Department of Chemistry, School of Science, Tianjin University, Tianjin, China.
School of Chemical Engineering and Technology, Tianjin University, Tianjin, China.
J Sep Sci. 2023 Jun;46(11):e2300075. doi: 10.1002/jssc.202300075. Epub 2023 Apr 3.
In this work, a novel allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase was fabricated via a surface-up thiol-ene click chemistry reaction between 7-SH-β-cyclodextrin and 1-allylimidazole-β-cyclodextrin bonded on a silica surface. The structure of the allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase was characterized by Fourier transform infrared spectra, C nuclear magnetic resonance, thermogravimetric analysis, and elemental analysis. Its chiral chromatographic performances were systematically evaluated by separating 35 racemic analytes including isoxazolines, dansyl-amino acids, and flavanones under reversed-phase high-performance liquid chromatography. Compared with the corresponding bottom and top layer of the β-cyclodextrin stationary phase, the allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase afforded significantly accentuated chiral recognition ability due to its abundant hydrogen bond sites, electrostatic interactions, and synergistic inclusion. Furthermore, the allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase showed better enantioseparation ability compared to other reported bridged cyclodextrin stationary phases. In particular, Ar-Phs and dansyl-amino acid could be completely separated by allylimidazolium-bridged bis(β-mono-6 -deoxy-6-allylimidazolium-β-cyclodextrin chiral stationary phase) chiral stationary phase with high resolutions of 1.14-7.20 and 3.16-5.82, respectively. Molecular docking reveals that good enantioseparation ability arises from the different interaction modes and the synergistic effect of allylimidazolium-bridged bis(β-cyclodextrin) chiral stationary phase.
在这项工作中，通过 7-SH-β-环糊精与键合在硅胶表面上的 1-烯丙基咪唑-β-环糊精之间的表面硫醇-烯点击化学反应，制备了一种新型的烯丙基咪唑桥联双（β-环糊精）手性固定相。通过傅里叶变换红外光谱、 13 C 核磁共振、热重分析和元素分析对烯丙基咪唑桥联双（β-环糊精）手性固定相的结构进行了表征。通过反相高效液相色谱法分离 35 种外消旋分析物，包括异恶唑啉、丹磺酰基氨基酸和黄烷酮，系统地评价了烯丙基咪唑桥联双（β-环糊精）手性固定相的手性色谱性能。与相应的β-环糊精固定相的底层和顶层相比，由于其丰富的氢键位、静电相互作用和协同包合作用，烯丙基咪唑桥联双（β-环糊精）手性固定相表现出显著增强的手性识别能力。此外，与其他报道的桥联环糊精固定相相比，烯丙基咪唑桥联双（β-环糊精）手性固定相具有更好的对映体分离能力。特别是，烯丙基咪唑桥联双（β-单-6-脱氧-6-烯丙基咪唑-β-环糊精）手性固定相与高分辨率（1.14-7.20 和 3.16-5.82）完全分离 Ar-Phs 和丹磺酰基氨基酸。分子对接表明，良好的对映体分离能力源于烯丙基咪唑桥联双（β-环糊精）手性固定相的不同相互作用模式和协同效应。
