以前,由于 dA 和 dC 的氨基对三价磷 (III) 型亚磷酸化试剂具有高反应性,因此无法在 N-未保护的亚磷酰胺方法中进行聚合物载体上的 O 选择性磷酸化。在本文中,我们开发了一种名为“活化亚磷酸酯方法”的新偶联策略,其中亚磷酸三酯中间体 1 介导了亚磷酸化。将 1-羟基苯并三唑作为促进剂应用于固相合成导致了优异的 O-选择性超过 99.7%。这种 O 选择性可以通过反应中间体和亲核试剂(如核苷的氨基或羟基)之间的前沿分子轨道相互作用来解释。此外,更长的寡核苷酸不仅可以通过手动操作合成,也可以通过 DNA 合成仪合成。通过成功合成具有 4-N-乙酰脱氧胞苷残基的碱不稳定修饰寡脱氧核糖核苷酸,证明了我们新方法的实用性。最后,通过使用 6-三氟甲基-1-羟基苯并三唑和苯并咪唑鎓三氟甲磺酸盐的组合试剂,可以以良好的产率合成含有 dA 或 dC 的 DNA 20 聚体。
Facile Synthesis of Oligodeoxyribonucleotides via the Phosphoramidite Method without Nucleoside Base Protection
作者:Yoshihiro Hayakawa、Masanori Kataoka
DOI:10.1021/ja973731g
日期:1998.12.1
N-free nucleosidephosphoramidite and an N-unblocked nucleoside to give, after oxidation with bis(trimethylsilyl)peroxide or with tert-butyl hydroperoxide, a dinucleoside phosphate in >95% yield. In the solid-phase synthesis, which requires an excess amount of the phosphoramidite for the condensation, deoxyadenosine and deoxycytidine undergo N-phosphitylation to some extent. The undesired product, however
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...
A Strategy for the Stereoselective Preparation of Thymidine Phosphorothioates with the (R) or the (S) Configuration at the Stereogenic Phosphorus Atom and Their Application to the Synthesis of Oligodeoxyribonucleotides with Stereochemically Pure Phosphate/Phosphorothioate Chimeric Backbones
(Sp)-thymidine 3′,5′-cyclic phosphate to give the (Sp) isomer as the major component, 2) stereospecific sulfurization of the allyl (Sp)-thymidine 3′,5′-cyclic phosphate to afford an allyl (Rp)-thymidine 3′,5′-cyclicphosphorothioate, 3) regioselective and stereoselective methanolysis of the allyl (Rp)-thymidine 3′,5′-cyclicphosphorothioate to provide an allyl methyl (Rp)-thymidine 3′-phosphorothioate
Site-Specific Insertion of the (5R*) and (5S*) Diastereoisomers of 1-[2-Deoxy-β-D-erythro-pentofuranosyl]-5-hydroxyhydantoin into Oligodeoxyribonucleotides
The insertion of the (5R*) and (5S*) diastereoisomers of 1-[2-deoxy-β-D-erythro-pentofuranosyl]-5-hydroxyhydantoin (1) − a major oxidation product of 2′-deoxycytidine upon exposure to ·OH radicals, excited photosensitizers, or ozone − into oligonucleotides is reported. It was achieved by means of phosphoramidite chemistry, using the solid-phase synthesis approach. The synthesis of the phosphoramidite
1- [2-脱氧-β-D-赤型-戊呋喃糖基] -5-羟基乙内酰脲(1)的(5 R *)和(5 S *)非对映异构体的插入-2'-脱氧胞苷的主要氧化产物据报道,暴露在寡核苷酸中的· OH自由基,激发的光敏剂或臭氧-中。它是通过亚磷酰胺化学方法,采用固相合成方法来实现的。亚磷酰胺合成子7的合成从3'- O-(叔)开始需要6个步骤-丁基二甲基甲硅烷基)-2'-脱氧胞苷,并涉及通过非标准乙酰丙酰基对修饰碱基的仲羟基(5-OH)的保护。通过固相支持组装,将修饰的亚磷酰胺合成子7有效地掺入了几种寡核苷酸(3聚体,14聚体,22聚体)中。1- [2-deoxy-β-D-erythro(1- R2 -deoxy-β-D- erythro)的(5 R *)和(5 S *)非对映异构体的存在和完整性通过电喷雾电离质谱法,酶消化的HPLC和MALDI-TOF质谱分析法确定了合成低聚物中的[1-戊呋喃糖基] -5
Synthesis of oligodeoxynucleotides using the oxidatively cleavable 4-methoxytritylthio (MMTrS) group for protection of the 5′-hydroxyl group
We examined the synthesis of oligodeoxynucleotides containing all four nucleobases using the 4-methoxytritylthio (MMTrS) group for protection of the 5′-hydroxyl group. The MMTrS group could be introduced into 3′-O-TBDMS-deoxycytidine, -deoxyadenosine and -deoxyguanosine with the appropriate base protecting groups using strongbases such as n-butyl lithium and lithium hexamethyldisilazide. Because the
Proton-Block Strategy for the Synthesis of Oligodeoxynucleotides without Base Protection, Capping Reaction, and P−N Bond Cleavage Reaction
作者:Mitsuo Sekine、Akihiro Ohkubo、Kohji Seio
DOI:10.1021/jo034204k
日期:2003.7.1
longer oligomer, d[CpApGpTpCpApGpTpCpApGpT], a mixed solvent of CH(3)CN-N-methylpyrrolidone (1:1, v/v) was superior to THF so that the desired oligodeoxynucleotide could be isolated in a satisfactory yield. These results suggest that DNA synthesis can be carried out simply by using the protonated bases at the oligomer level not only without base protection but also without the capping reaction and the