In Situ Generation of PalladiumNanoparticles: Reusable, Ligand-Free Heck Reaction in PEG-400 Assistedby Focused Microwave Irradiation

A rapid and efficient Heck coupling reaction of aryl iodideswith terminal olefins was conducted in PEG-400 at 120 ˚Cin the presence of potassium carbonate and palladium nanoparticles formedin situ from palladium chloride under focused microwave irradiation.High to excellent product yields were achieved. The reaction mediumand catalyst could be easily recycled at least five times withoutsignificant loss in reactivity.