A convenient, efficient and reusable N-heterocyclic carbene-palladium(ii) based catalyst supported on magnetite for Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions

Abstract

In the present work, a new magnetic nanoparticle supported N-heterocyclic carbene-palladium(II) (NO₂-NHC-Pd@Fe₃O₄) nanomagnetic catalyst was synthesized by a facile multistep synthesis under aerobic conditions using inexpensive chemicals. The NO₂-NHC-Pd@Fe₃O₄ nanomagnetic catalyst was characterized by various analytical techniques such as attenuated total reflectance infrared spectroscopy (ATR-IR), inductively coupled plasma-atomic emission spectroscopy (ICP-AES), energy-dispersive X-ray spectroscopy (EDS), field-emission scanning electron microscopy (FESEM), transmission electron microscopy (TEM), X-ray powder diffraction (XRD), thermogravimetric analysis (TGA) and Brunauer–Emmett–Teller surface area analysis (BET). The synthesized NO₂-NHC-Pd@Fe₃O₄ nanomagnetic catalyst showed excellent catalytic activity in both Suzuki–Miyaura and Mizoroki–Heck cross-coupling reactions for various substrates under mild reaction conditions. Recovery of the NO₂-NHC-Pd@Fe₃O₄ nanomagnetic catalyst from the reaction mixture was easily accomplished by applying an external magnet. The recovered NO₂-NHC-Pd@Fe₃O₄ nanomagnetic catalyst exhibited very good catalytic activity up to seven recycles in Suzuki–Miyaura and five recycles in Mizoroki–Heck cross-coupling reactions without considerable loss of its catalytic activity.