Hydroxylation and expoxidation reactions catalyzed by synthetic metalloporphyrinates. Models related to the active oxygen species of cytochrome P-450

Abstract

Iodosylbenzene has been found to react with catalytic amounts of synthetic metalloporphyrinates to give epoxides and alcohols from olefins and alkanes. Tetraphenylporphinatoiron(III) chloride (TPPFeCl) catalyzed the epoxidation of cis-stilbene to cis-stilbene oxide whereas the trans isomer was unreactive. Dioctyl protoporphyrin IX reacted with iodosylbenzene to give significant oxidation of the side chain alkyl groups. The distribution of products is interpreted to be the result of an intramolecular oxygen transfer reaction.Treatment of tetra-ortho-tolylporphinatoiron(III) chloride (TTPFeCl) with iodosylbenzene afforded a reactive intermediate which degraded the porphyrin in the absence of a oxidizable substrate. Similar oxidation of tetraphenylporphinatochromium(III) chloride with iodosylbenzene gave a stable intermediate which has been characterized as an oxochromium(V) complex.