网学网为需要应用化学的朋友们搜集整理了含二催化中心配体的合成及其纯化相关资料,希望对各位网友有所帮助!
论文编号:HG239 论文字数:13259,页数:21
摘 要:手性仲醇是许多药物、农药及功能材料等的重要有机合成中间体,获得手性仲醇高对映体过量百分率(e.e.值)的重要方法之一是由手性氨基醇配体催化还原前手性酮获得。本论文在查阅相关资料基础上综述了不对称催化还原反应研究新进展。
为寻找性能优异的催体,基于多催化中心配体在不对称催化还原反应中的协同效应,可获得手性仲醇较高的e.e.值。我们分别使用了(1S,2R)-(+)和(1R,2S)-(-)-2-氨基-1,2-二苯基乙醇为手性源与间二苄溴反应,经优化反应条件后在乙醇溶液中,于70℃下,以KI为催化剂K2CO3为吸氢剂首次合成了含二催化中心配体,N-(1ˊR,2ˊS)-(1ˊ,2ˊ-二苯基-2ˊ-羟基)乙基-间二苄胺和N-(1Sˊ,2ˊR)-(1ˊ,2ˊ二苯基-2ˊ-羟基)乙基-间二苄胺,经硅胶柱色谱纯化得无色晶体,产率分别为80.3%和78.8% 。产物经IR和1HNMR等确证。在所合成的一对对映体中,其光谱性质、熔点及比旋光度等物理常数均得到很好的验证。以天然麻黄碱(-)为手性源,类似地进行上述反应得到了同样好的结果。
关键词:手性氨基醇;配体;合成
Abstract: Chiral secondary alcohol is the important organic synthesis intermediates of many drugs, pesticides and functional materials and so on. Catalytic reduction of prochiral ketone is one of the important ways to acquire chiral secondary alcohols high enantiomeric excess percentage (e.e. value) by chiral amino alcohols ligand. This paper summarizes the new progress of the asymmetric catalytic reduction reaction on the basis of relevant references.
In order to find high-powered catalyst remains and achieve available chiral secondary alcohols higher e.e. value, on the basis of collaborative effects of multiple catalysis center ligand in asymmetric catalytic reduction of synergies, we had used (1S,2R)-(+) and (1R,2S)-(-) -2-amino-1,2-diphenyl ethanol as chiral sources with 1,3-benzyl bromide reaction respectively. By optimizing the reaction conditions in ethanol solution at 70 ℃, KI as a catalyst and K2CO3 as a hydrogen absorption reagent first synthesized the catalysis center with two ligand, N-(1ˊR,2ˊS)-(1ˊ,2-diphenyl-2ˊ-hydroxyl) ethyl-1,3-benzyl amine and N-(1ˊS,2ˊR)-(1ˊ,2- diphe nyl-2ˊ-hydroxyl) ethyl-1,3-benzyl amine, getting the colorless crystal by silica gel column chromatographyl, and yields were 80.3% and 78.8% respectively. Products have been confirmed by IR and 1HNMR, etc. Among pairs of enantiomers in synthesis, their action spectrum character, the melting point and specific rotation etc. other physical constants are well proofed.
Natural ephedrine (-) as chiral source, has been done the above reaction similarly, getting the same good results.
Keywords:Chiral Amino Alcohols; Ligand; Synthesis