Highly Enantioselective Michael Addition of Cyclic 1,3‐Dicarbonyl Compounds to β,γ‐Unsaturated α‐Keto Esters

Abstract

AbstractA highly enantioselective Michael addition of cyclic 1,3‐dicarbonyl compounds to β,γ‐unsaturated α‐keto esters catalyzed by amino acid‐derived thiourea‐tertiary‐amine catalysts is presented. Using 5 mol% of a novel tyrosine‐derived thiourea catalyst, a series of chiral coumarin derivatives were obtained in excellent yields (up to 99%) and with up to 96% ee under very mild conditions within a short reaction time.