CHIRAL DIAMINES FOR A NEW PROTOCOL TO DETERMINE THE ENANTIOMERIC COMPOSITION OF ALCOHOLS, THIOLS, AND AMINES BY P-31, H-1, C-13, AND F-19 NMR

A new experimental protocol is described which greatly improves our recently reported method for the determination of the enantiomeric composition of alcohols, phenols, thiols, and amines. Thus, successive addition into the NMR tube of (1) a chiral fluorinated diamine (or any other chiral C-2 symmetrical diamine), (2) CDCl3, (3) a tertiary amine, (4) PCl3, and 5) the chiral alcohol, phenol, thiol, or amine allows a P-31 NMR spectrum of the diastereomeric derivatives to be recorded in 5 min. The method is accurate and very general, and no kinetic discrimination is observed. Sulfuration or selenation of the trivalent phosphorus derivatives, carried out in the NMR tube, allows for a second P-31 NMR determination, in addition to the H-1, C-13, and F-19 NMR spectra which may also be recorded.