14034-69-6Relevant 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.
Bimolecular Nucleophilic Substitution (SN2) Reactions of Neopentyl Arenesulfonates with Anilines and Benzylamines in Methanol
Koh, Han Joong,Lee, Hai Whang,Lee, Ikchoon
, p. 253 - 258 (2007/10/02)
Bimolecular nucleophilic substitution (SN2) reactions of neopentyl arenesulfonates with anilines and benzylamines in methanol at 55.0 deg C are reported.The tightness of the transition state (TS) is similar to that for other typical SN2 processes at a primary alkyl carbon centre based on the magnitude of the cross-interaction constant ρxz (0.30) between the substituents in the nucleophile (X) and leaving group (Z).The TS variation is in accord with that predicted by the potential energy surface diagram, which in turn is consistent with the positive sign of ρxz; a later TS is obtained with a weaker nucleophile and nucleofuge.Taft's polar substituent constant, ?*, for the trimethylsilyl group is estimated to be -0.48 by using a factor of 1.875 for the fall-off of ?* from the tert-butyl to the neopentyl group and extrapolating from the experimental Taft plot.
Nucleophilic Substitution Reactions of Indan-2-yl Arenesulfonates with Anilines in Methanol
Lee, Ikchoon,Lee, Young Sook,Huh, Chul,Lee, Hai Whang,Lee, Byung Choon
, p. 2415 - 2418 (2007/10/02)
The nucleophilic substitution reactions of (Y)-indan-2-yl (Z)-arenesulfonates with (X)-anilines in methanol at 55.0 deg C are reported.Sign reversals in all three second-order cross-interaction constants, ρXY, ρYZ and ρXZ, are observed at non-interaction points Z = -0.11 (ρXY = 0), X = -0.02 (ρYZ = 0) and Y = 0.43 (ρXZ = 0) respectively, which have been ascribed to an unusually large third-order cross-interaction constant, ρXYZ = -0.53, for the reaction series.An SN2 transition state with a tilted, parallel stacked and displaced structure of the three benzene rings in the nucleophile (X), substrate (Y) and leaving group (Z) is proposed to rationalize the strong three-body coupling manifested by the large ρXYZ value.
