Asymmetric Michael Addition of Aromatic Ketones to Nitroolefins Catalyzed by Simple Chiral Bifunctional Primary Amine-Thioureas

Simple chiral primary amine-thiourea catalysts derived from chiral 1,2-diphenylethylenediamine were found to catalyze direct Michael addition of aromatic ketones to nitroolefins with good enantioselectives (up to 86% ee) and excellent yields (up to 97%) for a broad range of substrates and successfully used in the preparation of (R)-Balcofen.