Kinetics and mechanism of the anilinolysis of dimethyl and diethyl chloro(thiono)phosphates.

The deuterium kinetic isotope effects (KIEs) involving deuterated aniline nucleophiles (XC₆H₄ND₂) are reported for the reactions of dimethyl chlorophosphate (1), dimethyl chlorothionophosphate (2), diethyl chlorophosphate (3) and diethyl chlorothionophosphate (4) in acetonitrile at 55.0 °C. The obtained k_H/k_D values are 0.798–0.979, 0.945–1.06, 0.714–0.919 and 1.01–1.10 for 1, 2, 3 and 4, respectively. A concerted mechanism with dominant backside nucleophilic attack is proposed for the reactions of 1 and 3. A concerted mechanism involving partial frontside attack through a hydrogen-bonded four-centre-type transition state (TS) is proposed for the reactions of 2 and 4. Copyright © 2008 John Wiley & Sons, Ltd. [ABSTRACT FROM AUTHOR]