Heteronuclear selective refocusing 2D NMR experiments for the spectral analysis of enantiomers in chiral oriented solvents
Résumé
We report the use of carbon–proton heteronuclear selective refocusing 2D NMR experiments dedicated to the spectral analysis of enantiomers dissolved in weakly ordering chiral liquid crystalline solvents. The method permits the extraction of carbon–proton residual dipolar couplings for each enantiomer from a complex or unresolved proton-coupled 13C spectral patterns. Illustrative examples are analysed and discussed. It is shown that an accurate determination of enantiomeric excess is possible.