Assigning the Stereochemistry of Pairs of Diastereoisomers Using GIAO NMR Shift Calculation
Assigning the Stereochemistry of Pairs of Diastereoisomers Using GIAO NMR Shift Calculation
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DOI：
10.1021/jo900408d
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发表时间：
2009-06-19
影响因子：
3.6
通讯作者：
Goodman, Jonathan M.
中科院分区：
文献类型：
--
作者：
Smith, Steven G.;Goodman, Jonathan M.
已经计算了一组28对非对映异构体的GIAO NMR化学位移，以测试NMR位移计算区分非对映异构体结构的能力。我们从分配结构的角度比较了几种不同参数用于量化计算和实验位移之间的一致性的性能，并基于比较计算位移与实验位移的差异，引入了一个新的参数CP 3，其在以高置信度进行正确的结构分配方面比当前使用的平均绝对误差的参数显著更成功相关系数：使用我们的新参数结合贝叶斯定理，立体结构分配可以量化的信心，使用单点计算中获得的分子力学几何形状的变化，而无需计算昂贵的从头几何优化。
GIAO NMR chemical shifts have been calculated for a set of 28 pairs of diastereoisomers in order to test the ability of NMR shift calculation to distinguish between diastereomeric structures. We compare the performance of several different parameters for quantifying the agreement between calculated and experimental shifts from the point of view of assigning structures and introduce a new parameter, CP3, based on comparing differences in calculated shift with differences in experimental shift, which is significantly more successful at making correct structure assignments with high confidence than are the currently used parameters of the mean absolute error and the correlation coefficient: Using our new parameter in conjunction with Bayes' theorem, stereostructure assignments can be made with quantifiable confidence using shifts obtained in single point calculations on molecular mechanics geometries without computationally expensive ab initio geometry optimization.