Single-atom iron-anchored graphitic C3N5 for photocatalytic trifluoromethylation of aromatics and N-heterocycles in water

Abstract

The introduction of a trifluoromethyl group into aromatics is a key strategy for modulating the properties of chemicals and materials. The main challenge lies in the direct conversion of inert C(sp²)–H bonds into trifluoromethyl groups via an efficient, low-cost, and environmentally benign approach. Herein, we developed an iron single-atom-anchored carbon nitride (Fe₁@C₃N₅) photocatalyst to achieve direct C(sp²)–H trifluoromethylation of (hetero)arenes. The advantages of this approach include the use of water as the only solvent, mild conditions (35 °C, 12 W-415 nm light), a recyclable and cheap catalyst (up to 8 times, $0.06 per g) and a broad substrate scope (32 examples). Notably, Fe doping significantly enhances visible-light absorption, promotes efficient charge separation, and facilitates radical generation. This methodology offers a sustainable and scalable alternative to traditional transition metal-mediated trifluoromethylation pathways.