Methods of Determining Enantiomeric Excess of Secondary Phosphines.

Abstract

Abstract Secondary Phosphines can be directly synthesized through P-C cross-coupling.1 However, there is no published method for determining the enantiomeric excess of secondary phosphines. Development of a method to measure the enantiomeric excess of secondary phosphines is crucial for the ongoing utility of these compounds in pharmaceutical and industrial applications. Using phenyl(xylyl) phosphine as a test case, a series of chiral shift reagents were employed to find a method of determining the enantiomeric excess. Following this, several chiral derivatization agents were employed to convert phenyl(xylyl) phosphine into a pair of identifiable diastereomers to allow measuring the enantiomeric excess. The most promising option was R-menthyl-chloroformate, although the conversion percentage did not exceed 30%.