CuCF3 mediated deoxyfluorination of redox-active esters

Trifluoromethyl copper (CuCF3), as a diverse fluorination reagent, has been widely used in trifluoromethylation, perfluoroalkylation, and difluorocarbene reactions. However, it has rarely been reported as a single fluorine source involved in nucleophilic fluorination reactions. This work describes a general strategy involving copper-mediated deoxyfluorination of redox-active esters to rapidly access various aliphatic and aromatic acyl fluorides. The highly active CuF species could be generated from either copper fluoride salts or CuCF3. A plausible mechanism of CuCF3 forming an [F-CuCF2F5]- intermediate and NHBC ester forming acyl fluoride has been derived from DFT calculations.