Synthesis of N-vinylazoles from vinyl acetate without using mercury catalysts
摘要:
N-Vinyl-substituted pyrazole, 3(5)-methylpyrazole, imidazole, and 1,2,4-triazole were synthesized by addition of the corresponding azoles to vinyl acetate under conditions of phase-transfer catalysis, followed by pyrolysis of N-(1-acetoxyethyl)azoles thus formed at 350-400 degrees C in the presence of water.
Anhydrous potassium phosphate promoted the aza-Markovnikov addition of a variety of N-heterocycles to vinyl esters in DMF at room temperature in moderate to excellent yields.
Solvent-free aza-Markovnikov and aza-Michael additions promoted by a catalytic amount of imidazolide basic ionic liquids
作者:Xuewei Chen、Xuehui Li、Hongbing Song、Yu Qian、Furong Wang
DOI:10.1016/j.tetlet.2011.04.117
日期:2011.7
A family of imidazolide ionicliquids were synthesized and characterized. These ionicliquids combined the virtues of strong basicity and relatively good thermal stability. Catalytic properties of these imidazolide ionicliquids were investigated and satisfactory yield was achieved when 2.0 mol % of [Bmim]Im was used as catalyst for aza-Markovnikov addition under solvent-free condition at room temperature
合成并表征了咪唑类离子液体家族。这些离子液体结合了强碱性和相对良好的热稳定性的优点。研究了这些咪唑化物离子液体的催化性能,当在室温下在无溶剂条件下,于一小时内将2.0 mol%的[Bmim] Im用作aza-Markovnikov加成催化剂时,获得了令人满意的产率。实验结果表明,[Bmim] Im /咪唑与乙烯基酯之间不形成氢键,并且[Bmim] Im催化的氮杂-马尔可夫尼可夫加成反应也不是必须存在的。提出了[Bmim] Im催化aza-Markovnikov加成反应的可能机理。还研究了咪唑化物离子液体在氮杂-迈克尔加成中的使用。
Basic Ionic Liquid as Catalysis and Reaction Medium: A Novel and Green Protocol for the Markovnikov Addition of <i>N</i>-Heterocycles to Vinyl Esters, Using a Task-Specific Ionic Liquid, [bmIm]OH
作者:Jian-Ming Xu、Bo-Kai Liu、Wei-Bo Wu、Chao Qian、Qi Wu、Xian-Fu Lin
DOI:10.1021/jo0600914
日期:2006.5.1
A basicionicliquid, 1-methyl-3-butylimidazolium hydroxide ([bmIm]OH), has been introduced as a catalyst and reactionmedium for the Markovnikov addition of N-heterocycles to vinyl esters under mild conditions. The evidence for the role of this basicionicliquid [bmIm]OH in promoting the Markovnikov addition has been given. On the basis of the evidence, a mechanism was postulated.
A novel and highly efficient protocol for Markovnikov’s addition using ionic liquid as catalytic green solvent
作者:Jian-Ming Xu、Wei-Bo Wu、Chao Qian、Bo-Kai Liu、Xian-Fu Lin
DOI:10.1016/j.tetlet.2006.01.001
日期:2006.3
A novel and highly efficient protocol for Markovnikov’s addition using ionic liquid as a catalytic green solvent is described. The strategy is especially useful in the synthesis of N-heterocycle derivatives with biological activity. This reaction widens largely the applicability of ionic liquid in organic synthesis.
A simple and efficient methodology for Markovnikov addition of azoles with vinyl acetate catalyzed by potassiumtert-butoxide is described. N-heterocyclic compounds are synthesized from simple and commercially available starting materials under mild conditions in high yields.