Mechanistic Study on Ring-Contracting Skeletal Rearrangement from Porphycene to Isocorrole by Experimental and Theoretical Methods

In this study, the ring contracting skeletal rearrangement reaction in one-pot under basic conditions from octaethylporphycene to two types of isocorroles, i.e., the meso-formyl and meso-free forms, was confirmed and the reaction mechanism was proposed by the comparative analyses of the experimental and theoretical studies. The electron accepting nature of the porphycene and imine-amine conversion of pyrrole rings make it possible to react with hydroxide ions and the following reaction to afford isocorroles. Based on this reaction, the valence of the compound as a ligand as well as the photochemical and electrochemical properties were dramatically changed.