Microwave-Assisted Click Chemistry for Nucleoside Functionalization: Useful Derivatives for Analytical and Biological Applications

A series of novel 5-(1,2,3-triazolyl)-2'-deoxyuridines were synthesized using a simple and convenient one-step synthetic procedure via the Huisgen reaction. The key step in these syntheses is a click reaction at the C-5 position under solvent free microwave irradiation and CuI as a catalyst. 5-Azidomethyl-2'-deoxyuridine was synthesized from thymidine and its click reactions with several alkynes provided triazole derivatives in good yields. The synthesized compounds showed only marginal antiviral activities [against human rhinovirus (HRV), hepatitis C virus (HCV) and HIV] and antibacterial activities against a series of Gram positive and Gram negative bacteria. Evaluation of fluorescence properties of pyrene-modified and EPR studies of nitroxyl spin-labeled deoxyuridines demonstrate the applicability of these compounds as valuable analytical tools.