title: 7-substituted 8-aza-7-deazapurines and 2,8-diaza-7-deaza-purines: synthesis of nucleosides and oligonucleotides.
abstract: 7-Substituted 8-aza- 7-deazaadenosines 1a-e were synthesized by Sonogashira cross coupling from the corresponding 7-iodo nucleoside in 36-79% yields. Starting from 7-bromo (or 7-iodo)-8-aza-7-deazaadenine, 2a,b were obtained by acid-catalyzed glycosylation followed by deprotection in 53 and 35% yields, repectively. Compounds 2b was applied to cross coupling reaction to give 2c-d in 34-95% yield. Compounds 2a and 4b were further transformed to the phosphoramidites 5 and 6b in 9 and 49% overall yields, which were incorporated into oligonucleotides.
authors.affiliation: Laboratorium für Organische und Bioorganische Chemie, Institut für Chemie, Universität Osnabrück, Germany.
authors.forename: Wenqing
authors.initials: W
authors.lastname: Lin
authors.forename: Kuiying
authors.initials: K
authors.lastname: Xu
authors.forename: Frank
authors.initials: F
authors.lastname: Seela
mesh_terms: D002384:Catalysis; D006031:Glycosylation; D008956:Models, Chemical; D008967:Molecular Biology / Q000379:methods*; D009705:Nucleosides / Q000138:chemical synthesis* / Q000737:chemistry; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000737:chemistry; D009943:Organophosphorus Compounds / Q000737:chemistry; D011687:Purines / Q000737:chemistry*; D011741:Pyrimidine Nucleosides / Q000737:chemistry
chemical_list: D009705:Nucleosides; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D011687:Purines; D011741:Pyrimidine Nucleosides; C434331:phosphoramidite