A Well-Defined Silica-Supported Tungsten Oxo Alkylidene Is a Highly Active Alkene Metathesis Catalyst

Conley, Matthew P.; Mougel, Victor; Peryshkov, Dmitry V.; Forrest, William P.; Gajan, David; Lesage, Anne; Emsley, Lyndon; Copéret, Christophe; Schrock, Richard R.

doi:10.1021/ja410052u

Cited by 85 publications

(87 citation statements)

References 14 publications

Supporting

Mentioning

Contrasting

Unclassified

Order By: Relevance

“…In contrast, using Surface Organometallic Chemistry, [3][4][5][6] a large family of highly active supported alkene metathesis catalysts has been reported based on welldefined metal alkylidenes in the past 15 years. [7][8][9][10][11][12][13][14][15] These numerous complexes have given access to a large number of spectroscopic and catalytic data set that have contributed to a better understanding of the mechanism and reaction intermediates involved in alkene metathesis. 10,12,14 In an attempt to bridge the gap between these and classical illdefined WO 3 /SiO 2 catalysts, 1,2,16 we have recently investigated the synthesis of silica supported oxo alkylidene complexes, which present very high activity ( Figure 1b).…”

Section: Supporting Information Placeholdermentioning

confidence: 99%

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO₃/SiO₂ Metathesis Catalysts

Mougel

Copéret

2015

ACS Catal.

Self Cite

View full text Add to dashboard Cite

In classical, ill-defined WO 3 /SiO 2 alkene metathesis catalysts, isolated, silica-supported tungsten oxo alkylidene species are suspected to represent the catalytically active species. Here, we report the synthesis and the characterization of molecular and supported isostructural mimics of these active sites. The good activities at room temperature of these well-defined oxo alkylidene complexes indicate that the lower activity of WO 3 /SiO 2 , even after preactivation, is likely due to the difficulty to generate active alkylidene sites from W oxo species in the classical system.

show abstract

Section: Supporting Information Placeholdermentioning

confidence: 99%

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO₃/SiO₂ Metathesis Catalysts

Mougel

Copéret

2015

ACS Catal.

Self Cite

View full text Add to dashboard Cite

show abstract

“…4,5 Major research efforts have been conducted in the past 40 years to generate the corresponding well-defined molecular and surface mimics (Figure 1C). 4,6−10 Such catalysts display very high activity at room temperature (> 100 turnover number (TON)/min) 11,12 in contrast to industrial catalysts, showing that the low activity of the industrial WO 3 /SiO 2 catalysts is presumably due to the difficulty to generate the active oxo alkylidene from the oxo surface species rather than an intrinsic low activity of tungsten oxo alkylidene moieties.…”

Section: Introductionmentioning

confidence: 99%

Low Temperature Activation of Supported Metathesis Catalysts by Organosilicon Reducing Agents

et al. 2016

Self Cite

View full text Add to dashboard Cite

Alkene metathesis is a widely and increasingly used reaction in academia and industry because of its efficiency in terms of atom economy and its wide applicability. This reaction is notably responsible for the production of several million tons of propene annually. Such industrial processes rely on inexpensive silica-supported tungsten oxide catalysts, which operate at high temperatures (>350 °C), in contrast with the mild room temperature reaction conditions typically used with the corresponding molecular alkene metathesis homogeneous catalysts. This large difference in the temperature requirements is generally thought to arise from the difficulty in generating active sites (carbenes or metallacyclobutanes) in the classical metal oxide catalysts and prevents broader applicability, notably with functionalized substrates. We report here a low temperature activation process of well-defined metal oxo surface species using organosilicon reductants, which generate a large amount of active species at only 70 °C (0.6 active sites/W). This high activity at low temperature broadens the scope of these catalysts to functionalized substrates. This activation process can also be applied to classical industrial catalysts. We provide evidence for the formation of a metallacyclopentane intermediate and propose how the active species are formed.

show abstract

“…For example, it has been shown that well-defined zirconium hydrides supported on alumina are highly active catalysts for alkane hydrogenolysis (Fig. 6a) [74] and silica-supported tungsten [75][76][77][78] and molybdenum complexes (Fig. 6b) [79][80][81][82] are effective catalysts for alkane metathesis [69,71,77,[83][84][85].…”

Section: Introductionmentioning

confidence: 99%

Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

2014

View full text Add to dashboard Cite

Single-site organometallic catalysts supported on solid inorganic or organic substrates are making an important contribution to heterogeneous catalysis. Early and late transition metal single-site catalysts have changed the polyolefin manufacturing industry and research with their ability to produce polymers with unique properties. Moreover, several of these catalysts have been commercialized on a large scale. Their heterogenization for slurry or gas phase olefin polymerization is important to produce polyolefin as beads and to avoid reactor fouling. The large majority of supports currently used in industry are inorganic materials (SiO 2 , Al 2 O 3 , MgCl 2 ), with silica being the most important. Single-site supported catalysts are most commonly prepared by molecular-level anchoring/chemisorption, in which a molecular precursor undergoes reaction with the surface while maintaining most of the ligand sphere of the parent molecule. Chemisorption of discrete organometallic complexes on solid supports yields catalysts with well-defined active sites, greater thermal stability than the homogeneous analogues, and decreased reactor fouling versus the homogeneous analogues. This review presents a detailed account of the synthesis, characterization and polymerization properties of single-site catalysts supported on metal oxides and metal sulfated oxides, primarily carried out at Northwestern University.

show abstract

A Well-Defined Silica-Supported Tungsten Oxo Alkylidene Is a Highly Active Alkene Metathesis Catalyst

Cited by 85 publications

References 14 publications

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO₃/SiO₂ Metathesis Catalysts

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO₃/SiO₂ Metathesis Catalysts

Low Temperature Activation of Supported Metathesis Catalysts by Organosilicon Reducing Agents

Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

Contact Info

Product

Resources

About

A Well-Defined Silica-Supported Tungsten Oxo Alkylidene Is a Highly Active Alkene Metathesis Catalyst

Cited by 85 publications

References 14 publications

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO3/SiO2 Metathesis Catalysts

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO3/SiO2 Metathesis Catalysts

Low Temperature Activation of Supported Metathesis Catalysts by Organosilicon Reducing Agents

Supported Single-Site Organometallic Catalysts for the Synthesis of High-Performance Polyolefins

Contact Info

Product

Resources

About

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO₃/SiO₂ Metathesis Catalysts

Isostructural Molecular and Surface Mimics of the Active Sites of the Industrial WO₃/SiO₂ Metathesis Catalysts