PEG-modified N-heterocyclic carbene ligands for highly efficient and recyclable Pd-catalyzed Heck reaction in water

A water-soluble and air-stable Pd(OAc)2/mPEG n MeImI system was found to be a highly efficient and reusable catalyst for the coupling of aryl halides and styrene in neat water using K2CO3 as base. After extraction, the catalytic system could be reused several times with only a slight decrease in its activity.