The Design of Chiral Separation Media Using Monodisperse Functionalized Macroporous Beads: Effects of Polymer Matrix, Tether, and Linkage Chemistry
作者:Kevin Lewandowski、Peter Murer、Frantisek Svec、Jean M. J. Fréchet
DOI:10.1021/ac971196x
日期:1998.4.1
Porous size monodisperse methacrylate beads containing amino and hydroxyl groups, which can be used as a platform for the production of chiral separation media, have been prepared using the staged templated suspension polymerization process. The monomers 2-hydroxyethyl methacrylate and several tert-butoxycarbonyl-protected aminoalkyl methacrylates were used for the preparation of both hydroxyl- and amino-functionalized beads. Attachment of a chiral selector based on l-valine-3,5-dimethylanilide through a carbamate and a urea linkage, respectively, provides chiral stationary phases with excellent enantioselectivities in the separation of the enantiomers of 3,5-dinitrobenzamido derivatives of α-amino acids. For comparison purposes, a separation medium was also prepared by the direct polymerization of a chiral monomer analogous to the hydroxyethyl methacrylate-based stationary phase. The chiral stationary phases prepared with the N-methyl-2-aminoethyl methacrylate platform exhibit the best selectivity, and separation factors as high as 15 were achieved under normal-phase HPLC conditions.
采用分阶段模板悬浮聚合工艺制备了含有氨基和羟基的多孔尺寸单分散甲基丙烯酸酯珠,可用作生产手性分离介质的平台。单体甲基丙烯酸2-羟乙酯和几种叔丁氧基羰基保护的甲基丙烯酸氨基烷基酯用于制备羟基和氨基官能化的珠子。分别通过氨基甲酸酯和脲键连接基于 L-缬氨酸-3,5-二甲基苯胺的手性选择剂,为分离 α-氨基 3,5-二硝基苯甲酰氨基衍生物的对映体提供了具有优异对映选择性的手性固定相酸。为了比较的目的,还通过类似于基于甲基丙烯酸羟乙酯的固定相的手性单体的直接聚合来制备分离介质。采用甲基丙烯酸N-甲基-2-氨基乙酯平台制备的手性固定相表现出最佳的选择性,在正相HPLC条件下分离因子高达15。