Ligand-Controlled Divergent CH Functionalization of Aldehydes with Enynes by Cobalt Catalysts

We describe a highly step and atom economical cobalt-catalyzed cyclization of 1,6-enynes with aldehydes to synthesize functionalized pyrrolidines and dihydrofurans with high chemo- and stereoselectivity. The catalytic reaction plausibly proceeds via the cobaltacycle intermediate generated from the reaction of enyne substrate with cobalt catalyst, followed by switchable CH functionalization of weakly coordinating aldehydes depending on the electronic nature of the ligand.