Benzoylbiliverdins from chemical oxidation of dodeca-substituted porphyrins.
Oxidation of dodeca-substituted porphyrin 1 in the presence of NaNO2/TFA and air afforded benzoylbiliverdin 3 in 77% yield; under similar conditions the Ni(II)-porphyrin 2 was mainly nitrated at a cyclohexenyl ring; key X-ray structures are presented.