the synthesis of pillar[6]arenes was developed. A series of pillar[6]arenes were prepared with FeCl3 as catalyst and chloroform as solvent at room temperature in moderate yields (30%–40%). Their host-guest properties with n-cetyltrimethyl ammonium bromide were investigated by 1 HNMR. The results showed that high selectivity in the host-guest relationship became apparent between pillar[6]arenes and
and distinct method of preparing pillar[5]arene and pillar[6]arene with high selectivity and efficiency has been achieved by condensation of 1,4-dialkoxybenzene and paraformaldehyde with the choline chloride (ChCl)/ferric chloride (FeCl3) deep eutectic solvent in CH2Cl2 at room temperature. Under the optimal conditions, the yield of pillar[5]arene and pillar[6]arene is 35% and 53%, respectively. The
The facile and efficient preparation of pillar[n]arenes (n = 5 or 6) was achieved by cyclooligomerization of 2,5-dialkoxybenzylalcohols or 2,5-dialkoxybenzylbromides with an appropriate Lewis acid catalyst at room temperature. The mechanism for this cyclooligomerization is presumed to be a Friedel–Crafts alkylation.