One-electron reduction of methyl(trifluoromethyl)dioxirane by iodide ion. Evidence for an electron-transfer chain reaction mediated by the superoxide ion

Abstract

One-electron-transfer processes, triggered by I - in catalytic amounts, convert methyl(trifluoromethyl)dioxirane (1) into 1,1,1-trifluoropropanone (trifluoroacetone) and dioxygen. It is proposed that the initially formed bis(oxy)methylene radical anion 1' performs nucleophilic attack at the dioxirane 1, yielding a dimeric radical anion 2'; the latter then fragments into trifluoroacetone and superoxide ion (O 2 .- ). The intermediacy of superoxide ion (the propagator of the electron-transfer chain reaction) is demonstrated by its trapping with either benzoyl chloride or chlorotrimethylsilane