AlCl3-mediated defluorinative diarylhydroxylation transformation of CF3: Chemoselective arylation of CF3 and chlorocarbonyl groups attached to aromatic rings

Abstract

The CF3 group in 4-trifluoromethylbenzoyl chloride is efficiently diarylated and converted, into a diarylhydroxymethyl group by treatment with AlCl3 in the presence of an excess amount of halobenzene (C6H5X; X = F, Cl, and Br). The diarylation is followed by arylation of the chlorocarbonyl group to afford triarylated products, diarylhydroxymethylated benzophenones. The employment of TfOH in place of AlCl3 promotes the exclusive arylation of the chlorocarbonyl group leaving the CF3 group unchanged, to afford selectively 4-trifluoromethylbenzophenones, which then undergo diarylhydroxymethylation with the aid of AlCl3. © 2010 The Chemical Society of Japan.