New N-Heterocyclic Carbene Palladium Complex/Ionic Liquid Matrix Immobilized on Silica:  Application as Recoverable Catalyst for the Heck Reaction

A new concept of simultaneous covalent anchoring of a N-heterocyclic carbene palladium/ionic liquid matrix on the silica surface and the application of the resulting catalyst in the Heck reaction of a variety of different haloarenes is described. The catalyst shows high thermal stability (up to 280 °C) and could be recovered and reused for four reaction cycles, giving a total TON ≅ 36 600. Furthermore, TEM coupled with EDX analysis indicate the formation of Pd nanoparticles within the immobilized IL layer.