A convenient application of the NMR and CD methodologies for the determination of enantiomeric ratio and absolute configuration of chiral atropoisomeric phosphine oxides

Certain commercial carboxylic acids appear to be powerful chiral solvating agents, which allow for a rapid determination of enantiomeric purity and, subject to some limitations, the absolute configuration of common classes of phosphine oxides by means of 1H and/or 31P NMR spectroscopy. The complementary application of CD spectroscopic measurement enables the determination of their absolute configuration. Herein, we report a convenient, inexpensive, and straightforward approach to the complete determination of the enantiomeric ratio of mono-phosphine oxides and bis-phosphine dioxides.

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