Supported Bis-(NHC)-P(II) Complex: A phosphine-Free Catalyst Supported on Magnetic Mesoporous Silica for The CO-Free Carbonylation of Aryl Halides

Abstract

In this work, our previously reported bis(NHC)-Pd(II) catalyst grafted on Fe3O4@SBA-15 has been successfully used as a phosphine-free heterogeneous magnetic catalyst in the CO-free carbonylation of aryl halides. It is shown that the immobilized Pd(II)-complex efficiently catalyzes the carbonylation of different aryl halides with HCOOH and DCC in the presence of Et3N as the base. Optimal reaction conditions were determined by screening various parameters such as solvent, HCOOH/DCC molar ratio, base, temperature, and catalyst dosage. The catalyst was magnetically retrievable and separated by an external magnet, washed, and re-used in the subsequent runs over seven catalytic cycles. The hot filtration experiment was conducted to determine the heterogeneous nature of the catalyst.