Highly Effective RecyclablePalladium-Catalyzed Ligand-Free Heck Reactions under AerobicConditions

An effective protocol was developed for the Heck coupling reactions between various aryl halides and olefins. In the presence of 2 mol% of Pd(OAc) 2 , the desired products could be obtained in good yields under ligand-free and aerobic conditions. The catalytic system could be easily recycled for five times with high efficiency.