4484-20-2Relevant articles and documents
Kinetics and mechanism of the aminolysis of cycloalkylmethyl arenesulfonates
Oh, Hyuck Keun,Song, Se Jeong,Jo, Dong-Soo,Lee, Ikchoon
, p. 91 - 96 (2007/10/03)
Nucleophilic substitution reactions of cycloalkylmethyl arenesulfonates (CmH2n-1 CH2OSO2C6H4Z) with anilines (XC6H4NH2) in methanol at 65.0 °C were studied. The reactivity order (n=4>6>7>5) reflects largely the order of steric effect of the ring size (SEs term) except for n=5, which exhibits the least reactivity. This reversal of the order for n=5 is considered to result from large rate retardation due to polar effect of the ρ*σ* term. Application of the Taft equation to the rate data for n=5 and 6 gives ρ=17·4 and 5=2·3 with correlation coefficient of 0·90. The σ* values for n=4 and 7 are estimated to be - 0·23 and - 0·11, respectively. The positive ρxz values of ca 0·3 are consistent with previous results for the reactions at primary reaction centers.
Nucleophilic Substitution Reaction of Cumyl Arenesulfonates with Anilines
Koh, Han Joong,Lee, Hai Whang,Lee, Ikchoon
, p. 125 - 130 (2007/10/02)
The nucleophilic substitution reaction of cumyl arenesulfonate with aniline has been investigated.The reaction in acetonitrile proceeds by the SN2 mechanism with probable frontside nucleophilic attack.The large magnitude of ρXZ (=-0.75) obtained results in an observable sign reversal of ρZ at ?'X = 0.83, with a negative ρZ value for ?X > ?'X.This rather unusual phenomenon can be rationalized by a strong interaction between the nucleophile and leaving group due to their close proximity in the transition state, which in turn is a result of the frontside nucleophilic attack.The reactions in methanol indicate that the SN1 channel competes with the SN2 pathway and ion-pair return is observed when the aniline nucleophhile concentration is low.
Nucleophilic Substitution Reactions of Allyl Arenesulphonates with Anilines and N,N-Dimethylanilines
Oh, Hyuck Keun,Koh, Han Joong,Lee, Ikchoon
, p. 1981 - 1984 (2007/10/02)
Kinetic studies of the reaction of allyl arenesulphonates, I, with anilines and N,N-dimethylanilines in acetonitrile at 45.0 deg C are reported.The sign and magnitude of the cross-interaction constants ρxz (and βxz) between substituents in the nucleophile (X) and leaving group (Z) indicate that the transition state (TS) for I is relatively tight and is similar to that for the corresponding reactions of ethyl systems, rather than for benzyl systems.Variations of the simple Hammett (and Broensted) coefficients ρx (βx) and ρz (βz) with substituents Z and X, respectively, are consistent with the trend expected from a positive ρxz, i.e., that predicted by the potential energy surface diagram.The kinetic isotope effects involving N-deuteriated anilines support the mechanism proposed based on ρxz (βxz) for the reactions of I, i.e., an associative SN2 process with an earlier TS for a stronger nucleophile and/or a better leaving group.
