Aryl radicals are important and versatile active intermediates in synthetic chemistry, and the chemical conversions involved are regarded as perfect complements to the transition-metal-catalyzed arylation reactions. The formation of aryl radicals is mainly achieved through reductive systems. Electrocatalysis has a safe and controllable potential range that can easily attain a reduction potential beyond the range of chemical reductants and excited photocatalysts, offering a synthetically attractive and environmentally friendly alternative for the production of aryl radicals. Remarkable achievements in the electrochemical functionalization of aryl radicals have been reported. This review primarily focuses on the generation of aryl radicals via an electroreduction strategy, and systematically elaborates on synthetic applications, scope, and limitations of the substrates. The full spectrum of aryl radical precursors applied in the electroreduction strategy, including aryl halides, aryl diazonium salts, arylazo sulfones, aryl amines, nitroarenes, aryl quaternary ammonium salts, aryl triflates, and aryl thianthrenium salts, is reviewed.

中文翻译：

---

电还原策略：产生芳基自由基的可持续工具


芳基自由基是合成化学中重要且用途广泛的活性中间体，所涉及的化学转化被认为是过渡金属催化芳基化反应的完美补充。芳基自由基的形成主要通过还原体系来实现。电催化具有安全可控的电位范围，可以轻松获得超出化学还原剂和激发光催化剂范围的还原电位，为芳基自由基的生产提供了一种合成有吸引力且环境友好的替代方案。芳基自由基电化学功能化方面取得了显着的成就。本综述主要关注通过电还原策略生成芳基自由基，并系统地阐述了底物的合成应用、范围和局限性。综述了应用于电还原策略的全谱芳基自由基前体，包括芳基卤化物、芳基重氮盐、芳基偶氮砜、芳基胺、硝基芳烃、芳基季铵盐、芳基三氟甲磺酸盐和芳基噻烯盐。