Palladium(0)-catalyzed allylation of uracils and 2-thiouracils drastic effect of an aqueous reaction medium on the regioselectivity
作者:Silvana Sigismondi、Denis Sinou、Montserrat Pérez、Marcial Moreno-Mañas、Roser Pleixats、Mercè Villarroya
DOI:10.1016/0040-4039(94)88232-0
日期:1994.9
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。