Molecular structures of β-amino-α-bromovinyl trifluoromethyl ketones

The molecular structures of β-amino-α-bromovinyl trifluoromethyl ketones was studied by UV, IR, ¹H, ¹³C, and ¹⁵N NMR spectroscopy and using the density functional (B3LYP/6-31G(d,p) and PBE/QZ3P) and ab initio riMP2/cc-pVTZm quantum-chemical calculations. Factors affecting stabilization of the EZE-conformation of the molecules, which is atypical of analogous unsubstituted amino enones, are considered.__________Published in Russian in Izvestiya Akademii Nauk. Seriya Khimicheskaya, No. 1, pp. 102–106, January, 2005.     

Underground Physics and the Nonlinear Delayed Barometric Effect of the Gamma-Ray Background

Journal of Experimental and Theoretical Physics - The electronic, magnetic, and optical properties of MnGa2O4 in the structure of the normal and inverse spinels are subjected to an ab initio...     

Search for inert oxide matrices for carrying out solid-phase ion-exchange reactions by the internal reaction scheme

Having a goal of studying the possibility of and develop methods for controlling internal solidphase reactions inside a solid matrix that is diffusionally saturated with several components simultaneously from different source phases, we experimentally checked whether it is possible to synthesize, for use as these matrices, ZrO₂-Nb₂O₅ solid solutions having distorted fluorite structure and NiO-CuO-Cu₂O solid solutions having rock salt structure (these solid solutions had been studied by computational techniques using the ion lattice mechanic approximation), with a controlled ratio of anionic and cationic conductivities.     

Mechanistic study of multi-step nucleophilic substitution for trifluoromethylated styrenes

The key steps of the reactions of nitrogen nucleophiles with β-halogen-β-trifluoromethylstyrenes have been studied by ¹⁹F and ¹H NMR monitoring and quantum-chemical calculations. In contrast to the mechanism proposed earlier for nucleophilic vinylic substitution of captodative carbonyl-bearing haloalkenes, this reaction proceeds via either E–Ad or Ad–E sequence depending on the nature of aromatic substituents of the parent styrenes.     

Experimental investigation of the boundary layer on ablating specimens in the joint presence of convective and radiant heat fluxes

The emission spectrum of the boundary-layer vapor on the interval 3800–6600 Å is presented for a specimen of asbestos-filled plastic in the air-plasma flow created by an electrodeless high-frequency discharge. The temperature profile in the boundary layer has been measured in the neighborhood of the stagnation point. A model of the boundary layer on an ablating specimen is proposed and the convective component of the heat flow to it is estimated.Moscow. Translated from Izvestiya Akademii Nauk SSSR. Mekhanika Zhidkosti i Gaza, No. 2, pp. 25–29, March–April, 1972.     

Condensation of α-ethoxyacrolein with secondary amines

Conclusions Morpholine, piperidine, and dibutylamine undergo both 1,2 and 1,4 addition to -ethoxyacrolein to form a mixture of 3,3- and 1,3-diamino-2-ethoxy-1-propenes. The N-formyl derivative of the starting amine is a side product. The reaction of -ethoxyacrolein with diethylamine gives only splitting of the C-C bond and formation of N-formyldiethylamine.Translated from Izvestiya Akademii Nauk SSSR, Seriya Khimicheskaya, No. 11, pp. 2610–2612, November, 1985.     

Assembly of nitrogen-containing heterocycles initiated by the aza-Michael reaction

The aza-Michael reaction is considered as the most popular method for the carbon–nitrogen bond formation and the shortest way to β-aminocarbonyl compounds, including β-amino acids and their derivatives. In many cases, conjugate addition of nitrogen-centered nucleophiles to the activated multiple bond triggers a series of cascade transformations being completed by the formation of heterocycles and analogs of natural compounds. The review summarizes the most important advances in the aza-Michael reaction-initiated synthesis of nitrogen-containing heterocycles from unsaturated ketones and enoates.     

Nonempirical calculations of NMR indirect spin-spin coupling constants. Part 14: azomethines of the alpha, beta-unsaturated aldehydes

Configurational assignment of seven azomethines obtained from the alpha-functionally substituted and nonsubstituted alpha,beta-unsaturated aldehydes has been performed on the basis of experimental measurements and the high-level ab initio calculations of their 1J(C,C) and 1J(C,H), involving the alpha-imino carbon that demonstrated the marked stereochemical dependence of both coupling constants upon the orientation of the nitrogen lone pair in the diverse isomers of the title azomethines.     

Captodative Formyl- and Acyl(amino)alkenes Containing a Terminal Double Bond or a Weakly Basic Tertiary Amino Group

Piperidine reacts with 3-bromo-3-buten-2-one to give a mixture of 3,4-dipiperidinobutan-2-one and 3-piperidino-3-buten-2-one. The latter is also formed by the action of a strong base (Et₃N in THF or MeONa in MeOH) on the dipiperidino derivative. Analogous reaction of 2-bromo-3-phenylpropenal with N-methylaniline affords 2-[methyl(phenyl)amino]-3-phenylpropenal which is the first captodative formyl(amino)alkene having a weakly basic tertiary amino group.