have been prepared from a tandemMichael–Henryreaction between cyclohexane-1,2-diones and nitroalkenes using a quinine-derived thiourea as the catalyst. Although four stereogenic centers were created during the reaction, only two diastereomers were obtained in good diastereoselectivity and high enantioselectivity (92–99% ee). When 3-methylcyclohexane-1,2-dione (R1=Me) was used as the substrate, only
Catalytic Asymmetric Domino Michael-Henry Reaction: Enantioselective Access to Bicycles with Consecutive Quaternary Centers by Using Bifunctional Catalysts
Domino catalysis: Two consecutivequaternary stereocenters, three functional groups, and four stereogenic centers have been created in the newly developed dominoMichael–Henryreaction (see scheme) employing small amounts of a bifunctional organocatalyst.