Catalytic Asymmetric Synthesis of Vicinal Tetrasubstituted Diamines via Umpolung Cross-Mannich Reaction of Cyclic Ketimines.

A catalytic asymmetric umpolung cross-Mannich reaction of cyclic ketimines is realized. This protocol provides an efficient methodology for the facile synthesis of chiral vicinal tetrasubstituted diamines in high yields with excellent chemo-, regio-, diastereo-, and enantioselectivities using cinchona-derived bifunctional organocatalysts (85-98% yield, up to >20:1 dr, and >99% ee).