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.