The direct reduction of inert planar arenes and heteroarenes with visible light remains rarely explored, as the energy of one visible-light photon is unable to overcome the stabilization of aromatics. Here we report a system based on boron carbonitride semiconductor, which can reduce arenes and heteroarenes in water under blue light irradiation. The system features the advantage of low-cost, high-efficiency, facile separation, benign environmental profile and broad substituent tolerance. The methodology can be extended to late-stage functionalization and/or deuteration of drugs, hormones and axially chiral compounds with conserved chirality. Moreover, gram-scale synthesis is successfully implemented with catalyst recycling. Mechanistic investigations support a consecutive blue-light-induced energy and electron transfer process, which accumulates sufficient energy to reduce arenes to arene anions by absorbing two photons successively. The metal-free system introduces a simple and sustainable reactivity mode for semiconductor photocatalysts and enriches the chemical toolkit for a class of demanding and valuable organic transformations.

用可见光直接还原惰性平面芳烃和杂芳烃的研究很少，因为一个可见光光子的能量无法克服芳烃的稳定性。在这里，我们报告了一种基于碳氮化硼半导体的系统，它可以在蓝光照射下还原水中的芳烃和杂芳烃。该体系具有低成本、高效、易分离、环境友好、取代基耐受性广等优点。该方法可以扩展到药物、激素和具有保守手性的轴向手性化合物的后期功能化和/或氘化。此外，通过催化剂回收成功实现了克级合成。机械研究支持连续的蓝光诱导能量和电子转移过程，它通过连续吸收两个光子积累足够的能量将芳烃还原为芳烃阴离子。无金属系统为半导体光催化剂引入了一种简单且可持续的反应模式，并丰富了用于一类要求苛刻且有价值的有机转化的化学工具包。