Intramolecular condensation of nitro group with olefinic double bond

Conclusions A new reaction of nitro compounds was discovered on the example of the thermal isomerization of unsaturated nitrocarbinols and nitrodihydropyrans, consisting in the intramolecular addition of the nitro group to the olefinic double bond with the formation of the heterolytic 1,3,2-dioxazoline system.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 2, pp. 370–378, February, 1968.     

Synthesis of novel asymmetric dendritic‐linear‐dendritic block copolymers via “living” anionic polymerization of ethylene oxide initiated by dendritic macroinitiators

The first synthesis of asymmetric dendritic‐linear‐dendritic ABC block copolymers, that contain a linear B block and dissimilar A and C dendritic fragments is reported. Third generation poly(benzyl ether) monodendrons having benzyl alcohol moiety at their “focal” point were activated by quantitative titration with organometallic anions and the resulting alkoxides were used as initiators in the “living” ring‐opening polymerization of ethylene oxide. The reaction proceeded in controlled fashion at 40–50 °C affording linear‐dendritic AB block copolymers with predictable molecular weights (M_w = 6000–13,000) and narrow molecular weight distributions (M_w/M_n = 1.02–1.04). The propagation process was monitored by size‐exclusion chromatography with multiple detection. The resulting “living” copolymers were terminated by reaction either with HCl/tetrahydrofuran or with a reactive monodendron that differed from the initiating dendron not only in size, but also in chemical composition. The asymmetric triblock copolymers follow a peculiar structure‐induced self‐assembly pattern in block‐selective solvents as evidenced by size‐exclusion chromatography in combination with multi‐angle light scattering. © 2007 Wiley Periodicals, Inc. J Polym Sci Part A: Polym Chem 45: 5136–5148, 2007     

Measurement of longitudinal structure of hadron showers up to twenty nuclear interaction lengths

Longitudinal profiles of pion and proton showers are measured, up to 20 nuclear interaction lengths at the energies of 20–180 GeV, Measurements have been performed in the iron-scintillation hadron Tile calorimeter of the ATLAS Project on the beams of the Super Proton Synchrotron (SPS) at the European Organization of Nuclear Research (CERN). Comparative analysis of longitudinal profiles of pion and proton showers was made. The experimental data were parameterized and compared with the results of Monte-Carlo simulation.     

Michael Condensation in a Two-Phase System: The Application of Inverse Phase-Transfer Catalysis to the Reaction of Butyl Acrylate with Diethylamine in a Water–Heptane System

The kinetics of a heterogeneous reaction of fat-soluble butyl acrylate (BA) with water-soluble diethylamine (DEA) in a two-phase water–heptane system in the presence and absence of small amounts of water-soluble surfactants was studied by the methods of inverse phase-transfer and interfacial catalysis. It was found that the rate of the reaction in either a homogeneous medium or the two-phase system is described by the same equation, w ₀ = k[BA]₀[DEA]₀. The influences of the type and concentration of surfactant, temperature, stirring rate, interfacial surface area, and degree of dispersion on the reaction rate were studied. The rate of the reaction of BA with DEA in the presence of a cationic surfactant (dodecyltrimethylammonium bromide) increased by almost two orders of magnitude in the two-phase system at high stirring rates.     

Catalytic synthesis of aziridine from 1,2-diaminoethane

The contact conversion of 1,2-diaminoethane over a tungsten trioxide catalyst at 240–580°C has been studied by an impulse chromatographic method. The basic reaction path under these conditions is unimolecular deaminocyclization to give aziridine (31–35%). Piperazine and triethylenediamine, products of bi- and trimolecular deaminocyclization, are present as products. The deamination process is accompanied by coupled dehydrogenation and hydrogenolysis reactions. Addition of the acid anhydrides SiO₂, P₂O₅ and B₂O₃ to the catalyst increases its activity but has only a negligible affect on the activation energy of the process.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 10, pp. 1324–1332, October, 1993.     

Dicobalt hexacarbonyl complexes of conjugated enynes as equivalents of tetradentate synthons for the preparation of bicyclo [3.3.0] octanes

A method has been developed for the acylation of dicobalt hexacarbonyl (DCHC) complexes of conjugated enynes with , -unsaturated acylium salts as a general route to DCHC complexes of 3-keto-1,6-enynes. Conditions have been found for the selective Grignard reaction or hydride reduction of the carbonyl group of the latter. The method has been found to be applicable to [2+2+1]-cycloaddition at a sorbent surface for the DCHC complexes of a variety of functionally substituted 1,6-enyne substrates. A novel convergent strategy is proposed for the synthesis of substituted bicyclo[3.3.0]octanes by steps involving cationic acylation of the DCHC complexes of conjugated enynes with ,-unsaturated acylium salts, modification of the carbonyl function in the resulting adducts and intramolecular [2+2+1]-cycloaddition.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2756–2764, December, 1989.