Synthesis of bacteriochlorins and their potential utility in photodynamic therapy (PDT)

The porphyrins and related tetrapyrrole systems are among the most widely studied of all macrocyclic compounds. In fact, in one capacity or another these versatile molecules have influenced nearly all disciplines in chemistry. In recent years, efforts are underway to develop tetrahydroporphyrin-based (bacteriochlorin) compounds with long wavelength absorption in the range of 700-800 nm as photosensitizers for photodynamic therapy (PDT). This review article summarizes the synthetic methodologies that have been developed for the preparation of a variety of bacteriochlorins, either from porphyrins or chlorin systems.