Farajpour B, Alizadeh A. Chemoselective and one-pot synthesis of novel coumarin-based cyclopenta[
c]pyrans
via base-mediated reaction of α,β-unsaturated coumarins and β-ketodinitriles.
RSC Adv 2022;
12:7262-7267. [PMID:
35424660 PMCID:
PMC8982290 DOI:
10.1039/d2ra00594h]
[Citation(s) in RCA: 3] [Impact Index Per Article: 1.0] [Reference Citation Analysis] [Abstract] [Grants] [Track Full Text] [Download PDF] [Figures] [Journal Information] [Subscribe] [Scholar Register] [Received: 01/28/2022] [Revised: 03/17/2022] [Accepted: 02/18/2022] [Indexed: 11/21/2022] Open
Abstract
In this paper, the base-mediated cascade reactions of 4-chloro-3-vinyl coumarins with β-ketodinitriles were demonstrated, allowing the efficient synthesis of coumarin-based cyclopenta[c]pyran-7-carbonitriles with interesting chemoselectivity. These transformations include the domino-style formation of C-C/C-C/C-O bonds through a base-mediated nucleophilic substitution, Michael addition, tautomerization, O-cyclization, elimination, and aromatization. The presented synthetic strategy has many advantages such as simple and readily available starting materials, green solvent, highly chemoselective route, synthetically useful yields, and easy purification of products by washing them with EtOH (96%), described as GAP (Group-Assistant-Purification) chemistry.
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