Dual Oxidation of Epoxides with a High-Valent Cu(III)-CF₃ Compound and DMSO to Access 1,2-Diketones

This study reports sequential dehydrogenation and transfer oxygenation of 1,2-diarylepoxides by high-valent phenCu(III)(CF₃)₃ and DMSO to produce 1,2-diketones. The Cu(III)-CF₃ compound serves as a CF₃ radical source to abstract the hydrogen atom of the epoxide ring. The resulting ether α-carbon radical undergoes ring-opening rearrangement to give a ketone α-carbon radical intermediate, which is oxygenated by DMSO with the release of Me₂S. The combination of a Cu(III)-CF₃ compound and DMSO may be exploited to develop other novel oxidation reactions.