Fomenting proton anisochronicity in the CH2D group

被引:11
作者
Allen, BD [1 ]
O'Leary, DJ [1 ]
机构
[1] Pomona Coll, Dept Chem, Claremont, CA 91711 USA
关键词
D O I
10.1021/ja034242l
中图分类号
O6 [化学];
学科分类号
0703 ;
摘要
A novel C-D⋯N interaction promotes an equilibrium isotope effect that causes a large chemical shift difference (43 ppb, 22 °C) for the diastereotopic methyl protons in the (N-CH2D)-(-)-isosparteinium cation. The observed chemical shift difference is in surprising agreement with a prediction of 44 ppb based upon an ab initio protocol. These calculations are also shown to reproduce the experimental shift difference in Anet's α-deutero-1,2-dimethylpiperidine (theory, 17 ppb; experiment, 14 ppb). The isosparteine-derived system described herein may provide an improved method for assigning the configuration and enantiomeric purity of stereogenic methyl groups (R-CHDT) by tritium NMR spectroscopy. Copyright © 2003 American Chemical Society.
引用
收藏
页码:9018 / 9019
页数:2
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