Pillar[5]arene-based N-heterocyclic carbene ligand for Pd-catalysed Suzuki reaction

A pillar[5]arene-based N-heterocyclic carbene ligand was prepared by reaction of bromoethoxy pillar[5]arene with excess 1-methylimidazole at 130 °C in the absence of solvent and used as a catalyst for the Suzuki coupling reaction. Excellent yields were obtained when the Suzuki reactions were carried out under ambient atmosphere in ethanol, employing 0.2 mol% ligand, 1 mol% PdCl2(CH3CN)2 and 1.5 mmol of K2CO3. The novel pillar[5]arene-based imidazolium salt is a promising material for the construction of highly active supramolecular catalytic systems.