New porphyrinoid diimines by cyclization of 1,9-bis(5-formylpyrrol-2-yl)dipyrrins with arene-1,2-diamines and hydrazines

Four new porphyrinoid diimines 3, 4, 5, and 6 are synthesized from alkylate d 1,9-bis(5-formylpyrrol-2-yl)dipyrrins 1 and diaminobenzidine 2a, hydrazin e (2b), N,N'-diaminoguanidine (2c) and 3,4-diaminopyridine (2d). Macrocycle s 4 and 5 resist oxidation with DDQ (2,3-dichloro-5,6-dicyanobenzoquinone) to 18 pi or 22 pi aromatic systems, while 3 and 6 are readily obtained as a romatic macrocycles. From the latter, 6 exhibits deshielded protons outside and shielded NH protons inside due to 22 pi aromaticity.