Determination of the configuration in six-membered saturated heterocycles (N, P, S, Se) and their oxidation products using experimental and calculated NMR chemical shifts
作者:Miloš Buděšínský、Václav Vaněk、Martin Dračínský、Radek Pohl、Lenka Poštová-Slavětínská、Vladimír Sychrovský、Jan Pícha、Ivana Císařová
DOI:10.1016/j.tet.2014.04.047
日期:2014.6
standard chemical preparation and also by in situ oxidation with meta-chloroperbenzoic acid directly in the NMR tube. The experimental 1H and 13C chemical shifts were compared with corresponding calculated data obtained by GIAO approach with DFT, MP2, and HF methods and various basis sets. The correlation of experimental versus calculated data showed the possibility to determine the stereochemistry of the
六元饱和杂环-4-叔丁基-1-甲基哌啶,4-叔丁基-1-甲基膦,4-叔丁基-四氢-2 H-噻喃和4-叔丁基-四氢-2将H-硒代吡喃制备为具有明确几何结构的合适模型化合物,用于其氧化产物的NMR研究。通过标准化学制备以及通过直接在NMR管中用间-氯过苯甲酸原位氧化获得相应的差向异构N-氧化物,次膦氧化物,亚砜和亚硒酸盐。实验1 H和13将C化学位移与通过GIAO方法使用DFT,MP2和HF方法以及各种基础集获得的相应计算数据进行比较。实验数据与计算数据的相关性表明,可以使用快速DFT B3LYP / 6-31G *方法确定差向异构氧化产物的立体化学,以进行几何优化和NMR化学位移计算。