Bis(trimethylsilyl) Peroxide Extends the Range of Oxorhenium Catalysts for Olefin Epoxidation

Yudin, Andrei K.; Sharpless, K. Barry

doi:10.1021/ja973043x

Cited by 65 publications

(41 citation statements)

References 14 publications

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“…Upon reaction, BTSP is converted into hexamethyldisiloxane, thereby assuring anhydrous conditions. In initial experiments, MTO showed little or no reactivity towards BTSP under stoichiometric conditions [115]. This was very surprising, in view of the high reactivity observed for BTSP relative to hydrogen peroxide in oxidation of sulfides to sulfoxides [116].…”

Section: Other Oxidantsmentioning

confidence: 99%

“…of BTSP were used for efficient epoxide formation. The discovery of these essentially water-free epoxidation conditions resulted in another interesting breakthrough: the use of simple oxorhenium compounds as catalyst precursors [115,117]. The catalytic activity of rhenium compounds such as Re 2 O 7 , ReO 3 (OH), and ReO 3 in oxidation reactions with aqueous hydrogen peroxide as the terminal oxidant is typically very poor.…”

Section: Other Oxidantsmentioning

confidence: 99%

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Metal‐catalyzed Synthesis of Epoxides

Adolfsson

Balan

2006

Aziridines and Epoxides in Organic Synthesis

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Section: Other Oxidantsmentioning

confidence: 99%

Section: Other Oxidantsmentioning

confidence: 99%

Metal‐catalyzed Synthesis of Epoxides

Adolfsson

Balan

2006

Aziridines and Epoxides in Organic Synthesis

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“…After 4 hours, a TON (based on tungsten species) of 135 is reached (selectivity > 99%) with 0.4 mol % of the tungsten catalyst (0.2 mol % Na 2 WO 4 and 0.2 mol % H 2 WO 4 ); this is a significant rate enhancement compared to the ones reported in the literature for this substrate. [28,29] Another All epoxidation reactions were performed at 60 8C terminal alkene, i.e., 1-hexene, can also be selectively oxidized with a high TON of 150 (entry 4). The homoallylic alcohol, 3-methyl-3-buten-1-ol (entry 5) is converted to the epoxide with good yield and selectivity after a reaction time of 4 hours.…”

mentioning

confidence: 99%

A Na₂WO₄/H₂WO₄‐Based Highly Efficient Biphasic Catalyst towards Alkene Epoxidation, using Dihydrogen Peroxide as Oxidant

Maheswari¹,

Hoog²,

Hage³

et al. 2005

Adv Synth Catal

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Abstract:The tungsten-containing biphasic catalytic system [Na 2 WO 4 /H 2 WO 4 /PTR/chloroacetic acid] effectively epoxidizes alkenes with 50% H 2 O 2 as terminal oxidant, under organic solvent-free conditions. The catalytic process is proposed to proceed via a dinuclear tungsten peroxo species with coordinated chloroacetic acid, as suggested by ESI-MS measurements. The catalytic system is suggested to involve tungsten-peroxo and/or peracetic acid type of epoxidation catalyzed by the tungsten(VI) in the presence of an organic acid and H 2 O 2 . The reaction conditions employed for various alkenes for epoxidation are mild compared to the earlier studies and result in high product selectivity and conversion rate.Keywords: alkenes; chloroacetic acid; epoxidation; hydrogen peroxide; tungsten The development of efficient and clean processes for the epoxidation of alkenes on a million-ton-per-year scale remains an important objective in the fine chemical industry. [1 -5] There is an increasing need for the elaboration of selective catalytic systems involving cheap, readily available, and ecologically friendly oxidants, such as hydrogen peroxide. [6,7] In this context, polyoxotungstates have been extensively and successfully used during the past 20 years. [8 -11] A key experiment was performed by Venturello who selectively epoxidized 1-octene with a turnover number (TON, defined as mol product per mol catalyst) of 20 (82% yield based on H 2 O 2 ) using a Na 2 WO 4 -H 3 PO 4 -quaternary ammonium chloride catalyst.[12] Since then, this system has been intensely studied. [13,14] Nevertheless, this catalytic biphasic procedure is less desirable, as it requires the use of chlorinated solvents such as 1,2-dichloroethane. [15 -17] A first breakthrough occurred in 1996 when Noyori [18] reported a significant improvement of the original Venturello system. The epoxidation of terminal alkenes could be carried out within 4 hours, without organic solvents, and with up to 49.5 TON (99% yield, based on the olefin), using a catalytic mixture of Na 2 WO 4 dihydrate, (aminomethyl)phosphonic acid and the phase transfer reagent (PTR) methyltri-n-octylammonium hydrogen sulfate. [19] Recently, outstanding procedures involving tungsten-containing catalysts for the production of propylene oxide [20] and the epoxidation of allylic alcohols [21] were reported. The new catalytic system reported here consists of easily available, low-cost chemicals [Na 2 WO 4 /H 2 WO 4 / Aliquat 336 (PTR)/chloroacetic acid], which can be easily handled (Scheme 1). Typically, 200 mmoles of ciscyclooctene were reacted with 300 mmoles of hydrogen peroxide (50%) at 60 8C. The epoxidation is catalyzed by 0.025 mol % of Na 2 WO 4 and 0.025 mol % H 2 WO 4 with 0.2 mol % of chloroacetic acid in the presence of methyltri-n-octylammonium chloride (0.2 mol %) as PTR (Scheme 1). A maximum TON of as high as 1800 is reached after 4 hours with 99% selectivity. This rate of the epoxidation is compared under similar experimental conditions as above, to the one of Noyori et a...

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“…[5] Recent experimental work shows the possibility for olefin epoxidation also by inorganic compounds like ReO À 4 , even without explicit use of H 2 O 2 . [6] Herrmann et al [5] and Espenson et al [7] have proposed reaction mechanisms for epoxidation by MTO-related complexes that involve differently oxygenated and hydrated forms of these catalysts. Also conceivable are processes in which hydroperoxo species participate.…”

mentioning

confidence: 99%

“…[5] Although to date the vast majority of compounds have been derived from main group elements such as silicon and aluminum, [2] over recent years there has been increasing interest in incorporating transition metals within three-dimensional and layered framework structures. [6] Such materials have the potential of combining the shape selectivity demonstrated by framework materials with the catalytic, magnetic, optical, and redox properties associated with d-block elements.…”

mentioning

confidence: 99%

Olefin Epoxidation by Methyltrioxorhenium: A Density Functional Study on Energetics and Mechanisms

Gisdakis

Antonczak

Köstlmeier

et al. 1998

Angewandte Chemie International Edition

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A spiro attack on a peroxo group is calculated to be the preferred reaction pathway for olefin epoxidation with the catalytic system CH ReO /H O (see picture). This finding is supported by density functional calculations on more than ten transition states for the most probable mechanisms. Hydration has significant effects on various reaction species: it stabilizes the intermediates and destabilizes, with one exception, the transition states.

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Bis(trimethylsilyl) Peroxide Extends the Range of Oxorhenium Catalysts for Olefin Epoxidation

Cited by 65 publications

References 14 publications

Metal‐catalyzed Synthesis of Epoxides

Metal‐catalyzed Synthesis of Epoxides

A Na₂WO₄/H₂WO₄‐Based Highly Efficient Biphasic Catalyst towards Alkene Epoxidation, using Dihydrogen Peroxide as Oxidant

Olefin Epoxidation by Methyltrioxorhenium: A Density Functional Study on Energetics and Mechanisms

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Bis(trimethylsilyl) Peroxide Extends the Range of Oxorhenium Catalysts for Olefin Epoxidation

Cited by 65 publications

References 14 publications

Metal‐catalyzed Synthesis of Epoxides

Metal‐catalyzed Synthesis of Epoxides

A Na2WO4/H2WO4‐Based Highly Efficient Biphasic Catalyst towards Alkene Epoxidation, using Dihydrogen Peroxide as Oxidant

Olefin Epoxidation by Methyltrioxorhenium: A Density Functional Study on Energetics and Mechanisms

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A Na₂WO₄/H₂WO₄‐Based Highly Efficient Biphasic Catalyst towards Alkene Epoxidation, using Dihydrogen Peroxide as Oxidant