|
KMID : 1059520230670030191
|
|
Journal of the Korean Chemical Society
2023 Volume.67 No. 3 p.191 ~ p.198
|
|
|
A Kinetic Study on the Nucleophilic Substitution Reaction of 2,4-dinitrophenyl 5-substituted-2-furoates Under R2NH/R2NH2 + in 20 mol% DMSO(aq). Effects of Nonleaving Group and Leaving Group on the Reaction Mechanism
|
|
Pyun Sang-Yong
Paik Kyu-Cheol
Han Man-So
Cho Bong-Rae
|
|
|
Abstract
|
|
|
|
Acyl transfer reactions of 2,4-dinitrophenyl-5-substituted-2-furoates (1a-d) promoted by R2NH/R2NH2 + in 20 mol% DMSO(aq) have been studied kinetically. The reactions are second-order and exhibit downward curves of the Bronsted plots with pKa 0 = 9.5, β1 = 0.23-0.35 and β2 = 0.88 ? 0.99. The k1 values increased with a stronger nucleophile and as the electron- withdrawing ability of the 5-furyl substituent increases. In contrast, the k2/k-1 values were nearly idential regardless of the 5-furyl substituents. From these results, a stepwise mechanism with a change in the rate-determining step(RDS) is proposed.
|
|
|
KEYWORD
|
|
|
Concerted and stepwise reaction, Bronsted-plot
|
|
|
FullTexts / Linksout information
|
|
|
|
|
|
Listed journal information
|
|
|