Annulation of α,β-Unsaturated Imines and Alkynes via Cobalt-Catalyzed Olefinic C–H Activation

A cobalt–triarylphosphine catalyst promotes an annulation reaction of an α,β-unsaturated imine and an internal alkyne to afford a polysubstituted dihydropyridine derivative in good yield under mild conditions. The reaction likely involves alkenylation of the olefinic C–H bond via cobalt-mediated nitrogen-assisted C–H activation followed by facile 6π electrocyclization of the resulting azatriene intermediate