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

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 N-2-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.