SBA-15-functionalized palladium complex partially confined with ionic liquid: an efficient and reusable catalyst system for aqueous-phase Suzuki reaction

Abstract

A novel SBA-15 functionalized palladium complex partially confined with 1-butyl-3-methylimidazolium hexafluorophosphate ionic liquid (Material 4) was found to be a very efficient and reusable catalyst in the Suzuki–Miyaura coupling reaction of aryl halides including aryl chlorides and heteroaryl halides with different aryl boronic acids under aqueous conditions without any organic co-solvents. Our studies showed that 4 is a more efficient catalyst in comparison with the catalyst not containing IL or catalyst with a higher ratio of IL. The materials were characterized by N₂-sorption analysis, TGA and transmission electron microscopy before and after catalysis. While our studies showed that the catalyst can be successfully recycled and reused in at least 4 reaction runs, in contrast, several poisoning experiments and kinetic studies provide the notion that homogeneous (dissolved) species are responsible for the observed catalysis.