Heterogeneous copper and palladium catalysts for cross-coupling reactions

The purpose of this research was to prepare heterogeneous copper and palladium catalysts and apply for catalyzing cross-coupling reactions. Copper and copper (I) oxide nanoparticle catalysts (CuNPs and Cu2ONPs) were synthesized by simple chemical reduction, while palladium (II) catalysts (Fe3O4-DOPA-Pd and CAT1) were prepared by supporting palladium (II) chloride on the surface of dopamine and caebene complex modified nanoferrite, respectively. We demonstrated that CuNPs and Cu2ONPs effectively catalyzed C-O and C-N bond formations to synthesize corresponding diarylethers and arylimidazoles. In addition, heterogeneous Pd-catalyzed Suzuki-Miyaura and Sonogashira reactions were successfully developed to synthesize various kinds of biaryls and diarylacetylenes using Fe3O4-DOPA-Pd and CAT1 catalyst, respectively. The advantages of these heterogeneous catalysis protocols over the traditional homogeneous catalysis are their simple catalyst separation by filtration or external magnet and reusability that are important for developing economic and green organic synthesis methods.