SPIONs-bis(NHC)-palladium(II): A novel, powerful and efficient catalyst for Mizoroki-Heck and Suzuki-Miyaura C-C coupling reactions

A novel, stable and powerful nano Pd-NHC complex utilizing N-methylimidazole bounded to 1,3,5-triazine-tethered SPIONs (superparamagnetic iron oxide nanoparticles) as a bidentate NHC ligand is reported. This well-defined complex was used as an efficient (NHC)-based catalyst for Mizoroki-Heck and Suzuki-Miyaura cross coupling reactions. These cross coupled products were produced in excellent yields under conventional heating or microwave irradiation at extremely low palladium loading (similar to 0.002 mol%) with perfect high turnover frequencies (TOFs) (10(3)-10(6) h(-1)). Moreover, the catalyst could be quickly and completely recovered by external magnetic field and be reused for seven reaction cycles without any change in catalytic activity. (C) 2014 Elsevier B.V. All rights reserved.