Instituto de Química Médica, IQM-CSIC, Consejo Superior de Investigaciones Científicas, Juan de la Cierva, 3, 28006 Madrid (Spain).
Angew Chem Int Ed Engl. 2015 Mar 23;54(13):3997-4000. doi: 10.1002/anie.201412144. Epub 2015 Feb 3.
The first example in the literature of a compound showing anisochronous (15) N atoms resulting from diastereotopicity is described. Racemic 1,3-dimethyl-2-phenyloctahydro-1H-benzimidazole was prepared and studied by (1) H, (13) C and (15) N NMR spectroscopy. If convenient conditions were used (monitored by theoretical calculations of (2) JN-H spin-spin coupling constants), two (15) N NMR signals were observed and corresponded to the diastereotopic atoms. GIAO/density-functional calculations of chemical shifts were not only in good agreement with the experimental values but also served as prediction tools. This study suggests that (15) N NMR spectroscopy could be used to probe chirality.
文献中首次描述了一种化合物中由于非对映异构性导致（15）N 原子不等时性的实例。通过（1）H、（13）C 和（15）N NMR 光谱法制备并研究了外消旋 1,3-二甲基-2-苯基八氢-1H-苯并咪唑。如果使用方便的条件（通过理论计算（2）JN-H 自旋-自旋耦合常数进行监测），则可以观察到两个（15）N NMR 信号，它们对应于非对映异构原子。（15）N NMR 化学位移的 GIAO/密度泛函计算不仅与实验值吻合良好，而且还可用作预测工具。这项研究表明，（15）N NMR 光谱法可用于探测手性。
