Nandwana N, Patel OPS, Srivathsa MR, Kumar A. Dual Role of Glyoxal in Metal-Free Dicarbonylation Reaction: Synthesis of Symmetrical and Unsymmetrical Dicarbonyl Imidazoheterocycles.
ACS OMEGA 2019;
4:10140-10150. [PMID:
31460106 PMCID:
PMC6648449 DOI:
10.1021/acsomega.9b00716]
[Citation(s) in RCA: 11] [Impact Index Per Article: 2.2] [Reference Citation Analysis] [Abstract] [Track Full Text] [Subscribe] [Scholar Register] [Received: 03/14/2019] [Accepted: 05/22/2019] [Indexed: 05/28/2023]
Abstract
A practical and efficient method has been developed for the dicarbonylation of imidazoheterocycles using glyoxals as dicarbonyl precursors under metal-free conditions in acetic acid. A series of symmetrical and unsymmetrical dicarbonyl imidazoheterocycles was synthesized in good yields. Aryl and alkyl glyoxals also demonstrated excellent reactivity under similar reaction conditions and delivered corresponding dicarbonyl imidazoheterocycles in high yields. It is believed that the glyoxal plays a dual role both as a dicarbonyl source and as an oxidant in this transformation. A probable mechanistic pathway has been proposed based on control experiments and electrospray ionization high-resolution mass spectrometry analysis.
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