Novel Primary Amine Organocatalysts Derived from Cinchona Alkaloids for Asymmetric Direct Aldol Reactions in Brine

摘要

Abstract A series of Cinchona alkaloids derived organocatalysts have been developed and evaluated in the direct asymmetric intermolecular aldol reaction of 4-nitrobenzaldehyde and cyclohexanone. The catalyzed reactions of various aldehydes and ketones gave the corresponding aldol products with moderate to high enantioselectivities (up to 92%) and diastereoselectivities (up to >99/1, anti/syn) in the presence of 3e in brine.