Catalytic Enantioselective Synthesis of N,N-Acetals from α-Dicarbonyl Compounds Using Chiral Imidazoline-Phosphoric Acid Catalysts

The enantioselective synthesis of chiralN,N-acetals derived from alpha-dicarbonyl compounds has been achieved. Good yields and enantioselectivities were observed for the reaction with various alpha-dicarbonyl compounds with 2-aminobenzamides using chiral bis(imidazoline)-phosphoric acid catalysts. Based on these experimental investigations, a possible transition state is proposed to explain the origin of the asymmetric induction.