Microwave-Assisted, Ligand-Free, Copper-Catalyzed Reaction of Aryl Halides with Phenyl Urea.

Abstract The ligand free coupling reaction of phenyl urea with different functionalized aryl halides in the presence of air stable Cu 2 O and t -BuOK as a base gives symmetrical and unsymmetrical diarylureas in relatively high yields. This method is milder than the palladium catalyzed arylation and avoids the use of toxic phosphine ligand.