Convenient synthesis of a galacturonic acid based macrocycle with potential copper-complexation ability

Abstract

A convenient approach to the construction of a galacturonic acid based macrocycle containing an amide group and a triazole ring has been achieved. The key step relies on the efficient formation of a 16-membered ring by a copper-catalysed intramolecular cycloaddition reaction applied to analkyne-azide galacturonate. Depending on the reaction conditions, the outcome of the 1,3-dipolar cycloaddition varied; the expected intramolecular 1,4-triazole was obtained as well as a C 2-symmetric dimer in different ratios. A preliminary study of the complexation properties of this macrocycle towards Cu II cations revealed the formation of cryptates in a 1:1 metal/ligand ratio. A galacturonic acid based macrocycle containing an amide group and a triazole ring has been synthesized by a procedure involving a copper-catalysed intramolecular cycloaddition reaction as the key step. The results of a preliminary study of the complexation properties of this macrocycle towards Cu II cations are described. Copyright © 2012 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim.