Giant macrocycles from fused polynorbornanes

Since the field was first established, the synthesis and application of macrocycles has been a critical aspect of supramolecular chemistry. Indeed the 1987 Nobel Prize in chemistry was awarded in part for the discovery of macrocycles. Of the methods used for the formation of macrocycles, self-assembly through dynamic covalent bond formation/cleavage stands out as an efficient method to access macrocycles through simple, one pot processes.In particular, the formation of boronate esters has been used to construct a number of self-assembled covalent organic macrocycles. Many of these larger structures have been synthesised by combining a catechol species (benzene-1,2-diol) and a boronic acid. It has been shown that norbornane 1,2-diols form more thermodynamically stable boronate esters than those made from catechols yet this approach has never been used for the formation of a larger covalent organic macrocycle.In this project, the assembly of a covalent organic macrocycle from a fused polynorbornane tetraol was performed. Firstly, a tetraol of suitable geometry was designed and subsequently synthesised. Then, the tetraol was reacted with benzene-1,4-di-boronic acid to assemble the overall macrocycle.The outcomes of this project were the successful synthesis and characterisation of both a novel polynorbornane tetraol and novel macrocycle (characterised using 1H, 13C, DOSY, and HRMS). These results confirm the validity of this new approach and it is expected that this method can be used for the synthesis of a wide range of covalent organic structures.