title: Synthesis of bitriazolyl nucleosides and unexpectedly different reactivity of azidotriazole nucleoside isomers in the Huisgen reaction.
abstract: Novel bitriazolyl nucleosides were synthesized via the Huisgen reaction, starting with 3-azidotriazole nucleoside (1). Surprisingly, its isomer, 5-azidotriazole nucleoside (1') did not yield the corresponding Huisgen reaction products efficiently because it was rapidly reduced to amine in the presence of Cu(II)-ascorbate. The significant differences between the reactivity of these two isomers in Cu(II)-ascorbate mediated reactions are mainly due to differences in their electronic properties and steric congestion as a result of different relative positions of the azido and the ribosyl moieties.
authors.affiliation: College of Chemistry and Molecular Sciences, Wuhan University, Wuhan 430072, P. R. China.
authors.forename: Yi
authors.initials: Y
authors.lastname: Xia
authors.forename: Wei
authors.initials: W
authors.lastname: Li
authors.forename: Fanqi
authors.initials: F
authors.lastname: Qu
authors.forename: Zhijin
authors.initials: Z
authors.lastname: Fan
authors.forename: Xiufeng
authors.initials: X
authors.lastname: Liu
authors.forename: Charles
authors.initials: C
authors.lastname: Berro
authors.forename: Evelyne
authors.initials: E
authors.lastname: Rauzy
authors.forename: Ling
authors.initials: L
authors.lastname: Peng
mesh_terms: D001205:Ascorbic Acid / Q000737:chemistry; D001386:Azides / Q000737:chemistry; D002384:Catalysis; D003300:Copper / Q000737:chemistry; D007536:Isomerism; D008826:Microbial Sensitivity Tests; D008956:Models, Chemical; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry*; D010084:Oxidation-Reduction; D014230:Triazoles / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001386:Azides; D009705:Nucleosides; D014230:Triazoles; D003300:Copper; D001205:Ascorbic Acid