β-Formyl- and β-Vinylporphyrins: Magic Building Blocks for Novel Porphyrin Derivatives

Porphyrins bearing formyl or vinyl groups have been explored as starting materials to prepare new compounds with adequate features for different applications. In this review it is discussed mainly synthetic strategies based on the reaction of meso-tetraarylporphyrins bearing those groups at β-pyrrolic positions. The use of some of the obtained porphyrin derivatives for further transformations, namely via pericyclic reactions, is also highlighted.