High-yield epoxidations with hydrogen peroxide and tert-butyl hydroperoxide catalyzed by iron(III) porphyrins: heterolytic cleavage of hydroperoxides

The reactions of hydrogen peroxide or tert-butyl hydroperoxide with cyclooctene and norbornene, catalyzed by iron(III) tetrakis(pentafluorophenyl)porphyrin chloride and other electronegatively-substituted porphyrins, produced 60-100% epoxide yields. The epoxynorbornane yield has the same ratio of exo/endo isomers as is obtained using pentafluoroiodosylbenzene, an oxidant which produces the iron(IV) radical cation (oxene) intermediate. These results demonstrate heterolytic cleavage of these peroxides in the catalyzed reaction