Recent advances in the synthesis of diazaporphyrins and their chalcogen derivatives

Porphyrins are highly influential functional materials in the field of science owing to their fascinating colors and diverse electrochemical and optical properties. Peripheral modification of porphyrin rings with nitrogen is an attractive approach for imparting unprecedented functions to both natural and artificial pophyrins. Diazaporphyrins (DAPs) are a class of compounds that have two meso-nitrogen atoms. DAPs exhibit characteristic redox and optical properties that differ significantly from those of porphyrins. The preparation and chemical functionalization of DAP-based sensitizers, catalysts, and materials have gained significant attention in various fields such as medical science, organic synthesis, and materials chemistry. This review focuses on recent advances in the synthesis of diazaporphyrins and their chalcogen derivatives, including historically important examples.