Development of New HPLC Chiral Stationary Phases Based on Native and Derivatized Cyclofructans
作者:Ping Sun、Chunlei Wang、Zachary S. Breitbach、Ying Zhang、Daniel W. Armstrong
DOI:10.1021/ac902257a
日期:2009.12.15
An unusual class of chiral selectors, cyclofructans, is introduced for the first time as bonded chiral stationary phases. Compared to native cyclofructans (CFs), which have rather limited capabilities as chiral selectors, aliphatic- and aromatic-functionalized CF6s possess unique and very different enantiomeric selectivities. Indeed, they are shown to separate a very broad range of racemic compounds. In particular, aliphatic-derivatized CF6s with a low substitution degree baseline separate all tested chiral primary amines. It appears that partial derivatization on the CF6 molecule disrupts the molecular internal hydrogen bonding, thereby making the core of the molecule more accessible. In contrast, highly aromatic-functionalized CF6 stationary phases lose most of the enantioselective capabilities toward primary amines, however they gain broad selectivity for most other types of analytes. This class of stationary phases also demonstrates high “loadability” and therefore has great potential for preparative separations. The variations in enantiomeric selectivity often can be correlated with distinct structural features of the selector. The separations occur predominantly in the presence of organic solvents.
首次引入一类不寻常的手性选择剂——环糊精作为键合型手性固定相。与天然环糊精(CFs)相比,其作为手性选择剂的能力相当有限,而脂族和芳族功能化的CF6具有独特且截然不同的对映体选择性。事实上,它们能够分离非常广泛的消旋化合物。特别是,低取代度的脂族衍生化CF6能够基线分离所有测试的手性伯胺。似乎部分衍生化作用于CF6分子会破坏分子内部的氢键,从而使分子核心更易接近。相比之下,高度芳族功能化的CF6固定相在伯胺的对映选择能力方面丧失了大部分能力,但它们对大多数其他类型的分析物获得了广泛的选择性。这类固定相还表现出高“负荷能力”,因此具有在制备分离方面的巨大潜力。对映体选择性的变化通常可以与选择剂的独特结构特征相关联。分离主要在有机溶剂存在下发生。