A.E. Favorsky Irkutsk Institute of Chemistry

Molecular design of cage phosphine oxides (6-phospha-1,3,9,12-tetrasila-bicyclo[4.4.4]tetradecan-6-oxides) with four Si-containing acceptor fragments and one P=O donor fragment was performed using density functional theory methods (B3PW91 and ωB97X-D). Substituents at the silicon and phosphorus atoms were selected to favor the existence of the structures in the endo form containing a P=O···Si interaction. The competition of four silicon atoms for bonding to the phosphoryl oxygen atom was used to assess the coordinating ability of the phosphoryl group and to determine the nature of the P=O bond in phosphine oxides.

Catalyst- and solvent-free reaction of pyridine-d5 with secondary phosphine oxides and sulfides and phosphinic acid esters in the presence of benzoylphenylacetylene (50-55 or 70-75 °C, 7-35 h) gives 4-phosphorylated pyridines-d4 and -d3 (the latter having hydrogen at position 2) in 43-73% total yield along with differently deuterated chalcones, the reduced benzoylphenylacetylene. The scrutinized analysis of deuterium distribution in the above substitution products with emphasis on protium insertion in the pyridine ring reveals that the substitution studied involves the isomerization of the primary 1,3(4)-dipole intermediate to carbene localized at the position 2. Quantum chemical calculations (B3LYP/6-311++G**) indicate that diphenylphosphine oxide or trace water likely mediates the carbene generation stage.

This review summarizes the latest advances in the chemistry of β,γ-ethylenic ketones, which have emerged over the last decade as valuable synthetic building blocks to create molecules of high complexity and diversity. This family of multifunctional γ-aryl-β,γ-ethylenic ketones has now become accessible owing to the discovery and systematic development of a new general C(sp<sup>3</sup>) – C(sp<sup>2</sup>) bond-forming reaction, namely superbase-mediated <i>C</i>-vinylation of ketones with alkynes. In the context of the Favorsky reaction (the addition of acetylenic carbanions to the carbonyl group of ketones), this discovery represents a chemical paradox in the form of temperaturecontrolled inversion of electrophilicity and nucleophilicity of acetylenes and ketones. Various transformations of β,γ-ethylenic ketones: nucleophilic addition reactions, inverse-electron-demand Diels–Alder reactions, reactions involving a carbonyl group followed by transformations of functionalized adducts, <i>etc.</i> are discussed. The review also highlights the cascade reactions, in which the <i>in situ</i> formed β,γ-ethylenic ketones, are key intermediates in the synthesis of various highly functionalized carbo- and heterocyclic systems. <br> The bibliography includes 102 references.

The electron ionization fragmentation of previously unavailable 3,6-substituted 5,6-dihydropyridin-2(1H)-ones synthesized from allenic and acetylenic carbanions, isothiocyanates, and methyl iodide has been studied for the first time. All the studied compounds form the molecular ion M+•, the fragmentation pathway of which depends on the substituents in both position 3 and position 6. The fragmentation of the molecular ion of 3-methoxy-5,6-dihydropyridin-2(1H)-one is initiated at the radical site, leading to the loss of a radical from position 6 and the localization of the positive charge on the endocyclic nitrogen atom. For 3-phenyl-5,6-dihydropyridin-2(1H)-one, the primary fragmentation pathway involves the formation of an odd-electron ion with m/z 144 (Irel 100%) via the loss of an HNCO molecule from the M+• ion or of an MeCH=NH molecule from the isomerized molecular ion M1+•. The fragmentation of the molecular ion of 3-methyl-1-azaspiro[5.5]undec-3-en-2-one is characterized by the formation of the radical ions [M – HNCO]+• (Irel 100%) and [M – C4H8]+• (Irel 92%). Experimental evidence has been obtained for the formation of the precursors of 5,6-dihydropyridin-2(1H)-ones―2-(methylsulfanyl)-1,2,5,6-tetrahydropyridin-2-ols, which undergo heteroring cleavage under electron ionization.

The synthesis of trifluoromethylated isothiazolium thiocyanates and 4-thiocyanato-2,5-dihydrofurans is presented through hydrothiocyanation/cyclization of CF3-iminopropargyl alcohols using NaSCN in AcOH/MeCN. The formation of the two products can be explained by different directions of cyclization of the primary adducts of thiocyanic acid at the triple bond – vinyl thiocyanates. This protocol features simple operating, readily prepared starting materials and occurs under relatively mild conditions.

The following are considered key areas of new resource and industrial development: in the east of Russia, the taiga regions (Katanga and Ust-Kut districts of Irkutsk oblast, Kalar district of Zabaykalsky krai, and Neryungri district of the Republic of Sakha (Yakutia)) and, in the south of Mongolia, the arid (Gobi) regions (Tsogttsetsii and Khanbogd soums of the Umnugovi aimag). The main focus is on assessing the impact of economic development on the socioeconomic and demographic situation in the respective areas. The general features of the development of key areas have been identified: low population density, the beginning of intensive development at the close time (mainly in 2009–2013), the predominance of the shift method of development, and the orientation of exports of extracted mineral raw materials to a large extent to the Chinese market. Significant differences in development processes between countries have been established. The studied regions of Russia are characterized by an unfavorable transport and geographical location relative to sales markets, a declining population and an insufficient level of budgetary and financial security, and the dominance of the interests of resource companies over the interests of territories and the local population. Meanwhile, the developed soums of Mongolia are characterized by a favorable position relative to the Chinese market, intensive settlement and development, a more pronounced social orientation of development, and an effective role of the state in controlling the activities of mining companies.

The article discusses the participation of large businesses in socioeconomic processes in the territory of their presence in small settlements of Siberia. Based on available statistical data and conducted expeditionary research, the behavior of key enterprises in four towns—Ust-Kut, Taishet, Baikalsk (located in Irkutsk Oblast), Igarka (Krasnoyarsk Krai)—and the urban-type settlement of Sheregesh (Kemerovo Oblast) is characterized in terms of economic, social, and environmental aspects. It has been established that the behavior of enterprises is influenced by their size and sectoral affiliation, as well as the size of the settlement. The degree of rootedness and spatial configuration of business did not show a clear influence. Among the cases examined, the “host” model was found in Ust-Kut, Taishet, and Igarka. The mechanisms and practices of interaction used there can be adapted for other small settlements in Russia.