Department of Chemistry, Yunnan Normal University, Kunming 650500, P.R. China.
Department of Chemistry, Yunnan Normal University, Kunming 650500, P.R. China.
J Chromatogr A. 2022 Aug 30;1679:463415. doi: 10.1016/j.chroma.2022.463415. Epub 2022 Aug 9.
Porous organic cages (POCs) are a new kind of porous molecular materials, which have gained widespread interest in many fields due to their intriguing properties, including excellent molecular solubility, inherent molecular cavity and rich host-guest chemistry. To date, many chiral POCs have been explored as chiral stationary phases (CSPs) for gas chromatographic (GC) separation of enantiomers. However, the applications of chiral POCs for high performance liquid chromatography (HPLC) enantiomeric separation is extremely rare. In this study, we report the construction of thiol-ene click reaction for the preparation of CSP for HPLC by using a [4+8]-type chiral POC NC4-R as chiral selector. The fabricated CSP showed good chiral resolution performance not only in normal-phase HPLC (NP-HPLC) but also in reversed-phase HPLC (RP-HPLC). Seventeen and ten racemates were well resolved in the two separation modes, respectively, including ketones, esters, alcohols, phenols, amines, ethers, organic acids, and amino acids. Moreover, the fabricated column also shows good chiral recognition complementarity to two popular chiral HPLC columns (Chiralpak AD-H and Chiralcel OD-H columns) and previously reported chiral POC NC1-R-based HPLC column, which can resolve some racemates that unable to be resolved by the two commercially available chiral HPLC columns and NC1-R-based column. The relative standard deviation (RSD) values (n = 4) of retention time and resolution (Rs) of analytes separated on the column were less than 0.3 % and 0.5 % after it was subjected to different injections, showing the good reproducibility and stability of the NC4-R-based column. This work demonstrated high potentials of chiral POCs for HPLC enantioseparation and the applicability of chiral POC-based HPLC columns can be broadened by developing more chiral POCs with diverse structures as chiral selector for HPLC.
多孔有机笼（POC）是一种新型的多孔分子材料，由于其独特的性质，包括优异的分子溶解性、固有分子空腔和丰富的主客体化学，在许多领域引起了广泛的关注。迄今为止，许多手性 POC 已被探索作为气相色谱（GC）拆分对映异构体的手性固定相（CSP）。然而，手性 POC 在手性高效液相色谱（HPLC）拆分中的应用极为罕见。在本研究中，我们报告了通过使用[4+8]-型手性 POC NC4-R 作为手性选择剂，通过硫醇-烯点击反应制备用于 HPLC 的 CSP。所制备的 CSP 在正相 HPLC（NP-HPLC）和反相 HPLC（RP-HPLC）中均表现出良好的手性拆分性能。在两种分离模式下，17 种和 10 种外消旋体得到了很好的拆分，包括酮、酯、醇、酚、胺、醚、有机酸和氨基酸。此外，所制备的色谱柱还与两种常用的手性 HPLC 色谱柱（Chiralpak AD-H 和 Chiralcel OD-H 色谱柱）和以前报道的基于手性 POC NC1-R 的 HPLC 色谱柱具有良好的手性识别互补性，可以拆分一些不能被两种市售手性 HPLC 色谱柱和 NC1-R 柱拆分的外消旋体。该色谱柱上分析物的保留时间和拆分度（Rs）的相对标准偏差（RSD）值（n=4）在不同进样后小于 0.3%和 0.5%，表明该 NC4-R 柱具有良好的重现性和稳定性。这项工作证明了手性 POC 在 HPLC 对映体分离中的巨大潜力，通过开发更多具有不同结构的手性 POC 作为 HPLC 的手性选择剂，可以拓宽基于手性 POC 的 HPLC 色谱柱的适用性。
