Dual Oxidation of Epoxides with a High-Valent Cu(III)-CF 3 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)(CF 3 ) 3 and DMSO to produce 1,2-diketones. The Cu(III)-CF 3 compound serves as a CF 3 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 Me 2 S. The combination of a Cu(III)-CF 3 compound and DMSO may be exploited to develop other novel oxidation reactions.