Mechanism of the Epoxidation of Alkenes by Molecular Oxygen

Filippova, T. V.; Blyumberg, E. A.

doi:10.1070/rc1982v051n06abeh002867

Cited by 30 publications

(8 citation statements)

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“…A further rationalization for the requirement of a minimum aldehyde/alkene ratio can be found in the work of Filippova and Blyumberg. 43 They observed that the rate of the uncatalyzed alkene epoxidation with aldehyde co-oxidation ceases to depend on the alkene concentration above a certain threshold value of this concentration. They assume that the acylperoxy radical and the alkene form an adduct (Scheme 1, eq 3) so that at a certain alkene concentration all acylperoxy radicals are trapped in this adduct.…”

Section: Discussionmentioning

confidence: 99%

Mechanistic Studies on the Mukaiyama Epoxidation

et al. 2004

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A detailed mechanistic study on the M ukaiyam a epoxidation of lim onene with dioxygen as oxidant, bis(acetylacetonato)nickel(II) as catalyst, and an aldehyde as co-reagent is reported.All m ajor products of the reaction have been quantitatively identified, both with i-butyraldehyde and 2-methylundecanal as co-reacting aldehydes. Lim onene epoxide is form ed in good yield. The main products evolving from the aldehyde are carboxylic acid, CO2, C O , and low er m olecular w eight ketone and alcohol (K+A). A m echanism is proposed in which an acylperoxy radical form ed by the autoxidation of the aldehyde is the epoxidizing species. The observation of carbon dioxide and (K+A) in a 1:1 m olar ratio supports this mechanism. CO 2 and (K+A) are form ed in m olar amounts of 50-60% with respect to the am ount of epoxide produced, indicating that epoxidation not only takes place via acylperoxy radicals, but also via a peracid route.Cyclohexene epoxidation was also investigated with a num ber of different metal com plexes as catalysts. Cyclohexene is very sensitive for allylic oxidation, which provides inform ation about the action of the catalyst, e.g. metals which form strongly oxidizing stable high valence com plexes are more likely to induce allylic oxidation. Color changes in the reaction m ixture indicate the presence of such high valence species. In the case of nickel, it was found that high valence com plexes are absent during the reaction which is in line with the fact that this metal displays the highest selectivity for epoxide. A mechanism which accounts for the observations is presented.

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Section: Discussionmentioning

confidence: 99%

Mechanistic Studies on the Mukaiyama Epoxidation

et al. 2004

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“…Autoxidation of double bonds can also occur by direct addition across the double bonds to form epoxides [ 226 – 228 ]. The subsequent ring opening ability of epoxides from petroleum-based alkenes has long been exploited to create resins with a broad range of useful properties specific for application such as high strength, excellent corrosion and weather resistance, and excellent electrical insulation [ 229 , 230 ].…”

Section: Lipidsmentioning

confidence: 99%

Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

et al. 2017

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With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass—carbohydrates, lipids, and proteins—there are long-established processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage.

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“…Autoxidation of double bonds can also occur by direct addition across the double bonds to form epoxides [226][227][228]. The subsequent ring opening ability of epoxides from petroleum-based alkenes has long been exploited to create resins with a broad range of useful properties specific for application such as high strength, excellent corrosion and weather resistance, and excellent electrical insulation [229,230].…”

Section: Pectinmentioning

confidence: 99%

Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

Dugmore

Clark

Bustamante

et al. 2017

Topics in Current Chemistry Collections

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With crude oil reserves dwindling, the hunt for a sustainable alternative feedstock for fuels and materials for our society continues to expand. The biorefinery concept has enjoyed both a surge in popularity and also vocal opposition to the idea of diverting food-grade land and crops for this purpose. The idea of using the inevitable wastes arising from biomass processing, particularly farming and food production, is, therefore, gaining more attention as the feedstock for the biorefinery. For the three main components of biomass-carbohydrates, lipids, and proteins-there are longestablished processes for using some of these by-products. However, the recent advances in chemical technologies are expanding both the feedstocks available for processing and the products that be obtained. Herein, this review presents some of the more recent developments in processing these molecules for green materials, as well as case studies that bring these technologies and materials together into final products for applied usage.

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Mechanism of the Epoxidation of Alkenes by Molecular Oxygen

Cited by 30 publications

References 1 publication

Mechanistic Studies on the Mukaiyama Epoxidation

Mechanistic Studies on the Mukaiyama Epoxidation

Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

Valorisation of Biowastes for the Production of Green Materials Using Chemical Methods

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