First Synthesis of Azachlorins and Azacorrins with a N‐Atom in β ‐Pyrrolic Positions

Azachlorins 7 and 11 , and azahexadehydrocorrin rac ‐ 10 are novel structural types of tetrapyrrolic macrocycles. Synthesis of the target structures bearing N‐atoms in the β ‐periphery of the macrotetracycles could be achieved by attaching an imidazole moiety 4 to the tricyclic Ni complex rac ‐ 5 , followed by cyclization. Depending on the central metal ion of the bilin intermediates rac ‐ 6a and rac ‐ 6b , chlorin‐ or corrin‐type structures were formed by cyclization.