Organocatalytic asymmetric α-bromination of aldehydes and ketones

Abstract

The first organocatalytic enantioselective α-bromination of aldehydes and ketones is presented; a C₂-symmetric diphenylpyrrolidine catalyst afforded the α-brominated aldehydes in good yields and up to 96% ee, while ketones were α-brominated by a C₂-symmetric imidazolidine in up to 94% ee; furthermore, the organocatalytic enantioselective α-iodination of aldehydes is also demonstrated to proceed with up to 89% ee.