Microwave-assisted copper catalysis of α-difluorinated gem-diol toward difluoroalkyl radical for hydrodifluoroalkylation of para-quinone methides

Reported herein is a unified strategy to generate difluoroalkyl radicals from readily prepared α-difluorinated gemdiols by single electron oxidation. Under microwave irradiation, a catalytic amount of oxidant Cu(OAc)2 succeeds in the formation of transient difluoroalkyl radicals in situ, for the first time. The reaction features a simple protocol, short reaction time, scalability, and high yield. The synthetic utility of this new methodology was also explored for the synthesis of difluoroalkylated spiro-cyclohexadienones, which is an important core structure in natural products and pharmaceuticals.