Cobalt-catalyzed enantioselective intramolecular reductive cyclization via electrochemistry.

Transition-metal catalyzed asymmetric cyclization of 1,6-enynes has emerged as a powerful method for the construction of carbocycles and heterocycles. However, very rare examples worked under electrochemical conditions. We report herein a Co-catalyzed enantioselective intramolecular reductive coupling of enynes via electrochemistry using HO as hydride source. The products were obtained in good yields with high regio- and enantioselectivities. It represents the rare progress on the cobalt-catalyzed enantioselective transformation via electrochemistry with a general substrate scope. DFT studies explored the possible reaction pathways and revealed that the oxidative cyclization of enynes by LCo(I) is more favorable than oxidative addition of HO or other pathways.