Efficient alkene epoxidation catalyzed by molybdenyl acetylacetonate supported on aminated UiO-66 metal−organic framework

•UiO-66-NH2 was modified with salicylaldehyde and thiophene-2-carbaldehyde.•The Schiff base groups were used for immobilization of MoO2(acac)2.•The heterogeneous catalysts were prepared.•The prepared catalysts were used for epoxidation of alkenes.•Compared to other catalyst, our catalysts were more efficient and forceful.

Metal–organic frameworks (MOFs) containing Mo Schiff base complexes were prepared by post-synthesis method and applied as efficient catalysts in the epoxidation of alkenes with tert-BuOOH. In this manner, UiO-66-NH2 (UiO=University of Oslo) MOF was reacted with salicylaldehyde and thiophene-2-carbaldehyde to produce bidentate Schiff bases. Then, the Schiff base ligands were used for immobilization of molybdenyl acetylacetonate. These new catalysts were characterized by FT-IR, UV–vis spectroscopic techniques, X-ray diffraction (XRD), BET, inductively coupled plasma atomic emission spectroscopy (ICP-AES) and field emission scanning electron microscopy (FE-SEM). These catalytic systems showed excellent activity in the epoxidation of alkenes such as cyclic and linear ones with tert-butyl hydroperoxide (TBHP) in 1,2-dichloroethane, and reused several times without any appreciable loss of their activity.

Graphical abstractEfficient alkene epoxidation with TBHP catalyzed by heterogeneous and reusable molybdenum base catalysts is reported.Figure optionsDownload full-size imageDownload as PowerPoint slide