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Asymmetric Net Cycloaddition for Access to Diverse Substituted 1,5-Benzothiazepines

Yukihiro Fukata, Koichi Yao, Ryota Miyaji, Keisuke Asano* and Seijiro Matsubara*

*Department of Material Chemistry, Graduate School of Engineering, Kyoto University, Kyotodaigaku-Katsura, Nishikyo, Kyoto 615-8510, Japan, Email: asano.keisuke.5wkyoto-u.ac.jp, matsubara.seijiro.2ekyoto-u.ac.jp

Y. Fukata, K. Yao, R. Miyaiji, K. Asano, S. Matsubara, J. Org. Chem., 2017, 82, 12655-12668.

DOI: 10.1021/acs.joc.7b02451 (free Supporting Information)



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Abstract

An isothiourea-catalyzed enantioselective formal [4+3] cycloaddition of various α,β-unsaturated carboxylic acid derivatives with 2-aminothiophenols proceeds via a reversible sulfa-Michael addition to α,β-unsaturated acylammonium intermediates, followed by an enantioselective formation of a seven-membered ring. This method enables a facile and divergent synthesis of optically active 2- and 3-substituted 1,5-benzothiazepines.

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proposed mechanism



Key Words

benzo-fused N-heterocyles, benzo-fused S-heterocycles, organocatalysis


ID: J42-Y2017