title: "Photoclick" postsynthetic modification of DNA.
abstract: A new DNA building block bearing a push-pull-substituted diaryltetrazole linked to the 5-position of 2'-deoxyuridine through an aminopropynyl group was synthesized. The accordingly modified oligonucleotide allows postsynthetic labeling with a maleimide-modified sulfo-Cy3 dye, N-methylmaleimide, and methylmethacrylate as dipolarophiles by irradiation at 365 nm (LED). The determined rate constant of (23±7) M(-1)  s(-1) is remarkably high with respect to other copper-free bioorthogonal reactions and comparable with the copper-catalyzed cycloaddition between azides and acetylenes.
authors.affiliation: Institute of Organic Chemistry, Karlsruhe Institute of Technology (KIT), Fritz-Haber-Weg 6, 76131 Karlsruhe (Germany).
authors.forename: Stefanie
authors.initials: S
authors.lastname: Arndt
authors.forename: Hans-Achim
authors.initials: HA
authors.lastname: Wagenknecht
mesh_terms: D001393:Azoles / Q000737:chemistry; D001483:Base Sequence; D002232:Carbocyanines / Q000737:chemistry; D061565:Cycloaddition Reaction; D004247:DNA / Q000138:chemical synthesis / Q000737:chemistry*; D003857:Deoxyuridine / Q000737:chemistry; D008027:Light; D008301:Maleimides / Q000737:chemistry
chemical_list: D001393:Azoles; D002232:Carbocyanines; D008301:Maleimides; C089187:cyanine dye 3; D004247:DNA; C527323:N-methylmaleimide; D003857:Deoxyuridine
keywords: bioorthogonality; cycloaddition; oligonucleotides; photochemistry; tetrazoles