Synthesis of difluoromethylated diarylmethanes via Fe(OTf)3-catalyzed Friedel-Crafts reaction of 2,2-difluoro-1-arylethyl phosphates.

The Fe(OTf)3-catalyzed Friedel-Crafts reaction of 2,2-difluoro-1-arylethyl phosphates with electron-rich (hetero)arenes afforded difluoromethylated diarylmethanes. Control experiments showed that Fe(OTf)3 behaves as the Lewis acid, and that the phosphate leaving group and o- or p-alkoxy substituents on the substrates are necessary for the Fe(OTf)3-catalyzed reaction to proceed under mild conditions.