Synthesis of β-(trifluoromethyl)furans and spiro-gem- dichlorocyclopropanes from cyclic 1,3-dicarbonyl compounds and α-(trihaloethylidene)nitroethanes

While 1,3-dicarbonyl compounds react with (E)-1,1,1-trifluoro-3-nitrobut-2- ene in the presence of sodium acetate to produce the target β- (trifluoromethyl)furans, their reaction with (E)-1,1,1-trichloro-3-nitrobut-2- ene, under the same conditions, took an entirely different course and gave spiro-gem-dichlorocyclopropanes bearing a 1-nitroethyl moiety, with high diastereoselectivity and in good yields. © 2013 Elsevier Ltd. All rights reserved

Domino reaction of 3-nitro-2-(trifluoromethyl)-2H-chromenes with 2-(1-phenylalkylidene)malononitriles: Synthesis of functionalized 6-(trifluoromethyl)-6H-dibenzo[b,d]pyrans and a rare case of [1,5] sigmatropic shift of the nitro group

A variety of functionalized 6-(trifluoromethyl)-6H-dibenzo[b,d]pyrans were easily synthesized in good yields under mild conditions by a domino reaction of 3-nitro-2-(trifluoromethyl)-2H-chromenes with 2-(1-phenylethylidene)- and 2-(1-phenylpropylidene)malononitriles. In the latter case, intermediate 7-amino-10-methyl-10-nitro-9-phenyl-6-(trifluoromethyl)-10,10a-dihydro-6H- benzo[c]chromene-8-carbonitriles were isolated as a result of a rare [1,5] sigmatropic shift of the nitro group. © 2013 Elsevier Ltd. All rights reserved

Highly regio-and stereoselective addition of ethyl 3-aminobut-2-enoates to 2-substituted 3-nitro-2H-chromenes

Ethyl 3-aminobut-2-enoates MeC(NHR)=CHCO2Et (R = H, Me, Bn) whose reaction site is C(2) atom add to 2-R-3-nitro-2H-chromenes at their C(4) atom to give the corresponding trans,trans-2,3,4-trisubstituted chromanes. Analogous substrates MeC(NR2)=CHCO2Et (NR2 is piperidin-1-yl or morpholin-4-yl) react by their C(4) methyl group to afford cis,trans-2,3,4-trisubstituted chromanes. The stereochemistry of the products was established by X-ray diffraction analysis. © 2013 Mendeleev Communications. All rights reserved

Synthesis of 5-(trifluoromethyl)-5H-chromeno[3,4-b]pyridines from 3-nitro-2-(trifluoromethyl)-2H-chromenes and aminoenones derived from acetylacetone and cyclic amines

Reactions of 3-nitro-2H-chromenes with aminoenones derived from acetylacetone and cyclic amines proceed diastereoselectively to give functionalized 2,3,4-trisubstituted chromanes as a result of nucleophilic addition of the vinylogous β-methyl group at the C-4 atom of the chromene system. From these compounds, under acidic conditions, 5-(trifluoromethyl)-5H- chromeno[3,4-b]pyridines and 4-acetoacetonyl-3-nitro-2-(trichloromethyl/phenyl) chromanes, depending on the substituent at the 2-position, were obtained in moderate to good yields. © 2013 Elsevier Ltd. All rights reserved

Structure of Ti-Al-Si-N gradient coatings

The microstructure, the stresses, and the elemental composition of Ti-Al-Si-N gradient coatings are studied by transmission electron microscopy and electron-probe microanalysis of thin foils prepared in the cross section of the coatings. As the concentration of the elements that alloy titanium nitride increases across the coating thickness, the structure of the coating changes from submicrocrystalline columnar grains to nanocrystalline grains. In these structural states, the structural characteristics (lattice parameter, lattice bending-torsion, crystal size, type of intragranular defect structure) and the residual stresses change. The magnitude and the sign of residual stresses change when the type of structural state changes

Thermal stability of Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings

The results of the microstructure, mechanical and tribological properties investigations of Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings based on amorphous carbon in the initial state and after the annealing to 900 °C are presented. The effect of annealing temperature on the microstructure, tribological and mechanical properties of Ti-C- Ni-Cr and Ti-C-Ni-Cr-Al-Si nanostructured coatings is discussed

Investigation of the microstructure, mechanical properties and thermal stability of nanocomposite coatings based on amorphous carbon

The Ti-C-Ni-Cr and Ti-C-Ni-Cr-Al-Si nanocomposite coatings based on amorphous carbon and the nanosized particles were synthesized by magnetron method. The results of the microstructure features and mechanical properties investigations of these coatings are presented. The thermal stability of microstructure and properties of these coatings at tempering up to 900°C were investigated. These coatings have a high (11–18 GPa) hardness, low (μ < 0.2) the coefficient of friction and high thermal stability of the microstructure and properties up to 700°C. The features of elastically stressed state of nanosized particles in these coatings were founded. A high local internal stresses in the TiC nanoscale particles do not observed

Kinetics of epitaxial formation of nanostructures by Frank-van der Merwe, Volmer-Weber and Stranski-Krastanow growth modes

Nowadays, two-dimensional crystals (2D materials) and structures with quantum dots (0D materials) are considere

Highly diastereoselective 1,3-dipolar cycloaddition of nonstabilized azomethine ylides to 3-nitro-2-trihalomethyl-2H-chromenes: Synthesis of 1-benzopyrano[3,4-c]pyrrolidines

Reactions of 3-nitro-2-trifluoro(trichloro)methyl-2H-chromenes, including 2-unsubstituted derivatives, with N-alkyl-α-amino acids (sarcosine, proline) and paraformaldehyde proceed diastereoselectively to give 1-benzopyrano[3,4-c]pyrrolidines in good yields as a result of a 1,3-dipolar cycloaddition of the intermediate nonstabilized azomethine ylide at the Δ3-bond of the chromene system. © 2013 Elsevier Ltd. All rights reserved

Developed and developing countries: towards the common target with different speeds

Objective: to analyze the expected economic transformations in the 21st century in various countries of the world. Methods: abstract-logical method, methods of modeling of socio-economic self-organization, methods of long-term forecasting of world dynamics, theory of institutional matrices.Results: based on the performed analysis, the following conclusions are made: 1) in the coming decades, a complex continuum of types, transitions, combinations and forms of economic structures will be observed in the world (with an increase in the proportion of post-industrial forms). At the same time, there will be a shift towards strengthening distributive institutions in developed countries and a shift towards strengthening market institutions in developing countries that continue the processes of economic and socio-political modernization; 2) the process of internationalization of the labor force will be intensified (due to the development of remote employment) along with the internationalization of capital; 3) a new technological wave (2030s – 2070s) will bring new resources and expand the sphere for production and services, which will support economic growth in both developed and developing countries; 4) at the same time in some areas, in particular in medicine, a very significant regulation of economic activity is inevitable, while in other areas, in particular in robotics, economic mechanisms of a market-corporate type may strengthen; 5) thus, the most important task in the coming decades is to increase the flexibility of socio-economic development of all countries of the world, namely, gaining the ability to regulate the ratio of market and distribution mechanisms depending on the spheres of activity and tasks to be solved without the pressure of ideological dogmas.Scientific novelty: based on the historical trends analysis using the theory of institutional matrices, a forecast of economic transformations in the 21st century is made for the countries of various types and the expected features of these transformations are substantiated.Practical significance: the proposed methods of long-term forecasting can be used in strategic planning systems in the Russian Federation