Cobalt-Catalyzed Asymmetric Reductive Propargylic Addition of α-Ketimino Esters.

The Nozaki-Hiyama-Kishi (NHK) reaction serves as a powerful method for stereoselective carbon-carbon bond formation under mild conditions. While significant progress has been made in the enantioselective propargylation of carbonyl compounds, its application to imines remains underdeveloped. Herein, we report a catalytic asymmetric reductive propargylic addition to α-ketimino esters, providing direct access to chiral propargylated amines with high chemoselectivity and enantioselectivity. This method expands the synthetic utility of NHK-type reactions toward nitrogen-containing scaffolds, offering a complementary route to enantioenriched amine derivatives under mild and efficient conditions.