Electrostatic Grafting of a Palladium N-Heterocyclic Carbene Catalyst on a Periodic Mesoporous Organosilica and its Application in the Suzuki-Miyaura Reaction

A periodic mesoporous organosilica material functionalized with a Pd N-heterocyclic carbene complex was synthesized by applying an electrostatic grafting method. The resulting hybrid material was characterized by solid-state Si-29 and C-13 cross-polarization magic-angle spinning NMR spectroscopy, XRD, thermogravimetric analysis, and BET measurements. The hybrid was applied as a catalyst for the Suzuki-Miyaura cross-coupling between aryl chlorides and phenylboronic acid under heterogeneous and aerobic conditions. The supported catalyst exhibited excellent activity and stability and it could be reused at least six times without any loss of activity. Atomic absorption spectroscopy detected no Pd contamination in the products, and leaching tests verified that the reaction was truly heterogeneous.