Synthetic utility of glycosyl triazoles in carbohydrate chemistry

Abstract

We report herein a study of the synthetic utility of the glucosyl triazole moiety in carbohydrate chemistry. A model glucosyl triazole was prepared by a modified Huisgen 1,3-dipolar cycloaddition reaction. The relative rate of cycloaddition was investigated using a variety of alcohol co-solvents and reaction temperatures. It was found that the reaction proceeded with similar efficiency irrespective of co-solvent, however mildly elevated temperatures (40 àcf. rt) increased the speed of reaction significantly (2 h cf. 8 h). The robustness of the triazole moiety was then interrogated under conditions typically encountered in carbohydrate chemistry reaction sequences-alcohol group protection/deprotection, nucleophilic displacement, and O-glycosylation. The triazole integrity was retained in all cases studied as evidenced from full compound characterization. Finally, a diverse set of triazole-linked glycoconjugates was synthesized. Collectively, our results demonstrated that the glucosyl triazole moiety was indeed a robust entity for carbohydrate chemistry.