70138-27-1Relevant articles and documents
Kinetics and mechanism of the anilinolysis of bis(aryl) chlorophosphates in acetonitrile
Barai, Hasi Rani,Lee, Hai Whang
, p. 1939 - 1944 (2012/02/05)
The nucleophilic substitution reactions of bis(Y-aryl) chlorophosphates (1) with substituted anilines and deuterated anilines are investigated kinetically in acetonitrile at 35.0 °C. The kinetic results of 1 are compared with those of Y-aryl phenyl chlorophosphates (2). The substrate 1 has one more identical substituent Y compared to substrate 2. The cross-interaction between Y and Y, due to additional substituent Y, is significant enough to result in the change of the sign of cross-interaction constant (CIC) from negative ρXY = -1.31 (2) to positive ρXY = +1.91 (1), indicating the change of reaction mechanism from a concerted SN2 (2) to a stepwise mechanism with a rate-limiting leaving group departure from the intermediate (1). The deuterium kinetic isotope effects (DKIEs) involving deuterated anilines (XC6H4ND2) show secondary inverse, k H/kD = 0.61-0.87. The DKIEs invariably increase as substituent X changes from electron-donating to electron-withdrawing, while invariably decrease as substituent Y changes from electron-donating to electron-withdrawing. A stepwise mechanism with a rate-limiting bond breaking involving a predominant backside attack is proposed on the basis of positive sign of ρXY and secondary inverse DKIEs.
