Enantioselective desymmetrization of prochiral ketones via an organocatalytic deprotonation process

The first desymmetrization of 4-substituted cyclohexanones by organocatalytic asymmetric deprotonation at low catalyst loading is reported. The combination of N,O-bis(trimethylsilyl)acetamide (BSA) and chiral quaternary ammonium aryloxide salts has been used as an efficient organocatalytic system to provide silyl enolates in high yields and with modest ee.