排序方式: 共有5条查询结果,搜索用时 0 毫秒
1
1.
Konrad Misiura 《Tetrahedron letters》2004,45(22):4301-4305
The reactivity of protected thymidine 3′-O- and 5′-O-(2-thio-1,3,2-oxathiaphospholanes) towards various nucleophiles in the presence of DBU is presented and mechanistic implications are discussed. 相似文献
2.
Piotr Guga Boles?aw Karwowski Damian B?aziak Magdalena Janicka Andrzej Okruszek Beata R?bowska Wojciech J. Stec 《Tetrahedron》2006,62(11):2698-2704
The SP-isomer of 5′-OH-N4-benzoyl-2′-deoxycytidine-3′-O-(2-thio-4,4-pentamethylene-1,3,2-oxathiaphospholane) undergoes DBU-promoted intramolecular cyclization providing as a sole product SP-deoxycytidine cyclic 3′,5′-O,O-phosphorothioate. Unexpectedly, the RP-counterpart yields a mixture of products consisting of RP-deoxycytidine cyclic 3′,5′-O,O-phosphorothioate and macrocyclic oligo(deoxycytidine phosphorothioate)s. The results of molecular modeling indicate that the dychotomy observed for the RP substrate may result from remarkably higher energy of the corresponding transition states, caused by the presence of bulky ‘spiro’ pentamethylene substituent at the position C4 in the oxathiaphospholane ring. 相似文献
3.
Conjugates of 3′-azido-2′,3′-dideoxythymidine (AZT) and 2′,3′-didehydro-2′,3′-dideoxythymidine (D4T) with the hydroxyl group of tyrosine containing boranephosphate and boranephosphorothioate moieties were prepared via the oxathiaphospholane and dithiaphospholane methodology as a mixture of P-diastereomers. Their structures were confirmed by MS analysis and 1H, 31P NMR spectroscopy. It has been shown that the boranephosphorothioate linkage is unstable under acidic conditions. The first nucleoside-alanine conjugates connected through a boranephosphoramidate linkage were also obtained. 相似文献
4.
Janina Baraniak Renata Kaczmarek Ewa Wasilewska Wojciech J. Stec 《Phosphorus, sulfur, and silicon and the related elements》2013,188(6-7):1667-1670
Based upon 1,3,2-oxathiaphospholane chemistry, 5'-O-derivatization of nucleosides with the O-methyl esters of amino acids was performed and corresponding conjugates were obtained in satisfactory yield. 相似文献
5.
Janina Baraniak Renata Kaczmarek Ewa Wasilewska Dariusz Korczyński Wojciech J. Stec 《Tetrahedron letters》2004,45(22):4269-4272
N-[2-(X)-1,3,2-Oxathiaphospholane] derivatives (X = S, Se, O) of carboxamides were prepared and their DBU-assisted reaction with alcohols led to the corresponding O-alkyl-N-acylphosphoramido(thio)(seleno)ates. Their structures were confirmed by MS analysis and 1H and 31P NMR spectroscopy. Independently N-acylphosphoramidoselenoates were converted to N-acylphosphoramidates by treatment with tert-butylperoxytrimethylsilane. The oxathiaphospholane approach was also applied to the synthesis of derivatives having N-prolylphosphoramido(thio)(seleno)ate linkages on the 5′-OH group of AMP. 相似文献
1