Reduction of nitrosoarene ligands in binuclear palladium(ii) complexes

Reduction of the binuclear Pd^II complexes Pd₂(OCOR)₂(o-CH₂C₆H₄—NO)₂ (1) and Pd₂(OCOR)₂(o-PhN—C₆H₄—NO)₂ (2) (where R = Me, CF₃, Bu^t, or Ph) by sodium borohydride, an ethanolic solution of KOH, or molecular hydrogen was examined. The first stage of reduction was demonstrated to afford metallic palladium and aromatic amines, viz., o-toluidine o-Me—C₆H₄—NH₂ from complex 1 and aniline Ph—NH₂ from complex 2. The reactions with molecular hydrogen involve deeper stages to yield cyclic ketones (o-methylcyclohexanone and cyclohexanone) and then cycloalkanes (methylcyclohexane and cyclohexane, respectively). The latter reactions are accompanied by elimination of N₂. The mechanism of reduction of complexes 1 and 2 with molecular hydrogen was proposed.     

焦炉烟气中有机污染物的GC-MS测定

以玻璃纤维滤膜采集焦炉烟气样品,比较了索氏提取和超声波提取两种前处理方法效果,用ＧＣ－ＭＳ法进行分析研究,检出苯并「ａ」芘等多种多环芳烃类有机污染物,并对部分化合物进行了定量分析。     

The Regioselective Methylation of Polycyclic Aromatic Hydrocarbons through Tricarbonylchromium Coordination

Deprotonation, methylation, and air oxidation of polycyclic arenes coordinated to chromium(0), (η⁶-arene)Cr(CO)₃, produced ring-methylated products with high selectivity and in good yield. This procedure gave 3-methylbenz[a]anthracene from (η⁶-benz[a]anthracene)Cr(CO)₃, 3-methylphenanthrene from (η⁶-phenanthrene)Cr(CO)₃, 2-acetyl-6-methylphenanthrene from (η^6?2-acetylphenanthrene)Cr(CO)₃, and 3,7,12-trimethylbenz[a]anthracene from (η^6?7,12-dimethylbenz[a]anthracene)Cr(CO)₃.     

Heterogeneous catalytic transformation of isobutyl benzoate by the inverse Tishchenko reaction

Using the catalytic transformation of isobutyl benzoate at 663 K in the presence of 12 % MnO₂/-Al₂O₃ in a He atmosphere as an example, it has been shown that the inverse Tishchenko reaction can take place at a temperature above 600 K. Isobutyl benzoate gives isobutanal and benzaldehyde as well as products of their transformation,i.e., benzyl isobutyrate, isobutanol, benzyl alcohol, and toluene.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 8, pp. 1494–1496, August, 1994.     

Dechlorination of Aromatic Chlorides in Aqueous System Catalyzed by Functionalized MontK10 Supported Palladium—tin

A novel bisupporter binetal catalyst PVP-PdCl2-SnCl4/MonK10-PEG400,using for dehalogenation of insoluable aromatic halides in aqueous system,has shown high dechlorination activity and selectivity,without any organic solvent or phase transfer catalyst.The conversion of aromatic chlorides can reach 100%.The catalyst is easy to prepare and has good reusability.     

酚酞芳香酯环状二聚体核磁共振谱

报道了酚酞芳香酯环状二聚体核磁共振氢 和碳谱，通过与模型化合物标准谱图的比较以及化学位移取代基效应的计算，归属了其碳谱和氢谱峰。     

Dynamics of contact radical ion pairs C60—aromatic amines. A study by picosecond laser photolysis

Charge transfer complexes between C₆₀ and ternary aromatic amines (N,N,N,N-tetramethyl-p-phenylenediamine,p-methoxy-N,N-dimethylaniline,p-methyl-N,N-dimethylaniline,N,N-diethylaniline,N,N-dimethylaniline, and triphenylamine) were studied in chlorobenzene solutions. The lifetimes of the excited state with charge transfer in these complexes were measured by the method of picosecond laser photolysis. The dependence of the rate constant of the back electron transfer on G in the back electron transfer reaction with relaxation of the charge-transfer state exhibits the Marcus-inverted region.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 6, pp. 1078–1089, June, 1995.The authors are grateful to D. V. Khudyakov and I. V. Rubtsov for help in experiments and to A. S. Lobach for the C₆₀ supplied.The work was financially supported by the Russian Foundation for Basic Research (Projects No. 93-03-05254 and 93-03-0217).     

Fully regio- and endo-stereoselective synthesis of new polycyclic allylic sulfides via a Diels-Alder reaction. Synthetically useful transformations of these sulfides

Thermal and Lewis acid catalyzed cycloadditions of (Z)-1,2-diheterosubstituted-1,3-dienes to a variety of dienophiles are described. Both endo/exo and regioselectivity have been investigated. In all cases cycloaddition reactions exhibited full regio- and endo-stereoselectivity. The obtained cycloadducts are new polycyclic allylic sulfides carrying much structural and stereochemical informations. Work on transformation of the adducts, mainly to the corresponding new 1,3-dienes and aromatic compounds, is also presented.     

Preparation and properties of novel soluble aromatic polyimides from 4,4′-diaminotriphenylamine and aromatic tetracarboxylic dianhydrides

New aromatic polyimides containing triphenylamine unit were prepared by two different methods, i.e., a conventional two-step method starting from 4,4′-diaminotriphenylamine and aromatic tetracarboxylic dianhydrides and the one-step thioanhydride method starting from the aromatic diamine and aromatic tetracarboxylic dithioanhydrides. Both procedures yielded high-molecular-weight polyimides with inherent viscosities of 0.47–1.17 dL/g. Some of these polymers were soluble in organic solvents such as N,N-dimethylacetamide, N-methyl-2-pyrrolidone, m-cresol, and pyridine. All the polyimides afforded transparent, flexible, and tough films, and the color varied from pale yellow to dark red, depending markedly on the tetracarboxylic acid components. The glass transition temperatures (T_gs) of these polyimides were in the range of 287–331°C and the 10% weight loss temperatures were above 520°C in air. The polyimides prepared by the one-step method exhibited better solubility in organic solvents and had somewhat lower T_gs than the polymers prepared by a conventional two-step method.     

Molecular iodine-catalyzed efficient and highly rapid synthesis of bis(indolyl)methanes under mild conditions

Highly rapid and efficient electrophilic substitution reactions of indoles with various aldehydes and ketones were carried out using I₂ in CH₃CN to afford the corresponding bis(indolyl)methanes in excellent yields.