Molybdenum containing surface complex for olefin epoxidation

Silica-supported molybdenum surface complexes were prepared by the reaction between (N≡)Mo(OtBu) ₃ and silica via displacement of the tert-butoxy ligands for siloxyls from the silica surface. The structure of the surface molybdenum complexes was well defined by in-situ FT-IR, elemental analysis, ¹ H NMR and ¹³ C CP/MAS NMR techniques. The surface complexes could undergo alcoholysis reaction with CD ₃ OD and CH ₃ OH in the same way as free (N≡)Mo(OtBu) ₃ and they show high catalytic activity and selectivity in olefin epoxidation. Initial rates up to 24.9 mmol epoxide (mmol Mo) ^-1 min ^-1 were achieved in the epoxidation of cyclohexene using TBHP as oxidant.