Highly Efficient Alkene Radical Difunctionalization toward Alkyl Azide and Nitrile Achieved by Copper Single-Atom Catalysts

Organic azides and nitriles are privileged motifs in pharmaceuticals, agrochemicals, and functional materials, yet their direct and modular installation via radical difunctionalization remains a major challenge. Many current catalytic systems are generally limited to single transformations and suffer from poor recyclability, limiting practical utility. Herein, we present a heterogeneous single-atom Cu-N₄ catalytic system that can mediate multiple radical difunctionalizations of alkenes under reaction-specific conditions. These include diazidation, aminoazidation, trifluoromethylazidation, trifluoromethylcyanation, and aminocyanation, all with efficient catalyst recycling. The system is based on a bowl-shaped carbon-supported Cu-N₄ single-atom catalyst (Cu-N₄/BSC), in which atomically dispersed Cu-N₄ sites are precisely coordinated. This catalyst exhibits a broad substrate scope (58 examples), high efficiency (up to 93% yield), and gram-scale applicability, while retaining 93% activity after seven cycles. Product diversification further highlights its synthetic utility. Spectroscopic and mechanistic studies confirm the Cu-N₄ coordination environment and a radical-mediated pathway. Together, this work demonstrates a versatile "single-atom catalysis-modular synthesis-recyclability" approach for sustainable access to nitrogen-containing heterocycles.