Kinetics and Mechanism of the Anilinolysis of DiisoPropyl Thiophosphinic Chloride in Acetonitrile

The nucleophilic substitution reactions of diisopropyl thiophophinic chloride (3) with substituted anilines (XC6H4NH2) and deuterated anilines (XC6H4ND2) are investigated kinetically in acetonitrile at 65.0 degrees C. The anilinolysis rate of 3 is rather slow to be rationalized by the conventional stereoelectronic effects. The obtained deuterium kinetic isotope effects (DKIEs; k(H)/k(D)) are secondary inverse (k(H)/k(D) = 0.80-0.96). The anilinolyses of ten P=S systems in MeCN are reviewed on the basis of DKIEs and selectivity parameters to obtain systematic information on the DKIEs and mechanism for thiophosphoryl transfer reactions. The steric effects of the two ligands on reactivity, DKIEs, mechanism, and substituent effects of the nucleophile (X) on the DKIEs are discussed.