The catalytic asymmetric Mannich reaction is arguably the most useful approach to synthesize chiral β-amino carbonyl compounds.[1] Six years ago, we discovered a proline- catalyzed version of this powerful reaction.[2] Originally, ketones, aldehydes, and an aniline as the amine component were used in a catalytic asymmetric three-component reaction. Since then, the reaction has found utility in the synthesis of chiral nonracemic nitrogenous ...