Recoverable Palladium Catalysts for Suzuki-Miyaura Cross-Coupling Reactions Based on Organic-Inorganic Hybrid Silica Materials Containing Imidazolium and Dihydroimidazolium Salts

The systems formed by palladium acetate [Pd(OAC)(2)] and hybrid silica materials prepared by sol-gel from monosilylated imidazolium, and disilylated dihydroimidazolium salts show catalytic activity in Suzuki-Miyaura cross-couplings with challenging aryl bromides and chlorides. They are very efficient as recoverable catalysts with aryl bromides. Recycling is also possible with aryl chlorides, although with lower conversions. In situ formation of palladium nanoparticles has been observed in recycling experiments.