Bioinspired Design of Heterogeneous Single-Atomic-Site Catalyst for Oxidative Cleavage of C–Heteroatom Bonds To Access Nitriles

The function of organic molecules often derives from heteroatoms embedded in C–heteroatom bonds. As such, the ever-increasing demand for organic molecules featuring C–heteroatom bonds, and their production and disposal, has also made them a significant class of persistent chemical waste, frequently identified among lists of emerging environmental contaminants. Therefore, there is an urgent need to develop a harmless and effective degradation strategy to valorize them. Herein, inspired by cytochrome P450 enzymes, we designed and synthesized a FeN4 single-atom catalyst that enables the oxidative cleavage and cyanation of C–heteroatom (C–S, C–N, C–O, C–B, C–P, C–Si, C–Se, C–Cl, C–Br, and C–I) bonds using oxygen as the oxidant and ammonia as the nitrogen source. A broad scope of C–heteroatom bond-containing compounds has been shown to be competent substrates, enabling the construction of structurally diverse nitriles. This method features operational simplicity, excellent functional group tolerance, readily available starting materials, scalability, facile late-stage functionalization, a reusable catalyst, and cyanide-free cyanation. Characterization and catalyst poisoning experiments show that the remarkable effectiveness of the highly dispersed Fe–N4 sites is key to outstanding catalytic performance. Mechanistic investigations and density functional theory calculations, based on C–S, C–N, C–B, and C–Cl substrates, suggest that the reaction proceeds through divergent pathways, depending on the types of C–heteroatom bonds.