在硅胶粉末存在下,在无溶剂条件下,空间拥挤的稳定磷叶立德与苯肼的反应在 100°C 下顺利进行,得到二烷基 2-(3,5-二甲基-1-苯基-1H-吡唑-4-基) )-2-丁烯二酸酯收率良好。产物的结构由它们的IR、 1 H NMR和13 C NMR光谱推断。这些化合物的质谱在适当的 z 值处显示出分子离子峰。化合物的 1 H NMR (CDCl 3 ) 谱表明每种吡唑存在两种酯异构体(E 和 Z)。E 和 Z 异构体的相对数量是通过它们的 1 H NMR 光谱确定的。该反应具有相当的立体选择性。
Stable crystalline phosphorus ylides were obtained in good to excellent yields from the 1:1:1 addition reaction between triphenylphosphine, dialkyl acetylenedicarboxylates and β -dicarbonyl or heterocyclic compounds such as, diethyl malonate, acetyl acetone, 1, 3-dimethylbarbituric acid, meldrum's acid, 2-benzoxazolinone, pyrrole-2-carboxaldehyde, benzotriazole, 5-methyl benzotriazole, and 5-chloro
Magnesium Sulfate Catalyzed Intermolecular Wittig Reaction of Dialkyl 2-(1-acetyl-2-oxopropyl)-3-(triphenylphosphoranylidene) Succinates with Ninhydrin in Solvent-Free Conditions
作者:Ali Ramazani、Nader Noshiranzadeh
DOI:10.1080/10426500307899
日期:2003.6
A facial one-pot stereoselective synthesis of dialkyl 3,3-diacetyl-3 a -hydroxy-8-oxo-2,3,3 a ,8-tetrahydrocyclopenta[ a ]indene-1,2-dicarboxylates in fairly high yields by the intermolecular Wittig reaction of dialkyl 2-(1-acetyl-2-oxopropyl)-3-(triphenylphosphoranylidene) succinates and ninhydrin in the presence of MgSO 4 in solvent-free conditions at 100°;C is reported.
3,3-二乙酰-3 a -羟基-8-氧代-2,3,3 a ,8-四氢环戊二烯[a]茚-1,2-二羧酸二烷基酯的表面一锅立体选择性合成2-(1-乙酰基-2-氧代丙基)-3-(三苯基亚膦基)琥珀酸二烷基酯和茚三酮在MgSO 4 存在下在无溶剂条件下在100°C 下发生分子间Wittig 反应。
Introduction of a Novel Reaction of Triacetylmethane: One-Pot Synthesis of Dialkyl-2-(3,1-hydroxyethylidene-2,4-pentanedione-3-yl)-3-(triphenylphosphoranylidene)-butanedioate
Protonation of reactive 1:1 intermediates produced in the reaction between triphenylphosphine and dialkyl acetylenedicarboxylate by 3-(1-hydroxyethylidene)-2,4-pentanedione leads to vinyl phosphonium salts, which undergo Michael addition with the conjugate base of CH-acid to produce the title compounds in high yield.
——
作者:M. R. Islami、I. Yavari、A. M. Tikdari、L. Ebrahimi、S. Razee、H. R. Bijanzadeh
DOI:10.1023/a:1022187419289
日期:——
A convenient one-pot synthesis of stable phosphorus ylides by the condensation of triphenylphosphine with dialkyl acetylenedicarboxylate and CH acids, such as penta-2,4-dione or diethyl propane-1,3-dioate, in the presence of beta-cyclodextrin as a catalyst (to increase the solubility of the reactants in water) without using toxic organic solvents was proposed. This methodology is of interest due to the use of water as a solvent, thus minimizing such factors as the cost, operational hazards, and environmental pollution.