Heterogenized peroxopolyoxotungstate catalyst on the surface of clicked magnetite‐graphene oxide nanocomposite: Magnetically recoverable epoxidation catalyst

Abstract

A new heterogeneous catalyst for the epoxidation of olefins was prepared by immobilization of peroxophosphotungstate anions on the surface of clicked magnetite‐graphene oxide as magnetically recoverable support. To prepare the heterogeneous catalyst, the clicked magnetite‐graphene oxide support was prepared by thiolene click reaction of thiol functionalized graphene oxide with vinyl modified magnetite nanoparticles. The tailored support was then modified with aminopropyl groups followed by electrostatic interaction with peroxophosphotungstate anions to achieve the desired heterogeneous catalyst. Characterization of the catalyst was performed by various physicochemical methods which confirmed the successful immobilization of peroxopolyoxotungstate species on the surface of clicked magnetite‐graphene oxide. Catalytic activity of the catalyst revealed its high catalytic activity and selectivity in the epoxidation of various olefins in the presence of H2O2 as green oxidant. This heterogeneous catalyst can be magnetically reused several times without significant loss of activity and selectivity.

Recent Progress in Application of Molybdenum-Based Catalysts for Epoxidation of Alkenes

“…Introducing active sites with diverse protocols on proper supports is a common and valid strategy of preparing heterogeneous catalysts. Impregnation [35], co-precipitation [36] and chemical bonding [37] are conventional and facile methods to achieve this goal.…”

Copper(II) complex intercalated graphene oxide nanocomposites as versatile, reusable catalysts for click reaction

“…[ 32 ] Epoxidation of olefins was performed by Masteri‐Farahani et al using peroxophosphotungstate anion in the GO basal planes. [ 33 ] Gorji et al reported the synthesis of Cu(II) Schiff base complex immobilized on GO/α‐Fe 2 O 3 as heterogeneous catalyst for the three‐component synthesis of 2‐Amino‐4H‐Chromenes derivatives. [ 34 ] Therefore, it is of our interest to prepare the versatile GO nanocomposites through the intercalation of high stable Cu II complexes in the GO basal planes and to demonstrate its catalytic activity towards the click reaction.…”

Recent Advancements in Graphene‐Based Supports of Metal Complexes/Oxides for Epoxidation of Alkenes

“…[35] However,A u/SBA-15-Py( Py = pyrrolidinone) showedg ood activity for the aerobic oxidation of cyclohexene and styrene, owing to the interaction between gold and Py. [37] The hybrid nanomaterial of peroxopolyoxotungstate and GO (PW/ GO) prepared by the immobilization of the venturello anion, [39] GO/MNPs/PW was easily separated by using an externalm agnet, and was stable with no clear decrease in catalytic performance after being recycled five times. [37] The hybrid nanomaterial of peroxopolyoxotungstate and GO (PW/ GO) prepared by the immobilization of the venturello anion, [39] GO/MNPs/PW was easily separated by using an externalm agnet, and was stable with no clear decrease in catalytic performance after being recycled five times.…”

“…The epoxide yield is enhanced with increasing nucleophilicity of the olefin. [39] The active site of the GO/MNPs/PW catalyst has electrophilicity,a nd could be used as an ucleophilic reagent to transfer oxygen to the C=Cb onds through electrophilic addition. It was reported that cyclohexene and cyclooctene, containing internal double bonds, revealed higherr eactivity than that of 1-hexene and 1-octene, with terminal double bonds, owing to higher electron densi-ties.…”

“…Masteri-Farahania nd Modarres reported that GO/MNPs/PW showed betterc onversion for cyclic olefins (e.g.,c yclooctene) than that for linear alkenes (1-octene), owing to the highere lectron density of C=C in the former. [39] The active site of the GO/MNPs/PW catalyst has electrophilicity,a nd could be used as an ucleophilic reagent to transfer oxygen to the C=Cb onds through electrophilic addition. The Mo-GO/g-C 3 N 4 catalyst exhibited superior activity for styrenee poxidation,o wing to p-p interactions between the sp 2 -hybridized carbon atoms of GO and the benzene ring, whicha ccelerated electron transfer.…”