Synthesis of chlorins and bacteriochlorins from cycloaddition reactions with porphyrins

Abstract

Dedicated to Prof. Girolamo Cirrincione in recognition of his outstanding organic and medicinal chemistry contributions, on the occasion of his university retirement Abstract Chlorins and bacteriochlorins are reduced porphyrin-type derivatives displaying characteristic structural, physical, and chemical features. Such features make chlorins and bacteriochlorins key "players" in several fields, and specifically in medicine as photosensitizers (PSs) for the diagnosis and treatment of neoplastic situations by photodynamic therapy. Cycloaddition approaches have become important synthetic tools to prepare chlorin and bacteriochlorin macrocycles. This review highlights the procedures developed over the last 10 years to synthesize chlorins and bacteriochlorins, namely through Diels-Alder and 1,3-dipolar reactions using porphyrin macrocycles as templates.