Addition of Carboxylic Acids to gem-Difluoroalkenes for the Synthesis of gem-Difluoromethylenated Compounds

We herein describe a straightforward protocol for the synthesis of carboxylic esters containing a gem-difluoromethylene unit. Readily available carboxylic acids can act as nucleophiles to add regioselectively to tetrasubstituted or trisubstituted beta,beta-difluoroacrylates (formal hydroacetoxylation) for the construction of RCO2-CF2 bonds. Thermal conditions are sufficient without the use of catalysts or additives.