Solid-Phase Synthesis of Stereoregular Oligodeoxyribonucleoside Phosphorothioates Using Bicyclic Oxazaphospholidine Derivatives as Monomer Units
作者:Natsuhisa Oka、Mika Yamamoto、Terutoshi Sato、Takeshi Wada
DOI:10.1021/ja805780u
日期:2008.11.26
Nucleoside 3'-O-bicylic oxazaphospholidine derivatives were designed as monomer units for a solid-phase synthesis of stereoregular oligodeoxyribonucleoside phosphorothioates (PS-ODNs). The trans-isomers of appropriately designed nucleoside 3'-O-bicyclic oxazaphospholidine derivatives were generated exclusively by the reaction between the 3'-OH of the corresponding protected nucleosides and 2-chloro-1
核苷 3'-O-双环 oxazaphospholidine 衍生物被设计为单体单元,用于固相合成有规立构寡脱氧核糖核苷硫代磷酸酯 (PS-ODNs)。适当设计的核苷 3'-O-双环 oxazaphospholidine 衍生物的反式异构体仅通过相应受保护核苷的 3'-OH 与 2-氯-1,3,2-oxazaphospholidine 衍生物之间的反应生成。得到的反式-氧氮杂磷脂异构体在构型上是稳定的,在固体载体上缩合过程中,在酸性活化剂存在下差向异构化不会损害它们的非对映纯度。因此,通过使用氧氮杂磷脂单体和酸性活化剂形成 (Rp)- 和 (Sp)-硫代磷酸酯核苷酸间键的过程中,非对映纯度没有任何损失(非对映选择性 > 或 = 99:1)。此外,从头分子轨道计算表明,氧氮杂磷脂衍生物的差向异构化最有可能通过 N-质子化加速的边缘反转过程进行。计算不仅合理化了本研究中观察到的环结构与 oxazaphospholidines