On Chiral Space Groups and Chiral Molecules

This note explains the relationship (as well as the absence of a relationship) between chiral space groups and chiral molecules (which have absolute configurations).For a chiral molecule,which must crystallize in a chiral space group,the outcome of the absolute configuration determination must be linked to some other properties of the chiral crystal such as its optical activity for the observation to the relevant.     

16种手性化合物在不同自制手性固定相上的拆分比较

采用高效液相色谱法,在自制的纤维素-三(3,5-二甲基苯基氨基甲酸酯)(ATEO-OD)、纤维素-三(4-甲基苯基氨基甲酸酯)(ATEO-OG)和纤维素-三(4-甲基苯基甲酸酯)(ATEO-OJ)3种手性柱上对16种不同结构的手性化合物进行了拆分和比较.试验结果表明:16个手性样品在这3种手性固定相上分别获得了不同程度的拆分,A TEO-OD对所分析样品具有更好的手性识别能力,ATEO-OG和ATEO-OJ的手性识别能力相当.     

Chiral fluorophosphonomethylbenzaldehydes

Russian Journal of General Chemistry -     

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。     

Chiral phosphonohydroxymethylbenzaldehydes

Russian Journal of General Chemistry -     

The Practical Asymmetric Syntheses of Key Chiral Intermediates of Chiral Drug from Four-Carbon Chiral Pool

(S)-or (R)-2-Amino-4-phenylbutyric acid and (S)-or (R)-2-hydroxy-4-phenylbutyric acid and their ethyl esters are key chiral intermediates for the preparation of angiotensin converting enzyme inhibitors (ACEI) and other chiral drugs. Their practically asymmetric synthetic methods in large scale from four-carbon chiral pool, commercially available L-aspartic acid and L-malic acid, will be presented (as scheme). (S)-2-Amino-4-phenylbutyric acid and its ethyl ester hydrochloride were prepared from the easily available L-aspartic acid via activation by forming anhydride hydrochloride, Friedel-Crafts reaction with benzene, hydrogenolysis and esterification with ethanol in the presence of thionyl chloride in overall yield of 80% and 73.6% respectively with 99% ee. We first used amino acid anhydride hydrochloride as the acylating agent in Friedel-Crafts reaction without racemization. [1]     

手性冠醚为手性分离选择剂的胶束毛细管电泳在线富集分离吉米沙星对映体

以手性冠醚为胶束毛细管电泳手性分离选择剂,对吉米沙星对映体药物的在线富集分离进行了研究.考察了阳离子表面活性剂十二烷基三甲基溴化铵浓度、运行缓冲溶液中有机添加剂含量和进样方式对对映体的富集和分离度的影响.使用未涂层毛细管柱(37 cm×51 μm,有效柱长30 cm),45 mmol/L Bis-Tris缓冲液+10 mmol/L十二烷基三甲基溴化铵(DTAB)+1 mmol/L手性冠醚+11%乙腈为运行缓冲溶液(pH=4.0),在紫外检测波长280 nm、运行电压-10 kV、电动进样条件下,对吉米沙星对映体进行在线推扫(sweeping)富集分离,在基线分离的前提下,富集倍数可达600～700倍.吉米沙星浓度为0.3 μmol/L时,两对映体峰高的相对标准偏差<4.0%(n=7).本方法为毛细管电泳在痕量对映体药物分析等方面的应用提供了新方法.     

乙酰螺旋霉素作为手性选择剂对手性药物的毛细管电泳拆分

毛细管区带电泳添加的手性选择剂常见的有环糊精类、蛋白质以及大环抗生素等[1].作者以乙酰螺旋霉素为手性选择剂,对两种手性药物进行了拆分研究,并初步讨论了部分操作参数的影响.     

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.     

Preparation of Chiral 1,4-Phenylene-silicas via Chiral Low-molecular-weight Amphiphiles

Chiral organic-inorganic hybrid silicas can be prepared via the self-assemblies of chiral surfactants and gelators as templates. However, the relationship between the chirality of the hybrid silica and the structure of the surfactant/gelator has not been systemically studied. Herein, a series of chiral low-molecular-weight amphiphiles(LMWAs) derived from L-valine was synthesized. Their alkyl chains were n-butadecyl, n-hexadecyl and n-octadecyl, respectively. They can form viscous liquids in pure water, and physical gels in tetrahydrofuran, cyclohexanone, acetonitrile, acetone, chlorobenzene and nitrobenzene. Chiral 1,4-phenylene-silicas were prepared viathe self-assemblies of these LMWAs as templates. With increasing the alkyl chain length, the 1,4-phenylene-silicas changed from short mesoporous nanorods to long nanotubes. The circular dichroism spectra of the 1,4-phenylene-silicas indicated that the long nanotubes exhibit the strongest chirality.     

Organocatalytic Formation of Chiral Trisubstituted Allenes and Chiral Furan Derivatives

A novel reaction that provides chiral allenes by amino catalytic activation of either aldehydes or α,β‐unsaturated aldehydes for reaction with alkynyl‐substituted enones is presented. The reaction forms a variety of trisubstituted allenes in high yields and with excellent stereoselectivities. The utility of the reaction concept is demonstrated by the synthesis of chiral furan derivatives in high yields and stereoselectivities.     

手性物质的色谱分离

本文报道所近来对映体分离的主要技术，它包括气相色谱和高效液相色谱领域中的所使用的手性固定相的发展状况，衍生化技术，以及柱联用技术。     

Chiral Gold Nanoparticles

Nanoparticle chirality has attracted much attention recently, and the application of chiral nanoparticles to chiral technologies (see figure) is also of interest. This Minireview deals with advances in the preparation and characterization of chiral gold nanoparticles. Origins of the chiroptical properties and potential applications are discussed.

     

手征导电聚苯胺

综述了手征导电聚苯胺的研究进展。对手征导电聚苯胺的制备方法、手征构象的形成及影响因素、应用研究的现状及发展趋势作了扼要论述。