Oxoiron(IV) species are the active oxidants in catalytic oxidation reactions by nonheme iron enzymes, but have been rarely captured and/or identified as the actual oxidizing species in catalytic epoxidation or hydroxylation reactions involving synthetic nonheme iron complexes. We now report the generation of a nonheme oxoiron(IV) intermediate, [(cyclam)FeIV(O)(CH3CN)]2+ (2; cyclam = 1,4,8,11-tetraazacyclotetradecane), in the reactions