作者:Lomary S. Moon、Mohan Pal、Yoganjaneyulu Kasetti、Prasad V. Bharatam、Ravinder S. Jolly
DOI:10.1021/jo100445d
日期:2010.8.20
as an ion pair of (R)- or (S)-mandelate and dimethylamminopyridinium ions possesses structural features that are sufficient for NMR enantiodiscrimination of cyanohydrins. Moreover, 1H NMR data of cyanohydrins of known configuration obtained in the presence of the mandelate−dimethylaminopyridinium ion pair point to the existence of a correlation between chemical shifts and absolute configuration of cyanohydrins
我们已经表明,简单的结构如(R)-或(S)-扁桃酸盐和二甲基am基吡啶鎓离子对就具有足以对氰醇进行NMR对映异构的结构特征。此外,在扁桃酸-二甲基氨基吡啶鎓离子对存在下获得的已知构型的氰醇的1 H NMR数据表明,化学位移与氰醇的绝对构型之间存在相关性。扁桃酸酯-DMAPH +离子对和扁桃腈形成(1:1)配合物,(R)-扁桃腈/(R的缔合常数为338 M -1(ΔG 0,-3.4 kcal / mol))-扁桃酸酯-DMAPH +和(R)-扁桃腈/(S)-扁桃酸酯-DMAPH +络合物的139 M -1(ΔG 0,-2.9 kcal / mol)。为了理解enantiodiscrimination的起源,(三元配合物的模型的几何形状的优化和能量最小化小号)-mandelonitrile /([R )-扁桃酸盐/ DMAPH +和(小号)-mandelonitrile /(小号) -扁桃酸盐/