The small stones of Coimbra in the huge tetrapyrrolic chemistry building

Abstract

Improvements over the Rothemund classical reaction methods have allowed the development of capacity to obtain a wide range of structures that were earlier unavailable. Performing the reaction in a mixed nitrobenzene/carboxylic acid medium allowed improvements of yield and purity of the porphyrin obtained, and in some cases the control of the oxidation level of the macrocycle. More recently, novel microwave synthetic methodologies were exploited to achieve important improvements in simple porphyrin chemistry. Tidy sulphonations of simple porphyrins opened the way to diverse desired, inexpensive structures in a very simple manner. The option to concentrate interests on improvements of synthetic methods to obtain simple and diversified tetrapyrrolic structures proved to be advantageous. Interesting biomimetic oxidation and photooxidation systems and PDT sensitizers were developed and significant knowledge was achieved in these specific and related areas. This review presents a view of our own results in the synthetic area, and outlines the contributions therefrom to the study of biomimetic and therapeutic processes.