已经开发了一种通过亚磷酰胺方法轻松合成寡脱氧核糖核苷酸的方法,无需对构建块进行碱基保护;它依赖于使用咪唑鎓三氟甲磺酸盐作为核苷亚磷酰胺和核苷缩合的促进剂。在溶液相中,通过使用等摩尔量的无 N 核苷亚磷酰胺和 N-未封闭核苷以高度 O 选择性的方式完成缩合,在用双(三甲基甲硅烷基)过氧化物或叔丁基过氧化氢氧化后得到, 产率 > 95% 的磷酸二核苷。在固相合成中,需要过量的亚磷酰胺进行缩合,脱氧腺苷和脱氧胞苷都进行了一定程度的N-亚磷酸化。然而,不想要的产品,可以通过在甲醇中用苯并咪唑鎓三氟甲磺酸盐短暂处理转化为不含 N 的衍生物。因此,整个过程允许化学选择性地形成核苷酸间连接。低聚物制备...
Backbone-modified DNA analogs were synthesized in good yields by the boranophosphotriester method on a solid support. The oligodeoxyribonucleoside boranophosphates, protected with 2-(azidomethyl)benzoyl groups for nucleobases, were converted into DNA and its backbone-modified analogs via the corresponding H-phosphonate intermediates. A newprotectinggroup for the O6 position of 2'-deoxyguanosine,
Mellor, Ben J.; Thomas, Eric J., Journal of the Chemical Society. Perkin transactions I, 1998, # 4, p. 747 - 757
作者:Mellor, Ben J.、Thomas, Eric J.
DOI:——
日期:——
The 4-[<i>N</i>-Methyl-<i>N</i>-(2,2,2-trifluoroacetyl)amino]butyl Group as an Alternative to the 2-Cyanoethyl Group for Phosphate Protection in the Synthesis of Oligodeoxyribonucleotides
作者:Andrzej Wilk、Andrzej Grajkowski、Lawrence R. Phillips、Serge L. Beaucage
DOI:10.1021/jo990835w
日期:1999.10.1
The 4-[N-methyl-N-(2,2,2-trifluoroacetyl)amino]butyl group for phosphate protection in the synthesis of oligodeoxyribonucleotides has been developed to completely prevent nucleobase alkylation by acrylonitrile that could potentially occur upon deprotection of the traditional 2-cyanoethyl phosphate protecting group. The properties of this new phosphate protecting group were evaluated using the model phosphotriester 9. The mechanism of phosphate deprotection was studied by treating 9 with concentrated NH4OH. NMR analysis,of the deprotection reaction demonstrated that cleavage of the N-trifluoroacetyl group is rate-limiting. The resulting phosphotriester intermediate 13 was also shown to undergo rapid cyclodeesterification to produce O,O-diethyl phosphate 15 and N-methylpyrrolidine -16 (Scheme 2). Given the facile removal of the 4-[N-methyl-N-(2,2,2-trifluoroacetyl)amino]butyl phosphate protecting group under mild basic conditions, its utilization in oligonucleotide synthesis began with the preparation of the deoxyribonucleoside phosphoramidites 4a-d (Scheme 3). The coupling efficiency of 4a-d and conventional a-cyanoethyl deoxyribonucleoside phosphoramidites 24a-d was then compared in the solid-phase synthesis of the 20-mer d(ATCCGTAGCTAAGGTCATGC). As previously observed in the deprotection of 9, the 4-[N-methyl,N-(2,2,2-trifluoroacetyl)amino]butyl phosphate protecting groups were easily and completely removed from the oligonucleotide by using either concentrated NH4OH or pressurized ammonia gas. Analysis of the deprotected oligomer by polyacrylamide gel electrophoresis (Figure 3) indicated that the phosphoramidites 4a-d are as efficient as the 2-cyanoethyl phosphoramidites 24a-d in the synthesis of the 20-mer. Furthermore, following digestion of the crude 20-mer by snake venom phosphodiesterase and bacterial alkaline phosphatase, HPLC analysis showed complete hydrolysis to individual nucleosides and no detectable nucleobase modification.
Specific Binding and Separation of Dinucleotides by Ferrocene-Modified Artificial Receptors