Synthesis of deoxy analogs of HEPT involving a palladium (0) catalyzed coupling
摘要:
Deoxy analogs of HEPT (4-7) were prepared by Pd(0) catalyzed coupling between 6-(phenylthio)thymine and cinnamyl acetate or 3-(heteroaryl) allyl acetates.
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.
achieved in an organic-aqueous medium in the presence of palladium(II) acetate and the water-soluble sulfonated triphenylphosphine P(C6H4-m-SO3Na)3 (tppts). Similar reactions with 2-thiouracils are also drastically dependent on the solvent, taking place at N-1 and N-3 (in dioxane) or at sulfur (organic-aqueous medium). Probably reactions in the organic-aqueous medium are kinetically controlled whereas
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。
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).