Visible-light photoredox-catalyzed selective carboxylation of C(sp2)−F bonds in polyfluoroarenes with CO2

Visible light-driven carboxylation with CO2 have emerged as a sustainable and powerful way to transfer waste to treasure. However, it is still challenging for aryl fluorides due to the low reactivities of both C(sp2)−F bonds and CO2. Herein, we report the first photocatalytic carboxylation of aryl C−F bonds with CO2. The visible-light photoredox catalysis enables selective carboxylation of strong C(sp2)−F bonds in diverse polyfluoroarenes, such as penta-, tetra-, and tri-fluoroarenes under mild conditions, providing a facile access to a series of important polyfluoroaryl carboxylic acids with good yields. In contrast to previous reports of direct capture of polyfluoroaryl radicals, mechanistic studies suggest that the reduction of fleeting polyfluoroaryl radicals into polyfluoroaryl anions might be involved in this transformation, which may open a new avenue for photocatalytic functionalization of aryl C−F bonds.