Metalloporphyrin-catalyzed oxidations [1] 2. Inhibition and re-activation of metalloporphyrin catalysts. A simple model for hormone action

Abstract

Cobalt(III) and iron(III) porphyrins have been found to catalyse the autoxidation of cyclohexene to allylic hydroperoxides which then decomposed to give 2-cyclohexenone as the main product. If molybdenum of vanadium complexes (porphyrinates of acetylacetonates) were added in equimolar amounts to the cobalt or iron porphyrins, the reaction was stopped. Addition of steroids, deazaflavin or chrysene, led to a re-activation of the iron and cobalt porphyrin catalysts. With lanosterol equimolar amounts were sufficient to produce this effect. The main oxidation product of cyclohexene was again 2-cyclohexenone. Reactivation could also be achieved with high concentrations of cumene. In this case a 1|1 mixture of cyclohexane epoxide and 2-cyclohexenol were formed. The possible bearing of the findings on the action of steroid hormones in nature is briefly discussed.