Untersuchung des Zerfalls verschiedener Azoinitiatoren in Lösung

The decomposition of various symmetric and unsymmetric azo-initiators (1,1-dichloro-1,1-diphenyl-1,1-azoethane, 2,2-dichloro-2,2-azopropane, 1,1-dichloro-1,1-azocyclohexane, 2,2-diacetoxy-2,2-azopropane, 1,1-diacetoxy-1,1-diphenyl-1,1-azoethane, 1,1-diacetoxy-1,1-azocyclohexane, 2,2-dipropionoxy-2,2-azopropane, 2,2-dicapronoxy-2,2-azopropane, 4,4-dimethyl-1,4-azobutyrolactone, azoisobutyronitrile, 2-t-butylazo-2-cyanobutan, 2-t-bytylazo-1-cyanocyclohexan) in solution was studied in dependence of temperature. Volumetry and differential-scanning-calorimetry (DSC) were used to determine decomposition rates; first order kinetics was found in all cases.

     

Synthesis and reactivity of 3-(2-chloroalkyl)-2,2-dihaloaziridines

3-(2-Chloroalkyl)-2,2-dihaloaziridines were synthesized via cycloaddition of dihalocarbenes to the CN double bond of β-chloroimines. Under the action of Lewis acids or HCl, N-C³ bond cleavage occurred, giving rise to N-substituted 2,4-dichloro-3,3-dimethylbutanamides, which were further converted to 3-chloropyrrolidin-2-ones under alkaline conditions. When 2,2-dichloro-3-(2-chloro-1,1-dimethylethyl)-1-phenylaziridine was reacted with sodium methoxide, aziridine ring opening with N-C² bond cleavage took place, leading to methyl 4-chloro-3,3-dimethyl-2-(phenylamino)butanoate.     

Ferrocene derivatives,part 70: Syntheses and stereochemistry of chiral 1,1′-biferrocenyls (stereochemistry of metallocenes,part 55)

Summary 2,2-Disubstituted 1,1-biferrocenyls have been prepared by coupling of appropriate ferrocene derivatives. The stereochemistry of the diastereoisomers obtained thereby is discussed on the basis of n.m.r.-spectroscopy and in two cases (2a, b) from X-ray structure analyses. Chiroptical properties of optically active 1,1-biferrocenyls — obtained from (+)(R)-1-ferrocenyl-N,N-dimethylaminoethane — are reported. Attempts to prepare 2,2,5,5-tetrasubstituted biferrocenyls failed.Dedicated to Prof. Dr. Edwin Hengge on the occasion of his 60th birthday     

Enantioselective Catalysis. Part 156 [1]. Ruthenium Procatalysts and 2-Pyridinealdehyde/( S)- NOBIN-Derived Cocatalysts in the Transfer Hydrogenation of Acetophenone with 2-Propanol

Several ruthenium procatalysts were tested in the transfer hydrogenation of acetophenone with 2-propanol using the chiral imine ligand (S)-2-(2-pyridinylmethyleneamino)-2-hydroxy-1,1-binaphthyl and the corresponding amine (S)-2-(2-pyridinylmethylamino)-2-hydroxy-1,1-binaphthyl. Ru(PPh ₃)₃Cl₂ was the best procatalyst. Its triphenylphosphane ligands were crucial for the catalytic activity and take part in the chirality transfer. Triphenylphosphane removing reagents such as copper(I) chloride, TEMPO, or TMAO improved the catalytic performance to enantioselectivities up to 99% ee. The findings led to a mechanistic proposal including dissociation equilibria of triphenylphosphane and chelate ring opening of the tridentate chiral binaphthyl ligand. New ligands with an additional chiral center were synthesized and tested as cocatalysts. The nature of catalytically active intermediates was examined by MS and NMR spectroscopy.     

On the mechanism of formation of 1,1-dimethylpyrazolin-3-oxides

Conclusions The primary product during the acylation of N,N-dimethylhydrazine with anhydrides of,-unsaturated acids is the N,N-dimethylhydrazide of the acid, which at elevated temperatures rearranges to its tautomer — the corresponding 1,1-dimethylpyrazolin-3-oxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 917–918, April, 1970.`     

Aminomethylation of ethylferrocene

Summary Ethylferrocene was subjected to dimethylaminomethylation. The isolated products were the 1,2-,1,3- and l,l'-(N,N-dimethyIaminomethyl)ethylferrocenes, and the 1,1-di(N,N-dimethylaminomethyl)-2- and -3-ethylferrocenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 12, pp. 2239–2240, December, 1966.     

Metalation of methoxy- and 1,1′-dimethoxyferrocenes

Conclusions 1-Methoxyferrocene-2-carboxylic acid, 1,1-dimethoxyferrocene-2-carboxylic acid, and 2-methoxy-ferrocenyl diphenyl carbinol have been obtained via the lithium derivatives of methoxy- and 1,1-dimeth-oxyferrocenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1867–1869, August, 1967.The authors express their thanks to V. N. Drozd for much valuable advice in the performance of this work.     

Densities and excess molar volumes for binary mixtures of N,N-dimethylformamide+ 1,2-dimethoxyethane

Densities are reported for N,N-dimethylformamide and 1,2-dimethoxyethane binary mixtures at different mole fractions covering the whole miscibility range and at 19 temperatures ranging from –10 to 80°C. The experimental density data have been fitted by empirical relations and the excess volumes by a Redlich-Kister equation. The 11 N,N-dimethylformamide and 1,2-dimethoxyethane adduct appears to be stable throughout the temperature range. A comparison with other DMF containing mixtures is made.     

Addition of mercaptans to acetylenic γ-hydroxy ketones

Conclusions Both the nucleophilic and the free radical addition of n-butyl mercaptan to acetylenic-hydroxy ketones (1,1-disubstituted derivatives of 2-pentyn-1-ol-4-one) lead to the formation of the corresponding 1,1-disubstituted derivatives of 2-butylthio-2-penten-1-ol-4-one in 41–65% yield.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 7, pp. 1669–1670, July, 1973.     

An investigation of the structure of salts of 1,1-dinitroalkanes and trinitromethane by spectral methods

Summary An investigation of the infrared spectra showed that the salts (potassium, sodium, ammonium, and lithium) of 1,1-dinitroalkanes and trinitromethane have three absorption bands: 1480, 1210, and 1120 cm^–1. The infrared spectra do not contain absorption bands characteristic of the C=N double bond or an uncharged nitro group. Therefore, it is confirmed that salts of 1,1-dinitroalkanes and trinitromethane do not contain a C=N bond, and that all the nitro groups are equivalent and participate equally in the formation of the anion.     

Dimerization of N-(pyrid-2-YL)- and N-(5-methylpyrid-2-YL) cyanoacetamides by the action of butylthiodibutylborane

The reaction of N-(pyrid-2-yl) and N-(5-methyipyrid-2-yl) cyanoacetamides with butylthiodibutylborane in a 23 ratio leads to the formation of trinuclear complex boron compounds, the alcoholysis of which gave N,N-di(pyrid-2-yl) 3-amino-2-cyanopent-2-ene-1,5-diamides. The latter are dimers of the starting cyanamides, which are capable of acting as hexadentate chelating agents.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 168–173, January, 1991.     

Oxidation of 1-aminobenzimidazoles. Synthesis and properties of 1,1′-azobenzimidazoles

1-Amino-2-R-benzimidazoles are oxidized by lead tetraacetate to give, depending on the substituent in the 2-position, either to 1,1-azobenzimidazoles (R=H, CH₃, C₆H₅, Cl, N(CH₃)₂) or 3-R-benzo-1,2,4-triazines (R=NH₂, NHCH₃, NHC₆H₅, OH). The factors affecting the course of the reaction are discussed. The physicochemical properties of the 1,1-azobenzimidiazoles obtained have been examined.For preliminary communication, see [1].Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 11, pp. 1486–1499, November, 1989.     

Bis-(tetraethylammonium)[tetraazidocuprate(II)] and catena-di-μ-1,1-azido-[di-μ-1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)]

Two new copper(II) azido complexes, namely bis-(tetraethylammonium)[tetraazidocuprate(II)] (1) and catena-di--1,1-azido-[di--1,1-azido-bis-(2,4-dimethylpyridine)dicopper(II)] (2), have been prepared and characterized by spectroscopic and crystallographic methods. Complex (1) consists of isolated NEt⁺ ₄ cations and [Cu(N₃)₄]^2– anions. The site symmetry around the copper atom in the anion is 4/m. Complex (2) features a 1 D chain structure, five coordinated square pyramidal copper(II) atoms with both azides functioning as -1,1-bridges. The i.r. spectra reveal that both complexes contain asymmetric azido ligands. The solid and solution electronic spectra of (1) and (2) show very strong absorption bands in the visible region associated with N^– ₃ Cu^II charge-transfer transitions. The e.p.r. spectra of powder samples and solutions at room temperature were recorded and discussed.     

Fluoroindenes. 10. Cyclization of difluorocarbene to perfluoro-3-methylindene and perfluoro-1-methyleneindane. Thermolysis and bromination of the resultant cyclopropane derivatives

Conclusions Upon reaction of perfluoro-3-methylindene and perfluoro-1-methyleneindane with hexafluoropropylene oxide at 225°C the corresponding cyclopropane derivatives are formed: perfluoro-la-methyl-1,1a,6,6a-tetrahydrocycloprop[a]indene and perfluorospiro[indane-1,1-cyclopropane], which are transformed during thermolysis in the presence of bromine into 1-bromo-2-difluorobromomethylperfluoro-1-methylindane and 1-bromo-1-(2-bromotetrafluoroethyl)perfluoroindane respectively, and in the absence of bromine into the starting olefins.Deceased.For previous report, see [1].Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 8, pp. 1839–1845, August, 1988.     

Synthesis and Characterization of Solid Coordination Complexes of Diamides for Uranium(VI) and Thorium(IV)

Five kinds of solid coordination complexes of uranium(VI) and thorium(IV) with the diamide (N,N,N,N-tetrabutylmalon-amide (TBMA), N,N,N,N-tetrabutylsuccinylamide (TBSA), N,N,N,N-tetrabutylglutaramide (TBGA), N,N,N,N-tetrabutyl-adipicamide (TBAA)) were synthesized. All these complexes of UO₂(NO₃)₂·TBMA, UO₂(NO₃)₂· TBSA, [UO₂(NO₃)₂·(TBGA^1/2)₂] _x , UO₂(NO₃)₂·TBAA and Th(NO₃)₄·2TBMA were characterized by elemental analysis, UV spectra, IR spectra and ¹³C NMR spectra. The coordination form and proposed structures of the complexes are also discussed.     

Acylation of benzimidazole by the regel-buechel method. 2. Deacylation and dissociation of 1-methyl-3-acyl-2-(1′-methyl-2′-benzimidazolyl)-4-benzimidazolines

With excess acyl halide 1-methyl-3-acyl-2-(1-methyl-2-benzimidazolyl)-4-benzimidazoline is converted to an unstable 1-methyl-3-acyl-2-(1-methyl-3-acyl-4-benzimidazolin-2-yl)benzimidazolium chloride, which undergoes intramolecular redox cleavage with the formation of 1,1-dimethyl-2,2-dibenzimidazolyl and an aldehyde and dissociates at the C-C bond that connects the benzimidazolium and benzimidazoline fragments into a carbene yield and a 1-methyl-3-acylbenzimidazolium chloride.See [1] for communication 1.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 3, pp. 339–342, March, 1987.     

Reactions of 1,1-disubstituted hydrazines with derivatives ofα,β-unsaturated acids

Conclusions The reactions of 1,1-dimethylhydrazine hydrochloride with ,-unsaturated acid chlorides were studied. In this reaction l,1-dimethyl-3-oxopyrazolidinium chlorides are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 1, pp. 162–164, January, 1967.     

Synthesis of heterocycles using the products of the addition of polyhaloalkanes to unsaturated systems. 7. reactions of 5-aryl-1,1-dichloro-1,3-pentadien-5-ones and 6-aryl-2-pyrones with hydrazines

Substituted ²-pyrazolines were synthesized from 5-aryl-1,1-dichloro-1,3-pentadien-5-ones and 6-aryl-2pyrones. A detailed analysis of the¹H and¹³C NMR spectra of the starting compounds and final products was carried out.N. D. Zelinskii Institute of Organic Chemistry, Russian Academy of Sciences, 117913 Moscow. Translated from Khimiya Geterolsiklicheskikh Soedineii, No. 11. pp. 1511–1524. November, 1995. Original article submitted November 14, 1995.     

Synthesis and properties of N(7)-Β-D-glucofuranouronosides of theophyllin and 3-isobutyl-1-methylxanthine

Condensation of the trimethylsilyl derivatives of theophyllin and 3-isobutyl-1-methylxanthine with -D-glucofuranourono-6,3-lactone in the presence of trimethylsilyl trifluoromethanesulfonate has given N(₇)--D-glucofuranouronosides. Their hydrolytic stability has been examined at pH 1.4 and 7.4.Translated from Khimiya Geterotsiklicheskikh Soedinenii, No. 2, pp. 241–245, February, 1989.