Vitkovskaya, Nadezhda M

Trofimov B., Schmidt E., Semenova N., Ivanova E., Ushakov I., Bidusenko I., Bobkov A., Vitkovskaya N.

AbstractPharmaceutically prospective 2‐substituted‐4,5‐dimethyloxazoles are synthesized in 16–58% yield via cascade assembly of one molecule of primary amide with two molecules of acetylene gas in the KOH/MeOH/DMSO catalytic triad (90 °C, 2 h). This self‐organization of oxazoles demonstrates unexpected successful competition with the alkaline hydrolysis of amides. The mechanism involving amide N‐vinylation, enamine‐imine isomerization, imine ethynylation and intramolecular O‐vinylation cascade sequence has been deduced and supported by quantum‐chemical calculations using the B2PLYP−D3/6‐311+G**//B3LYP/6‐31+G*+IEF PCM (B3LYP/6‐31+G*) approach.

Orel V.B., Zubarev A.A., Vitkovskaya N.M., Schmidt E.Y., Trofimov B.A.

AbstractThe mechanism of 1‐azadienes formation from aldimines and arylacetylenes in the KOtBu/DMSO superbasic medium has been explored theoretically using a DFT approach [B2PLYP(D2)/6‐311+G(d,p)//B3LYP/6‐31+G(d)] and a sophisticated model taking the potassium tert‐butoxide and the nearest solvation shell of the potassium cation explicitly into account. The main focus is placed on (i) a detailed analysis of the kinetic and thermodynamic characteristics of the isomerization of intermediate propargylamine into 1‐azadienes, and (ii) the factors determining the isomeric composition of 1‐azadienes with different substituents in the starting arylaldimines and arylacetylenes. Our findings clearly indicate that the mild experimental conditions of 1‐azadienes formation are accounted for by the relatively small activation barrier (ΔG≠≤16.2 kcal/mol) of the limiting step (ethynylation of aldimine with arylacetylenes). The rapid isomerization of propargylamine to 1‐azadiene is found to be due to low activation barriers (ΔG≠≤9.1 kcal/mol) related to the protons transfer. The isomeric composition in the case of various substituted 1‐azadienes is determined solely by the difference in the thermodynamic stability of the 1E,2E‐ and 1Z,2E‐forms.

Orel V.B., Gnatovskiy G.R., Vitkovskaya N.M.

Hydrazine complexes with formic acid, free formate ion, and a potassium formate complex 5DMSO · K+HCOO− formed in the system N2H4—HCOOH—K+HCOO−— DMSO were studied. The possibility for hydrazine formylation to occur was assessed. According to calculations, a [N2H6(HCOO)3]− complex is formed in the system in question. The calculated kinetic and thermodynamic characteristics suggest that hydrazine formylation can occur in this complex. The reaction is reversible; as a consequence, the reaction medium can contain both the [N2H6(HCOO)3]− complex and formylhydrazine. All calculations were carried out using the B2PLYP-D2/6-311+G**//B3LYP/6-31+G* approach with inclusion of solvation effects in terms of the IEFPCM continuum model with DMSO as solvent and with explicit inclusion of the nearest solvation shell of the potassium cation (five DMSO molecules).

Bobkov A.S., Orlyuk Y.A., Vitovskaya O.P., Vitkovskaya N.M.

Vitkovskaya N.M., Orel V.B., Kobychev V.B., Bobkov A.S.

Abstract The chemistry of acetylenes has gained significant development in the context of using superbasic media in organic synthesis. Studies of reaction mechanisms require a combination of chemical, physicochemical, and theoretical methods to be applied. The review discusses the results of recent quantum chemical studies on the mechanisms of assemblies of complex highly functionalized molecular structures based on reactions of acetylene and its derivatives in superbasic media performed at the Favorsky Irkutsk Institute of Chemistry (Siberian Branch, Russian Academy of Sciences).

Ivanov A.V., Bobkov A.S., Martynovskaya S.V., Budaev A.B., Vitkovskaya N.M.

Ivanov A., Bobkov A.S., Martynovskaya S.V., Budaev A.B., Vitkovskaya N.M.

AbstractThe effect of substituents in the pyrrole ring and at the triple bond on the formation of fused pyrrolooxazines from 1H‐pyrrol‐2‐ylmethanols and propargyl chlorides has been theoretically and experimentally studied. The energy characteristics of the reaction are evaluated using quantum‐chemical calculations (CBS‐Q//B3). A one‐pot transition metal‐free synthesis of substituted 3‐methyl‐1H‐pyrrolo[2,1‐c][1,4]oxazines in good yields has been implemented in the superbasic system NaOH/DMSO.

Orel V.B., Zubarev A.A., Bidusenko I.A., Ushakov I.A., Vitkovskaya N.M.

Teplyashin N.V., Bobkov A.S., Korchevin N.A., Rozentsveig I.B., Vitkovskaya N.M.

AbstractThe reactivity of bis(2‐chloroprop‐2‐enyl)sulfide in the system hydrazine hydrate/alkali has been studied using quantum‐chemical methods. The B2PLYP‐D2//B3LYP approach shows a good agreement between the relative values of activation barriers compared to high‐precision CBS//Q‐B3. The correction for the entropy change during the transition from the gas phase to the binary solvent hydrazine hydrate is calculated. The IEF PCM model was parameterized for hydrazine hydrate solvent. The studied reaction routes includes (i) a competition between migration of the C=C bond and dehydrochlorination of bis(2‐chloroprop‐2‐enyl)sulfide; (ii) 1,3‐prototropic rearrangements of bis (allenyl)sulfide resulting from a dehydrochlorination; (iii) the possible substitution of sulfur and chlorine atoms with hydrazine. The probable formation of the thiiranium and thiirenium cations formation in the above has also been evaluated.

Absalyamov D.Z., Vitkovskaya N.M., Orel V.B., Schmidt E.Y., Trofimov B.A.

Absalyamov D.Z., Vitkovskaya N.M., Orel V.B., Schmidt E.Y., Trofimov B.А.

AbstractThe self‐organization of functionalized diamines, 1‐acetyl‐1,3‐bis(haloarylamines), from three molecules of acetylene and two molecules of haloanilines in the KOH/DMSO superbase medium, has been analyzed quantum chemically in some detail in the framework of the B2PLYP(D3)/6‐311+G**//B3LYP/6‐31+G* approach. We have established that the diamines are constructed in a cascade manner via the sequential alternating additions of haloaniline anions to acetylene. The reaction sequence is catalyzed by a superbase pentacoordinated complex, KOH ⋅ 5DMSO, where the hydroxide ion is significantly separated from the potassium cation (the K−OH bond length is by 0.4–0.5 Å longer than in the bare KOH molecule). The latter imparts pronounced superbasicity to the complex and provides for a shuttle‐like proton transfer (H++OH−=H2O) during the whole cascade process.

Bidusenko I.A., Schmidt E.Y., Ushakov I.A., Vashchenko A.V., Protsuk N.I., Orel V.B., Vitkovskaya N.M., Trofimov B.A.

Semistabilized diazatrienyl anions are generated by the reaction of 2-pyridylarylimines with arylacetylenes in superbase systems MOtBu (M = Li, Na, K)/DMSO at ambient temperature for 15 min. The initial intermediate N-centered propargyl-1,3-diaza-1,3,5-trienyl anions undergo intermolecular cyclization to benzyl imidazopyridine anions (formally [3 + 2] cycloaddition), further intercepting a second molecule of the starting pyridylimines or a proton of medium to afford (Z)-stilbene/imidazopyridine ensembles and benzyl imidazopyridines. The charge distribution in all intermediate anions and their synthetic evolution are consistent with quantum-chemical analysis (B2PLYPD/6-311+G**//B3LYP/6-31+G*).

Orel V.B., Vitkovskaya N.M., Bobkov A.S., Semenova N.V., Schmidt E.Y., Trofimov B.A.

The mechanism of aldol condensation of ketones in KOH/DMSO superbasic media has been investigated using the B2PLYP(D2)/6-311+G**//B3LYP/6-31+G* quantum-chemical approach. It is found that the interaction of three ketone molecules resulting in the formation of the cyclohex-2-enone structure [isophorone or 3,5-dicyclohexyl-5-methylspiro(5.5)undec-2-en-1-one] is thermodynamically more favorable than the interaction of two, three, or four molecules of ketone, resulting in the formation of linear products of the condensation. The formation of the condensation products with the isophorone skeleton can significantly hinder the cascade reactions of ketones with acetylenes [to afford 6,8-dioxabicyclo(3.2.1)octanes or acylcyclopentenols] promoted by superbases. In particular, the kinetically more preferable reactions of autovinylation of 2-methyl-3-butyn-2-ol and autocondensation of acetone are the reasons why interaction of acetone with acetylene does not lead to the products of the cascade assemblies. The predominant formation of the products of these side reactions is confirmed experimentally.

Bobkov A.S., Vitkovskaya N.M.

Abstract Quantum-chemical modeling of the mechanism of 1,4,5,6-tetrahydrocyclo-penta[b]pyrrole assembly from cyclopentanone oxime and acetylene has been carried out. The kinetic and thermodynamic characteristics of all reaction stages are calculated. The computation results have revealed a fundamental possibility of 1,4,5,6-tetrahydro-cyclopenta[b]pyrrole formation via the Trofimov reaction.

Absalyamov D.Z., Vitkovskaya N.M.

Abstract The B2PLYP/6-311+G**//B3LYP/6-31+G* approach was applied to study the superbase-activated interaction of aniline molecule with three molecules of acetylene. The mechanism of the new cascade assembly of N-phenyl-2,5-dimethylpyrrole has been investigated and presented. It is shown that the cascade competes with the experimentally observed reaction of acetylene polymerization due to the comparable activation barriers of the rate-determining stages.

Stepanov M.A., Bolgova Y.I., Trofimova O.M., Belogolova E.F., Emel'yanov A.I., Albanov A.I., Pozdnyakov A.S.

Delgado A.A., Matthews D.A.

Reliable computational methodologies and basis sets for modeling x-ray spectra are essential for extracting and interpreting electronic and structural information from experimental x-ray spectra. In particular, the trade-off between numerical accuracy and computational cost due to the size of the basis set is a major challenge, since molecular orbitals undergo extreme relaxation in the core-hole state. To gain clarity on the changes in electronic structure induced by the formation of a core-hole, the use of sufficiently flexible basis for expanding the orbitals, particularly for the core region, has been shown to be essential. This work focuses on the refinement of core-hole ionized state calculations using the equation-of-motion coupled cluster family of methods through an extensive analysis on the effectiveness of “hybrid” and mixed basis sets. In this investigation, we utilize the CVS-EOMIP-CCSD method in combination and construct hybrid basis sets piecewise from readily available Dunning’s correlation consistent basis sets in order to calculate x-ray ionization energies (IEs) for a set of small gas phase molecules. Our results provide insights into the impact of basis sets on the CVS-EOMIP-CCSD calculations of K-edge IEs of first-row p-block elements. These insights enable us to understand more about the basis set dependence of the core IEs computed and allow us to establish a protocol for deriving reliable and cost-effective theoretical estimates for computing IEs of small molecules containing such elements.

Kobychev V.B., Belyaeva K.V., Trofimov B.A.

AbstractPossible mechanisms of cyclodimerization of benzoylethynyl pyrrole to give 2,2′‐(dipyrrolo[1,2‐a:1′,2′‐d]pyrazine‐5,10‐diylidene)bis(1‐phenylethanone) have been investigated by using a DFT B2PLYP‐D3/6–311+G**//B3LYP‐D3/6–31+G*+PCM/MeCN approach. This study shows that the cyclodimerization induced by 1‐methylimidazole, and that observed in the presence of strong bases (NaOH or KOH) occur by different mechanisms. The reaction pathway involving 1‐methylimidazole, which starts with the formation of a zwitterionic adduct, was compared with the cyclization pathway as expected by analogy with the acylethynyl pyrrole reaction with 1‐pyrroline. The C─N bond formed by the attack of the acetylene triple bond with the 1‐methylimidazole molecule is maintained throughout the reaction, and the elimination of the imidazole molecule is eliminated only in the final step after pyrazine cycle formation. The formation pathways for the Z,Z‐, Z,E‐, and E,E‐isomers of the product were analyzed. An explanation for the low yield of the final product in the presence of strong bases is proposed and the possible pathways for oligomerization of the initial benzoylethynyl pyrrole are considered.

Shcherbakova V.S., Martynovskaya S.V., Ushakov I.A., Ivanov A.V.

Dumitrascu F., Georgescu E., Georgescu F.

Korabelnikova V.A., Gyrdymova Y.V., Gordeev E.G., Potorochenko A.N., Rodygin K.S., Ananikov V.P.

Working with liquid/gas-phase systems in chemical laboratories is a fundamentally important but difficult operation, mainly due to the explosion risk associated with conventional laboratory equipment.

YesuJyothi Y., Venkateswarlu Y.

Li S., Cheng S., Du Y., Yan L., Wu J., Han L., Zhu N.

Díaz Mirón G., Lien-Medrano C.R., Banerjee D., Monti M., Aradi B., Sentef M.A., Niehaus T.A., Hassanali A.

Wu X., He J., Hu R., Tang B.Z.

AbstractSulfur‐containing polymers with unique structures and fascinating properties have attracted much attention recently, the efficient and economic synthetic approaches for various sulfur‐containing polymers have rapidly developed. Herein, the multicomponent reaction of elemental sulfur, isocyanide, and alcohol was designed at mild condition in the presence of NaOH, and the corresponding NaOH‐assisted multicomponent polymerization of elemental sulfur, diisocyanides, and diols were developed at room temperature or 40 °C in air, to produce poly(O‐thiocarbamate)s with well‐defined structures, high molecular weights (Mws up to 32 500 g/mol) and high yields (up to 99 %). The facilely available monomers, mild condition, and high efficiency of this MCP enabled scale‐up synthesis of poly(O‐thiocarbamate)s, and 7.33 g polymer was obtained in 98 % yield. These functional poly(O‐thiocarbamate)s could enrich Au3+ from aqueous solution with high enrichment capacity (983 mg⋅Au3+/g) and high efficiency (>99.77 %) in 1 min, demonstrating superior gold enrichment performance and their potential industrial and economic values.

Trofimov B., Schmidt E., Semenova N., Ivanova E., Ushakov I., Bidusenko I., Bobkov A., Vitkovskaya N.

AbstractPharmaceutically prospective 2‐substituted‐4,5‐dimethyloxazoles are synthesized in 16–58% yield via cascade assembly of one molecule of primary amide with two molecules of acetylene gas in the KOH/MeOH/DMSO catalytic triad (90 °C, 2 h). This self‐organization of oxazoles demonstrates unexpected successful competition with the alkaline hydrolysis of amides. The mechanism involving amide N‐vinylation, enamine‐imine isomerization, imine ethynylation and intramolecular O‐vinylation cascade sequence has been deduced and supported by quantum‐chemical calculations using the B2PLYP−D3/6‐311+G**//B3LYP/6‐31+G*+IEF PCM (B3LYP/6‐31+G*) approach.

Schmidt Elena Yu, Trofimov Boris

This review highlights the dynamics of the development and synthetic application of the recently discovered reaction of acetylenic carbanions, generated in superbase media, with the C=N bond of different classes of substrates. A fundamental feature of this reaction is its synthetic divergence, i.e. its ability to proceed in different directions, which manifests itself in novel transformations to selectively deliver structurally different synthetically important products (depending on the structure of the acetylenes and substrates with C=N bond). The review also discusses cascade processes, in which the key intermediates containing the C=N bond add acetylenes thereby participating in the self-organization of diverse and potentially useful compounds. The competitive advantage of the reaction and its daughter branches is environmental safety (neutrality), based on the fundamental chemical nature of these reactions as addition processes that occur without the release of by-products.The bibliography includes 133 references.

Karimova N.V., Wang W., Gerber R.B., Finlayson-Pitts B.J.

Products of the oxidation of BTH by OH in air.

Lin Z., Liu J., Zhang C., Zheng X., Cheng L.

Ide Y., Matsuda N., Osada M., Yamamoto A., Tanaka K., Hashimoto Y., Morita N., Tamura O.

Rozentsveig I.B., Bogdanova I.N., Russavskaya N.V., Korchevin N.A.

The review describes the possibilities of the synthesis of organochalcogen compounds of different classes using elemental chalcogens or available organic dichalcogenides and hydrazine, which converts chalcogens and dichalcogenides into a reactive form of chalcogenide anions. The key features of reactions that occur in a hydrazine hydrate medium are considered.

Behera B.K., Arandhara P.J., Porashar B., Bora S.K., Saikia A.K.

Igidov S.N., Turyshev A.Y., Chashchina S.V., Shipilovskikh D.A., Chernov I.N., Zvereva O.V., Silaichev P.S., Igidov N.M., Shipilovskikh S.A.

N-Arylamides of 4-aryl/4-(thiophen-2-yl)-2-[2-(furan-2-carbonyl)hydrazono]-4-oxobutanoic acids were synthesized by the reaction of N′-(5-aryl/5-(thiophen-2-yl)-2-oxofuran-3(2H)-ylidene)furan-2-carbohydrazides with arylamines and evaluated for antiinflammatory activity.

Wu Z., Zhang H., Cao C., Lu C., Jiang A., He J., Zhao Q., Tang Y.

Developing new organic reactions with excellent atom economy and high selectivity is significant and urgent. Herein, by ingeniously regulating the reaction conditions, highly selective transformations of propargylamines have been successfully implemented. The palladium-catalyzed cyclization of propargylamines generates a series of functionalized quinoline heterocycles, while the base-promoted isomerization of propargylamines affords diverse 1-azadienes. Both reactions have good functional group tolerance, mild conditions, excellent atom economy and high yields of up to 93%. More importantly, these quinoline heterocycles and 1-azadienes could be flexibly transformed into valuable compounds, illustrating the validity and practicability of the propargylamine-based highly selective reactions.

Trofimov B., Schmidt E., Tatarinova I., Lobanova N., Ushakov I., Bagryanskaya I.Y.

We have discovered that three molecules of arylacetylenes are rapidly (15 min) assembled with a one molecule of nitriles at room temperature in the KOBut/DMSO system to afford 2-aryl-3-arylethynyl-4-aryl-5-benzyl-1H-pyrroles in...

Ivanov A., Bobkov A.S., Martynovskaya S.V., Budaev A.B., Vitkovskaya N.M.

AbstractThe effect of substituents in the pyrrole ring and at the triple bond on the formation of fused pyrrolooxazines from 1H‐pyrrol‐2‐ylmethanols and propargyl chlorides has been theoretically and experimentally studied. The energy characteristics of the reaction are evaluated using quantum‐chemical calculations (CBS‐Q//B3). A one‐pot transition metal‐free synthesis of substituted 3‐methyl‐1H‐pyrrolo[2,1‐c][1,4]oxazines in good yields has been implemented in the superbasic system NaOH/DMSO.

Orel V.B., Zubarev A.A., Bidusenko I.A., Ushakov I.A., Vitkovskaya N.M.

Teplyashin N.V., Bobkov A.S., Korchevin N.A., Rozentsveig I.B., Vitkovskaya N.M.

AbstractThe reactivity of bis(2‐chloroprop‐2‐enyl)sulfide in the system hydrazine hydrate/alkali has been studied using quantum‐chemical methods. The B2PLYP‐D2//B3LYP approach shows a good agreement between the relative values of activation barriers compared to high‐precision CBS//Q‐B3. The correction for the entropy change during the transition from the gas phase to the binary solvent hydrazine hydrate is calculated. The IEF PCM model was parameterized for hydrazine hydrate solvent. The studied reaction routes includes (i) a competition between migration of the C=C bond and dehydrochlorination of bis(2‐chloroprop‐2‐enyl)sulfide; (ii) 1,3‐prototropic rearrangements of bis (allenyl)sulfide resulting from a dehydrochlorination; (iii) the possible substitution of sulfur and chlorine atoms with hydrazine. The probable formation of the thiiranium and thiirenium cations formation in the above has also been evaluated.

Liu B., Lin Z., Cheng T., Cao T., Zhu S.

Liu B., Lin Z., Wang Y., Cheng T., Cao T., Zhu S.

Absalyamov D.Z., Vitkovskaya N.M., Orel V.B., Schmidt E.Y., Trofimov B.А.

AbstractThe self‐organization of functionalized diamines, 1‐acetyl‐1,3‐bis(haloarylamines), from three molecules of acetylene and two molecules of haloanilines in the KOH/DMSO superbase medium, has been analyzed quantum chemically in some detail in the framework of the B2PLYP(D3)/6‐311+G**//B3LYP/6‐31+G* approach. We have established that the diamines are constructed in a cascade manner via the sequential alternating additions of haloaniline anions to acetylene. The reaction sequence is catalyzed by a superbase pentacoordinated complex, KOH ⋅ 5DMSO, where the hydroxide ion is significantly separated from the potassium cation (the K−OH bond length is by 0.4–0.5 Å longer than in the bare KOH molecule). The latter imparts pronounced superbasicity to the complex and provides for a shuttle‐like proton transfer (H++OH−=H2O) during the whole cascade process.

Pradedova A.G., Kobychev V.B.

Semenova N.V., Schmidt E.Y., Ushakov I.A., Trofimov B.A.

Acetylene reacts with 2-aminopyridines in the superbase system KOBut/DMSO (the initial acetylene pressure ∼8 atm, 80 °C, 5 min) to give 2,3-dimethylimidazo[1,2-α]-pyridines in up to 60% yields. In the case of 2-amino-5-chloropyridine, along with ‘normal’ product, (Z)-5-chloro- N-[2-(2,3-dimethylimidazo[1,2-α]pyridin-6-yl)vinyl]pyridin-2-amine is formed in 40% yield. These multi-molecular assemblies involve parallel nucleophilic addition of N-centered anions to the triple bond and ethynylation of the forming C=N bond.

Bidusenko I.A., Yu. Schmidt E., Protsuk N.I., Ushakov I.A., Trofimov B.A.

N-Benzyl aldimines react with arylacetylenes in the presence of ButOK/DMSO superbase system to afford 2,3,5-triaryl-1-pyrrolines as two tautomers with 1,2- and 1,5-location of the double bond, both being the trans-diastereomers. This version of the C=N bond ethynylation differs from the previous one with N-benzyl ketimines. The oxidation of the pyrroline tautomeric mixtures without their isolation gives 2,3,5-triaryl-1H-pyrroles.

Nie X., Wang M., Fu Y., Xu J., Zheng X., Chen H., Su Z., Fu H., Li R.

We have developed a new catalytic system for preparing amides by tandem acceptorless dehydrogenation of amines and oxygen transfer of DMSO. This system shows very good catalytic activity and selectivity, a variety of primary amines and even diamines are converted into the corresponding amides in good to quantitative yields (>99 %). The unprecedented catalytic performance of this binuclear ruthenium complex was attributed to a unique chelating model wherein one Ru center combines with N atom of RCHNH produced from the dehydrogenation of RCH2NH2 and the other co-ordinates with the S atom of DMSO, thus bringing the DMSO and imine molecules into proximate to enhance the efficiency of the oxygen transfer from DMSO via a six-membered ring transition state. The mechanism study indicated that the oxygen in the product amides came from DMSO and CH bond cleavage in DMSO was the rate determining step.