- Negative-working photosensitive poly(phenylene ether) based on poly(2,6-dimethyl-1,4-phenylene ether), a cross-linker, and a photoacid generator
-
A novel benzyl cation type cross-linker, hex-1,6-ylenebis[oxy(2,4,6- tris(acetyloxymethyl)-3,5-dimethylbenzene)] (HOAD), that suppresses acid-catalyzed self-polycondensation has been developed. Furthermore, a negative-working, photosensitive poly(phenylen
- Mizoguchi, Katsuhisa,Higashihara, Tomoya,Ueda, Mitsuru
-
experimental part
p. 2832 - 2839
(2011/10/09)
-
- Remarkable effect of water on functionalization of the phenyl ring in methyl-substituted benzene derivatives with F-TEDA-BF4
-
Various N-F reagents reacted with hexamethylbenzene (1) forming side chain substituted alkoxides or esters in protic solvents, Ritter type side chain functionalization was observed in acetonitrile in the presence of trifluoroacetic acid, while in aqueous
- Kralj, Petra,Zupan, Marko,Stavber, Stojan
-
p. 3880 - 3888
(2007/10/03)
-
- Effective and versatile functionalisation of hexamethylbenzene using N-F reagents
-
Effective direct introduction of alkoxy, amido, azido or halogeno functional groups on the benzylic position in hexamethyl-benzene was mediated by the N-F reagents F-TEDA-BF4, NFTh, NFSi or FP-B800 in the presence of alcohols, carboxylic acids, cyanides or trimethylsilyl derivatives as sources of an external nucleophile.
- Stavber,Kralj,Zupan
-
p. 1152 - 1154
(2007/10/03)
-
- Attempts at Direct Detection of Reactive Species in Selective Excitation of the Contact Charge Transfer Pairs of Hexamethylbenzene and Oxygen
-
Pulsed laser excitation of contact charge transfer pairs of hexamethylbenzene (HMB) and oxygen in methanol-acetonitrile gave no evidence for intermediacy of reactive species such as HMB radical cations and penthamethylbenzyl cations (ArCH2+), though stationary irradiation of the pair in hydroxylic solvents afforded distinct products arising from the cationic species.The mechanism of reactions was discussed in comparison with 9,10-dicyanoanthracene-sensitized oxygenation of HMB.
- Komatsu, Toshiki,Tsuchiya, Masahiro,Furusawa, Gen-ichi,Kuriyama, Yasunao,Sakugari, Hirochika,et al.
-
p. 277 - 281
(2007/10/02)
-
- Electron Transfer Reactions in Organic Chemistry. VII. Oxidative Acetoxylation of Aromatic Compounds by Tungsten Hexachloride
-
Tungsten hexachloride, a high-potential oxidant, causes fast oxidative acetoxylation of ring and/or α positions of aromatic compounds, even as difficalty oxidizable ones as mesitylene and p-xylene.Chlorination is a completing reaction which cannnot be completely suppressed.The acetoxylation process in all likelihood proceeds via an electron transfer mechanism, involving initial formation of the radical cation of the substrate.
- Eberson, Lennart,Joensson, Lennart,Saenneskog, Owe
-
p. 113 - 122
(2007/10/02)
-
- OXIDATION OF HEXAMETHYLBENZENE AND 2,3,4,5,6-PENTAMETHYLBENZYL CATION IN FLUOROSULFONIC ACID
-
The oxidation of hexamethylbenzene in HSO3F-PbO2 takes place with the participation of the 1-H+-1,2,3,4,5,6-hexamethylbenzenonium ion and the intermediate formation of the 2,3,4,5,6-pentamethylbenzyl cation, which is capable of entering into further oxidative transformations leading to substitution of the hydrogen atom in two and three methyl groups.The structure of the final products from the observed transformations were established, and a mechanism is proposed for their formation.
- Rudenko, A. P.,Zarubin, M. Ya.,Fedorova, E. M.
-
p. 1609 - 1618
(2007/10/02)
-
- The Liquid-phase Oxidation of the Methylbenzenes by the Cobalt-Copper-Bromide System
-
The liquid-phase oxidation of the methylbenzenes catalyzed by a catalyst system composed of cobalt(II) and copper(II) acetates and sodium bromide was carried out in the acetic acid at 150 deg C.The corresponding benzyl acetates and benzaldehydes were obtained in high selectivities in most cases.A nuclear-brominated product, i.e., 3-bromo-4-methoxytoluene was also obtained in the oxidation of p-methoxytoluene, wich has two different reaction sites, i.e., o-positions to the electron-donating methoxyl substituent and the benzyl position.However, the substitution of the bromide ion for the acetate ion in the catalyst system gave satisfactory selectivities for the side-chain oxidation products.In the p-xylene oxidation, α,α'-diacetoxy-p-xylene and p-(acetoxymethyl)benzoic acid were also obtained, as well as p-methylbenzyl acetate, though their amounts were small.The oxidation of polymethylbenzenes was also carried out.
- Okada, Toshihiko,Kamiya, Yoshio
-
p. 2724 - 2727
(2007/10/02)
-
- Metal Ion Oxidation. VII. Oxidation of Aromatic Hydrocarbons by Potassium 12-Wolframocobalt(III)ate, a "Soluble Anode"
-
The oxidation of aromatic compounds with potassium 12-wolframocobalt(II)ate in acetic acid media has been investigated.A wide range of alkylaromatics can be acetoxylated in the α position, whereas nuclear substitution can be effected in the presence of acetate ion.In a few cases acetoxymethylation is observed, presumably via intermediate arylacetic acid. 4-Fluoroanisole is converted to 4-acetoxyanisole.In all preparative aspects, the reaction is closely similar to anodic and Ag(II) mediated acetoxylation.A study of substituted effects upon α acetoxylation showed a good linear relationship between log krel and Eo for oxidation of the alkylaromatic substrates (slope -3.2 V-1).A strong deuterium isotope effect (KH/kD ca. 6) is indicative of a rate-determining step involving hydrogen atom transfer ("concerted electron/proton transfer") from the α C-H bond to an oxygen of the heteropoly ion.
- Eberson, Lennart,Wistrand, Lars-Goeran
-
p. 349 - 358
(2007/10/02)
-