Catalytic Epoxidation of Olefins with Graphene Oxide Supported Copper (Salen) Complex

Immobilization of metal complexes on solid supports is an efficient approach to remedy the drawbacks of homogeneous catalysis. In this study, an in situ strategy of synthesis and immobilization of a copper (salen) complex onto graphene oxide (GO) support has been developed. To provide the salen ligands, GO was covalently modified with an aminosilane, followed by condensation with salicylaldehyde. The copper (salen) complex was subsequently synthesized and simultaneously immobilized onto the GO surface with a designed tetrahedral chelate structure. The immobilized copper (salen) complex [Cu(salen)–f–GO] kept the two-dimensional sheetlike character of GO and was demonstrated to be highly effective for the epoxidation of olefins. It could be readily reused for successive twelve times without discernible activity and selectivity deterioration, which displays potential for practical applications.