Amide-based oligocatenanes by an iterative template strategy

A new pathway for the supramolecular synthesis of oligocatenanes is develop ed. It is based on a combination of most suitable macrocyclic structural un its, obtained from tert-butyl-substituted isophthalic acid and terephthalic acid building blocks. These structural parts guarantee, on the one hand, t he solubility of the catenanes and their intermediates, and, on the other h and, the preferred formation of larger ring sizes of the macrocycles to be intertwined. Acting as monotopic and ditopic concave templates, the tetra- and octalactam macrocycles were submitted to threading procedures to yield higher-order catenanes of the amide type. By repetition of the threading st eps, it was possible to isolate multiply mechanically connected [n]catenane s up to n = 4 composed of various macrocyclic units.