Direct Conjugate Addition of Alkynes with α,β-Unsaturated Carbonyl Compounds Catalyzed by NCN-Pincer Ru Complexes

NCN-pincer Ru-complexes containing bis(oxazolinyl) phenyl ligands serve as suitable catalysts in the direct conjugate additions of alpha,beta-unsaturated carbonyl compounds, including ketones, esters, and amides, as well as vinylphosphonates, giving various beta-alkynyl carbonyl and phosphonate compounds. A bis(oxazolinyl) phenyl (phebox)-Ru complex also catalyzes the asymmetric conjugate addition of an alkyne with a beta-substituted, alpha,beta-unsaturated ketone to produce a chiral beta-alkynyl ketone.