title: Solution-phase synthesis of branched DNA hybrids based on dimer phosphoramidites and phenolic or nucleosidic cores.
abstract: Branched oligonucleotides with "CG zippers" as DNA arms assemble into materials from micromolar solutions. Their synthesis has been complicated by low yields in solid-phase syntheses. Here we present a solution-phase synthesis based on phosphoramidites of dimers and phenolic cores that produces six-arm or four-arm hybrids in up to 61% yield. On the level of hybrids, only the final product has to be purified by precipitation or chromatography. A total of five different hybrids were prepared via the solution-phase route, including new hybrid (TCG)(4)TTPA with a tetrakis(triazolylphenyl)adamantane core and trimer DNA arms. The new method is more readily scaled up than solid-phase syntheses, uses no more than 4 equiv of phosphoramidite per phenolic alcohol, and provides routine access to novel materials that assemble via predictable base-pairing interactions.
authors.affiliation: Institute for Organic Chemistry, University of Stuttgart, 70569 Stuttgart, Germany.
authors.forename: Helmut
authors.initials: H
authors.lastname: Griesser
authors.forename: Mariyan
authors.initials: M
authors.lastname: Tolev
authors.forename: Arunoday
authors.initials: A
authors.lastname: Singh
authors.forename: Thomas
authors.initials: T
authors.lastname: Sabirov
authors.forename: Claudia
authors.initials: C
authors.lastname: Gerlach
authors.forename: Clemens
authors.initials: C
authors.lastname: Richert
mesh_terms: D000218:Adamantane / Q000031:analogs & derivatives* / Q000737:chemistry*; D020029:Base Pairing; D004247:DNA / Q000138:chemical synthesis* / Q000737:chemistry*; D009705:Nucleosides / Q000737:chemistry*; D009841:Oligonucleotides / Q000138:chemical synthesis* / Q000737:chemistry*; D009943:Organophosphorus Compounds / Q000737:chemistry*; D060327:Solid-Phase Synthesis Techniques; D012996:Solutions / Q000737:chemistry*
chemical_list: D009705:Nucleosides; D009841:Oligonucleotides; D009943:Organophosphorus Compounds; D012996:Solutions; C434331:phosphoramidite; D004247:DNA; D000218:Adamantane