Synthesis of Iron Oxide Palladium Nanoparticles and Their Catalytic Applications for Direct Coupling of Acyl Chlorides with Alkynes

A new, magnetic, silica-based, palladium nanocatalyst has been synthesized and employed for the first time in the direct coupling of acyl chlorides with terminal alkynes to prepare a variety of ynones. The synthesized nanocomposite is an excellent heterogeneous catalyst for copper-free, phosphine-free, C-C bond formation through the Sonogashira reaction under aerobic conditions at room temperature without the use of any additives and inert conditions. The synthesized catalyst has been comprehensively characterized by various techniques, such as XRD, SEM, TEM, energy-dispersive X-ray spectroscopy, X-ray photoelectron spectroscopy, inductively coupled plasma, FTIR spectroscopy, vibrating sample magnetometry, and atomic absorption spectroscopy. This nanocatalyst can be magnetically recovered and reused in multiple runs without any noticeable loss in catalytic activity.