Modification of beta-positions in porphyrazines by substitution reactions

Peripheral modification of the porphyrazine macrocycle is an important synt hetic approach to beta-substituted porphyrazine derivatives, especially tho se which cannot be obtained via direct template cyclotetramerization of mal eodinitriles and other similar synthons. The paper presents the last result s of the systematical investigation of the reactivity of unsubstituted porp hyrazine (tetraazaporphine) in the reactions of electrophilic and radical s ubstitution in pyrrole rings (bromination, chlorination, chloromethylation, nitration and sulfonation) and nucleophilic substitution reactions of chlo ro-, bromo- and sulfo-substituted porphyrazines. Copyright (C) 2000 John Wi ley & Sons, Ltd.