7] [Impact Index Per Article: 1.4] [Reference Citation Analysis] [Abstract] [Key Words] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 04/08/2019] [Accepted: 06/27/2019] [Indexed: 12/14/2022] Open
Abstract
Quinolinium salts, Q+-CH2-CO2Me Br- and Q+-CH2-CONMe2 Br- (where Q = quinoline), were prepared from quinolines. Deprotonation of these salts with triethylamine promoted the reaction of the resulting quinolinium ylides (formally azomethine ylides) with electron-poor alkenes by conjugate addition followed by cyclization or by [3 + 2] dipolar cycloaddition. The pyrroloquinoline products were formed as single regio- and stereoisomers. These could be converted to other derivatives by Suzuki-Miyaura coupling, reduction or oxidation reactions.
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