Synthesis of 4-Substituted 1H-Benzimidazole 2?-Deoxyribonucleosides and Utility of the 4-Nitro Compound as Universal Base
作者:Frank Seela、Werner Bourgeois、Helmut Rosemeyer、Thomas Wenzel
DOI:10.1002/hlca.19960790216
日期:1996.3.20
The stereoselective synthesis of 4-substituted 1H-benzimidazole 2′-deoxyribonucleosides is described. Regioisomeric (N1 and N3) β-D-deoxyribonucleosides 2a–c and 3a–c were formed. 13C-NMR Chemical shifts of the 1H-benzimidazole 2′-deoxy-β-D-ribofuranosides were correlated with point charges of C-atoms as well as with Hammett constants of the exocyclic substituents. Phosphonate and phosphoramidite building
描述了4-取代的1 H-苯并咪唑2'-脱氧核糖核苷的立体选择性合成。形成了区域异构体(N 1和N 3)β-D-脱氧核糖核苷2a–c和3a–c。13 C-NMR 1 H-苯并咪唑2'-脱氧-β-D-呋喃呋喃糖苷的化学位移与C原子的点电荷以及环外取代基的Hammett常数相关。制备了4-硝基-1 H-苯并咪唑2'-脱氧核糖呋喃糖苷(2a)的膦酸酯和亚磷酰胺结构单元(参见4a,b)。d(A合成了20)型,其中两个中心dA碱基被4-硝基-1 H-苯并咪唑残基取代。它们与具有与4-硝基-1 H-苯并咪唑部分相反的其他常规碱基的低聚dT和相关的低聚物杂交。在这些双链体(12· 13、12 · 14、12 ·15和12·16)中,不稳定几乎与通用碱基所需的不匹配无关。热力学数据表明4-硝基-1 H-苯并咪唑残基不与相反的碱基形成氢键,而是通过堆积相互作用和有利的熵变来稳定双链体。