Multicomponent Aqueous Synthesis of Iodo-1,2,3-triazoles: Single-Step Models for Dual Modification of Free Peptide and Radioactive Iodo Labeling

Abstract

Iodo-1,2,3-triazoles are of considerable interest for chemical and biomedical applications. However, current synthetic methods for preparing iodo-1,2,3-triazoles cannot easily be applied to the direct modification of bioactive molecules in water. Through the combination of water-compatible oxidative iodination and the copper-catalyzed alkyne-azide cycloaddition reaction, a novel copper-catalyzed aqueous multicomponent synthetic method for the preparation of 5-iodo-1,2,3-triazoles has been developed. The method is highly effective and selective for substrates including biologically relevant compounds with nucleoside, sugar, and amino acid moieties. Based on this aqueous tandem reaction, a direct single-step multicomponent dual modification of peptide is developed from readily available starting materials. Furthermore, the method could also be applied to concise and fast multicomponent radioactive ¹²⁵ I labeling from an aqueous solution of commercially available sodium ¹²⁵ iodide as a starting material.

Keywords: iodination; peptides; synthesis design; triazoles; water chemistry.