Preparation for Supramolecular Complexes of Chiral Diols BDPDD, DMBDPD and BINOL with Some Prochiral Compounds

Interaction between chiral diols BDPDD, DMBDPD and BINOL with prochiral compounds was examined and some new supramolecular complexes were prepared. It was found that these chiral hosts could include prochiral guests, a, b-unsaturated compounds or piper- azinedione derivatives to give inclusion crystals in different molar ratio. Formations of these supramolecular complexes were characterized by the data of IR and 1H NMR spectra.

Construction of axially chiral compounds via catalytic asymmetric radical reaction

The chemistry of axially chiral compounds has emerged as a subject of increasing interest due to their widespread presence in natural products,bioactive molecules,advanced materials,and chiral ligands/catalysts.On the other hand,catalytic asymmetric radical-based transformations provide a complementary platform for the construction of enantiomerically enriched molecules that are in growing demand in the chemical and pharmaceutical in-dustries.In recent years,considerable research efforts have been devoted to the development of catalytic asymmetric radical reactions for the construction of axially chiral compounds based on the unique reactivity modes of diverse radicals.In this review,we critically illustrate these recent achievements according to different radical precursors and catalytic activation modes.Wherever possible,special emphasis is also placed on the discussion of mechanistic features underlying these works and substrate scopes.This review should be of great interest to the experts in this area,but also serve as a helpful starting point for new researchers in this field.

Separation mechanism of chiral compounds in chiral stationary phase liquid chromatography

In this paper,the concept of reversed-or normal-phase chiral stationary phase liquid chromatography has been put forward according to the polar strength of mobile and stationary phases. The statistical model developed in HPLC has been used to investigate the separation mechanism of D-and L-enantiomer in chiral stationary phase liquid chromatography.It has been observed that the variation of capacity factor of enantiomers with mobile phase composition in both reversed-phase and normal-phase chiral stationary phase liquid chromatography can be described by the fundamental elution equation lnk'=a+blnC_b+cC_b.The effect of mobile phase composition on the selec- tivity of enantiomers D and L in normal-phase chiral stationary phase liquid chromatography cam be described by the equation lnα=⊿a+⊿blnC_b,but in reversed-phase chiral stationary phase liquid chromatography the selectivity is almost independant of the mobile phase composition.

Chiral Separation of Spiro-compounds and Determination Configuration

Chiral spirocyclic compounds have attracted the attention of scholars and scientists owing to their potential applications in the pharmaceutical industry as either active pharmaceutical ingredients, catalysts in synthesizing active enantiomers, or as surface modifiers on silica particles to resolve entantiomers. In this study, five spiro compounds of 3,9-diphenyl-2,4,8,10-tetraoxaspiro[5.5]-undecane（1）, 3,9-（4-methoxyphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（2）, 3,9-（4-methylphenyl）-2,4,8,10-tetraoxaspiro [5.5] -undecane（3）, 4,4＇-（2,4,8,10-tetraoxaspiro[5.5]undecane-3,9-diyl）dibenzoic acid（4） and 3,9-di（4-formyl-phenyl）-2,4,8,10-tetraoxa-spiro[5.5]-undecane（5） were synthesized by grinding pentaerythritol with benzaldehyde, 4-methoxybenzaldehyde, 4-methylbenzaldehyde, 4-carboxybenzaldehyde or terephthalaldehyde monoacetal in the presence of InI3r3 under solvent-free conditions. A normal phase HPLC method was successfully developed to resolve entantiomers of compounds 1--5 on a chiral column. Specific optical rotation of R or S entantiomers（1） was determined and the corresponding configurations were proposed based on Lowe＇s rule.

Synthesis of novel chiral compounds of purine and pyrimidine bases

The physiologically active groups such as purine and pyrimidine bases are introduced to the asymmetric synthesis. The optically pure compounds bearing purine and pyrimidine bases (5a—5e) were prepared via the asymmetric Michael addition reaction of purines and pyrimidines as Michael donators with the chiral source 5-(R)-[(lR, 2S, 5R)-menthyloxy]-2(5H)-furanone (3a), which was prepared from the natural chiral auxiliary (-)-menthol. The synthetic method was studied in detail and the new compounds were identified on the basis of their analytical data and spectroscopic data, such as [α] D 20 , IR, UV,1H NMR,13C NMR and MS. The absolute configuration of5a was established by X-ray crystallography. The results provided an efficient synthetic route to chiral purines and pyrimidine analogues, and offered chiral sources for further research on the physiologically active compounds of chiral nucleotides.

Asymmetric Reductive Amination of Carbonyl Compounds by Using<i>N,N,N</i>-Tributylpropanaminium Based Novel Chiral Ionic Liquid

Asymmetric reductive amination of carbonyl compounds was carried out using a novel class of aliphatic quarternary ammonium based chiral ionic liquid. S-(+)-2,3-dihydroxy-N,N,N-tributylpropanaminum bromide chiral ionic liquid has been synthesized, characterized and used for asymmetric reductive amination of carbonyl compounds in the presence of sodium borohydride. These preliminary results are encouraging and advocate dual role of novel ionic liquid as a medium and reducing agent for proficient conversion of ketones to amines, however, reductive amination reaction needs to be established for other substituents.

Enantioseparation of some Racemic Compounds on Cellulose Tris (3,5-dimethylphenylcarbamate) Chiral Stationary Phase

Seven chiral compounds were resolved on cellulose tris (3,5-dimethylphenylcarbamate) chiral stationary phase (CDMPC-CSP) using n-hexane/alcohol as mobile phase. Solvent strength and structural characteristics of the compounds effecting on the retention and resolution were discussed. Satisfactory separation was obtained.

固有手性化合物

手性的研究在化学特别在有机化学领域具有非常重要的理论意义和应用前景,随着科学技术的发展及人们认识的提高,新概念新技术层出不穷。固有手性是无垂直对称面的曲面引起的手性,它不同于一般的中心手性、轴手性、面手性、螺旋手性,具有特殊的立体化学和广泛的应用前景。本文综述了天然固有手性化合物,合成的固有手性杯芳烃、柱芳烃、环三藜芦烃、三苯三戊并烯、马鞍状八元环、素馨烯、笼状化合物等的结构特点、合成及拆分,并展望了该领域的未来发展方向和新机遇。

基于D-(-)-/L-(+)-对羟基苯甘氨酸的两对手性钴配合物的合成、晶体结构和电化学识别

采用常温溶液挥发法,以D-(-)-/L-(+)-对羟基苯甘氨酸(D-/L-Hhpg)为主配体,2种含氮吡啶配体4,4'-联吡啶(4,4'-bipy)和5,5'-二甲基-2,2'-联吡啶(5,5'-BM-2,2'-bipy)为辅助配体,与Co Cl_(2)·6H_(2)O反应合成了2对手性配合物{[Co(D-hpg)(4,4'-bipy)(H_(2)O)]Cl·H_(2)O}_(n )(1-D)、{[Co(L-hpg)(4,4'-bipy)(H_(2)O)]Cl·H_(2)O}_(n )(1-L)、[Co(D-hpg)_(2)(5,5'-BM-2,2'-bipy)]Cl·5.5H_(2)O (2-D)、[Co(L-hpg)_(2)(5,5'-BM-2,2'-bipy)]Cl·5.5H_(2)O (2-L)。通过单晶X射线衍射、元素分析、红外光谱、粉末X射线衍射等多种测试方法对其结构进行分析和表征。配合物的单晶X射线衍射数据表明,配合物1-D和1-L属于单斜晶系,P2_(1)手性空间群,分别呈现1D左手螺旋链和右手螺旋链,通过4,4'-bipy分子扩展为2D网状矩形格子结构。配合物2-D属于单斜晶系,P2_(1)手性空间群,为0D小分子,在氢键的作用下形成1D超分子双链,并以ABAB形式在a轴方向堆积排布。这些配合物的结构差异归因于辅助配体和Hhpg配位模式的影响。此外,还研究了配合物的电化学性质。配合物1-D表现出电化学可逆的氧化还原行为,并可作为电化学传感器用于有效地检测组氨酸对映体和定量测定组氨酸混合物中的对映体过量。

不对称催化构建轴手性化合物的研究进展

多数具有重要生理活性的天然产物和手性药物分子中都含具有轴手性骨架,研究如何构建具有轴手性化合物并将其应用于手性药物及天然产物的高效合成具有十分重大的实际意义。对联芳基、杂联芳基以及其他类型的轴手性化合物的研究进展进行了讨论,并对轴手性化合物的不对称催化合成策略作了重点介绍,同时举例说明所得轴手性化合物的潜在应用价值。

联芳基轴手性化合物当前研究进展

轴手性化合物在天然产物、药物研发以及有机不对称催化等领域中有着广泛的应用,由2个六元全碳芳香单元为骨架构建的轴手性化合物的相关研究近年来不乏很多优秀的报道.而相较之下,五元芳杂环联芳基轴手性化合物的不对称合成研究至今仍未成熟.文章介绍了近年来轴手性联芳基化合物主要研究进展,并分类介绍了一系列具有代表性的不对称合成方案.同时,简要探讨了吡唑联芳基轴手性化合物在各个领域中的应用价值与不对称合成所遇到的困境与挑战,并介绍了几种当前比较优秀的合成方案,综合探讨了其当前的研究概况.

硒代缩水甘油醚和硫代缩水甘油醚在Chiralcel OD-H柱上反相条件下的手性拆分

在纤维素-三(3,5-二甲基苯基氨基甲酸酯)(Chiralcel OD-H)手性色谱柱上反相条件下拆分了硒代缩水甘油醚和硫代缩水甘油醚手性化合物,大多数化合物获得了基线分离(Rs>1.5)。同时讨论了反相条件下流动相的组成、溶质的结构对拆分的影响。

硒代缩水甘油醚在Chiralcel OJ-H手性柱上的拆分

采用高效液相色谱Chiralcel OJ-H色谱手性柱,在正相条件下对硒代缩水甘油醚手性化合物进行手性拆分,讨论流动相的组成、溶质的结构对手性拆分的影响。

手性螺环氧化吲哚类化合物的设计、合成及抗肿瘤活性研究

前期利用[2+1]环化反应合成了一系列手性螺环氧化吲哚类化合物,研究采用MTT法对这些化合物在结肠癌细胞CT26和宫颈癌细胞Hela中的抗肿瘤活性进行了评价,探析其构效关系,并在苗头化合物的基础上进行了结构优化设计合成了目标化合物,并再次评价其抗肿瘤效果。结果显示,27个手性螺环氧化吲哚-环丙烷-茚二酮类化合物对CT26和Hela细胞均具有良好的抗增殖作用。其中,16个化合物对CT26细胞的抑制活性优于阳性对照顺铂,14个化合物对Hela细胞的抗增殖能力与顺铂相当或更优。进一步,结构优化得到的化合物均能有效抑制CT26和Hela细胞的增殖,部分手性螺环氧化吲哚类目标化合物可作为抗肿瘤药物候选先导化合物,具有较好的研发潜力。

手性磷酸不对称催化合成四氢吡喃杂环化合物

四氢吡喃环结构广泛存在于天然活性物质中。四氢吡喃环类化合物及其衍生物有良好的降糖、抗菌、抗炎、抗肿瘤等药理学活性。本文以4-戊炔-1-醇为起始原料,经烷基化、Dess-Martin氧化、Witting反应、脱保护基、Diels-Alder反应等利用手性磷酸催化剂不对称催化合成含有四氢吡喃环单元的六元骈六元环化合物,并且产物有良好的对映选择性(93%ee)。

Performance comparison of chlorinated chiral stationary phases in supercritical fluid chromatography for separation of selected pyrrolidone derivatives

The effects of two chlorinated chiral stationary phases, namely, Lux Cellulose-2 and Lux i-Cellulose-5, flow-rate, percentage of co-solvent and chemical structures of the compounds on retention and resolution were studied within this article. In this work a backpressure of 150 bar, a temperature of 40 ℃ and 10% of methanol as co-solvent were chosen as operating conditions. The optimum flow-rate was 2 mL/min. The percentage of co-solvent was studied between 7.5% and 15%.We have observed that 15% of methanol gave the best results for most of the compounds. For all the derivatives, the Lux Cellulose-2 provided better resolutions going from 1.50 to 3.59 compared with Lux i-Cellulose-5.

A Chiral Three Dimensional Potassium(I)/Strontium(II)/Chromium(III) Oxalato-Bridged Coordination Polymer: Synthesis, Characterization and Thermal Analysis

A new compound of general formula {[(H2O)2K(μ-H2O)Sr]@[Cr(C2O4)3]}n (1) has been synthesized in water and characterized by elemental and thermal analyses, EDX, IR and UV-Vis spectroscopies and by single crystal X-ray structure determination. Compound 1 crystallizes in the chiral space group Fdd2 of orthorhombic system with a = 14.110 (4) ?, b = 36.074 (11)?, c =11.034 (3)? and Z = 16. Compound 1 is a coordination polymer in which the three-dimensional lattice framework is realized by the interconnectivity between K+ cations, Sr2+ cations, aqua ligands and [Cr(C2O4)3]3– complex anions. The asymmetric unit of 1 consists of one cationic motif formally written [(H2O)2K(μ-H2O)Sr]3+ and one anionic entity, [Cr(C2O4)3]3–. The K+ and Sr2+ ions in the cationic motif are both eight-coordinate while the Cr3+ ions in the anionic complex are six-coordinate in a distorted octahedral geometry. Coulombic interactions between the ionic motifs and the three-dimensional H-bonding involving aqua ligands help to consolidate the bulk structure. Thermogra-vimetric analysis (TGA) shows that compound 1 is stable to heat up to ca. 80℃.

手性萜类香料化合物制备的研究进展

手性萜类香料化合物具有柠檬、柏油、留兰香等香气,广泛应用于食品、日用品行业中。由于手性萜类香料对映体具有不同的香气特征,加上消费者对高品质天然香料的青睐,手性萜类香料化合物的生物制备法备受关注。文章介绍了柠檬烯、乙酸香茅酯、α-松油醇、香芹酮等萜类香料化合物的制备方法,分析了手性萜类香料生物法制备中面临的问题,旨在为更经济高效的生物法转化手性萜类香料提供借鉴。

Synthesis and crystal structure of axial chiral-chiral oxazoliline ligands

Seven 2,2'-bipyridine-based oxazole derivatives have been synthesized through multi-step reactions using 2,2'-bipyridine-3,3'-dicarboxylic acid as raw material.The structures of compounds 1-6 were characterized by using 1H NMR,13C NMR,MS,and X-ray single crystal diffraction techniques.The results indicate that only axially chiral enantiomers were observed in the single crystal structures of products 1 and 3 synthesized from achiral amino alcohols;Using racemic amino alcohol((±)-2-aminopropanol)as the raw material,only axial chiral isomers were observed in the single crystal structure of product 2,and no racemic isomer was found.The crystal structure of product 4 based on chiral amino alcohol((S)-valinol)contains non axial chiral isomers and S-type isomers.However,the other two optically pure amino alcohols((S)-phenylpropanol,(R)-phenylpropanol)can only obtain optically pure axially chiral and chiral products 5 and 6,respectively,maintaining the configuration of the raw amino alcohol and no non axial chiral isomer is observed.The product using(±)-2-aminobutanol as the raw material cannot be determined for its absolute configuration as a single crystal of the product has not been obtained.

基于共价有机框架的色谱固定相制备及其应用研究进展

工业领域与科学研究的不断发展,使得复杂体系的高灵敏、高通量和高选择性分离分析面临新的挑战。色谱法在分离科学中发挥着不可替代的作用,已被广泛应用于环境监测、药物分析和食品安全等领域。由于载样量高、定量分析精确和重现性好等突出优势,基于多种保留机制的色谱分离技术已被应用于不同分析物的检测。固定相作为色谱柱的核心,对色谱的分离性能有着极其重要的影响。分离的选择性和效率极大程度上取决于所采用的固定相。然而,传统固定相如硅胶基质制备工艺复杂、pH适用范围窄,聚合物基质机械稳定性较差且易溶胀等缺点限制了其在分离领域的进一步应用。因此,开发高效的新型色谱固定相以满足不同情况下的分离要求是提高色谱分离效率的关键。共价有机框架(COFs)是一类由共价键连接而成的多孔晶体聚合物,具有低密度、高孔隙率、大比表面积和性质稳定等优点。这些突出优势使得COFs材料在分离分析领域具有潜在应用价值,且被认为是新型色谱固定相的理想材料。本文综述了最近5年基于COFs的色谱固定相的制备及其应用的最新研究进展,简要介绍了基于COFs的色谱固定相的制备,详细总结了基于COFs的固定相在色谱分离领域方面的最新应用,展望了基于COFs的色谱固定相的未来发展前景与趋势。