Development of the first well-defined tungsten oxo alkyl derivatives supported on silica by SOMC: towards a model of WO3/SiO2 olefin metathesis catalyst

Mazoyer, Etienne; Merle, Nicolas; Mallmann, Aimery De; Basset, Jean‐Marie; Berrier, Élise; Delevoye, Laurent; Paul, Jean‐François; Nicholas, Christopher P.; Gauvin, Régis M.; Taoufik, Mostafa

doi:10.1039/c0cc02507k

Cited by 68 publications

(129 citation statements)

References 32 publications

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“…As a result, after 95 h the TON is 22,000 for 22 and ca. 2,500 for 23 [83]. In terms of selectivity, complex 22 is stable with equimolar amounts of ethylene and but-2-ene while in the case of compound 23 isobutene and higher oleins (pentenes and hexenes) are also formed (Figure 22b).…”

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 92%

“…This species is formed in situ by coordination of propene to tungsten (which is electro-deicient), leading to a hexacoordinated complex with a great steric hindrance which will favor the α-H abstraction. DFT calculations show that the formation of the carbene species is thermodynamically favored, the energy barrier being ΔE = −29 kJ.mol −1 [83]. (Figure 22a) while complex 22 remains stable.…”

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 99%

“…This hydride is then converted into an inactive tungsten(IV) species with the evolution of isobutene by reductive elimination (Figure 23) [83].…”

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 99%

“…Upon α-H abstraction, these complexes can lead to supported oxo-alkylidene species. The irst oxo-alkyl complex of tungsten supported on silica was prepared by reaction of W(═O)(CH 2 tBu) 4 with silica dehydroxylated at 700°C [83]. The reaction occurs via breaking of a W─C bond and leads selectively to [(≡SiO)(W═O)(CH 2 tBu) 3 ] 22 (Figure 20).…”

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 99%

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Olefin Metathesis by Group VI (Mo, W) Metal Compounds

Lefèbvre¹,

Bouhoute²,

Szeto³

et al. 2018

Alkenes

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Olein metathesis is an important reaction not only in petroleum chemistry but also in ine chemistry. Professors Grubbs, Schrock, and Chauvin obtained the Nobel Prize in 2005 for the development of this reaction (determination of the mechanism and synthesis of homogeneous catalysts). This reaction can be described as the redistribution of carbon chains of oleins via a breaking of their C═C double bonds. It is catalyzed by metal carbenes and the catalytic cycle passes through a metallacyclobutane. The purpose of this chapter is to give an overview of catalysts based on tungsten or molybdenum active for this reaction. Numerous tungsten and molybdenum organometallic complexes displaying a carbene functionality were synthesized. Some of them are highly active in olein metathesis. Industrially, tungsten oxide on silica is used as a precursor of the propene production by olein metathesis of but-2-ene and ethylene. However, the active sites are not well known but they can be modeled by grafting, via surface organometallic chemistry, perhydrocarbyl complexes of molybdenum or tungsten on oxide surfaces. After a review of the complexes used in homogeneous catalysis, a review of the industrial catalysts and their models will be given.

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Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 92%

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 99%

“…This hydride is then converted into an inactive tungsten(IV) species with the evolution of isobutene by reductive elimination (Figure 23) [83].…”

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 99%

Section: Supported Oxo-alkyl and Oxo-carbene Tungsten Complexesmentioning

confidence: 99%

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Olefin Metathesis by Group VI (Mo, W) Metal Compounds

Lefèbvre¹,

Bouhoute²,

Szeto³

et al. 2018

Alkenes

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“…microelectronic industry. Such reactions with water have attracted much attention [4][5][6][7][8][9][10][11][12][13]. Schrock, Lippard and coworkers reported the formation of the dimer W 2…”

mentioning

confidence: 99%

Unusual reaction of a tungsten alkylidyne complex with water. Formation, characterization, and crystal structures of oxo trimers

Dougan

Chen

2011

Sci. China Chem.

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O) 3 ]·2benzene-d 6 (3·2benzene-d 6 ), respectively, each containing two alkyl ligands per W atom. This is in contrast to the dimer W 2 O 2 (-O)(CH 2 CMe 3 ) 6 , containing three alkyl ligands per W atom, from the previously reported reaction of the alkyl alkylidyne analog W(CH 2 CMe 3 ) 3 -(CCMe 3 ) with H 2 O. In the reaction of 1 with D 2 O in THF, an unstable intermediate W 2 O 2 (-O)(CD 2 SiMe 3 ) 2 (CH 2 CMe 3 ) 4 (4-d 4 ) was identified. Kinetic studies of the reactions of 1 with excess H 2 O and D 2 O in THF-d 8 , yielding 4 and 4-d 4 , respectively, give a kinetic isotope effect (KIE) of 3.46(3) at 298(1) K, suggesting that the disappearance of 1 is a rate-determining step. alkylidyne, water, oxo complexes, kinetic isotope effectMany early transition metal complexes are moisturesensitive, and reactions of metal complexes with water have been used to make metal oxides [1][2][3] in, e.g. microelectronic industry. Such reactions with water have attracted much attention [4][5][6][7][8][9][10][11][12][13]. Schrock, Lippard and coworkers reported the formation of the dimer W 2

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Immobilization of Olefin Metathesis Catalysts

Buchmeiser¹

2014

Olefin Metathesis

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Development of the first well-defined tungsten oxo alkyl derivatives supported on silica by SOMC: towards a model of WO3/SiO2 olefin metathesis catalyst

Cited by 68 publications

References 32 publications

Olefin Metathesis by Group VI (Mo, W) Metal Compounds

Olefin Metathesis by Group VI (Mo, W) Metal Compounds

Unusual reaction of a tungsten alkylidyne complex with water. Formation, characterization, and crystal structures of oxo trimers

Immobilization of Olefin Metathesis Catalysts

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