Thiazolium-Based Catalysts for the Etherification of Benzylic Alcohols under Solvent-Free Conditions

Thiazolium and imidazolium hybrid materials were prepared by radical reactions between a mercaptopropyl‐modified SBA‐15 mesoporous silica and bis‐vinylthiazolium or bis‐vinylimidazolium dibromide salts. These hybrid materials were characterized by several techniques and were employed in the etherification reaction of 1‐phenylethanol. Solvent‐free conditions at 160 °C under different gas phases (oxygen, air, nitrogen and argon) were used. The thiazolium‐based material displayed excellent performances. Further studies were carried out using unsupported thiazolium salts, with or without a methyl group at the C‐2 position of the thiazolium moiety. These studies allowed us to propose a reaction mechanism. The supported thiazolium‐based material was successfully used in the etherification reaction of two other benzylic alcohols and also in seven consecutive cycles. This work represents the first use of thiazolium‐based compounds as catalysts for the etherification reaction of alcohols.