Oxazine containing molybdenum(VI)–oxodiperoxo complex immobilized on SBA-15 as highly active and selective catalyst in the oxidation of alkenes to epoxides under solvent-free conditions

Abstract Molybdenum(VI)–oxodiperoxo complex containing an oxazine ligand, ([MoO(O 2 ) 2 (phox)], phox: 2-(2′-hydroxyphenyl)-5,6-dihydro-1,3-oxazine) was conveniently synthesized and immobilized onto chloro-functionalized mesoporous silica SBA-15 by covalent bonding between the chloropropyl group on the internal surface of the pores and the nitrogen atom of oxazine ligand yielding [MoO(O 2 ) 2 (phox)]/SBA-15. The resulting material was characterized by FT-IR, TGA, XRD, SEM, TEM, EDX, ICP-AES, BET and UV–vis spectroscopy. The heterogeneous catalyst [MoO(O 2 ) 2 (phox)]/SBA-15 was employed in the epoxidation of alkenes, exhibiting high catalytic performance and selectivity for epoxide similar to that of homogeneous catalyst, [MoO(O 2 ) 2 (phox)] under solvent-free conditions. Finally, it was found that the heterogeneous catalyst had virtually no degree of leaching, which allowed its recyclability to nine cycles without loss of catalytic performance.