Polyvinylpolypyrrolidone-Bromine Complex, Mild and Efficient Polymeric Reagent for Selective Deprotection and Oxidative Deprotection of Silylethers

Lakouraj, Moslem Mansour; Mokhtary, Masoud

doi:10.2174/157017807780037379

Cited by 15 publications

(4 citation statements)

References 29 publications

(28 reference statements)

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“…There are a number of families of polymeric systems capable of acting as oxidants . Among them, polymer-bound halogenating and oxidizing agents such as halamines (halogenated imide, amide, or amine groups), pyridine- and pyrrolidone-based molecular halogen complexes, and ion-exchange resins in anionic form, seem to be quite amenable for utilization in protective materials and industrial collective and individual protective equipment due to their compatibility with a variety of other polymeric matrices and a great multitude of available processing options. − There is a significant body of literature related to the utilization of N -haloamines as biocidal, antiseptic, halogenating and oxidizing agents in polymeric coatings, resins, fibers, paints, etc. − Pyrrolidone-based molecular halogen complexes such as poly( N -vinylpyrrolidone) (PVP)-bromine complexes have been utilized in alcohol and acetal oxidation, alkene dibromination, oxidative cleavage of silyl ethers, and conversion of dithioacetals to oxothioesters. − Functionality of PVP stems from its hydrophilicity, benign nature, film-forming properties, ease of cross-linking, and ability to form adduct-type complexes with halogens. , PVP-based networks are water-dispersible and can be synthesized in situ by UV-initiated polymerization. Monomer and cross-linker solutions of such systems can be applied to porous surfaces such as in textiles by either batch coating or dip coating, followed by cross-linking and halogenation .…”

Section: Introductionmentioning

confidence: 99%

Degradation of Chemical Threats by Brominated Polymer Networks

Bromberg

Pomerantz

Schreuder-Gibson

et al. 2014

Ind. Eng. Chem. Res.

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Poly(N-bromomaleimide) (PMAi-Br), poly(N-vinylpyrrolidone)-bromine adducts (PVP–Br), and poly(ethylene-alt-N-bromomaleimide) (PEMAi-Br) and their cross-linked networks are introduced as reactive, self-decontaminating components of protective barriers. Synthetic routes toward polymaleimides include free-radical copolymerization of maleimide with divinyl cross-linkers as well as amidation of poly(ethylene-alt-maleic anhydride) with urea. The polymers are brominated by bromine in carbon tetrachloride or by copper(II) bromide in dimethylformamide, with the active bromine contents up to and above 4 mequiv/g, or >30 wt %. The brominated polymer networks exhibit considerable swelling in water and possess reversible redox peak potentials in cyclic voltammetry experiments due to the redox reactions of the bromine present in the polymer structures. In acidic aqueous media, PVP–Br, PMAi-co-DVB-Br, and PEMAi-Br materials are able to degrade 100% of hydrazine, monomethylhydrazine, and 1,1-dimethylhydrazine down to concentrations below detectable levels of 0.15–0.25 mM. The hydrazine is converted to nitrogen gas. The insecticide malathion, tested as a simulant of a combat warfare agent VX, is efficiently and selectively oxidized to malaoxon in the presence of the brominated networks, whereas 2-(chloroethyl)ethyl sulfide (CEES), a simulant of the sulfur mustard agent, is rapidly oxidized, in both vapor and liquid states, into its less-toxic sulfone derivative, 1-chloro-2-(ethylsulfinyl)ethane (CEESO), with the only side product being 1,2-bis(ethylthio)ethane. The oxidation of CEES is proven to be selective, in that no toxic overoxidized CEES analogue, 1-chloro-2-(ethylsulfonyl)ethane, is formed. The developed brominated polymer networks are versatile materials with potential applications in coatings, filters, fabrics, and sorbents.

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Section: Introductionmentioning

confidence: 99%

Degradation of Chemical Threats by Brominated Polymer Networks

Bromberg

Pomerantz

Schreuder-Gibson

et al. 2014

Ind. Eng. Chem. Res.

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“…The formation of the same lactone compound can be explained by the fact that the reaction does not proceed similarly to compound 7 as a result of the removal of the silyl group in compound 10 under the reaction conditions. It is predicted that the reaction takes place through the mechanism given in Scheme . − …”

Section: Resultsmentioning

confidence: 99%

Unusual Rearrangements in Cyclohex-3-ene-1-carboxamide Derivatives: Pathway to Bicyclic Lactones

Gundogdu,

Aytaç,

Şahin

et al. 2024

ACS Omega

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The synthesis of new bicyclic lactone derivatives was carried out starting from 2-methyl/phenyl-3a,4,7,7a-tetrahydro-1H-isoindole-1,3(2H)-dione. 6-(Hydroxymethyl)-N-methyl/phenylcyclohex-3-ene-1-carboxamide derivatives were obtained from the reduction of tetrahydro-1H-isoindole-1,3(2H)-diones with NaBH4. Bromination and epoxidation reactions of both compounds were examined, and the structures of the resulting products were determined by spectroscopic methods. Substituted bicyclic lactone compounds, which are interesting rearrangement products in both bromination and epoxidation reactions, were obtained. In particular, hydroxymethyl (−CH2OH) and amide (−CONHR) groups attached to the cyclohexene ring in the bromination and epoxidation reactions were found to be effective in product formation. As a result, a new and applicable method was developed for the synthesis of bicyclic lactone derivatives.

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“…Selective oxidation of benzyl alcohol in the presence of 2-phenylethanol was also achieved at room temperature in the presence of PVP-Br 2 (Scheme 3). In the next research, Lakouraj and Mokhtary have developed a convenient method for deprotection and direct oxidative deprotection of silylethers to the corresponding hydroxy and carbonyl compounds using polyvinylpolypyrrolidone-bromine complex (PVPP-Br 2 ) (Scheme 4) [7]. Selective oxidative deprotection of benzylic silyl ethers in the presence of primary aliphatic alcohols was also achieved at room temperature.…”

Section: Polyvinylpyrrolidone Supported Reagentsmentioning

confidence: 99%