Ultrasound-Promoted Ligand-Free Heck Reaction in Water

[image omitted] An ultrasound irradiation-promoted Heck reaction catalyzed by ligand-free palladium acetate was described. The ultrasound-promoted Heck reaction was carried out under mild and environmentally friendly conditions, resulting in the corresponding products with good to excellent chemical yields (up to 96% yield) and high regioselectivities and stereoselectivities (E/Z99:1). Acrylamide and acrylic acid were used for the first time as substrates in the ultrasound-promoted Heck reaction. It was found that the reaction could be finished within 20min.