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.5w
kyoto-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.
see article for more reactions
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.
see article for more examples
proposed mechanism
Key Words
benzo-fused N-heterocyles, benzo-fused S-heterocycles, organocatalysis
ID: J42-Y2017
