High-Speed Heck Reactions in Ionic Liquid with Controlled Microwave Heating

Palladium-catalyzed Heck arylations in the polar and robust ionic liquid, 1-butyl-3-methylimidazolium hexafluorophosphate (bmimPF6), have for the first time been accomplished under microwave irradiation. The couplings were efficiently performed in sealed tubes within 5−45 min of heating. Without significant reductions in yield, a phosphine-free ionic catalyst phase could be recycled in five successive 20 min reactions at 180 °C. The product was easily removed from the reaction medium by distillation.