Palladium immobilized onto 1,4-bis(pyrid-4-yl)benzene grafted to n-propyl-functionalized Fe₃O₄@MCM-41 nanoparticles (PBPBPMF) as a novel, green, reusable, and versatile catalyst for preparing bis(pyrazolyl)methane and biphenyl derivatives

In this research, a novel and efficient nanocatalyst, namely, palladium immobilized onto 1,4-bis(pyrid-4-yl)benzene grafted to n-propyl-functionalized Fe₃O₄@MCM-41 nanoparticles (PBPBPMF), was synthesized and introduced. Then, its catalytic activity was tested in the synthesis of bis(pyrazolyl)methane (14 examples, 90–97%, 9–25 min, solvent-free, 60 °C) and biphenyl (13 examples, 80–98%, 10–120 min, PEG-400, 70 °C) derivatives. Bis(pyrazolyl)methane derivatives were synthesized via a one-pot pseudo-five-component reaction of aldehydes, ethyl acetoacetate, and phenylhydrazine, and biphenyl derivatives were obtained by a Stille coupling reaction. Transmission electron microscopy (TEM), energy-dispersive X-ray spectroscopy (EDS), scanning electron microscopy (SEM), N₂ sorption isotherms, vibrating sample magnetometer (VSM), inductively coupled plasma atomic emission spectrometer (ICP-OES), X-ray diffraction (XRD), thermogravimetric analysis (TGA), Fourier transform infrared spectroscopy (FT-IR), and elemental mapping analyses were used to identify the catalyst. The PBPBPMF is a heterogeneous catalyst with several advantages, including a large specific surface area, ease of purification, and separation from the reaction mixture; furthermore, the nanocatalyst was recycled six times without appreciably altering its catalytic properties.