作者:Yu. S. Simanenko、A. F. Popov、E. A. Karpichev、T. M. Prokop'eva、V. A. Savelova、C. A. Bunton
DOI:10.1023/a:1021655813700
日期:——
1-Cetyl-3-(2-hydroxyiminopropyl)imidazolium chloride and bromide were synthesized for the first time. These compounds are functionalized zwitterionic surfactants which give rise to micelle formation in aqueous solution. Kinetic and thermodynamic analysis of nucleophilic cleavage of p-nitrophenyl p-toluenesulfonate, diethyl p-nitrophenyl phosphate, and ethyl p-nitrophenyl ethylphosphonate in the presence of 1-cetyl-3-(2-hydroxyiminopropyl)irriidazolium halide micelles showed that the latter are powerful nucleophilic reagents whose kinetic behavior can be described in terms of a simple pseudophase distribution model. The efficiency of substrate solubilization with zwitterionic surfactant micelles and the reactivity of the oximate fragment in the micelle phase were estimated on a quantitative level. The observed acceleration of S(N)2 reactions with the examined p-nitrophenyl esters relative to analogous reactions of zwitterionic 1-methyl-3-(2-hydroxyiniinopropyl)imidazolium halides is, respectively, 12800, 550, and 900 times; it is explained mainly by increased concentration of the reactants in micelles.