Photoredox/Cobalt Cooperative Catalysis for Cycloisomerization of 1,6-Enynes

Under visible-light photocatalysis facilitated by cobalt coordination, a highly regio- and stereoselective cycloisomerization reaction of 1,6-enynes has been developed. This method enables the efficient synthesis of various skipped 1,4-diene products with excellent stereoselectivity, using commercially available cobalt catalysts, ligands, and reagents. Notably, the reaction exhibits remarkable regioselectivity (>20:1), stereoselectivity (<i>Z</i>/<i>E</i> > 20:1), and high yields (58-92%) under mild conditions, along with a broad substrate scope and good functional group tolerance.