一种预测醇化学位移的新方法(英文)

A New Method for Predicting ^(13)C Chemical Shifts of Alcohols

诱导效应是有机化学中最重要的效应之一,本文给出一套新的中性基团诱导效应参数(IG).结合极化效应指数(PEI),以及α,β,γ结构参数,提出核磁共振"内屏蔽"和"外屏蔽"的概念及碳谱位移"内屏蔽"和"外屏蔽"模型,由此定量描述了饱和醇类化合物13C NMR化学位移:CS=-2.3+[20.696 7(ΣΔI)+18.386 5(ΣΔPEI)-0.0111(ΣΔI/ΣΔPEI)+1.2397(ΣΔPEI/ΣΔI)-5.8009NαC+4.2604NβC-1.7583-3.3460NCγ+32.3763].相关系数R为0.9947,LOO法交互检验系数RCV=0.9927,模型具有优良的预测性和稳定性.

Inductive effect is one of the most important effects in organic chemistry. We propose a new inductive effect parameter for neutral groups （IG）, which describes the ＂inner-shielding＂ and ＂outer-shielding＂ effects in NMR. It was shown that the ^13C NMR chemical shifts （CS） of alcohols can be predicted from 16, polarization effect index （PEI） and α,β,γ structural parameters as follow：CS=-2.3＋[20.6967（∑△I）＋18.3865（∑△PEI）-0.111（∑△PEI）＋1.2397（∑△PEI/∑△I）-5.8009NC^α＋4.2604NC^β-1.7583-3.3460NC^γ＋32.3763].Experimental results showed that the above model had good stability and predictive ability. The correlation coefficient R of the equation was found to be 0. 994 7, and the cross--validation correlation coefficient Rcv by the LOO method was 0. 992 7.