手性离子液体在毛细管电泳手性分离中的应用

简要介绍了手性离子液体用于毛细管电泳手性分离的一般原理,系统地介绍了基于手性离子液体的毛细管电泳对映体拆分的一元手性选择体系和二元手性选择体系,并在国内外研究现状的基础上展望了手性离子液体在毛细管电泳手性分离中的应用前景。     

用环瑚精分离取代四氢—β—咔啉类手性化合物

毛细管电泳是一种分离手性化合物极为有效的工具。本文用β－环糊精作为手性选择剂在ＣＺＥ的模式下对取代四氢β－咔啉类手性化合物进行了成功的拆分。     

毛细管电泳在手性化合物分离中的应用进展

由于手性化合物尤其是手性药物的两个对映体具有不同的化学性质和生理活性,对手性化合物进行分离在医药、生物、食品和环境等领域都具有十分重要的意义。毛细管电泳由于其独特的优势已广泛应用于手性物质的分离。本文对2013~2015年毛细管电泳用于手性分离的最新进展进行了综述,并对其发展前景进行了展望。     

涂层技术在毛细管电泳手性分离中的应用

手性是自然界的本质属性之一。手性分离分析技术对生命科学、环境科学、生物工程和药物工程等许多学科都具有十分重要的意义。当前,对不同种类手性化合物进行拆分已成为毛细管电泳技术最具特色的研究和应用领域之一。然而,被分析物(或拆分剂)在毛细管内壁的吸附是毛细管电泳手性分离中的常见问题。涂层技术就是采用不同的方法对毛细管内壁进行改性,是抑制非特异性吸附、提高分离效率及分离重现性最简便和最有效的方法。本文主要综述了近十几年来各种涂层技术在毛细管电泳手性分离领域的应用现状,并对毛细管涂层技术今后的发展进行了展望。     

高效毛细管电泳分离手性化合物

毛细管电泳作为分析分离技术是在近十年来得到迅速发展起来的一个新领域。本文主要对用毛细管电泳技术直接分离手性化合物的几种常方法及所遵循的机理作一概述。     

红霉素作为手性选择剂对手性药物的毛细管电泳拆分

以大环内酯类抗生素红霉素作为手性选择剂，在普通熔融石英毛细管上对两种酸性联苯双酯类保肝的性药物进行了毛细管电泳手性拆分研究；当用30mmol/L的红霉素、50mmol/L的磷酸盐体系（pH=6.0，含50％（Φ）的甲醇）时两种手性化合物的分离度分别为3.11和8.28，证明红霉素可以作为一种新的手性选择剂应用于毛细和泳手性分离中；通过实验研究了缓冲液种类及浓度、红霉素浓度、分离电压及温度、样品载入量、有机添加剂种类及含量对手性分离的影响。     

毛细管电泳手性分离进展*

评述了近年来毛细管电泳手性分离的进展。以各种手性选择剂的发展为线索介绍了毛细管电泳手性分离理论、方法及应用。简要说明了分离中应注意的一些关键问题。     

毛细管电泳的手性拆分(文献综述)

 根据最近文献,对毛细管电泳在手性拆分领域中的应用和发展进行了评述,包括各种操作模式和各类手性选择剂,进一步评述了手性拆分机理的研究,显示出毛细管电泳是手性拆分的一种高效、快速、简便的分离手段。     

毛细管电泳在手性氨基酸拆分中的研究进展

毛细管电泳(capillary electrophoresis,CE)作为一种强有力的手性分离技术,由于操作简单、试剂消耗少及柱效高等优点,受到广泛关注,是近年来手性分离领域的研究热点.氨基酸是组成蛋白质的基本单元,且大多数氨基酸具有手性中心,手性氨基酸是生命体系的一个重要特征.具有手性中心的氨基酸,其对映体间的生物活性往往存在着较大的差异,因此,氨基酸的手性拆分对了解人体及动物生命活动起着举足轻重的作用.主要总结了近5年来毛细管电泳的3种分离模式(毛细管区带电泳、胶束电动毛细管色谱、毛细管电色谱)在氨基酸手性拆分中的发展和应用.     

毛细管电泳手性分离中的协同效应

综述了毛细管电泳手性分离中的协同效应。介绍了毛细管电泳手性分离中双手性选择剂的应用情况。表明用CDs/CDs.CDs/crown组成的双选择剂及聚合环糊精衍生物,聚合手性胶束体系有可能改善难拆分的对映体物质的分离效果,展示了协同效应的毛细管电泳拆分复杂物质对映体中的应用前景。     

手性化合物

手性问题与我们的生活密切相关，它涉及到生命、动植物、药物、食品、香料、农药等诸多领域，本文介绍了手性化合物的一些性质、手性药物、手性化合物的拆分、尤其是手性化合物的现代色谱分离方法。     

Synthesis of new chiral pyrylium salts and their phosphinine and pyridine derivatives

Despite their versatility, chiral pyryliums are almost unknown in the literature. Reported here is the synthesis of several new chiral pyrylium salts and the corresponding pyridines and phosphinines. This work more than doubles the number of reported chiral pyryliums, and also represents the first racemizable/epimerizable pyryliums. The derived phosphinines and pyridines represent rare α-chiral ligands for transition metals.     

Past,present, and future developments in enantioselective analysis using capillary electromigration techniques

Enantioseparation of chiral products has become increasingly important in a large diversity of academic and industrial applications. The separation of chiral compounds is inherently challenging and thus requires a suitable analytical technique that can achieve high resolution and sensitivity. In this context, CE has shown remarkable results so far. Chiral CE offers an orthogonal enantioselectivity and is typically considered less costly than chromatographic techniques, since only minute amounts of chiral selectors are needed. Several CE approaches have been developed for chiral analysis, including chiral EKC and chiral CEC. Enantioseparations by EKC benefit from the wide variety of possible pseudostationary phases that can be employed. Chiral CEC, on the other hand, combines chromatographic separation principles with the bulk fluid movement of CE, benefitting from reduced band broadening as compared to pressure-driven systems. Although UV detection is conventionally used for these approaches, MS can also be considered. CE-MS represents a promising alternative due to the increased sensitivity and selectivity, enabling the chiral analysis of complex samples. The potential contamination of the MS ion source in EKC-MS can be overcome using partial-filling and counter-migration techniques. However, chiral analysis using monolithic and open-tubular CEC-MS awaits additional method validation and a dedicated commercial interface. Further efforts in chiral CE are expected toward the improvement of existing techniques, the development of novel pseudostationary phases, and establishing the use of chiral ionic liquids, molecular imprinted polymers, and metal-organic frameworks. These developments will certainly foster the adoption of CE(-MS) as a well-established technique in routine chiral analysis.     

Chiral resolution of some environmental pollutants by capillary electrophoresis

The chiral resolution of the environmental pollutants by capillary electrophoresis is reviewed. Various aspects of the chiral resolution such as chiral selectors, optimization of capillary electrophoresis conditions including composition of the background electrolyte (BGE), pH of the BGE, ionic strength of the BGE, structures and types of the chiral selectors, applied voltage, temperature, structures of the chiral pollutants, use of organic modifiers and other parameters are presented. Furthermore, detection, sample treatment, validation of the methods, and the chiral recognition mechanisms, have been discussed.     

(S)-(−)-Fluorenylethylchloroformate (FLEC); preparation using asymmetric transfer hydrogenation and application to the analysis and resolution of amines

Fluorenylethylchoroformate (FLEC) is a valuable chiral derivatisation reagent that is used for the resolution of a wide variety of chiral amines. Herein, we describe an improved preparation of (S)-(−)-FLEC using an efficient asymmetric catalytic transfer hydrogenation as the key step. We also demonstrate the application of FLEC as a chiral Fmoc equivalent for chiral resolution, with facile deprotection, of tetrahydroquinaldines, and its capacity for inducing regioselective outcomes in nitration reactions.     

New Chiral Calixarene Derivatives： Syntheses and Their Chiral Recognition Toward Amino Acids by UV-Vis Spectroscopy

Three novel types of chiral calixarene derivatives 5, 8, and 10 were designed and synthesized by introducing chiral units to parent calixarenes. Their chiralities were confirmed by rotational analysis. Chiral recognition properties of these host compounds towards L- and D-threonine were studied by UV-Vis spectroscopy. The results indicated that calixarene derivatives 5 and 8 exhibited good chiral recognition capabilities toward L- or D-threonine. Although calixarene derivative 10 had no evident chiral recognition ability, the supramolecules of calixarene derivative 10 with L- or D-threonine showed a hypochromic effect or hyperchromic effect respectively. Therefore, calixarene derivative 10 might serve as a good chiral UV-indicator.     

Chiral Carbon Nanorings: Synthesis,Properties and Hierarchical Self-assembly of Chiral Ternary Complexes Featuring a Narcissistic Chiral Self-Recognition for Chiral Amines

We report the synthesis and chiroptical properties of novel chiral carbon nanorings S p-/Rp-[12]PCPP containing a planar chiral [2.2]PCP unit, and demonstrate that S p-/Rp-[12]PCPP can not only host crown ether 18-Crown-6 to form ring-in-ring complexes with a binding constant 3.35×10³ M⁻¹, but also accommodate the complexes of 18-Crown-6 and S/R-protonated amines to form homochiral S @Sp -/ R @Rp - and heterochiral S @Rp -/ R @Sp - ternary complexes, displaying significantly larger binding constants of up to 3.31×10⁵ M⁻¹ depending on the chiral guests. Importantly, homochiral S @Sp -/ R @Rp - ternary complexes exhibit an enhanced CD signal, while the heterochiral S @Rp -/ R @Sp - ones have a constant CD signal compared with the chiral carbon nanorings, respectively, which suggests that homochiral S @Sp -/ R @Rp - ternary complexes display a highly narcissistic chiral self-recognition for S/R-protonated chiral amines, respectively. Finally, the chiral ternary complexes can be further applied to determine the ee values of chiral guests. The findings highlight a new application of carbon nanorings in supramolecular sensors, beyond the common recognition of π-conjugated molecules.     

The Resolution of Enantiomeric Ibuprofen on Chiral Stationary Phases Containing N-Arylcarbamoyl Derivatives of Phenylglycine

A series of fourteen anilide derivatives of ibuprofen were resolved on six chiral stationary phases (CSPs) derived from N-arylcarbamoyl derivatives of (S)-phenylglycine. Excellent chiral resolutions were achieved on these CSPs. The ionic-type CSPs showed better chiral recognition abilities than the corresponding covalent-type CSPs, and the CSP bearing two chiral centers has better performance than the CSPs bearing only one chiral center. The highest separation factor was achieved using the ionic-type CSP bearing two chiral centers for the resolution of the 3,5-dinitroanilide derivative of ibuprofen. This result is better than those reported in literature for the resolution of ibuprofen on the CSPs derived from amino acids, According to the chromatographic behaviors, the hydrogen bonding interaction, the π-π interactions provided by the phenyl groups in CSPs bearing one chiral center, and the phenylethylcarbamoyl moiety in CSPs bearing two chiral centers dominate the chiral recognition.     

Practical and highly stereoselective technology for preparation of enantiopure sulfoxides and sulfinamides utilizing activated and functionally differentiated N-sulfonyl-1,2,3-oxathiazolidine-2-oxide derivatives

A simple, general, and practical technology to prepare enantiopure 1,2,3-oxathiazolidine-2-oxide derivatives using chiral aryl N-sulfonyl aminoalcohol derivatives and thionyl chloride is reported. The versatility of these novel chiral building blocks (MIOO and TMPOO), was exemplified by the expedient production of a variety of unique chiral sulfoxides and valuable chiral sulfinamides in excellent yields and enantiopurities.     

Scalemic and racemic imprinting with a chiral crosslinker

The development of molecularly imprinted chiral stationary phases has traditionally been limited by the need for a chiral pure template. Paradoxically, availability of a chiral pure template largely defeats the purpose of developing a chiral stationary phase. To solve this paradox, imprinting of scalemic and racemic template mixtures was investigated using both chiral (N-α-bismethacryloyl-l-alanine) and achiral (N,O-bisacrylamide ethanolamine) crosslinkers. Imprinting of scalemic mixtures provided polymers capable of partial separation of Boc-tyrosine enantiomers with virtually the same results when using either the chiral or achiral crosslinker. However, the chiral crosslinker was required for chiral differentiation by the racemic imprinted polymers which were evaluated in both batch rebinding and chromatographic modes. Batch rebinding analysis revealed intersecting binding isotherms for the L- and D-Boc-tyrosine, indicating bias for the D or L enantiomer is concentration dependent. Partial chromatographic separation was achieved by the racemic imprinted polymers providing variable D or L bias in equal probability over multiple replicates of polymer synthesis. Correlation of enantiomer bias with the batch rebinding results and optimization of HPLC parameters are discussed.