β-Aminosulfonamide-Catalyzed Direct Asymmetric Aldol Reaction in Brine

Direct asymmetric aldol reactions of aldehydes with ketones in the presence of a catalytic amount of beta-aminosulfonamide 2 and trifluoroacetic acid in brine results in the formation of the corresponding anti-aldol products in high yields with up to 96% enantiomeric excess. The anti-aldol products obtained by using organocatalyst 2 have the opposite absolute configuration to those obtained using the similar sulfonamide catalyst 1, which was reported previously by us.