Phosphine-free cross-coupling reaction of arylboronic acids with carboxylic anhydrides or acyl chlorides in aqueous media

The palladium acetate-catalyzed coupling reaction of aryl boronic acid with carboxylic anhydride or acyl chloride was carried out smoothly in water in the presence of poly(ethylene glycol) (PEG) or 1-butyl-3-methylimidazolium hexafluorophosphate (bmim]PF6]) to give high yields of ketones without the use of phosphine ligands. The Pd(OAc)2-H2O-bmim]PF6] catalytic system can be recovered and reused eight times with high efficiency for both carboxylic anhydride and acyl chloride.