Phenyl Vinyl Ether Research Articles

Thermal decomposition behavior of 1,2-bis-(2,4,6-tribromophenoxy)ethane

The thermal decomposition behavior of 1,2-bis-(2,4,6-tribromophenoxy)ethane (BTBPE) widely used as flame retardant plastics additive was studied by HRTG and differential scanning calorimetries. It was pyrolysed in inert atmosphere at 240 and 340 °C in isothermal conditions, the decomposition products were collected and investigated by means of IR and GC-MS, most of them are identified. It was found that BTBPE mostly evaporates at 240 °C. The decomposition products at 340 °C depend on rate of their removal from the hot reaction zone. Main primary decomposition products found in case of rapid removal are tribromophenol and vinyl tribromophenyl ether. Whereas, prolonged contact with heating zone also produces hydrogen bromide, ethylene bromide, polybrominated vinyl phenyl ethers and diphenyl ethers, and dibenzodioxins. The nature of the identified compounds are in accordance with a molecular and radical pyrolysis reaction pathway.

Synthesis of Vinyl Phenyl Ether and Its Use for Ammetric Titration of Silver(I)

Catalytic vinylation of phenol with acetylene at atmospheric pressure was studied. The yield of vinyl phenyl ether was determined as influenced by the solvent, reaction temperature, and catalyst amount. The mechanism of formation of vinyl phenyl ether was proposed. Ammetric titration of silver(I) with a solution of vinyl phenyl ether in nonaqueous acetic acid solutions was performed.

Phosphonates as non-salt-type latent initiators for vinyl ether polymerization

Phosphonates, O, O-di-1-phenylethyl phenylphosphonate ( 1), O, O-di- tert-butyl phenylphosphonate ( 2), and O, O-dicyclohexyl phenylphosphonate ( 3), were examined as non-salt-type latent initiators in the polymerization of isobutyl vinyl ether (IBVE), phenyl vinyl ether (PVE), and tri(ethylene glycol) divinyl ether (DVE-3). The polymerization of IBVE and PVE did not proceed below 90 and 120°C, but rapidly proceeded above these temperatures with 1, respectively. DVE-3 cured with 1 quantitatively at 150°C for 12 h to afford brown gel insoluble in common organic solvents. The phosphonates served as novel non-salt-type latent initiators in the polymerization of the vinyl ether monomers.

Applicability of vinyl phenyl ether as reagent in nonaqueous voltammetry

Applicability of vinyl phenyl ether as reagent in nonaqueous voltammetry

Carbon–oxygen and carbon–sulfur bond activation of vinyl esters, ethers and sulfides by low valent ruthenium complexes †

[Ru(cod)(cot)] (1) (cod: 1,5-cyclooctadiene, cot: 1,3,5-cyclooctatriene) reacts with phenyl vinyl ether and vinyl sulfides in the presence of the bidentate depe ligand affording the zerovalent (η2-vinyl ether or sulfide)ruthenium(0) complexes, [Ru(η2-C2H3YR)(cod)(depe)] [RY = PhO (2a), PhS (2b), PhCH2S (2c), EtS (2d), Me2CHS (2e), depe: 1,2-bis(diethylphosphino)ethane]. Whereas the vinyl ether or sulfide ligand is selectively displaced in 2a, 2d and 2e by monodentate phosphines giving [Ru(cod)(depe)L] [L = PMe3 (3a), PMe2Ph (3b)], partial exchange reactions of either the vinyl sulfide ligand or cod take place for 2b and 2c affording 3a and b and [Ru(η2-C2H3SR)(depe)(L)2] [L = PMe3, R = Ph (4a), L = PMe2Ph, R = Ph (4b); L = PMe3, R = CH2Ph (4c)]. The intermolecular C–S bond cleavage takes place in 4a promoted by MeI to form [Ru(I)(η1-C2H3)(depe)(PMe3)2] 5 with liberation of MeSPh. On the other hand, reactions of 1 with vinyl carboxylates in the presence of tertiary phosphines such as PMe3, PEt3 or depe give a series of (η1-vinyl)ruthenium(II) complexes cis-[Ru(η1-C2H3)(η1-OCOR′)(PMe3)4] [R′ = Me (6a), Et (6b), tBu (6c), Ph (6d)], mer-[Ru(η1-C2H3)(η2-OCOR′)(PEt3)3] [R′ = Me (7a), Et (7b), tBu (7c), Ph (7d), C(Me)CH2 (7e)], trans-[Ru(η1-C2H3)(η1-OCOR′)(depe)2] [R′ = Me (8a), Et (8b), tBu (8c), Ph (8d), C(Me)CH2 (8e)]. The structures of 2a, 2b, 3a, and 8a have been determined by X-ray crystallography. A mechanism including prior co-ordination of the vinylic moiety has been proposed for the C–O bond cleavage reaction on ruthenium(0).

Synthesis and Ligand Exchange Control of Ru(η2-C2H3YPh)(cod)(depe) (Y = O, S)

Abstract Reaction of Ru(cod)(cot) (1) [cod: 1,5-cyclooctadiene, cot: 1,3,5-cyclooctatriene] with phenyl vinyl sulfide or ether in the presence of depe [1,2-bis(diethylphosphino)ethane] gives the new complexes Ru(η2-C2H3YPh)(cod)(depe) [Y = S (2), O (3)]. Upon reaction with PMe3, selective ligand exchange of PhOC2H3 takes place exclusively in 3 to give Ru(cod)(depe)(PMe3) (4), whereas 2 gives exchange reaction of either PhSC2H3 or cod giving 4 or Ru(η2-C2H3SPh)(PMe3)2(depe) (5).

Organolithium reagents from alkyl phenyl ethers

The reaction of primary alkyl or vinyl phenyl ethers ( 1) as well as 2,3-dihydrobenzofuran ( 3) with an excess of lithium powder and a catalytic amount of DTBB (5 %) in THF at room temperature leads to the corresponding organolithium intermediates, which by treatment with different electrophiles [H 2O, D 2O, Me 3SiCl, Bu tCHO, PhCHO, Me 2CO, Et 2CO, (CH 2) 4CO, PCH 2) 5CO, PhCOMe] and final hydrolysis affords the expected products 2 and 4.

Synthesis of β-Alkoxy Ketones and α‘-Functionalized β-Alkoxy Ketones Utilizing Benzotriazole-Stabilized Acyl Anion Synthons

1-(α-Alkoxyalkyl)benzotriazoles 1a−d add to phenyl vinyl ether to form key intermediates 4a−d, which readily undergo lithiation and subsequent trapping by a variety of electrophiles to give the expected substituted derivatives 7a−d, 9a−c, 11, 13, 15, and 18 in high yields. Subsequent hydrolysis of these compounds provides a novel high-yield acyl anion synthon approach for the synthesis of β-alkoxy ketones 8 or α‘-functionalized β-alkoxy ketones 10, 12, 14, 16, and 19 by short procedures from readily available starting materials.

Carbon−Oxygen Bond Strength in Diphenyl Ether and Phenyl Vinyl Ether: An Experimental and Computational Study

The thermal decomposition of gaseous diphenyl ether (DPE) and phenyl vinyl ether (PVE) has been studied, at atmospheric pressure in hydrogen and in a very low-pressure reactor, over a temperature range of 1050−1200 K. The high-pressure rate constant for homolytic bond cleavage C6H5O−C6H5 → C6H5O• + C6H5• (1) obeys k1 (s-1) = 1015.50 exp(−75.7/RT). Two pathways can be distinguished for C6H5OC2H3: C6H5• + C2H3O• (2) and C6H5O• + C2H3• (3). The overall rate constant follows k2+3 (s-1) = 1015.50 exp(−73.3/RT). The rate ratio, v2/v3, amounts to 1.8 and appears to be temperature independent. These findings result in bond dissociation energies (BDE) at 298 K for C6H5O−C6H5, C6H5−OC2H3, and C6H5O−C2H3 of 78.8, 75.9, and 76.0 kcal mol-1, respectively. The enthalpies for reactions 1−3 have been also determined at 298 and 1130 K by ab-initio calculations using the density functional theory formalism on the B3LYP/6-31G(d) and B3LYP/6-311++G(d,p) level. Comparison between experiments and theoretical calculations reveals distinct variances (ca. 3−4 kcal mol-1) for the BDE(C−O) in aryl ethers and the BDE(O−H) in phenol and vinyl alcohol but a close agreement for the BDE(C−H) in the related hydrocarbons: toluene, benzene, and ethene.

The electrophilic, mutagenic and tumorigenic activities of phenyl and 4- nitrophenyl vinyl ethers and their epoxide metabolites

The metabolism and mutagenicity of phenyl and 4-nitrophenyl vinyl ethers (PVE and NPVE) and their epoxide metabolites, phenoxyoxirane (PO) and 2'-(4-nitro-phenoxy)oxirane (NPO), were studied including reactions with DNA and tests for carcinogenicity. PVE and NPVE were epoxidized in dry acetone by dimethyldioxirane to give high yields (95%) of the pure epoxides. The epoxides are unstable in aqueous media and in 0.1 N phosphate buffer, pH 7.4, at 37 degrees C; they had half-lives of 2.7 min (PO) and 4.4 min (NPO). These times were reduced to 1.9 min (PO) and 2.5 min (NPO) in the presence of isotonic (154 mM) chloride ion. In neutral phosphate buffer these epoxides hydrolyze to form glycolaldehyde and the corresponding phenols; in the presence of chloride ion, chloroacetaldehyde and several unknown compounds are also formed. Glycolaldehyde was also found as a hydrolysis product of the presumed epoxides generated in the hepatic microsomal oxidation of PVE and NPVE. PO and NPO reacted with DNA to form adducts that depurinated in weak acid to form 7-(2'-oxoethyl)guanine and N(2),3-ethenoguanine. PO was weakly mutagenic in Salmonella typhimurium TA1535 while NPO was much more mutagenic under the same conditions. PO and NPO were found to have mutagenic half-lives that matched their chemical half-lives. PO and NPO were found to be tumorigenic in the skin of mice after single or five initiating doses followed by multiple doses of phorbol ester (TPA). NPO was a stronger tumor initiator than PO. NPO had appreciable activity as an initiator of hepatoma formation in infant male B6C3F1 mice. Thus PO and NPO are electrophilic, mutagenic and tumorigenic metabolites of their corresponding phenyl vinyl ethers.

Synthesis and Cation-Binding Property of Copolymers with Benzo-19-crown-6 Units via Cationic Cyclocopolymerizations of 1,2-Bis[2-(2-vinyloxyethoxy)ethoxy]-benzene with Phenyl Vinyl Ether, 4-Methoxystyrene, and 9-Vinylcarbazole

Synthesis and Cation-Binding Property of Copolymers with Benzo-19-crown-6 Units via Cationic Cyclocopolymerizations of 1,2-Bis[2-(2-vinyloxyethoxy)ethoxy]-benzene with Phenyl Vinyl Ether, 4-Methoxystyrene, and 9-Vinylcarbazole

Characterization of Alternating Copolymers of Vinyl Ethers

Abstract Copolymerization of methyl 2-cyano-3-phenyl-2-propenoate (MCP) and 2-phenyl-1,1-dicyanoethene (PDE) with ethyl, n-butyl, i-butyl, 2-chloroethyl, and phenyl vinyl ethers in broad ranges of comonomer ratios always produces copolymers of an equimolar composition. The alternating structure of these copolymers was established by elemental analysis and by infrared, 1H− and 13C-NMR spectroscopy. Microstructure analysis of the copolymer of PDE and phenyl vinyl ether, as deduced from 1H and NOESY 13C-NMR data, demonstrated the formation of alternating monomer structures with different orientations of the monomer units. Additional characterization of the copolymers was carried out by DSC and TGA. The order of decreasing T g values, ethyl > phenyl > 2-chloroethyl >i-butyl >n-butyl vinyl ether, is the same for both MCP and PDE.

Hydroformylation of some functionalized olefins catalyzed by rhodium(I) complexes with pydiphos and its P-oxide

The chiral optically active pyridylphosphines pydiphos ( 10) and its P-oxide ( 11) were tested as ligands in rhodium(I) complexes to form catalysts for the enantioselective hydroformylation of some functionalized olefins. These hydroformylation reactions provide in most cases good chemo- and regioselectivity, but unsatisfactory enantioselectivity. In the hydroformylation of styrene, vinyl acetate and phenyl vinyl ether, the Rh (I) complex containing the P-oxide 11 is remarkably more active than the catalyst formed with the pyridylphosphine analogue 10.

Depletion of glutathione and hepato-toxicity caused by vinyl ethers in mice.

4-Nitrophenyl vinyl ether (NPVE) and phenyl vinyl ether (PVE) administered i.p. in mice lowered hepatic non-protein sulfhydryl (NP-SH) content, but did not elevate the serum glutamate pyruvate transaminase (GPT) activity. n-Butyl vinyl ether (BVE) showed no significant effects either on the NP-SH content or on the serum GP activity. Mice pretreated with buthionine sulfoximine were sensitive to the potential toxicity of NPVE. These results showed that aryl vinyl ethers, NPVE and PVE, are more toxic than the alkyl vinyl ether, BVE, and that glutathione plays an important role on the protection of hepatic injury by reactive metabolite(s) derived from vinyl ethers.

Cationic polymerization of vinyl monomers initiated by 10-methylphenothiazine cation radicals

A small quantity of 10-methylphenothiazine cation radical (MPT .+ ), electrochemically prepared and stocked in acetonitrile solution, initiated cationic polymerizations of n-butyl, t-butyl, and 2-methoxyethyl vinyl ethers and p-methoxystyrene, while no initiation occurred for phenyl vinyl ether, styrene, methyl methacrylate, and phenyl glycidyl ether. 1 H-NMR studies of oligomers and low molecular weight compounds isolated from the reaction mixture for the polymerization of t-butyl vinyl ether in the presence of a small amount of D 2 O indicated that electron transfer from the monomer to MPT .+ was involved in the initiation step

Radical alternating copolymerization of vinyl ethers

AbstractNew alternating equimolar copolymers of electrophilic trisubstituted ethylenes, methyl 3‐phenyl‐2‐cyanopropenoate and 2‐phenyl‐1,1‐dicyanoethene, with ethyl, n‐butyl, i‐butyl, t‐butyl, 2‐chloroethyl, and phenyl vinyl ethers were prepared by free radical initiation. Chemical compositions of the copolymers are 1 : 1 in broad ranges of monomer ratios. The copolymerization rate of both electrophilic monomers with the vinyl ethers increase in the series 2‐chloroethyl > ethyl > phenyl > n‐butyl > i‐butyl > t‐butyl. These variations in the reactivity of the vinyl ethers are discussed in terms of their preferred conformations in donor‐acceptor complexes with electrophilic trisubstituted ethylenes. © 1993 John Wiley & Sons, Inc.

1,3‐Dipolar cycloaddition reactions of some 3‐aryl‐phthalazinium‐1‐olates

AbstractThe participation of halogen substituted 3‐aryl‐phthalazinium‐1‐olates in cycloaddition reactions were studied with various olefinic and acetylenic dipolarophiles. The betaines gave the expected cycloadducts with vinyl acetate, vinyl phenyl ether, and vinyl phenyl sulfide. However, two isomeric products were obtained with diethyl acetylenedicarboxylate. One of them was the normal expected cycloadduct and the other one was the rearranged cycloadduct. On the other hand, reactions with phenyl acetylene produced only the rearranged cycloadducts.

Enantiodifferentiating photocyclodimerization of phenyl vinyl ethers and 4-methoxystyrene sensitized by chiral aromatic esters

Enantiodifferentiating [2+2] photocyclodimerizations of phenyl vinyl ethers ( 1 and 2) and 4-methoxystyrene ( 3) were performed in acetonitrile at 25 °C in the presence of optically active menthyl or 8-phenylmenthyl arene(poly)carboxylate sensitizers ( 7– 13) to give the corresponding cyclodimers ( 4– 6) in low to good chemical yields. The optical yields of 4t and the specific rotations of 5t and 6t were quite low: less than 1% enantiomeric excess (ee) and less than 0.2° respectively. These photosensitizations with chiral sensitizers, although not sufficiently enantiodifferentiating, provide mechanistic insights into the intermediate radical ion pairs and indicate that the monomer and/or dimer radical cations involved in the cyclodimerization process are not located within reach of the stereochemical control of the counter radical anions of the chiral sensitizers.

Stereoselektivität von Photocycloadditionen, 5[1] Photoreaktionen zwischen 2‐Cyclopenten‐1‐on und Enolethern

Stereoselectivity in Photocycloaddition Reactions, 5[1]. – Photoreaction of 2‐Cyclopenten‐1‐one with Enol EthersThe regio‐ and stereoselectivity of [2 + 2] photocycloaddition reactions between 2‐cyclopenten‐1‐one (1) and the electron‐rich alkenes: ethyl, isopropyl, and phenyl vinyl ether (2–4) as well as 2,3‐dihydrofuran (10) were examined. In all cases the annulated cyclobutene derivatives 5–7 and 11 were isolated in yields between 70 and 99%. The regioisomeric HT/HH products were formed in a ratio of 3:1 to 4:1. For the determination of the product stereochemistry, INADEQUATE and 1H,1‐decoupling experiments were performed. Computer‐assisted investigations on the molecular geometry and 1H,1H‐coupling constants were performed by using semiempirical methods (AM1, FINITE). The HT regioisomers were formed with moderate endo diastereoselectivity, whereas in the case of the HH regioisomers both diastereomers (exo/endo) were formed in equal amounts. Photoreaction with 2,3‐dihydrofuran (10) led to almost exclusive formation of exo‐diastereomeric HH and HT regioisomers 11. The observed stereoselectivity is rationalized by the optimal geometry of the intermediate triplet 1,4‐biradicals during intersystem crossing.

The propagation rate constants of the cationic polymerization of alkenes—part III. Indene, two vinyl ethers and general discussion

We report on the measurement of the propagation rate constants k p + of styrene, indene, phenyl vinyl ether (PhViE) and 2-chloroethyl vinyl ether (CEViE) in nitrobenzene at (mostly) 298 K with 4-ClC 6H 4CO +SbF 6 − as initiator. The dependence of the conductivity on the [4-ClC 6H 4CO +SbF 6 −] = c 0 helped to establish that [P n +] = c 0 and thus to validate the foundation of this work. It is shown that most probably the propagating species are the uncomplexed, unpaired, solvated carbenium ions. Some new enthalpies of polymerization have been found. Monomer Styrene Indene PhViE CEViE k p +/dm 3·mol −1·sec −1 195±15 373±15 1450±200 ca10 4 −ΔH p/kJ·mol −1 64±2.5 56±0.5 110±10 80±8