Aromatic C(sp2)−H Functionalization by Consecutive Paired Electrolysis: Dibromination of Aryl Amines with Dibromoethane at Room Temperature

Herein, we disclose a facile and efficient electrochemical method for the dibromination of aryl amines by double functionalization of aromatic C(sp2)−H (both para and ortho) under metal‐ and external oxidant‐free conditions at room temperature for the first time. The reaction is demonstrated using 1,2‐dibromoethane to dibrominate a wide range of N‐substituted aryl amines in a simple setup with C(+)/Pt(−) electrodes under mild reaction conditions. This transformation proceeds smoothly with a broad substrate scope affording the valuable and versatile N‐substituted 2,4dibromoanilines in moderate to excellent yields with high regioselectivity. In this convergent paired electrolysis, anodic oxidation and cathodic reduction occur simultaneously to generate two intermediates, which are then coupled to furnish the product. It represents a distinctive approach to challenging redox‐neutral reactions. The versatility of the electrochemical ortho‐, paradibromination was reflected by unique regioselectivities for challenging aryl amines and gram‐scale electrosynthesis without the use of a stoichiometric oxidant or an activating agent.