Rhodium(iii)/amine synergistically catalyzed enantioselective Michael addition of cyclic ketones with α,β-unsaturated 2-acyl imidazoles

Abstract

An enantioselective Michael addition of α,β-unsaturated 2-acyl imidazoles with cyclic ketones catalyzed synergistically by a chiral-at-metal Rh(III) complex and a secondary amine has been developed, affording the corresponding adducts with up to 98% yield and 99% ee. The diastereomeric ratios are in the range from 2 : 1 to 10 : 1. In these reactions, the combination of a chiral-at-metal complex and a secondary amine catalyst activates an electrophile and nucleophile separately.