Character of intermediate radicals in homolytic isomerization of cyclic acetals and their heteroanalogs

Conclusions Employing the EPR method and 2-methyl-2-nitrosopropane as the spin trap, we recorded the formation of the radicals (n = 1 and 2; X = O, N, or a chain composed of C and O atoms; R = H or alkyl) during the photolysis of acetals and their heteroanalogs in the presence of di-tertbutyl peroxide.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2097–2099, September, 1976.The authors are indebted to A. Sh. Mukhtarov for assistance in running the experiments.     

Reaction of silicon hydrides with primary aliphatic amines

Conclusions The direction of the reaction of the silicon hydrides: R₂SiH₂, RSiH₃, and with primary aliphatic amines, in the presence of catalysts based on Group VIII compounds, as a function of the structure of the silicon hydride and the nature of the employed catalyst, was established.Deceased.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 10, pp. 2330–2333, October, 1972.     

Thermische Umlagerung von Acetoxy-cyclohexadienonen, 2. Mitt.

Zusammenfassung Es wird die Frage untersucht, ob bei der thermischen Umlagerung von entsprechend allyl-substituierten o-Benzochinol-acetaten der Allyl- oder der Acetoxylrest rascher wandert. Das 2-Allyl-2-acetoxy-cyclohexadienon liefert bei der genannten Reaktion (es sind schon Temperaturen um 100° ausreichend) überwiegend ein Monoacetat des 4-Allylbrenzcatechins. Damit ist bewiesen, daß der Rest rascher als der Rest in die p-Stellung zur Carbonylgruppe des Chinolacetates wandert. Eine Wanderung des Acetoxylrestes in die o- oder in die p-Stellung zur Carbonylgruppe, welche zur Bildung von 3-Allyl-brenzcatechin bzw. 2-Allylhydrochinon führen müßte, konnte nicht beobachtet werden. Entsprechend liefert das 2,6-Diallyl-2-acetoxy-cyclohexadienon bei der thermischen Umlagerung überwiegend ein Monoacetat des 3,5-Diallyl-brenzcatechins. Nach einem anderen Mechanismus verläuft die Umlagerung des 2-Methyl-6-allyl-2-acetoxy-cyclohexadienons. Es entsteht neben wenig 2-Methyl-6-allyl-hydrochinon in der Hauptmenge ein Monoacetat des 3-Methyl-5-allyl-brenzcatechins. Es wird also die Allylgruppe durch den in die o-Stellung wandernden Acetoxylrest verdrängt. Auf diese Reaktion wird näher eingegangen, weil sie in engem Zusammenhang mit der Frage steht, ob ganz allgemein eine Umlagerung von o-Chinolacetaten vom Typ in die Isomeren möglich ist.Mit 2 AbbildungenHerrn Prof. Dr.F. Feigl zum 70. Geburtstag in alter Freundschaft!F. W. E. Zbiral, F. Wessely undE. Lahrmann, (gilt als 1. Mitt. dieser Reihe), Mh. Chem.91, 331 (1960).     

α-Ketothioketene dimers

Conclusions When,-dichlorovinyl ketones are reacted with Na₂S, NaSC(S)N(C₂H₅)₂, KSC(S)OC₂H₅, and NaSCOCH₃, two types of sulfur-containing heterocyclic compounds are formed: 1,3-dithietanes and 1,3-dithiols , at which time the ratio of the products depends on the nature of the sulfur-containing nucleophilic reagent.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 9, pp. 2940–2048, September, 1976.     

Kondensationsprodukte durch N-Aminomethylierung von Carbonsäureimiden

The common identification reaction of amines with phthalimide and formaldehyde yielding N-aminomethylimides is extended to other imides. The reaction of pyromellitic diimide with various diamines in the presence of formaldehyde leads to oligomeric products. p-Substituted aromatic diamines afford higher yields than o-substituted diamines, m-substituted diamines do not react at all according to the N-aminomethylation reaction. It was shown that imides of the following structure $$R - - \begin{array}{*{20}c} { / CH_2 CO} \\ N \\ { \setminus CH_2 CO} \\ \end{array} \begin{array}{*{20}c} \setminus \\ {NH} \\ / \\ \end{array} $$ generally do not react with formaldehyde (and amine), owing to the influence of the amine nitrogen on the imidic nitrogenhydrogen bond.     

LSER in the allylation of morpholine

The second order rate constants of allylation of morpholine are obtained conductometrically in different protic and aprotic solvents in the temperature range 303–318K. Correlation of the rate data with different solvent parameters indicates that, the reaction rate is simultaneously influenced by the hydrogen bond donor ability (α), nucelophilicity (B) and specific polarization (π*) of the solvent. Linear multiple regression analysis results in the LSER

Beitrag zur Kenntnis der Viskosezersetzung. Die Dissoziationskonstante der Cellulosexanthogensäure

Zusammenfassung Nachdem plausibel gemacht werden konnte, daß bei verschiedenen Zersetzungs- bzw. Regenerationsprozessen als Zwischenprodukt freie Cellulosexanthogensäure (CXS.) auftritt und dieselbe z. B. in vorliegender Arbeit im frisch gesponnenen Faden tatsächlich nachweisbar war, wurde auch versucht, die Dissoziationskonstante derselben abzuschätzen. Die dabei auftretenden Schwierigkeiten — sowohl hinsichtlich der experimentellen Durchführung wie auch die durch das Fehlen einer Theorie polyvalenter Makroionen — werden diskutiert. Aus mehreren unabhängigen Messungen, unter Bedachtnahme auf Ergebnisse an Celluloseglycolsäureäther vonKagawa undKatsuura, wird wahrscheinlich gemacht, daß die Dissoziationskonstante der verdünnten Säure zwischen 2,1 und 5,5·10^–5 liegt. Mithin ist die Cellulosexanthogensäure etwas stärker als Essigsäure, die im verdünnten Zustand bekanntlich Na-Cellulosexanthogenat ziemlich unzersetzt läßt^{2, 9, 12}.Abschließend wurde noch das Röntgendiagramm von präzipitiertem Na-Cellulosexanthogenat wiedergegeben.Mit 4 AbbildungenHerrn Prof. Dr.A. Skrabal zum 75. Geburtstag gewidmet.     

Telomerization of propylene with methyl propionate

Conclusions The principal products of the telomerization of propylene with methyl propionate are telomers with the structure , where n=1–4.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2534–2537, November, 1973.     

Reaction of 8-(dimethylamino)methyl-1-naphthyl phenyl silanethione with phosphorus ylides

The title silanethione reacts with phosphorus ylides under conditions of kinetic control to give betaines containing a linear fragment. Under conditions of thermodynamic control, the derivatives of phosphonium 1-silaacenaphthene-1-thiolate are formed.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2140–2141, December, 1993.     

Chemistry of 1,1,2,2-tetracyanoethane. Communication 13. Stereochemistry and structure of 5-methyl-3-(1-methyl-3-isopropoxyallyl)-1-formyl-3,4,4-tricyano-1-cyclopentene

The structure of 5-methyl-3-(1-methyl-3-isopropoxyallyl)-1-formyl-3,4,4-tricyano-1-cyclopentene was determined by an x-ray diffraction structural analysis. A discussion was given for the pseudoaxial orientation of the CN and C-H groups at the 3,5-positions, steric strain, the effect of this strain leading to a large ring flexure angle and extension of the C-C bonds, the bipolar nature of the enaminoformyl fragment, twisting of the NH₂ group due to an unusual intramolecular hydrogen bond involving the ethereal oxygen atom, the lack of extension of the bond under conditions of n_p(O)–^*(C=C) conjugation, and the conformation of the isopropyl group relative to the O-C(sp³) bond.Communication 12, see our previous work [1].Institute of Chemical Physics, Academy of Sciences of the USSR. Translated from Zhurnal Strukturnoi Khimii, Vol. 30, No. 5, pp. 108–113, September–October, 1989.     

β-Substituted cyclopropyl rádicals grafted to silica surface. Methods of preparation,structure, and properties

Cyclopropyl type radicals were identified on a surface of activated silica by ESR. The possibility of their preparation by two methods,i.e., by photocyclization of substituted allyl radicals and by interaction of cyclopropane molecules with particular surface defects, was demonstrated. The effects of -substituents on radiospectroscopic characteristics and thermal stabilities of the radicals were studied. Rate constants and activation energies of decomposition of substituted cyclopropyl radicals were estimated. The experimental data obtained were compared with the results of quantum-chemical calculations of model systems. The mechanism of photocyclization of allyl radicals was discussed. The transition states of decomposition of cyclopropyl and -fluorine-substituted cyclopropyl radicals were calculated. Electronegative substitution was found to result in a considerable decrease in the activation energy of the cyclopropane ring opening.The authors are grateful to E. G. Baskir for calling their attention to this publication.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 12, pp. 2409–2421, December, 1995.The work was carried out with financial support of the Russian Foundation for Basic Research (Project code 94-03-09137) and the International Science Foundation (Grant No. MK9000).     

PMR investigation of internal inhibited rotation in N1,N1-dimethyl-N2-trifluoro[chloro]acetylamidines of picolinic and nicotinic acids

Summary Hindered rotation around the bond in the N-acylamidines has been investigated by PMR spectroscopy, and the kinetic parameters of the hindered rotation have been determined.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 4, pp. 758–762, April, 1981.     

Synthesis of α-amino ketones

Summary A new method is described for synthesizing aromatic -amino ketones with the general formula , which is based on the condensation of azlactones with benzene in the presence of aluminum chloride.     

Die Entropien der Wasserstoffbrückenbindungen bei der Ionisation von Säuren in ihrer Beziehung zur Ionisationskonstante der Säuren,II

The author has replaced theBrönsted linear relation of the logarithm of the catalysis coefficient of the acid in the acid-base catalysis of the α-glucose mutarotation to the logarithm of the acid ionisation constant by the linear relation of the entropy change for the breaking of the hydrogen bond of the hydrated acid $$AH \ldots OH_2 = AH + OH_2 $$ to the logarithm of the base constant (reciprocal acid ionisation constant) and theBrönsted linear relation of the logarithm of the anion catalysis coefficient in the acid-base catalysis of the α-glucose mutarotation to the base constant by the linear relationship of the entropy change of the reaction $$\begin{gathered} A^ - + H_3 O^ + = AH \ldots OH_2 + 2 H_2 O \hfill \\ \begin{array}{*{20}c} \cdot \\ \cdot \\ \cdot \\ \end{array} \begin{array}{*{20}c} \cdot \\ \cdot \\ \cdot \\ \end{array} \hfill \\ H_2 O OH_2 \hfill \\ \end{gathered} $$ to the logarithm of the base constant. According to an equation, which is derived by the author, various causes contribute to the deviations from these linear relations. It is shown, that for acetate (propionate), formate (monochloracetic acid) and benzoate in each case another cause is determining.     

Determination of azoxy groups in polyazopolyarenes

Conclusions The band in the 1270–1280 cm^–3 region, corresponding to the vibrations of the -C -N=bond in the grouping , can be used to determine the presence of azoxy groups in polyazopolyarenes.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2623–2625, November, 1970.     

Hydrogen bonds and protonation of carbonyl-containing polynuclear rhodium complexes

According to IR spectroscopy data, the interaction of bi-, tri-, and tetranuclear cyclopentadienylcarbonyl rhodium complexes with rather weak protic acids (phenols, fluoroalcohols) in low-polarity media results in the formation of hydrogen bonds of the OH...O=C type with bridged carbonyl groups. According to¹H NMR data, protonation of these complexes with strong acids (CF₃COOH and HBF₄) occurs at the the Rh-Rh bond to give the symmetrical bridge.Translated fromIzvestiya Akademii Nauk. Seriya Khimicheskaya, No. 2, pp. 386–388, February, 1995.This work was carried out with the financial support of the Russian Foundation for Basic Research (Project No. 93-03-0461).     

Quantum-chemical study on the tautomerism of primary nitramines: the mechanism of N-nitro-anion protonation excludingaci-form formation

The values of the energy barriers to intramolecular 1,3-H shift reactions, in whichaci-forms of N- and C-nitro-compounds: 1 and are capable of transforming into 2 and , respectively, have been calculated by the semi-empirical AM1 method. The barrier heights (39 and 59.4 kcal/mol) reflect the kinetic stability of both tautomeric forms of the N- and C-nitro-compounds.Ab initio calculations in the 3–21G basis set of the structure and energies of stationary points on the potential energy surface of the system MeN=NO₂ H₃O demonstrated that there exists the principal possibility of the formation of only tautomer 2 (which is more stable than1).Translated fromIzvestiya Akademii Nauk, Seriya Khimicheskaya, No 1, pp. 100–104, January, 1993.     

Telomerization of vinyl chloride with methyl propionate

Conclusions The teloHierization of vinyl chloride with methyl propionate was accomplished and it was shown that telomers of type are formed.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2537–2540, November, 1973.     

Embedding with a rigid substructure

This paper presents a new distance geometry algorithm for calculating atomic coordinates from estimates of the interatomic distances, which maintains the positions of the atoms in a known rigid substructure. Given an M × 3 matrix of coordinates X for the rigid substructure, this problem consists of finding the N × 3 matrix Y which yields the global minimum of the so-called STRAIN, i.e., $$\mathop {\min }\limits_Y \left\| {\left[ {\begin{array}{*{20}c} {XX^T } \\ {YX^T } \\ \end{array} \begin{array}{*{20}c} {XY^T } \\ {YY^T } \\ \end{array} } \right] - \left[ {\begin{array}{*{20}c} A \\ {B^T } \\ \end{array} \begin{array}{*{20}c} B \\ C \\ \end{array} } \right]} \right\|_F^2 ,$$ where $A = XX^{\text{{\rm T}}} $ , and B, C are matrices of inner products calculated from the estimated distances. The vanishing of the gradient of the STRAIN is shown to be equivalent to a system of only six nonlinear equations in six unknowns for the inertial tensor associated with the solution Y. The entire solution space is characterized in terms of the geometry of the intersection curves between the unit sphere and certain variable ellipsoids. Upon deriving tight bilateral bounds on the moments of inertia of any possible solution, we construct a search procedure that reliably locates the global minimum. The effectiveness of this method is demonstrated on realistic simulated and chemical test problems.