Direct Determination of the Optical Purities of Phosphorus Compounds Using Nuclear Magnetic Resonance Spectroscopy.

摘要

Tris(3-trifluoroacetyl-d-camphorato)europium (III), Eu(facam)3, is a useful NMR shift reagent for the direct determination of the optical purities of many phosphorus compounds of interest to these laboratories. In the presence of the optically active lanthanide chelate, the optical isomers (enantiomers) have nonequivalent NMR spectra. Generally, the shift differences are large enough for complete separation of at least one set of enantiotopic signals, and enantiomeric compositions (optical purities) can be determined directly from relative peak areas. While Eu(facam)3 interacts successfully with most phosphoryl compounds of interest, it does not interact well with thiophosphoryl or trivalent phosphorus compounds. Thus, it cannot be used to determine the enantiomeric compositions of these classes of compounds.