Catalytic Asymmetric Addition of β‐Ketoesters to Various Imines by Using Chiral Palladium Complexes

A highly enantioselective Mannich-type reaction of β-ketoesters was developed using a catalytic amount of the Pd–aqua complexes 1 (see scheme; PG=protecting group). A variety of imines derived from glyoxylate, as well as simple aromatic and α,β-unsaturated aldehydes were successfully used. The corresponding Mannich adducts were obtained in high yield with excellent enantioselectivity.