Redox‐Active Reagents for Photocatalytic Generation of the OCF 3 Radical and (Hetero)Aryl C−H Trifluoromethoxylation

The trifluoromethoxy (OCF 3 ) radical is of great importance in organic chemistry. Yet, the catalytic and selective generation of this radical at room temperature and pressure remains a longstanding challenge. Herein, the design and development of a redox‐active cationic reagent ( 1 ) that enables the formation of the OCF 3 radical in a controllable, selective, and catalytic fashion under visible‐light photocatalytic conditions is reported. More importantly, the reagent allows catalytic, intermolecular C−H trifluoromethoxylation of a broad array of (hetero)arenes and biorelevant compounds. Experimental and computational studies suggest single electron transfer (SET) from excited photoredox catalysts to 1 resulting in exclusive liberation of the OCF 3 radical. Addition of this radical to (hetero)arenes gives trifluoromethoxylated cyclohexadienyl radicals that are oxidized and deprotonated to afford the products of trifluoromethoxylation.