6276-76-2Relevant articles and documents
Kinetics and mechanism of the anilinolysis of o-ethyl phenyl phosphonochloridothioate in acetonitrile
Ul Hoque, Md. Ehtesham,Lee, Hai Whang
, p. 2707 - 2710 (2012/10/29)
The nucleophilic substitution reactions of O-ethyl phenyl phosphonochloridothioate with substituted anilines (XC6H 4NH2) and deuterated anilines (XC6H 4ND2) are kinetically investigated in acetonitrile at 55.0 °C. The deuterium kinetic isotope effects (DKIEs) invariably increase from a secondary inverse DKIE (kH/kD = 0.93) to a primary normal DKIE (kH/kD = 1.28) as the substituent of nucleophile (X) changes from electron-donating to electron-withdrawing. These can be rationalized by the gradual transition state (TS) variation from a backside to frontside attack. A concerted SN2 mechanism is proposed. A trigonal bipyramidal TS is proposed for a backside attack while a hydrogen-bonded, four-center-type TS is proposed for a frontside attack.