Schiff base‐functionalized boehmite nanoparticle‐supported molybdenum and vanadium complexes: efficient catalysts for the epoxidation of alkenes

Abstract

Boehmite nanoparticles, with high surface area and high degree of surface hydroxyl groups, were prepared via hydrothermal-assisted sol-gel processing of aluminium 2-butoxide. The produced powder was covalently functionalized with 3-(trimethoxysilyl)propylamine, and then, in order to support vanadium oxosulfate and molybdenum hexacarbonyl complexes, all the terminal amine groups were changed to Schiff bases by refluxing with salicylaldehyde. These catalysts were applied in the epoxidation of cis-cyclooctene and other olefins with tert-BuOOH in CCl 4 . The catalytic procedures for both catalysts were optimized for various parameters such as solvent and oxidant. Recycling experiments revealed that these heterogeneous nano-catalysts could be repeatedly applied for the epoxidation of alkenes.

Preparation and characterization of Fe3O4@Boehmite core‐shell nanoparticles to support molybdenum or vanadium complexes for catalytic epoxidation of alkenes

“…As reported earlier, boehmite has a low efficiency in the epoxidation of alkenes . However, its surface is covered with hydroxyl groups, which are ready for further functionalization and supporting metal complexes . The presence of metal complexes is vital for the catalytic epoxidation of alkenes because the oxidant could coordinate to these sites and become activated for an epoxidation process.…”

“…The IR spectrum for Fe@B‐N (Figure c) shows new bands for the C‐H stretching and N‐H bending vibrations of grafted silyl propyl amine groups at 2928 and 1556 cm −1 , respectively, in addition to the characteristic boehmite bands . The N‐H stretching vibration of the amine group should be shown at 3300–3400 cm −1 but it is probably covered by the broad O‐H stretching vibration of boehmite in this region.…”

“…In continuation of our studies on the catalytic epoxidation of alkenes using chemically grafted vanadium‐ and molybdenum‐containing catalysts on the surface of boehmite nanoparticles, in this work, we tried to prepare a magnetite core‐boehmite shell, as a catalytic support that could easily be separated from the reaction medium by the use of a simple magnet. This was done by adding the pre‐treated magnetite nanoparticles to the aluminum alkoxide precursor solution in the formerly reported hydrothermal‐assisted sol–gel process for the production of boehmite nanoparticles .…”

Recent Advances in Facile Liquid Phase Epoxidation of Light Olefins over Heterogeneous Molybdenum Catalysts

“…It also confirmed the organic moieties from ethylenediamine and hydroquinone . Mirzaee et al . prepared boehmite nanoparticles (BNPs) via hydrothermal‐assisted sol‐gel processing of aluminium 2‐butoxide.…”

Ni–S-methylisothiourea complexes supported on boehmite nanoparticles and their application in the synthesis of 5-substituted tetrazoles

“…While, boehmite nanoparticles is not air or moisture sensitive, more importance boehmite nanoparticles can be prepared in water at room temperature using available materials such as NaOH and Al(NO 3 ) 3 .9H 2 O [25]. Boehmite nanoparticles have several advantages such as non-toxicity, stability, high specific surface area (>120 m 2 /g), ease of surface modification due to many hydroxyl groups on its surface, inexpensive and easily and readily availability [26][27][28]. The surface of boehmite nanoparticles are covered by many hydroxyl groups, which makes possible the modification of the surface of boehmite nanoparticles with other functional groups to supported catalysts such as metal complexes.…”