Thiophene-containing Schiff-base macrocycles: intermediate compounds between macroaromatics and azamacrocycles

Hybrid Schiff-base macrocycles were synthesized by acid-catalysed condensation of 1,14-bisformyl-16-thiatripyrromethane 1 with diamines. The condensation of aliphatic diamines with 1 resulted in the partially oxidized macrocycles 5–11. On the other hand, the condensation of aromatic diamines with 1 gave simply cyclized Schiff-base 16. Fully conjugated macrocycles were never formed and attempted oxidation of either macrocycles with various oxidants resulted in the extensive decomposition of the starting material. Hydride reduction of imine functions gave the new hybrid macrocycles.