Alkyl - , Aryl - , and Acyl - metal ( m ) Complexes of Aetioporphyrin I

Reaction of pyridinobromocobalt(llI) aetioporphyrin I with a variety of alkyland aryl-magnesium bromides gives the corresponding alkyland aryl-cobalt(lIl) derivatives. In an alternative synthesis, the cobalt(l) derivative of aetioporphyrin J reacts with alkyl or acyl halides to give the alkylor acyl-cobalt(llI) compounds. The latter approach has also been used for the preparation of hydroxyalky/cobalt(/II) porphin derivatives which are shown to yield aliphatic carbonyl derivatives on photolysis. The porphin ring exhibits a profound shielding effect on the protons of the alkyl-, aryl-. and acyl-cobalt groups and a maximum effect on the protons of the second carbon atom of the chain. p-Tolyland ethyl-iron(llI) derivatives of aetioporphyrin J are also described.