Porphyrins and derivatives: Synthetic strategies and reactivity profiles

Porphyrins, usually as metal complexes of either iron or magnesium, are widely distributed in nature, and exist as the prosthetic groups in a wide variety of primary metabolites such as hemoglobins, myoglobins, cytochromes, catalases, peroxidases, chlorophylls, and bacteriochlorophylls. This article describes the current best methodology for preparation of simple, symmetrical model porphyrins, as well as more complex protocols for preparation of unsymmetrical substituted porphyrin systems similar to those found in nature. Basic chemical reactivity of porphyrin and metalloporphyrin systems are then described systematically, using a reactivity profile approach. The discussion of reactivity includes newer developments in this field, focussing on electrophilic and nucleophilic reactions, oxidation, reduction, cycloaddition reactions and intramolecular cyclizations. Using the reactivity profiles presented, porphyrin systems can be functionalized and transformed into novel arrays and systems, and these are providing valuable contributions to catalytic, electron transport, biological and medicinal chemistry