title: Stepwise click functionalization of DNA through a bifunctional azide with a chelating and a nonchelating azido group.
abstract: A stepwise chemoselective click reaction was performed on nucleosides and oligonucleotides containing 7-octadiynyl-7-deaza-2'-deoxyguanosine and 5-octadiynyl-2'-deoxycytidine with unsymmetrical 2,5-bis(azidomethyl)pyridine using copper(II) acetate. The reaction is selective for the chelating azido group, thereby forming monofunctionalized adducts still carrying the nonchelating azido functionality. The azido-functionalized adduct was applied to a second click reaction, now performed in the presence of reducing agent, to generate cross-linked DNA or a pyrene click conjugate. The chelate-controlled stepwise click reaction is applicable to alkynylated nucleosides and oligonucleotides.
authors: Laboratory of Bioorganic Chemistry and Chemical Biology, Center for Nanotechnology, Heisenbergstraße 11, 48149 Münster, Germany.
authors: Sachin A
authors: SA
authors: Ingale
authors: Frank
authors: F
authors: Seela
mesh_terms: D001386:Azides / Q000737:chemistry*; D002614:Chelating Agents / Q000737:chemistry*; D057930:Click Chemistry; D004247:DNA / Q000737:chemistry*; D015394:Molecular Structure; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry
chemical_list: D001386:Azides; D002614:Chelating Agents; D009705:Nucleosides; D004247:DNA