Synthetic Approaches to Functional Derivatives of Cycl[3.2.2]Azine-1,2-Dicarboxylic Acid - Perspective Building Blocks for pi-Extended Macrocyclic Compounds

One of the actual goals in the field of macrocyclic research is to provide accessible chemically robust compounds with absorption in the NIR spectral region. This requirement can be fulfilled in the case of tetrapyrrolic derivatives such as porphyrins, phthalocyanines etc with extended system of electronic conjugation. In this short review, we focus on the available approaches for the synthesis of cycl[3.2.2]azine-1,2-dicarboxylic acid functional derivatives - an emerging class of - extended tetrapyrrolic macrocycle precursors.