Synthesis of a novel 8-hydroxyquinoline functionalized poly (ethylene glycol) bridged dicationic ionic liquid and its application in palladium-catalyzed Heck reaction under solvent-free conditions

A novel 8-hydroxyquinoline functionalized poly (ethylene glycol) bridged dicationic ionic liquid ([HQ-PEG1000-DIL][BF4]) was synthesized and characterized. It was applied as an efficiently recyclable ligand for Pd-catalyzed Heck reaction under solvent-free conditions. It is noteworthy that the Pd(OAc)2/[HQ-PEG1000-DIL][BF4] catalytic system could be easily recovered and reused without obvious loss of catalytic activity after five recycling runs.