Porphyrins and Derivatives  Synthetic Strategies and Reactivity Profiles

M.Graca   H.   Vicente; Kevin   M.   Smith

doi:10.2174/1385272003376346

Abstract

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 unsymmetrically 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 a re providing valuable contributions to catalytic, electron transport, biological and medicinal chemistry.

Keywords: Porphyrins, Hemoglobins, Myoglobins, Catalases, Peroxidases, Chlorophylls, Metalloporphyrin systems, Oxidation, Intramolecular cyclizations, Cycloaddition, Octaethylporphyrin, Monopyrrole tetramerization, Syntheses of dipyrromethanes, Tripyrrolic intermediates, Biladiene salts, Electropilic reaction, Nucleophilic reactions, Cycloadditions