Synthesis of Novel Nucleic Acid Mimics <i>via</i> the Stereoselective Intermolecular Radical Coupling of 3‘-Iodo Nucleosides and Formaldoximes<sup>1</sup>
作者:Balkrishen Bhat、Eric E. Swayze、Patrick Wheeler、Stuart Dimock、Michel Perbost、Yogesh S. Sanghvi
DOI:10.1021/jo961549c
日期:1996.11.15
5-methylcytosine) and purine (adenine, guanine) bases. The reaction was highly stereoselective, giving only a single dimeric species having the ribo-configuration of the newly introduced C-3'-branched methylene moiety. Also prepared were dimers 16, incorporating 2'-O-methyl ribonucleosides in both halves of the dimer. This required the synthesis of 3'-deoxy-3'-iodo-2'-O-methyl nucleosides 12 as well as 2'-O-me
由双(三甲基锡烷基)苯并频哪酸酯(8)介导的烷基碘和肟的高度收敛性自由基偶联已被用于制备一系列二聚核苷,以模拟天然核酸。反应条件的系统优化允许将适当的碘化物和肟单步转化为中等至极好的收率的2'-脱氧二聚体9。例如,3'-脱氧-3'-碘-5'-(三苯基甲基)胸苷(6a)与3'-O-(叔丁基二苯基甲硅烷基)-5'-O-(亚甲基亚氨基)胸苷(7a)的反应在8存在下,在脱气的苯中得到81%的3'-脱(氧膦)-3'-(亚甲基亚氨基)-5'-O-(三苯甲基)胸苷基-(3'-> 5')-3 -O-(叔丁基二苯基甲硅烷基)胸苷(9a)。同样制备的是含有嘧啶(胸腺嘧啶,5-甲基胞嘧啶)和嘌呤(腺嘌呤,鸟嘌呤)碱基的二聚体。该反应是高度立体选择性的,仅给出具有新引入的C-3'-支链亚甲基部分的核糖构型的单个二聚体物质。还制备了二聚体16,在二聚体的两半中都掺入了2'-O-甲基核糖核苷。这需要合成3'-脱氧-3