Metal-Assisted One-Pot Synthesis of Isoporphyrin Complexes

Abstract

Zinc and cadmium complexes of meso-arylisoporphyrins carrying a pyrrolyl or dipyrrinyl substituent at the sp(3) carbon atom were obtained through a simple one-pot variation of the Alder-Longo porphyrin synthesis. Key to the formation and stabilization of isoporphyrins is the presence of metal acetates during the oxidative macrocyclization step. The characteristic Q-bands of isoporphyrins are found in the NIR region between 750 nm and 880 nm. All of the isolated pyrrolyl- and dipyrrinyl-appended isoporphyrins are stable under typical laboratory conditions and allow chemical transformations like BF2 coordination, transmetalation, and ligand exchange.

Keywords: NIR dyes; isoporphyrins; macrocycles; porphyrinoids; templated synthesis.