NHC-Catalyzed [2 + 4] Annulation of Alkynyl Ester with Chalcone

Fangfang Lu, Yangxu Chen, Xue Song, Chenxia Yu, Tuanjie Li*, Kai Zhang* and Changsheng Yao*

*School of Chemistry & Materials Science, Jiangsu Normal University, Xuzhou, Jiangsu 221116, P. R. China, Email: ltj2008jsnu.edu.cn, zhangkaijsnu.edu.cn, csyaojsnu.edu.cn

F. Lu, Y. Chen, X. Song, C. Yu, T. Li, K. Zhang, C. Yao, J. Org. Chem., 2022, 87, 6902-6909.

DOI: 10.1021/acs.joc.2c00022

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Abstract

An NHC-catalyzed [2 + 4] cyclization of alkynyl ester with α,β-unsaturated ketone provides highly substituted 4H-pyran derivatives in gooy yields. This strategy offers cheap and easily available starting materials, mild reaction conditions, and high atom economy.

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proposed mechanism

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Key Words

4H-pyrans, organocatalysis

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ID: J42-Y2022