Cobalt-Catalyzed Regio- and Enantioselective Reductive Coupling of 1,3-Enynes with Imines

We report a cobalt-catalyzed asymmetric reductive coupling of 1,3-enynes with <i>N</i>-sulfonyl imines, affording chiral dienyl amines with excellent regio- and enantioselectivity. Using an Earth-abundant cobalt complex and a commercially available chiral diphosphine ligand, the method delivers up to 96% yield, up to >99% ee, and >20:1 regioselectivity. Water proved to be essential as an additive, enabling high yields with maintained stereocontrol. The reaction shows a broad scope, tolerating diverse aromatics and 1,3-enynes, and is effective for pharmaceutically relevant substrates, giving products with 99% ee. Mechanistic studies indicate a cobalt-mediated oxidative cyclization with water being critical for catalyst turnover.