Enantioselective direct aldol reaction of α-keto esters catalyzed by (Sa)-binam-D-prolinamide under quasi solvent-free conditions

(S-a)-Binam-D-prolinamide (20 mol%), instead of (S-a)-binam-L-prolinamide, in combination with chloroacetic acid (100 mol%) is an efficient organocatalyst for the direct aldol reaction between alpha-keto esters as electrophiles and alkyl and alpha-functionalised ketones, under quasi solvent-free conditions, providing access to highly functionalised chiral quaternary gamma-keto alpha-hydroxyesters with up to 92% ee.