Radical Trifluoromethoxylation of Arenes Triggered by a Visible‐Light‐Mediated N−O Bond Redox Fragmentation.

A simple trifluoromethoxylation method enables non‐directed functionalization of C−H bonds on a range of substrates, providing access to aryl trifluoromethyl ethers. This light‐driven process is distinctly different from conventional procedures and occurs through an OCF3 radical mechanism mediated by a photoredox catalyst, which triggers an N−O bond fragmentation. The pyridinium‐based trifluoromethoxylation reagent is bench‐stable and provides access to synthetic diversity in lead compounds in an operationally simple manner. N‐O problem: A bench‐stable pyridinium reagent transfers the elusive trifluoromethoxyl radical to a variety of arenes, including a selection of biorelevant compounds. By sidestepping limitations of traditional OCF3 sources, this approach enables late‐stage diversification by direct C−H functionalization in a mechanistically unique fashion. [ABSTRACT FROM AUTHOR]