Transition structures for the stepwise insertion of oxygen into alkane tertiary CH bonds by dimethyldioxirane

Oxygen insertion into the isobutane CH bond by dimethyldioxirane 1 was computationally studied at the R(U)B3LYP level to address the mechanistic concerted-stepwise problem. We located genuine TSs, diradicaloid in nature, that can lead to final products via radical pair intermediates. These TSs have lower energies than their concerted counterpart. Thus, calculations support the viability of radical pair formation in the reaction of dioxiranes with alkanes.