Synthesis of pillar[n]arenes (n = 5 and 6) with deep eutectic solvent choline chloride 2FeCl3

A novel and distinct method of preparing pillar[n]arenes with high selectivity and efficiency has been achieved by condensation of 1,4-dialkoxybenzene and paraformaldehyde with the deep eutectic solvent in CH₂Cl₂ at room temperature.