Palladium imine-pyridine-imine complex immobilized on graphene oxide as a recyclable catalyst for the carbonylative homo-coupling of aryl halides

Abstract

A heterogeneous 3-N,N,N-(II) Pd(OAc)₂ catalyst was prepared from the reaction of Pd(OAc)₂ with Si-Prn-N = C-Py-C = N-Prn-Si immobilized on graphene oxide (GO-Si-Prn-N = C-Py-C = N-Prn-Si-GO). The prepared catalyst was characterized by inductively coupled plasma optical emission spectroscopy, Fourier transform infrared (FT-IR) spectroscopy, Raman spectroscopy, energy dispersive X-ray spectroscopy, X-ray diffraction, UV-vis spectroscopy, BET surface area, scanning electron microscopy, transmission electron microscopy, and thermogravimetric analysis. The catalyst was employed as a heterogeneous catalyst for carbonylative homo-coupling of aryl iodides and bromides under carbon monoxide gas-free condition. Cr(CO)₆ was used as the carbon monoxide source and the desired symmetrical diaryl ketones were achieved in good to excellent yields. Moreover, the catalyst was reused up to five consecutive cycles without significant loss of activity.

Graphical abstract

Keywords:

• Carbonylative homo-coupling reaction
• Cr(CO)₆
• graphene oxide
• palladium catalyst
• symmetrical diaryl ketones

Acknowledgements

We gratefully acknowledge the financial support received from the Research Council of Shiraz University.

Disclosure statement

No potential conflict of interest was reported by the authors.