Amide-Based Oligocatenanes by an Iterative Template Strategy

Abstract

A new pathway for the supramolecular synthesis of oligocatenanes is developed. It is based on a combination of most suitable macrocyclic structural units, obtained from tert-butyl-substituted isophthalic acid and terephthalic acid building blocks. These structural parts guarantee, on the one hand, the solubility of the catenanes and their intermediates, and, on the other hand, 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 steps, it was possible to isolate multiply mechanically connected [n]catenanes up to n 4 composed of various macrocyclic units.

Distinctive features and challenges in catenane chemistry

“…50,51 A few other linear [4]-and [5] catenanes from either stepwise or one-pot synthesis have also been recently reported. [52][53][54][55] In 2017, Rowan and co-workers have explored the use of a metallopolymer to obtain [n]catenanes. 56 The metallopolymer consists of ditopic macrocycles and linear components coordinated via Zn 2+ ions in an alternate fashion, from which a mixture of branched, linear and cyclic [n]catenanes were obtained upon ring-closing metathesis (Fig.…”

The Effect of Ring Size on Catenane Synthesis

“…This issue has not been addressed for the other routes mentioned above. With one exception, [19] only modest changes in ring size have been made and systematic studies are completely lacking.…”

Hydrogen-Bond-Mediated Template Synthesis of Rotaxanes, Catenanes, and Knotanes

“…The structural variety of catenanes and rotaxanes of the amide type can be further extended by the synthesis of [n]catenanes (up to n=4) [166,167] or [n]rotaxanes (up to n=5) [168,169] that bear several catenated macrocycles or more than one macrocycle threaded onto the same axle, respectively. Also, 170 C. A. Schalley et al…”