1002-62-6Relevant articles and documents
Alkaline Hydrolysis of Methyl Decanoate in Surfactant-Based Systems
Schmidt, Marcel,Deckwerth, Johannes,Schom?cker, Reinhard,Schwarze, Michael
, p. 7398 - 7406 (2018)
Surfactant-modified reaction systems are one approach to perform organic reactions with water as the solvent involving hydrophobic reactants. Herein, the alkaline hydrolysis of the long-chain methyl decanoate in cationic and nonionic surfactant-modified systems is reported. The physicochemical behavior of the reaction mixture and the performance of the alkaline hydrolysis were systematically investigated. In water as the solvent, the reaction is slow, but at elevated temperatures, the alkaline hydrolysis of methyl decanoate is accelerated because the reaction product sodium decanoate acts as an ionic surfactant, leading to an increased solubility of methyl decanoate in the aqueous phase. The rate can be significantly increased by the addition of surfactants as solubilizers. In nonionic TX-100 solutions, the reaction rate can be increased by a factor of about 100 for a surfactant concentration of 5 wt %. If cationic surfactants are applied, the reaction rate can be further increased due to the electrostatic interaction between the hydroxide ions in solution and the charged head groups of the cationic micelles.
Salt effects on solvolysis reactions of p-nitrophenyl alkanoates catalyzed by 4-(dialkylamino)pyridine-functionalized polymer in buffered water and aqueous methanol solutions
Wang, Guang-Jia,Ye, Donghao,Fife, Wilmer K.
, p. 12536 - 12540 (1996)
Specific salting-in effects that lead to striking substrate selectivity were observed for the hydrolysis of p-nitrophenyl alkanoates 2 (n = 2-16) catalyzed by 4-(dialkylamino)pyridine-functionalized polymer 1 in aqueous Tris buffer solution at pH 8.0 and 30°C. Macromolecule 1 was found to exhibit clear substrate preference for 2 (n = 6) in 0.05 M aqueous Tris buffer solution, as contrasted with the corresponding reaction in 0.05 M aqueous phosphate or borate buffer solutions where the substrate selectivity is absent. The formation of a reactive catalyst substrate complex, 1·2, appears to be promoted by the presence of tris(hydroxymethyl)methylammonium ion, an efficient salting-in agent, from the Tris buffer system. The salting-in effect on formation of 1·2 complex is presumed responsible for the substrate specificity. The salting-out effects of sodium chloride on the solvolysis of 2 catalyzed by 1 were also investigated in 1:1 (v/v) methanol-water solution at pH 8.0 and 30°C. The rate of 1-catalyzed solvolysis of 2 (n = 10-16) was found to vary inversely with NaCl concentration (0-1.0 M). The magnitude of the salting-out effects is dependent on the alkyl chain length in 2 and the concentrations of 1 and NaCl. At 7.5 x 10-5 unit mol L-1 1 and 0-1.0 M NaCl the order of reactivity for 2 (n = 10-16) was n = 10 > 12 > 14 > 16. However, at 5.0 x 10-6 unit mol L-1 1, a revised reactivity order, 2, n = 14 > 12 > 16, was obtained at [NaCl] 0.15 M. A significant decrease in the substrate preference for 1-catalyzed solvolysis of 2 (n = 10-16) was observed at higher NaCl concentrations. We suggest that the reduced catalytic efficiency and selectivity expressed by 1 in the presence of sodium chloride should be attributed to changes in the morphology and composition of aggregates containing 1 and 2 in aqueous methanol solution that lead to decreased dependence of aggregate formation on the hydrophobicity of the substrate.
Solubilization and catalytic behavior of micellar system based on gemini surfactant with hydroxyalkylated head group
Mirgorodskaya, Alla B.,Yackevich, Ekaterina I.,Lukashenko, Svetlana S.,Zakharova, Lucia Ya.,Konovalov, Alexander I.
scheme or table, p. 106 - 109 (2012/07/27)
The correlation between aggregation, solubilization and catalytic properties has been found for series of cationic surfactants with hexadecyl radical of both monomeric and dimeric structures. The highest catalytic effect in the series, reaching three orde
