A Catalytic Method for the Enantioselective Synthesis of α‐Quaternary Ketones, α‐Ketoesters and Aldehydes

Abstract

AbstractA practical method for the efficient and enantioselective preparation of versatile ketones and aldehydes that contain an α‐quaternary stereocenter is described. Reactions utilize simple carboxylic acid or ester starting materials, a monodentate chiral phosphine, and afford a variety of aryl, alkenyl, alkynyl, and alkyl‐substituted ketone and aldehyde products in 25–94 % yield and 90 : 10 to >99 : 1 enantiomeric ratio. Reactions proceed by acyl substitution with in situ formed chiral allylic nucleophiles, and display selectivity and conversion dependence on a protic additive. The utility of the approach is demonstrated through several product transformations.