Electrochemically Enabled [3 + 2] Cycloaddition of Alkenes with Vinyl Azides: Direct Access to 2,4,5-Trisubstituted 1-Pyrrolines

Electrosynthesis provides an efficient route for the construction of heterocyclic compounds. Herein, we report an electrochemically promoted [3 + 2] cycloaddition of alkenes with vinyl azides under mild conditions. This strategy enables the direct synthesis of 2,4,5-trisubstituted-1-pyrrolines. Compared with conventional methods, this approach requires no oxidants, reductants, or metals. Mechanistic studies have revealed that the reaction proceeds via a cyclization process of alkene radical cations, and both the anode and the cathode play indispensable roles in the reaction.