Abstract: The first synthesis of 2, 3-diazaporphyrins 3 bearing two nitrogen atoms at peripheral positions from tripyrranes 1, prepared in situ by mild acidolysis and decarboxylation of the di-t-butyldicarboxylates, and 4H-1, 2, 4-triazol-3, 5-dicarbaldehyde (2) is described, using the [3+ 1] principle of porphyrine cyclization. Similar to the parent porphyrins, the new diazaporphyrins 3 exhibit significantly shielded inner protons, ...
