Copper-Catalyzed Innate Ethoxycarbonyldifluoromethylation of Electron-Rich Arenes

We report the direct introduction of the CF2CO2Et moiety into electron-rich arenes. The copper-catalyzed process uses commercially available and inexpensive BrCF2CO2Et as a fluorinated building block. This radical-free reaction proceeds smoothly to give the desired difluoromethylated arenes in modest to good yields with a Friedel-Crafts-type regioselectivity. The direct introduction of ,-difluoromethylated amides was also investigated, and this gave the corresponding difluoromethylated arenes, albeit in moderate yields. This method represents the first transition-metal-catalyzed direct introduction of a functionalized fluorinated moiety into electron-rich arenes.