A Unified Approach to the Aminoallylation of Carbonyl Compounds Through Cu-Catalyzed Enantioselective Reductive Coupling of Allenamides

Herein, we report the development of a highly enantioselective aminoallylation reaction of both aldehyde and ketone electrophiles through the Cu-catalyzed reductive coupling of N-substituted allenes (allenamides). Through optimization of the allenamide to avoid an on-cycle rearrangement, high enantioselectivities could be obtained for a variety of ketone and aldehyde electrophiles in up to >99% ee and >98:2 anti:syn diastereoselectivities. Use of the acyclic allenamides described in this report selectively generated anti-diastereomers in contrast to cyclic allenamides that were previously shown to favor the syn form. Rationale for this change in diastereoselectivity and synthetic applications are also presented.