The bifunctional and reusable catalyst of cerium/L‐arginine on mesoporous KIT‐6 in the chemoselective oxidation of sulfides and homoselective synthesis of tetrahydrobenzo[b]pyrans

Abstract

In this work, KIT‐6@Schiff‐base@Ce nanocatalyst was synthesized by immobilizing the Ce complex on KIT‐6 mesoporous silica framework modified with 3‐iodopropyltrimethoxysilane group. The surface area, total volume, and average diameter of pores, physical properties, functional groups, organic content, and element combination of the obtained nanocatalyst were identified using different techniques including BET, FT‐IR, XRD, WDX, SEM, and EDX. The KIT‐6@Schiff‐base@Ce was investigated as a novel stable and reusable catalyst with excellent performance for the selective synthesizing of sulfoxide and tetrahydrobenzo[b]pyrans. The designed catalyst successfully oxidized a large number of sulfides using hydrogen peroxide under solvent‐free conditions or in ethanol as a safe, green, and available solvent with good efficiency within short reaction times. Also, KIT‐6@Schiff‐base@Ce catalyzed a number of tetrahydrobenzo[b]pyrans using multicomponent condensation of dimedone, aldehydes, and malononitrile in water/ethanol (1:1) as ideal, safe, green and available solvent.