[Metal-free Synthesis of α,α-Difluorocarbonyl Compounds via Decarboxylative Arylation].

Decarboxylative arylation of α,α-difluoro-β-ketoacid salts with diaryliodonium(III) salts has been developed to synthesize α-aryl-α,α-difluoromethyl ketones, which are attractive synthetic intermediates for various difluorobenzyl units. This additive-free arylation represents an alternative approach to conventional synthetic methods that rely on transition metal catalysts and/or organometallic compounds. The reaction involves sequential ligand exchange of difluoroketoacid with tosylate ligand of diaryliodonium salt, followed by decarboxylative ligand coupling. Various functional groups, including ester, nitro, cyano, heteroarenes, and aryl halide groups, were tolerated during the present reaction. The resulting α-aryl-α,α-difluoromethyl ketones can be transformed into the corresponding esters, amides, and difluoromethyl compounds, which are commonly found in biologically active compounds.