Enantioselective Cross‐Aldol Reaction with Ketones and Non‐Enolizable Ketones Catalyzed by Tetrapeptides

Abstract

AbstractAn efficient strategy shaping the construction of (R)‐3‐alkyl‐3‐hydroxyindolin‐2‐one and (S)‐5‐trifluoromethyl‐4‐hydroxy‐4‐arylpentan‐2‐one derivatives catalyzed by the β‐turn tetrapeptide catalyst under mild conditions was developed. Various isatins and ketones could participate in this reaction, and the desired adducts were obtained with excellent yield (up to 99 %) and moderate to high enantioselectivity (ee up to 85 %) and excellent diastereoselectivity (dr up to >20 : 1). Moreover, a series of trifluoromethyl ketones with ketones also could participate in this reaction, and the resulting β‐trifluoromethyl‐β‐hydroxy ketones with excellent yields and moderate enantioselectivities (ee up to 58 %) were obtained. In addition, the strategy afforded better results than natural papain.