Photocatalyzed Aryl C-H Fluorocarbonylation with CFBr.

The use of abundant and inexpensive fluorine feedstocks to synthesize fluorinated compounds is a promising strategy that has not been extensively investigated. Dibromodifluoromethane (CFBr) is an inexpensive fluorine source that has rarely been used for C-H fluoroalkylation. This study reveals an iridium-catalyzed, tunable strategy for synthesizing acyl fluorides and difluorobromomethylated products using CFBr. To achieve the desired products, this process only requires the change of solvent (from DMSO to 1,4-dioxane) under blue LED illumination. A variety of arenes and heteroarenes with electron-donating substituents were successfully used, yielding the corresponding products in moderate to good yields. Mechanistic experiments revealed that DMSO served a dual role, functioning as both solvent and nucleophilic reagent in C-H fluorocarbonylation.