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.