Photocatalyst-Regulated Trifluoromethoxylation of Aryl Halides under Silver Promotion

Trifluoromethoxylated aromatics are crucial in pharmaceuticals and agrochemicals, yet their synthesis remains challenging. While aryl halides offer advantages such as commercial availability and facile regioselectivity control, their direct trifluoromethoxylation has remained unachievable, even with transition-metal catalysis. Here, we report the first trifluoromethoxylation of aryl halides, enabled by a photocatalytic strategy via aryl cationic radical intermediates. A key advancement is the use of silver salts, which unlocks the participation of electronically neutral and electron-withdrawing aryl halides. Moreover, this method demonstrates exceptional chemoselectivity for aryl chlorides and bromides.