Electrochemical Homo- and Crossannulation of Alkynes and Nitriles for the Regio- and Chemoselective Synthesis of 3,6-Diarylpyridines.

We disclose a mediated electrochemical [2+2+2] annulation of alkynes with nitriles, forming substituted pyridines in a single step from low-cost, readily available starting materials. The combination of electrochemistry and a triarylamine redox mediator obviates the requirements of transition metals and additional oxidants. Besides the formation of diarylpyridine moieties via the homocoupling of two identical alkynes, the heterocoupling of two different alkynes depending on their electronic nature is possible, highlighting the unprecedented control of chemoselectivity in this catalytic [2+2+2] process.