An Oxazaphospholidine Approach for the Stereocontrolled Synthesis of Oligonucleoside Phosphorothioates
作者:Natsuhisa Oka、Takeshi Wada、Kazuhiko Saigo
DOI:10.1021/ja034502z
日期:2003.7.1
diastereoselectivity. After sulfurization and deprotection, diastereopure (R(p))- and (S(p))-dinucleoside phosphorothioates were obtained in excellent yields. The present methodology was also applied to the solid-phase synthesis of stereoregulated PS-ODNs. all-(R(p))-[T(PS)](3)T, all-(S(p))-[T(PS)](3)T, all-(R(p))-d[G(PS)A(PS)C(PS)]T, and all-(R(p))-[T(PS)](9)T were synthesized on a highly cross-linked polystyrene resin
描述了使用核苷 3'-O-oxazaphospholidine 衍生物作为单体单元的低聚脱氧核糖核苷硫代磷酸酯 (PS-ODNs) 的立体控制合成。2-Chloro-1,3,2-oxazaphospholidine 衍生物由六种对映纯的 1,2-氨基醇制备而成,用于 5'-O-保护核苷的磷酸化反应。对这些反应的详细研究表明,该反应的非对映选择性取决于对映体纯 1,2-氨基醇的结构、反应温度和用作 HCl 清除剂的胺。此外,还对 2-氯氧氮杂磷脂衍生物进行了从头算分子轨道计算,以阐明这些非对映选择性磷酸化反应的机理。发现磷原子上的 2-氯-5-苯基氧氮杂磷脂衍生物的 LUMO 几乎与 P-Cl 键正交。该 LUMO 可能参与主要保留 P 构型的磷酸化反应。开发了一系列二烷基(氰甲基)铵盐,并将其用作非对映纯核苷 3'-O-oxazaphospholidines 与 3'-O-保护的核苷的缩合