Chemically modified bases are frequently used to stabilize nucleic acids, to study the driving forces for nucleic acid structure formation, and to tune DNA and RNA hybridization conditions. Nucleoside analogues are chemical means to investigate hydrogen bonds, base stacking, and solvation as the three predominant forces that are responsible for the stability of nucleic acids. To obtain deeper insight into the contributions of these interactions to RNA stability, we decided to synthesize some novel nucleic acid analogues where the nucleobases are replaced by fluoroindoles. Fluorinated indoles can be compared with fluorinated benzimidazoles to determine the role of nitrogen in five-membered ring systems. The synthesis of fluoroindole ribonucleosides as well as the X-ray crystal structures of all synthesized fluoroindole ribonucleosides are reported here. These compounds could also be building blocks for a variety of biologically active RNA analogues.Key words: indoles, nucleosides, crystal structure, glycosilation, indole-synthesis.
化学修饰碱基常用于稳定核酸、研究核酸结构形成的驱动力以及调整 DNA 和 RNA 杂交条件。核苷类似物是研究氢键、碱基堆积和溶解这三种导致核酸稳定性的主要作用力的化学手段。为了更深入地了解这些相互作用对 RNA 稳定性的贡献,我们决定合成一些新型核酸类似物,用氟化吲哚取代核碱基。氟化吲哚可与氟化苯并咪唑进行比较,以确定氮在五元环系统中的作用。本文报告了氟吲哚核糖核苷的合成以及所有合成的氟吲哚核糖核苷的 X 射线晶体结构。这些化合物也可能成为多种具有生物活性的 RNA 类似物的构建基块。