Reversible Cobalt-Nitrogen Alkyl and Acyl Group Migration in Cobalt Porphyrins
David Dolphin, Halko, D.J., and Johnson, E.
The 1-electron electrochemical oxididation of I (R = Et) gives II by an intramolecular rearrangement. NaBH4 reduction of II gives I (R = Et) by an intermolecular rearrangement. Similar treatment of I (R = CO2Et) at low temperature showed that the initial site of oxidation is in the porphyrin ring to give the corresponding π-cation radical. In this case the Co-to-N migration occurs upon warming a solution of the π-cation radical.