Cyclic Seleninate Esters as Catalysts for the Oxidation of Sulfides to Sulfoxides, Epoxidation of Alkenes, and Conversion of Enamines to α-Hydroxyketones

Mercier, Eric A.; Smith, Chris; Parvez, Masood; Back, Thomas G.

doi:10.1021/jo300313v

Cited by 46 publications

(38 citation statements)

References 108 publications

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“…α-Methylstyrene oxide was converted to acetophenone under the reaction conditions, while α-methylstyrenediol did not react. Oxidations of morpholinyl enamines proceeds by the initial formation of diaminodioxanes, which are hydrolyzed in situ to give α-hydroxyketones such as 2-hydroxycyclohexanone [152].…”

Section: Organoselenium Compounds As Oxidizing Agents and Oxidatiomentioning

confidence: 99%

Developments in Synthetic Application of Selenium(IV) Oxide and Organoselenium Compounds as Oxygen Donors and Oxygen-Transfer Agents

2015

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A variety of selenium compounds were proven to be useful reagents and catalysts for organic synthesis over the past several decades. The most interesting aspect, which emerged in recent years, concerns application of hydroperoxide/selenium(IV) oxide and hydroperoxide/organoselenium catalyst systems, as "green reagents" for the oxidation of different organic functional groups. The topic of oxidations catalyzed by organoselenium derivatives has rapidly expanded in the last fifteen years This paper is devoted to the synthetic applications of the oxidation reactions mediated by selenium compounds such as selenium(IV) oxide, areneseleninic acids, their anhydrides, selenides, diselenides, benzisoselenazol-3(2H)-ones and other less often used other organoselenium compounds. All these compounds have been successfully applied for various oxidations useful in practical organic syntheses such as epoxidation, 1,2-dihydroxylation, and α-oxyfunctionalization of alkenes, as well as for ring contraction of cycloalkanones, conversion of halomethyl, hydroxymethyl or active methylene groups into formyl groups, oxidation of carbonyl compounds into carboxylic acids and/or lactones, sulfides into sulfoxides, and secondary amines into nitrones and regeneration of parent carbonyl compounds from their azomethine derivatives. Other reactions such as dehydrogenation and aromatization, active carbon-carbon bond cleavage, oxidative amidation, bromolactonization and oxidation of bromide for subsequent reactions with alkenes are also successfully mediated by selenium (IV) oxide or organoselenium compounds. The oxidation mechanisms of ionic or free radical character depending on the substrate and oxidant are discussed. Coverage of the literature up to early OPEN ACCESSMolecules 2015, 20 10206 2015 is provided. Links have been made to reviews that summarize earlier literature and to the methods of preparation of organoselenium reagents and catalysts.

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Section: Organoselenium Compounds As Oxidizing Agents and Oxidatiomentioning

confidence: 99%

Developments in Synthetic Application of Selenium(IV) Oxide and Organoselenium Compounds as Oxygen Donors and Oxygen-Transfer Agents

2015

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“…In order to gain further insight into this process, which has both biological relevance for these and other GPx mimetics, as well as potential synthetic utility, we embarked on a further study of the oxidation of dibenzyl disulfide with hydrogen peroxide in the presence of 1 , as well as its extension to a variety of other symmetrical and unsymmetrical disulfides. It is also worth noting that 1 is an effective catalyst for the oxidation of sulfides to sulfoxides, alkenes to epoxides and enamines to α-hydroxy ketones (Scheme 2) [19].…”

Section: Introductionmentioning

confidence: 99%

Oxidation of Disulfides to Thiolsulfinates with Hydrogen Peroxide and a Cyclic Seleninate Ester Catalyst

et al. 2015

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Cyclic seleninate esters function as mimetics of the antioxidant selenoenzyme glutathione peroxidase. They catalyze the reduction of harmful peroxides with thiols, which are converted to disulfides in the process. The possibility that the seleninate esters could also catalyze the further oxidation of disulfides to thiolsulfinates and other overoxidation products under these conditions was investigated. This has ramifications in potential medicinal applications of seleninate esters because of the possibility of catalyzing the unwanted oxidation of disulfide-containing spectator peptides and proteins. A variety of aryl and alkyl disulfides underwent facile oxidation with hydrogen peroxide in the presence of catalytic benzo-1,2-oxaselenolane Se-oxide affording the corresponding thiolsulfinates as the principal products. Unsymmetrical disulfides typically afforded mixtures of regioisomers. Lipoic acid and N,N′-dibenzoylcystine dimethyl ester were oxidized readily under similar conditions. Although isolated yields of the product thiolsulfinates were generally modest, these experiments demonstrate that the method nevertheless has preparative value because of its mild conditions. The results also confirm the possibility that cyclic seleninate esters could catalyze the further undesired oxidation of disulfides in vivo.

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“…Apart from the undesired deactivating effect of selenenyl sulfide formation noted previously, this indicates that the seleninate esters could also be capable of oxidizing other disulfide bonds, possibly including those of native proteins and peptides in vivo, resulting in potentially deleterious effects. Indeed, in related work, it was found that 10 a can catalyze the oxidation of sulfides to sulfoxides, alkenes to epoxides and enamines to α‐hydroxy ketones in a preparatively useful manner, while the similar oxidation of various disulfides to thiolsulfinates provides synthetic access to the latter class of compounds …”

Section: Cyclic Seleninate Estersmentioning

confidence: 99%

Cyclic Seleninate Esters, Spirodioxyselenuranes and Related Compounds: New Classes of Biological Antioxidants That Emulate Glutathione Peroxidase

Sands

Tuck

Back

2018

Chemistry A European J

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Selenium compounds play an important role in redox homeostasis in living organisms. One of their major functions is to suppress the harmful effects of hydrogen peroxide, hydroperoxides and downstream reactive oxygen species that lead to oxidative stress, which has in turn been implicated in many diseases and degenerative conditions. The glutathione peroxidase (GPx) family of selenoenzymes plays a key protective role by catalyzing the reduction of peroxides with glutathione. Considerable effort has been expended toward the discovery of small-molecule selenium compounds that mimic GPx. To date, ebselen has been the most widely studied such compound, including in several clinical trials. However, despite its proven lack of significant toxicity, it displays only moderate catalytic activity and very poor aqueous solubility. The cyclic seleninate esters and spirodioxyselenuranes have recently been investigated as potential next generation GPx mimetics, along with structurally related selenenate esters, diazaselenuranes and pincer selenuranes. Their catalytic activities, redox mechanisms and structure-activity relationships are described in this Review, along with a description and discussion of the relative merits of assays for measuring their activities.

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Cyclic Seleninate Esters as Catalysts for the Oxidation of Sulfides to Sulfoxides, Epoxidation of Alkenes, and Conversion of Enamines to α-Hydroxyketones

Cited by 46 publications

References 108 publications

Developments in Synthetic Application of Selenium(IV) Oxide and Organoselenium Compounds as Oxygen Donors and Oxygen-Transfer Agents

Developments in Synthetic Application of Selenium(IV) Oxide and Organoselenium Compounds as Oxygen Donors and Oxygen-Transfer Agents

Oxidation of Disulfides to Thiolsulfinates with Hydrogen Peroxide and a Cyclic Seleninate Ester Catalyst

Cyclic Seleninate Esters, Spirodioxyselenuranes and Related Compounds: New Classes of Biological Antioxidants That Emulate Glutathione Peroxidase

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