PdCl2—CuCl2—手性膦催化苯乙烯不对称氢酯基化反应

首次将ＰｄＣｌ２－ＣｕＣｌ２－手性磷催化体系用于苯乙烯不对称氢酯基化反应，获得了非常好的结果，在此不对称氢酯基化反应中，考察了手性配体的结构及磷原子与钯原子的摩尔比对反应的影响，在Ｐ／Ｐｄ＝２－４的范围内，获得了较高的光学产率；     

一个手性配体的合成及其在钯催化苯乙烯的不对称氢酯基化中的诱导作用

不对称氢酯基化反应是不对称羰基化反应的一部分，与不对称氢甲酰化反应一样是产生多种手性分子的有力手段，比如重要的非麻醉性镇痛消炎药S-布洛芬、S-萘普生就可以通过芳香类烯烃的不对称氢酯基化反应来合成．在不对称羰基化中人们对不对称氢甲酰化的研究较为广泛，并取得了     

钯-手性膦催化降冰片烯的不对称氢酯基化反应

首次用Ｐｄ（ＯＡｃ）２－１，４∶３，６－双脱水－２，５－二（二苯基膦）－Ｌ－艾杜糖醇（ＤＤＰＰＩ）－ｐ－ＴｓＯＨ催化体系对降冰片烯进行了不对称氢酯基化反应，获得了较好的结果．考察了手性膦配体的结构以及磷原子与钯原子的摩尔比对反应的影响，发现在一个磷原子配位一个钯原子时，获得了较高的光学产率．同时考察了反应温度、反应压力及溶剂对降冰片烯不对称氢酯基化反应的影响，发现在１２０℃，５．０ＭＰａ，ｎ（Ｐ）／ｎ（Ｐｄ）＝１时，化学产率可达７１．６％，光学产率可达９２．２％．     

等瓣置换反应的研究——手性簇合物[η^—MeO2CC5H4）（CO）2Mo…

用Ｘ射线衍微法测定了由η＾５－ＭｅＯ２ＣＣ５Ｈ４（ＣＯ）３ＭｏＮａ和〔（η＾５－ＭｅＯ２ＣＣ５Ｈ４）（ＣＯ）２Ｗ〕Ｆｅ－（ＣＯ）３Ｃｏ（ＣＯ）３（μ３－Ｓ）的等瓣置换反应所生成的手性簇合物－〔（η＾５－ＭｅＯ２ＣＣ５Ｈ４）（ＣＯ）２Ｍｏ〕－〔（η＾５－ＭｅＯ２ＣＣ５Ｈ４）（ＣＯ）２Ｗ〕Ｆｅ（ＣＯ）３（μ３－Ｓ）的分子结构及晶体结构。晶体属Ｐ１空间群，晶胞参数ａ＝０．８７１６２（５）ｎｍ，ｂ＝０．８     

手性配体DDPPI-Pd(Ⅱ)催化α-烯烃不对称氢酯基化反应的研究

考察了手性双膦配体DDPPI在钯催化1-辛烯及官能化端烯的不对称氢酯基化反应中的手性诱导作用，最高得到了45．2％的ee值．其中在1-辛烯的不对称氢酯基化反应中，考察了不同的膦-钯比、反应温度、压力、不同的溶剂、不同的钯催化剂前体以及助催化剂对反应的影响．其中膦，钯比在2～4的范围内，催化反应获得了较高的光学产率；以丙酮作溶剂，得到较好的催化效果．     

手性Schiff Base—Ti（OR）4配合物催化醛的不对称硅腈化反应

设计合成了新型手性Ｓａｌｅｎ－Ｔｉ（ＯＲ）配合物催化剂，用其催化一系列醛的不同对称硅化反应，得到了ｅ，ｅ值为２２．４％～８７．１％的氰醇，催化剂中抗衡离子的Ｌｅｗｉｓ碱强烈地影响催化活性，但对反应的对映选择性影响很小，并探讨了其不对称催化反应机理。     

一种新型L-脯氨酸衍生的高效液相色谱手性固定相

设计和制备了一种用于手性化合物的高效液相色谱拆分的新型手性固定相（ＣＳＰ）。该固定相以构象刚性的Ｌ－脯氨酸为手性选择子,经引入保护基、萘酰胺化、加氢脱保护基、酰胺化和与ＬｉＣｈｒｏｓｏｒｂＮＨ２５μｍ微粒硅胶偶联等５步反应而制得。在此ＣＳＰ结构中引入萘酰胺,可增强ＣＳＰ和手性溶质之间的π－π相互作用,以提高该ＣＳＰ的对映体选择性。报道了４种Ｎ－３,５－二硝基苯甲酰－ＤＬ－氨基酸甲酯对映体色谱拆分的初步结果,对映体选择性在１．０４～１．１８之间。色谱拆分条件的优化和该固定相的应用将有待于进一步研究。     

新的手性双膦配体的合成及其在苯乙烯不对称氢酯基化中的应用

以甘露醇和山梨醇为原料,合成了2个新的手性膦配体,并用这些新的手性膦配体与钯原位生成的催化剂体系催化苯乙烯的不对称氢酯基化反应,得到R构型的2－苯基丙酸甲酯,其ee值分别为28.5%和13.6%。     

无定形（磷酸氢—二苯基次膦酸）锆—氯化铁复合物催化烷基化反应

制得无定形（磷酸氢－二苯基次膦酸）锆－氯化铁复合物Ｚｒ（ＨＰＯ４）１．５（Ｏ２Ｐ（Ｃ６Ｈ５）２）．（ＦｅＣｌ２（ＯＨ）。该复合不易吸潮，不冒烟，在空气中稳定，对代烷与芳得在液相的烷基化应有较好的催化活性，反应条件温和，产物收率高，操作方便，后处理简单，并可多次重复使用。     

手性硫代磷酸及其衍生物的研究（Ⅹ）—○—乙基—○—苯基硫…

旋光活性○－乙基－○－苯基硫代磷酰胺酯在４．７ｍｏｌ／Ｌ ＨＣｌ－ＭｅＯＨ溶液中进行酸性甲醇解时得到Ｐ－Ｎ键断裂的构型翻转产物，与ＭｅＯＮａ－ＭｅＯＨ的碱性甲醇解得到以ＰｈＯ基为离去基的构型翻转产物。两种甲醇解反应的机理均可用三角双锥（ＴＢＰ）中间体概念完满地解释。     

2，6-二-O-乙氧乙基-3-O-三氟乙酰基-β-环糊精气相色谱手性固定相的制备及应用

将β-环糊精的2,6-位引入乙氧乙基,3-位引入三氟乙酰基,合成了新的环糊精衍生物2,6-二-O-乙氧乙基-3-O-三氟乙酰基-β-环糊精,并采用静态法涂渍毛细管气相色谱柱,考察了毛细管柱的柱性能和分离性能。结果表明,该固定相对G rob试剂、苯的二取代位置异构体氯甲苯、硝基甲苯和溴甲苯以及10种手性化合物如α-取代丙酸酯化合物、1-(2′-硝基苯基)-乙醇、α-甲基-对氯苯乙腈和丙炔醇酮乙酸酯等具有良好的分离效果。其中,对α-甲磺酰基丙酸酯对映体的拆分效果最好;对α-取代丙酸的甲酯衍生物的分离效果优于乙酯衍生物;对α-羟基取代丙酸酯的分离效果优于α-卤代丙酸酯。     

Enantioseparation of Amino Acids on a Chiral Stationary Phase Derived from L‐α‐Norleucinyl‐ and Pyrrolidinyl‐disubstituted Cyanuric Chloride by High‐Performance Liquid Chromatography

A silica‐based chiral stationary phase (CSP) derived from L‐α‐norleucinyl‐ and pyrrolidinyl‐disubstituted cyanuric chloride was prepared for the enantioseparation of methyl esters of N‐(3,5‐dinitrobenzoyl) amino acids by high‐performance liquid chromatography. The chromatographic results show that effective enantioseparation of methyl esters of N‐(3,5‐dinitrobenzoyl)amino acids, except for proline, was achieved on this chiral stationary phase. The chromatographic resolution of racemic n‐propyl ester of N‐(3,5‐dinitrobenzoyl)valine on CSP‐B is better than that of racemic methyl ester of N‐(3,5‐dinitrobenzoyl)valine on CSP‐B or CSP‐A reported previously (J. Chromatogr. A, 676 (1994) 303). The comparison of the chromatographic results obtained in this study with those on CSP‐A reported previously reveals that steric effect, instead of hydrophobic interaction, between the n‐butyl group attached to the chiral center of the chiral selector and the alkyl group attached to the chiral center of the chiral selectand plays a significant role in chiral discrimination. The increase in the selectivity factor of methyl esters of N‐(3,5‐dinitrobenzoyl)amino acids with bulky alkyl groups was examined on CSP‐B.     

反相液相色谱法分离2-(4-羟基苯氧基)丙酸酯对映体

合成了三-(4-甲基苯甲酸)纤维素酯(MCTB)手性固定相，用反相高效液相色谱法在该手性固定相上对2-(4-羟基苯氧基)丙酸酯对映体进行拆分．实验结果表明，在三-(4-甲基苯甲酸)纤维素酯手性固定相上，以甲醇与水的体积分数为75：25做流动相能较好的拆分2-(4-羟基苯氧基)丙酸甲酯、乙酯和丁酯对映体，其分离因子分别为1．38、1．49、0．98；同时还发现2-(4-羟基苯氧基)丙酸酯中酯基团的大小对其对映体的分离也有明显的影响，其中以乙酯的拆分效果最佳。     

Stereoselective analysis of D and L dansyl amino acids as the mixed chelate copper(II) complexes by HPLC

This paper reviews the mixed chelation approach to resolution of the optical isomers of D and L dansyl amino acids by high performance liquid chromatography. The use of eluants containing Cu(II) complexes of L-proline, L-arginine, L-histidine, and L-histidine methyl ester effected the separation of many D and L amino acids, including those with aliphatic, polar, and aromatic substituents. The mechanism of separation, which is based on the preferential ternary complex formation of the analyte amino acid and the chiral chelate with Cu(II) in the mobile phase, is discussed. The stereoselectivity depends mainly on the different steric interactions between the alkyl side chains of the amino acid analytes and the chiral ligands coordinating around Cu(II), although such parameters as pH, temperature, organic modifier, and concentration of the chiral additive also affect the chromatographic separation. Among the chiral ligands studied, L-histidine methyl ester is unique in that it possesses both achiral selectivity for the dansyl amino acids and chiral selectivity for the respective D and L enantiomers. With a mobile phase gradient of acetonitrile in a buffer containing Cu(II) L-histidine methyl ester complex, a stereoselective procedure was devised for the analysis of D and L amino acid enantiomers, achieving the separation that the current amino acid analyzer could not perform. Finally, the use of the mixed chelation approach in two biomedical studies is described. In the first application, the histidine methyl ester gradient was adapted for analyzing amino acids in cerebrospinal fluid; in the second, an L-aspartame Cu(II) complex eluant was developed for measuring the urine concentration of D and L pipecolic acid (piperidine-2-carboxylic acid), a metabolite of lysine.     

大环手性磷酰胺对氨基酸衍生物的分子识别研究

以(S)-α-甲基苯乙胺和天然氨基酸(L-丙氨酸、L-苯甘氨酸及L-苯丙氨酸)为手性源,以2,5-二(邻羟基苯基)-1,3,4- 二唑和2,4-二(邻羟基苯基)-1,3,5- 二唑为刚性单元,合成了一系列具有光学活性的新型含 二唑磷酰胺和磷酯手性大环化合物.用NMR,IR和FABMS方法研究了所合成的手性大环对氨基酸甲酯盐酸盐和二肽的分子间相互作用和分子识别.结果表明,这些主体对D-或L-氨基酸甲酯盐酸盐和二肽具有选择性的结合作用.     

七(2,3,6-三-O-甲氧甲基)-β-环糊精的合成及其在气相色谱分离中的应用

将甲氧甲基引入β-环糊精的2,3,6-位合成了新的气相色谱手性固定相七(2,3,6-三-O-甲氧甲基)-β-环糊精,并采用静态法将其涂渍在毛细管内壁制备毛细管气相色谱柱。考察了毛细管柱的柱性能和分离性能。结果表明该固定相对Grob试剂、苯的二取代位置异构体(硝基甲苯、溴甲苯、二氯苯和二甲苯)及手性化合物(2-羟基丙酸甲酯、2-羟基丙酸乙酯和2-甲磺酰基丙酸甲酯)都具有良好的分离效果。与固定相2,3,6-三-O-甲基-β-环糊精的手性分离效果对比,结果显示两种手性固定相的分离能力各异,对一些手性脂类化合物对映体的分离存在互补性。     

Chiral calix[4]arenes bearing α-hydroxy amide units as membrane carriers for amino acid methyl esters

Novel chiral calix[4]arene derivatives functionalized at the lower rim have been prepared from the reaction of p-tert-butylcalix[4]arene diamine or acylhydrazine derivative with mandelic acid or hydroxyisovaleric acid. The structures of these receptors were characterized by FTIR, ¹H, ¹³C and 2D COSY NMR spectroscopy and elemental analysis. The transport of amino acid derivatives (phenylalanine, phenylglycine and tryptophan methyl ester hydrochlorides) was studied through bulk liquid membrane in the presence of chiral calix[4]arene derivatives. The receptors have been found to act as carriers for transport of aromatic amino acid methylesters from the aqueous source phase to the aqueous receiving phase. The transport rate and L/D selectivity of amino acid esters studied depend strongly upon the structure of the chiral receptors and guests. The best enantioselectivity was obtained in the case of phenylglycine methyl ester for all chiral carriers.     

Flexible Synthesis of Enantiomeric and Racemic 3-Hydroxymethyl-1,2,3,4-tetrahydroisoquinolines via Bischler-Napieralski Reaction

With methyl ester of N-acylated L-3-(3,4-dihydroxyphenyl)alanine(L-DOPA) as starting material, racemic derivatives of 3-hydroxymethyl-1,2,3,4-tetrahydroisoquinoline were obtained with cyclization by Bischler-Napie- ralski(BN) reaction followed by reduction of methyl ester group to hydroxymethyl, while the optical pure enantiomers were prepared by the reduction of the methyl ester group to hydroxymethyl prior to cyclization with BN reaction. Racemerization took place in the BN stage in the presence of methyl ester, an electron-withdrawing group adjacent to chiral center. Therefore, the sequence of synthetic stages of cyclization and reduction, and subsequently whether there is electron-withdrawing group or not determines the chiral optical activity of the products.     

高效液相色谱法分离2-(4-羟基苯氧基)丙酸酯的对映体

采用高效液相色谱法在手性柱上分离芳氧基苯氧基丙酸类除草剂中间体(±)-2-(4-羟基苯氧基)丙酸酯的对映体。实验结果表明,在三苯甲酸纤维素酯的手性柱上,以无水乙醇为流动相能较好地分离(±)-2-(4-羟基苯氧基)丙酸乙酯和甲酯,其分离因子α值分别为1.44和1.29;同时还发现在三苯甲酸纤维素酯的手性柱上2-取代芳氧基或芳基丙酸酯结构中的酯基团的大小对其对映体的分离有明显的影响,其中以乙基为最佳。并通过对照试验证实了2-(4-羟基苯氧基)丙酸乙酯的右旋体先流出,其左旋体后流出。     

Chromatographic resolution of dipeptide enantiomers and diastereomers on chiral stationary phases from poly(L-leucine) or poly(L-phenylalanine)

Two types of chiral stationary phase, polymer-bonded and non-bonded, containing poly(L-leucine) and poly(L-phenylalanine) were prepared. These stationary phases gave higher enantioselectivity for the optical resolution of various derivatives of leucylphenylalanine methyl ester by liquid chromatography than did poly(L-alanine) and poly(L-glutamate).