Efficient Heck reactions catalyzed by a palladium/diol–imidazolium salt in aerial atmosphere

A new diol–imidazolium salt, 1-(2,3-dihydroxypropyl)-3-methylimidazolium hexafluorophosphate (1), was found to be an efficient and reusable phosphine-free ligand for palladium catalyzed Heck reactions. The couplings of a variety of aryl iodides/aryl bromides with acrylates generated the corresponding products in good/excellent yields even in aerial atmosphere. In addition, the palladium catalyst mediated by 1 could be easily recovered and reused for ten runs without obvious loss of its activity.