Boosting Lewis Acid Catalysis in Water-in-Oil Metallomicroemulsions

María Méndez-Pérez, Luis García-Río, and Moisés Pérez-Lorenzo
ChemCatChem, 2012, 4, 1979–1986

 

A study on the effect of sodium bis(2-ethylhexyl)sulfosuccinate-based metallomicroemulsions on the Lewis acid-catalyzed hydrolysis of the ester 2,4-dinitrophenylpicolinate is reported. For a given amount of metal (Ni2+), the presence of these colloidal systems increases the catalytic efficiency of the Lewis acid approximately 1000 % over that found in bulk water. This finding is justified on the basis of the highly localized confinement of the catalyst at the aqueous interface of the microemulsion. In addition, the obtained results indicate that the encounter of the ester with the metal catalyst is significantly favored in the presence of this metallo-functionalized microreactor. The mathematical model developed herein also allows an accurate determination and prediction of the influence of the metallomicroemulsion composition on the catalytic effect on the reaction rate. The results obtained lead to the development of similar reaction systems involving the application of metal Lewis acid catalysts such as carbon–carbon bond-forming reactions.