Bio-inspired Mo(II) complexes as active catalysts in homogeneous and heterogeneous olefin epoxidation

MoO 2 nanoparticles with tremella-like morphology have been synthesized and characterized. Characterization by powder X-ray diffraction (XRD) and transmission electron micrographs (TEM) microscopy made possible to estimate that the nanosheets have ca. 12 nm and aggregate to form tremella-like structures. The resulting MoO 2 nanoparticles were used as catalyst for epoxidation of several olefins. The use of tert-butylhydroperoxide (tbhp), H 2 O 2 and cumenehydroperoxide (chp) as oxygen sources was screened under different reaction conditions, namely, solvent and temperature. The results from the catalytic experiments show that this catalyst was very efficient leading to very high conversion and product selectivity levels. In addition, the use of oxidant:olefin ratios close to 1 show that this catalyst is very efficient conducting olefin epoxidation. Further details are discussed in the work. The catalyst showed overall excellent performance with tbhp. When using H 2 O 2 , the catalyst showed good activity, which is very relevant as well. All these achievements contribute with a step forward in the development of more environmentally friendly processes.

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“…This has already been discussed in the literature [20,22], and will be further addressed later in this work.…”

Section: Catalytic Studiesmentioning

confidence: 91%

“…The course of the reactions was monitored by quantitative GC-MS analysis by collecting samples at 10, 30 min, 1 and 1.5 h, then at 2, 4, 6, 8, and 24 h of reaction. These samples were treated as described previously prior to injection in the GC column [20][21][22].…”

Section: Catalytic Testsmentioning

confidence: 99%

Catalytic Application of Fe-doped MoO2 Tremella-Like Nanosheets

et al. 2016

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“…A large variety of molybdenum complexes and molybdenum carbonyl compounds have also been immobilized on different inorganic and organic solids such as mesoporous MCM-41and in Mg/Al hydrotalcite (HTC) [21][22][23]; hybrid matrix synthesized by the sol-gel process, classed as ureasil, which combines a reticulated siliceous backbone linked by short polyether-based segments [24]; crystal-like mesoporous phenylene-silica [25]; polymers (e.g., polybenzimidazole, polystyrene 2-(aminomethyl)pyridine, and poly(4-vinylpyridine) [26,27]); and hydrotalcite clay materials [28]. The resulting solids have been used as catalysts for the oxidation of different substrates, like cis-cyclooctene, cyclohexene, styrene, 1-octene, trans-2-octene, (R)-(+)-limonene, and R-pinene.…”

Section: Introductionmentioning

confidence: 99%

Investigation of a molybdenum-containing silica catalyst synthesized by the sol–gel process in heterogeneous catalytic esterification reactions using methanol and ethanol

Bail

Santos

Freitas

et al. 2013

Applied Catalysis B: Environmental

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“…This fact was later confirmed by a structure-activity analy- sis conducted with other systems which showed that the presence of N-H groups leads to drastic catalyst deactivation [104]. I) and the substrate conversion.…”

Section: Indirect Grafting -Tetheringmentioning

confidence: 72%

The Versatility of Immobilized Mo Complexes in Organic Transformations - Epoxidation and Metathesis Reactions

Vaz¹,

Nunes²

2012

COC

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In most of the chemical and pharmaceutical industrial processes at least one catalytic step is essential during their synthesis. Catalysts speed up chemical reactions but can be recovered unchanged at the end of the reaction. In this respect, heterogeneous catalysts surpass their homogeneous congeners by offering better recyclability as well as an easier separation from the reaction medium. Increasing research in recent years has led to new catalysts capable of directing a given reaction towards a specific product as well as allowing reactions to be carried out at lower temperatures and pressures with higher selectivity towards the desired product.Due to their relevance in biological processes, Mo-catalyzed reactions have attracted considerable interest. In this context, the present work aims at reviewing some of the most recent advances on heterogenized Mo-species in mesoporous materials. In this way, two of the most relevant reactions using olefins as substrates-epoxidation and metathesis where Mo is a major player are assessed. The former is relevant because epoxides are important intermediaries in industry, while the latter is quite significant since without it many organic transformations would simply be impossible.Scheme 2. Preparation of heterogeneous catalysts by the co-condensation method, using PMO supports [46][47][48][49][50][51][52][53][54].

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Bio-inspired Mo(II) complexes as active catalysts in homogeneous and heterogeneous olefin epoxidation

Cited by 42 publications

References 48 publications

Catalytic Application of Fe-doped MoO2 Tremella-Like Nanosheets

Catalytic Application of Fe-doped MoO2 Tremella-Like Nanosheets

Investigation of a molybdenum-containing silica catalyst synthesized by the sol–gel process in heterogeneous catalytic esterification reactions using methanol and ethanol

The Versatility of Immobilized Mo Complexes in Organic Transformations - Epoxidation and Metathesis Reactions

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