DMSO中钯(0)催化的尿嘧啶烯丙基化发生在N-1和N-3处。与之形成鲜明对比的是,在乙酸钯(II)和水溶性磺化三苯膦P(C 6 H 4 - m -SO 3 Na)3(tppts )存在下,在有机水性介质中在N-1处实现了区域特异性烯丙基化)。与2-硫氧嘧啶的类似反应也完全取决于溶剂,该反应在N-1和N-3(在二恶烷中)或在硫(有机水溶液)中进行。可以动态控制有机-水性介质中的反应,而热力学控制DMSO或回流的二恶烷中的烯丙基化。
One-Pot Synthesis of N-Alkyl Purine, Pyrimidine and Azole Derivatives from Alcohols using Ph3P/CCl4: A Rapid Route to Carboacyclic Nucleoside Synthesis
A facile and efficient method for one-pot N-alkylation of nucleobases and azole derivatives from alcohols using triphenylphosphine in carbon tetrachloride is described. In this method, treatment of alcohols with a mixture of triphenylphosphine, carbon tetrachloride, nucleobase or azole derivatives and potassium carbonate in the presence of catalytic amounts of tetra-n-butylammonium iodide (TBAI) in
Regioselective synthesis of 1-allyl- and 1-arylmethyl uracil and thymine derivatives
作者:Vaishali Malik、Palwinder Singh、Subodh Kumar
DOI:10.1016/j.tet.2005.02.047
日期:2005.4
in the presence of I2 regioselectively provide 1-allyl-/1-arylmethyl-uracil and thyminederivatives. The secondary aryl alkyl and diaryl methyl halides with 1 provide chiral 1-arylalkyl/1-(diarylmethyl) uracil/thyminederivatives. The procedure has been extended to the synthesis of fluorescent uracil/thyminederivatives.
Uracil and 5-substituted uracils are monoallylated at N-1 in H2O-CH3CN with the catalytic (or tppts) although performing the reaction in H2O/THF with the system leads to diallylations at N-1 + N-3. 2-Thiouracil, 5-methyl-2-thiouracil (2-thiothymine) and 6-methyl-2-thiouracil are monoallylated at sulfur in with the catalytic system (or tppts). Performing the reactions in H2O/THF with the system leads
尿嘧啶和5-取代的尿嘧啶在H 2 O-CH 3 CN中的N-1处被催化(或tppts)单芳基化,尽管在H 2 O / THF中与该体系进行反应会导致N-1 + N-处的二烯丙基化3。2-硫氧嘧啶,5-甲基-2-硫氧嘧啶(2-硫胸腺嘧啶)和6-甲基-2-硫氧嘧啶在硫磺中通过催化体系(或tppts)被单芳基化。在系统中于H 2 O / THF中进行反应会导致2-硫尿嘧啶和2-硫胸腺嘧啶在N-1 + N-3处进行烯丙基化,而6-甲基-2-硫尿嘧啶则在S + N-3处进行二烯丙基化。
One-pot synthesis of N-alkyl purine and pyrimidine derivatives from alcohols using TsIm: a rapid entry into carboacyclic nucleoside synthesis
作者:Mohammad Navid Soltani Rad、Ali Khalafi-Nezhad、Somayeh Behrouz、Mohammad Ali Faghihi、Abdolkarim Zare、Abolfath Parhami
DOI:10.1016/j.tet.2007.11.101
日期:2008.2
A convenient and efficient one-pot N-alkylation of nucleobases from alcohols using N-(p-toluenesulfonyl)imidazole (TsIm) is described. In this method, treatment of alcohols with a mixture of purine or pyrimidine nucleobase, TsIm, K2CO3, and triethylamine in refluxing DMF regioselectively furnishes the corresponding N-alkyl nucleobases in good yields. This methodology is highly efficient for various structurally diverse primary alcohols. (C) 2007 Elsevier Ltd. All rights reserved.
Palladium-catalyzed allylation of pyrimidine-2,4-diones (uracils) and of 6-membered heterocyclic ambident sulfur nucleophiles
Pd(0)-Catalyzed allylation of six-membered ambident heterocycles bearing NH-CO, NH-CS and CH2-CO moieties obey the regioselectivity rules: C>O; N>O; S>N; NH-CO>NH-CS. Uracil and 5-methyluracil (thymine) do not show regioselectivity (N-1 = N-3) whereas 6-methyluracil is regioselectively allylated at N-3 (N-3>N-1).