Soluble polymer‐supported catalysts containing pendant quaternary onium salts for the addition reaction of oxiranes with carbon dioxide

Abstract

AbstractThe addition reaction of oxiranes (15a‐d) with carbon dioxide (CO2) was carried out using 1 mol % of soluble polymer‐supported quaternary onium salts as catalysts under atmospheric pressure. The reaction of 15a‐d with CO2 proceeded very smoothly to give the corresponding five‐membered cyclic carbonates (16a‐d) in high yields at 90‐100°C. The catalytic activity of the soluble polymer‐supported quaternary onium salts was strongly affected by the following factors: kind of reaction solvent, degree of introduction of the pendant onium salt residues in the polymer chain, and type of alkyl group on the onium salts due to the balance between lipophilicity and steric hindrance of the onium salt residue. Furthermore, these soluble polymer‐supported quaternary onium salts were found ordinarily to have higher catalytic activity than low molecular weight quaternary onium salts under the same reaction conditions. It was also found that the rate of reaction was proportional both to catalyst concentration and to oxirane concentration. © 1995 John Wiley & Sons, Inc.