Kinetics and Mechanism of the Anilinolysis of Dipropyl Chlorothiophosphatein Acetonitrile

摘要

The nucleophilic substitution reactions of dipropyl chlorothiophosphate (3) with substituted anilines (XC6H4NH2) and deuterated anilines (XC6H4ND2) are investigated kinetically in acetonitrile at 55.0 °C. The obtained deuterium kinetic isotope effects (DKIEs; k_H/k_D) are primary normal (k_H/k_D = 1.11 -1.35). A concerted mechanism involving predominant frontside nucleophilic attack is proposed on the basis of the primary normal DKIEs and selectivity parameters. Hydrogen bonded, four-center-type transition state is proposed. The steric effects of the two ligands on the anilinolysis rates of various substrates are discussed.