A functionalized ionic liquid, 1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate
([HEmim][BF4]), was found to be as an efficient and recyclable reaction medium for palladium-catalyzed
Heck reaction. The olefination of iodoarenes and bromoarenes with olefins generated
the corresponding products in good to excellent yields under phosphine-free reaction
conditions. The reaction involved the use of [HEmim][BF4] as the solvent, potassium phosphate as the base, and palladium acetate as the catalyst.
In addition, palladium and ionic liquid could be recovered and recycled for six consecutive
trials without significant loss of its reactivity.
Heck reaction - palladium acetate - phosphine-free - functionalized ionic liquid -
1-(2-hydroxyethyl)-3-methylimidazolium tetrafluoroborate ([HEmim][BF4])