Electrochemical synthesis of biaryls via C-H/C-H homocoupling of methoxyarenes

A direct and one-pot electrosynthesis method for the regioselective synthesis of bis methoxybiarenes via homocoupling of methoxyarenes has been studied in undivided cells in the transition-metal and oxidant-free conditions. The effect of various parameters, such as electrodes, electrolytes, and solvents has been studied and evaluated. To gain detailed mechanistic insight into the reaction, cyclic voltammetric (CV) studies of methoxyarenes were performed, and a radical pathway has been suggested. The reaction begins with an anodic oxidation of anisole to an anisyl cation radical followed by reaction with another anisole may form a new bisanisyl cation radical. The formed intermediate undergoes a hydrogen abstraction, followed by anodic oxidation gave bisanisyl cation and the bisanisole was obtained by abstraction of second hydrogen.