Palladium catalyst supported on PEGylated imidazolium based phosphinite ionic liquid-modified magnetic silica core–shell nanoparticles: a worthy and highly water-dispersible catalyst for organic reactions in water

Abstract

A highly water-dispersible palladium nanocatalyst was fabricated by the immobilization of Pd onto the surface of PEGylated imidazolium based phosphinite ionic liquid functionalized γ-Fe₂O₃@SiO₂ core–shell nanoparticles. This nanocatalyst (denoted as [Pd@PEGylated ImIL-OPPh₂-γ-Fe₂O₃@SiO₂]) was assessed as a promising Pd catalyst in different organic reactions including Mizoroki–Heck and Sonogashira coupling reactions of aryl halides and the reduction reaction of 4-nitrophenol (4NP) to 4-aminophenol (4AP). From the application point of view, this nanocatalyst showed high thermal versatility, stability, recoverability, and compatibility in aqueous media. The catalyst recovery test revealed that its performance and catalytic activity stayed indefectible during several sequential runs. The loading level of Pd in the [Pd@PEGylated ImIL-OPPh₂-γ-Fe₂O₃@SiO₂] catalyst was 0.087 mmol g⁻¹. Pivotal properties including high robustness, efficiency and turnover frequency (TOF), mild reaction conditions, utilization of water as a green solvent, simple product work-up, and facile catalyst recovery make this catalyst favourable from the environmental and economic points of view.