Wang ZL, Li HL, Ge LS, An XL, Zhang ZG, Luo X, Fossey JS, Deng WP. DDQ-mediated oxidative coupling: an approach to 2,3-dicyanofuran (thiophene).
J Org Chem 2014;
79:1156-65. [PMID:
24428373 DOI:
10.1021/jo4026034]
[Citation(s) in RCA: 61] [Impact Index Per Article: 6.1] [Reference Citation Analysis] [Abstract] [Track Full Text] [Journal Information] [Subscribe] [Scholar Register] [Indexed: 12/21/2022]
Abstract
A facile oxidative coupling of α-carbonyl radicals to 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) for the synthesis of 2,3-dicyanofurans and thiophenes starting from readily available β-diketones, simple ketones, and β-keto thioamides in up to 95% yield in one step was developed. Mechanistic investigations revealed that a radical process could be involved in this transformation, and a water promoted C-C bond cleavage pathway is proposed for the formation of 2,3-dicyanofurans and thiophenes.
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