Development of Ketone-Based Brominating Agents (KBA) for the Practical Asymmetric α-Bromination of Aldehydes Catalyzed by Tritylpyrrolidine

Abstract

Ketone-based brominating agents (KBA), ortho-substituted 2,2,2-tribromoacetophenones, have been developed, and the highly enantioselective and practical α-bromination of aldehydes with KBA was achieved. The reaction could be performed in the presence of only 0.1–1 mol % of catalyst without using a halogenated solvent at 0 °C and was found to be scalable.