Department of Chemistry and Biochemistry, The University of Texas at Arlington, Arlington, Texas 76019, USA.
Anal Chem. 2009 Dec 15;81(24):10215-26. doi: 10.1021/ac902257a.
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.
首次将一类非寻常的手性选择子——环果糖，作为键合手性固定相被引入。与作为手性选择子能力有限的天然环果糖（CFs）相比，脂肪族和芳香族功能化的 CF6 具有独特且非常不同的对映体选择性。事实上，它们被证明可以分离非常广泛的外消旋化合物。特别是，取代度较低的脂肪族 CF6 可以分离所有测试过的手性伯胺。似乎 CF6 分子的部分衍生化破坏了分子内部的氢键，从而使分子的核心更容易接近。相比之下，高度芳香族功能化的 CF6 固定相对手性伯胺的大部分对映选择性能力丧失，但对大多数其他类型的分析物具有广泛的选择性。这类固定相还表现出高的“载样量”，因此在制备性分离方面具有巨大的潜力。对映体选择性的变化通常可以与选择子的明显结构特征相关联。分离主要在有机溶剂的存在下进行。
