Herein we present a Zn-ProPhenol-catalyzed double Mannich reaction between ynones and imines that generates 1,3-diamines in excellent yield as well as diastereo- and enantioselectivity (>99.5% ). With 2.2 equiv of a single imine electrophile, we obtain -symmetrical diamines whereas, with two different imine partners, we obtain unsymmetrically substituted 1,3-diamines with three contiguous stereocenters. In addition, we showcase the utility of these double Mannich adducts by transforming the 1,3-diamine motif into a variety of interesting products.
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