Trifluoromethylation of (hetero)aryl iodides and bromides with copper(I) chlorodifluoroacetate complexes

A new copper-mediated trifluoromethylation reaction using copper(I) chlorodifluoroacetate complexes as reagents is reported. The complex [L2Cu][O2CCF2Cl] (L = bpy, dmbpy, phen) reacted with (hetero)aryl iodides and bromides in the presence of CsF in DMF at 75 degrees C to afford the trifluoromethylarenes in good to excellent yields. High compatibility with various chemical functions or (hetero) cycles was also observed in the reaction. A reaction mechanism involving a difluorocarbene intermediate, along with a subsequent formation of a -CF3 anion was proposed.