Synthetic methods: An asymmetric catalytic, desulfonylative Mannich reaction of α‐keto imines with aldehydes, as catalyzed by diarylprolinol silyl ether 1, was developed. It gave the Mannich product in good yield with excellent anti and enantioselectivity (see scheme; Boc=tert‐butoxycarbonyl, TMS=trimethylsilyl).