AbstractHerein, 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 2,4‐dibromoanilines in moderate to excellent yields with high regioselectivity. In this paired electrolysis, cathodic reduction of 1,2‐DBE followed by anodic oxidation generates bromonium intermediates, which then couple with anilines to furnish the dibrominated products. It represents a distinctive approach to challenging redox‐neutral reactions. The versatility of the electrochemical ortho‐, para‐dibromination was reflected by unique regioselectivities for challenging aryl amines and gram‐scale electrosynthesis without the use of a stoichiometric oxidant or an activating agent.
摘要在此,我们首次公开了一种在室温无金属和外部氧化剂条件下,通过芳香族 C(sp2)-H(对位和正位)双官能化二溴化芳基胺的简便高效的电化学方法。该反应使用 1,2-二溴乙烷进行演示,在温和的反应条件下,通过使用 C(+)/Pt(-) 电极的简单设置,对多种 N 取代芳胺进行二溴化处理。这一转化过程进展顺利,底物范围广泛,能以中等到极好的产率和高区域选择性获得有价值的多用途 N-取代型 2,4-二溴苯胺。在这种配对电解过程中,1,2-DBE 阴极还原后阳极氧化生成溴鎓中间体,然后与苯胺偶联生成二溴化合产物。这是一种具有挑战性的氧化还原中性反应的独特方法。电化学正、对二溴化反应的多功能性体现在对具有挑战性的芳基胺具有独特的区域选择性,以及无需使用化学氧化剂或活化剂即可进行克级规模的电合成。