STEREOCHEMICAL STUDIES ON REVERSIBLE METAL NITROGEN TRANSFER OF ALKYL AND ARYL GROUPS IN CHIRAL COBALT(III) PORPHYRINS - RELEVANCE TO THE MECHANISM OF A METABOLIC HEME INACTIVATION PROCESS

Resolution of the antipodes of chiral sigma-alkyl- and sigma-aryl-cobalt(III) complexes of etioporphyrin I was first achieved, where the latter was shown to be much more stable than the former toward thermal racemization. Use of these antipodes for stereochemical studies on the mechanism of reversible cobalt-nitrogen transfer of alkyl and aryl groups in cobalt porphyrins revealed that the transfers from cobalt to nitrogen and from nitrogen to cobalt both take place in intramolecular fashions.