First Pd@Organo−Si(HIPE) Open-Cell Hybrid Monoliths Generation Offering Cycling Heck Catalysis Reactions

The syntheses and characterization of a new class of grafted organo−Si(HIPE) “high internal phase emulsion” open-cell matrixes is first proposed. Second, internal palladium particles heterogeneous nucleation is briefly discussed, leading finally to the generation of the new Pd@organo−Si(HIPE) series. The matrixes synthesized offer good turnovers and cycling performances For instance, the Pd@mercapto−Si(HIPE) matrix allows reaching at least 96% of Heck coupling catalysis yield during seven cycling tests. The Pd/iodobenzene molar ratio was settled at 0.004 and 0.002. The turnover number (TON) and turnover frequency (TOF) addressed with these new monolith catalysts are reaching values comparable with the ones obtained with powdered catalysts. Considering the fact that the catalysts in use are not powders but rather monoliths bearing hierarchical porosities, the series of Pd@organo−Si(HIPE) compounds combine heterogeneous catalysis efficiency and facile reusability where catalyzed species and catalyst supports can be easily separated by a simple removal of either the monolith or the solution from the reaction media.