Novel palladium tagged ferrite nanoparticle supported ionic liquid phase catalyst for the efficient copper-free Sonogashira coupling

An efficient protocol for the copper-free Sonogashira coupling of aryl halides with terminal alkynes using novel palladium tagged, magnetic nanoparticle supported, ionic liquid phase catalyst (Pd-SILP-Fe3O4@SiO2) in water under aerobic conditions has been developed. The newly synthesized catalyst was characterized by FTIR, XPS, SEM, TEM, XRD, EDS, VSM, ICP-AES, and BET techniques. Various substituted aryl alkynes were synthesized with excellent yields using a highly water dispersible Pd-SILP-Fe3O4@SiO2 catalyst. The synthesized nanocatalyst displayed high thermal stability, compatibility in aqueous systems, high catalytic efficiency, high turnover frequencies (TOF), easy magnetic recovery, and reusability up to 6th run. The main advantages of the protocol are its robustness, mild reaction conditions, easy set-up, easy workup, low Pd loading (0.001 mol % of Pd), higher yields, and use of water as a green solvent, which makes it both environmentally and economically appealing.