Huang Ke, Breitbach Zachary S, Armstrong Daniel W
Department of Chemistry and Biochemistry, University of Texas at Arlington, Arlington, TX 76019, USA.
Tetrahedron Asymmetry. 2006 Oct 27;17(19):2821-2832. doi: 10.1016/j.tetasy.2006.10.014.
The enantiomeric excess of chiral reagents used in asymmetric syntheses directly affects the reaction selectivity and product purity. In this work, 84 of the more recently available chiral compounds were evaluated to determine their actual enantiomeric composition. These compounds are widely used in asymmetric syntheses as chiral synthons, catalysts, and auxiliaries. These include chiral alcohols, amines, amino alcohols, amides, carboxylic acids, epoxides, esters, ketones, and oxolanes among other classes of compounds. All enantiomeric test results were categorized within five purity levels (i.e. <0.01%, 0.01% to 0.1%, 0.1% to 1%, 1% to 10%, and >10%). The majority of the reagents tested were determined to have enantiomeric impurities over 0.01%, and two of them were found to contain enantiomeric impurities exceeding the 10% level. The most effective enantioselective analysis method was a GC approach using a Chiraldex GTA chiral stationary phase (CSP). This method worked exceedingly well with chiral amines and alcohols.
不对称合成中使用的手性试剂的对映体过量直接影响反应选择性和产物纯度。在本研究中，对最近可得的84种手性化合物进行了评估，以确定它们实际的对映体组成。这些化合物作为手性合成子、催化剂和助剂广泛用于不对称合成中。这些化合物包括手性醇、胺、氨基醇、酰胺、羧酸、环氧化物、酯、酮和四氢呋喃等其他类别。所有对映体测试结果被归类为五个纯度水平（即<0.01%、0.01%至0.1%、0.1%至1%、1%至10%和>10%）。测试的大多数试剂被确定含有超过0.01%的对映体杂质，其中两种被发现含有超过10%水平的对映体杂质。最有效的对映体选择性分析方法是使用Chiraldex GTA手性固定相（CSP）的气相色谱法。该方法对手性胺和醇效果极佳。
