Cobalt complex/Zn systems effectively catalyze the reductive coupling of activated alkenes with alkynes in the presence of water to give substituted alkenes with very high regio-and stereoselectivity in excellent yields. While the intermolecular reaction of acrylates, acrylonitriles, and vinyl sulfones with alkynes takes place in the presence of CoI2 (PPh3) 2/Zn, the reaction of enones and enals with alkynes requires the use of the CoI2 (dppe)/Zn ...
