C−H Fluoromethoxylation of Arenes by Photoredox Catalysis

Redox‐active N‐(fluoromethoxy)benzotriazoles were made accessible from fluoroacetic acid and hydroxybenzotriazoles via electrodecarboxylative coupling. After alkylation, they become effective monofluoromethoxylation reagents, enabling the photocatalytic C−H functionalization of arenes. Thus, irradiation of 1‐(OCH2F)‐3‐Me‐6‐(CF3)benzotriazolium triflate with blue LED light in the presence of [Ru(bpy)3(PF6)2] promotes the synthesis of diversely functionalized aryl monofluoromethyl ethers. This method allows the late‐stage functionalization of biologically relevant structures without relying on ecologically problematic halofluorocarbons. A new class of [N−OCH2F] redox‐active reagents were synthetized via electrodecarboxylative C(sp3)−O coupling of N‐hydroxybenzotriazoles with fluoroacetic acid and subsequent alkylation. By irradiation with blue LEDs in the presence of a photosensitizer, these bench stable reagents allow the synthesis of monofluoromethyl aryl ethers via functionalization of C−H bonds.