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 re cently reported method for the determination of the enantiomeric compo sition of alcohols, phenols, thiols, and amines. Thus, successive addi tion into the NMR tube of (1) a chiral fluorinated diamine (or any oth er 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 discrimi nation is observed. Sulfuration or selenation of the trivalent phospho rus 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.