Zn-mediated electrochemical α-alkylation of amines with halogenated alkanes through convergent paired electrolysis†

Abstract

Herein, we report a green and sustainable electrochemical strategy for α-alkylation of tertiary amines with halogenated alkanes under undivided electrolytic conditions. A Barbier–Grignard-type reaction at the cathode produces an organozinc reagent that reacts with an iminium ion produced at the anode to provide the α-alkylated amine. The reaction proceeds under mild reaction conditions with wide-ranging functional-group and substrate compatibilities, affording the products in good yields. More importantly, convergent pair electrolysis, an ideal but challenging electrochemical technique, is effectively utilized in this reaction system. Detailed mechanistic study indicated that an imine ion intermediate is involved in the reaction process.