14 results on '"E. V. Yarosh"'
Search Results
2. A Kinetic Study of the Step of Aryl Halide Activation in a Direct Arylation Reaction of Indole under Real Catalysis Conditions
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E. V. Yarosh, N. A. Lagoda, E. V. Larina, Alexander F. Schmidt, and A. A. Kurokhtina
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chemistry.chemical_classification ,Indole test ,010405 organic chemistry ,Aryl halide ,Aryl ,Halide ,Substrate (chemistry) ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Oxidative addition ,Combinatorial chemistry ,Catalysis ,0104 chemical sciences ,Computer Science Applications ,chemistry.chemical_compound ,chemistry ,Modeling and Simulation ,Reactivity (chemistry) - Abstract
This paper presents the results of a kinetic study on the step of activation of aryl iodides and aryl bromides under conditions of ligand-free catalysis in the direct arylation of indole at a C–H bond performed using an analysis of the integral kinetic curves of consumption of the competing aryl halides. In the course of an experiment under the conditions of competition between a pair of aryl halides having different reactivity, an acceleration in the consumption of a less active substrate was observed, which coincided in time with the almost complete consumption of a more active one. The experimental data unambiguously indicated a rapid character of the stage of oxidative addition with the participation of not only reactive aryl iodides but also nonactivated aryl bromides.
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- 2019
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3. Distinguishing between Homogeneous and Heterogeneous Catalytic Activity in C–H Arylation of an Indole with Aryl Halides under 'Ligandless' Conditions: Crucial Evidence from Real Catalytic Experiments
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A. A. Kurokhtina, Alexander F. Schmidt, N. A. Lagoda, E. V. Larina, and E. V. Yarosh
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Indole test ,010405 organic chemistry ,Aryl ,Organic Chemistry ,Halide ,chemistry.chemical_element ,Regioselectivity ,010402 general chemistry ,Heterogeneous catalysis ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Catalysis ,chemistry.chemical_compound ,chemistry ,Physical and Theoretical Chemistry ,Selectivity ,Palladium - Abstract
The kinetic approach for distinguishing between homogeneous and heterogeneous catalysis mechanisms by the analysis of differential selectivity was applied for direct C–H arylation of an indole with aryl halides under “ligandless” conditions. The differential selectivity of competing arylation of an indole with two aryl iodides or bromides and the differential regioselectivity of a parallel formation of C2- and C3-regioisomers of arylated indoles were studied by the simple method of phase trajectories needed for raw kinetic data only. The results obtained indicated that the selectivities strongly depended on the type (soluble or insoluble) and concentration of the Pd precursor. Considering the pathways of Pd transformations under the reaction conditions, this indicates a substantial contribution of catalysis occurring on the surface of metallic Pd (including nanoparticles).
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- 2019
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4. The role of phosphine ligands in the catalytic systems of the Heck reaction with aromatic carboxylic anhydrides
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E. V. Yarosh, A. A. Kurokhtina, E. V. Larina, Alexander F. Schmidt, and N. A. Lagoda
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chemistry.chemical_classification ,Coordination sphere ,Alkene ,chemistry.chemical_element ,General Chemistry ,Combinatorial chemistry ,Catalysis ,chemistry.chemical_compound ,Catalytic cycle ,chemistry ,Heck reaction ,Selectivity ,Phosphine ,Palladium - Abstract
The results of a comparative study of phosphine-containing and phosphine-free catalytic systems of the Heck reaction using aromatic carboxylic anhydrides as arylating agents are presented. It was demonstrated that the patterns of diff erential selectivity of the reaction under competition of two aromatic anhydrides or two alkenes are independent of the presence of a tertiary phosphine additive in the system. It was established that palladium complexes with no phosphine ligands in their coordination sphere are catalytically active at the step of activation of aromatic carboxylic anhydride and alkene. The patterns of diff erential selectivity for regioisomers of arylated products provide the evidence of the participation of phosphine-containing anionic palladium complexes in the regioselectivity-determining step of the catalytic cycle. The data obtained are in agreement with the phosphine involvement in the catalyst transformations proceeding outside the main catalytic cycle.
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- 2019
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5. Mechanistic Study of Catalysis in the Mizoroki–Heck Reaction with Anhydrides of Aromatic Acids
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E. V. Larina, A. A. Kurokhtina, E. V. Yarosh, N. A. Lagoda, and Alexander F. Schmidt
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chemistry.chemical_classification ,010405 organic chemistry ,Alkene ,Aryl ,Halide ,General Chemistry ,010402 general chemistry ,01 natural sciences ,Catalysis ,0104 chemical sciences ,Computer Science Applications ,chemistry.chemical_compound ,chemistry ,Homogeneous ,Modeling and Simulation ,Heck reaction ,Reagent ,Organic chemistry ,Selectivity - Abstract
A kinetic study of reaction of alkene arylation by anhydrides of aromatic acids (modified Mizoroki–Heck reaction) was carried out using differential selectivity as the main measured parameter. The results obtained under conditions of competition between a pair of alkenes or a pair of aromatic anhydrides point to the occurrence of the reaction via a homogeneous mechanism of catalysis analogously to a conventional variant of reaction with aryl halides as arylating reagents. The hypothesis that the active catalyst is homogeneous agrees with the results of kinetic studies of processes of catalyst formation and deactivation.
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- 2018
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6. Mechanistic Study of Direct Arylation of Indole Using Differential Selectivity Measurements: Shedding Light on the Active Species and Revealing the Key Role of Electrophilic Substitution in the Catalytic Cycle
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E. V. Larina, Alexander F. Schmidt, A. A. Kurokhtina, N. A. Lagoda, and E. V. Yarosh
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Indole test ,010405 organic chemistry ,Aryl ,Organic Chemistry ,Cationic polymerization ,Halide ,010402 general chemistry ,01 natural sciences ,Combinatorial chemistry ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry.chemical_compound ,Electrophilic substitution ,chemistry ,Catalytic cycle ,Physical and Theoretical Chemistry ,Selectivity - Abstract
Differential selectivity of the direct arylation of indole with aryl halides under competing and noncompeting conditions with a varying set of reaction parameters was determined using phase trajectories. The results described herein allow for conclusions to be drawn regarding the character of active complexes (cationic, neutral, or anionic) as well as realization of the indole electrophilic substitution in the catalytic cycle using the ligand-free catalytic system.
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- 2018
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7. Direct Kinetic Evidence for the Active Anionic Palladium(0) and Palladium(II) Intermediates in the Ligand-Free Heck Reaction with Aromatic Carboxylic Anhydrides
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A. A. Kurokhtina, N. A. Lagoda, E. V. Larina, E. V. Yarosh, and Alexander F. Schmidt
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chemistry.chemical_classification ,010405 organic chemistry ,Ligand ,Organic Chemistry ,Salt (chemistry) ,chemistry.chemical_element ,010402 general chemistry ,Kinetic energy ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Inorganic Chemistry ,chemistry ,Heck reaction ,Polymer chemistry ,Organic chemistry ,Physical and Theoretical Chemistry ,Selectivity ,Palladium - Abstract
Differential selectivity in the competitive Heck reaction with aromatic carboxylic anhydrides has been found to depend on the nature of both the cation and anion of a salt used as an additive for the catalytic system. This fact indicates that the anions present in the system are involved in active anionic species.
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- 2017
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8. Kinetic investigation of cross-coupling reaction steps by advanced competing reaction methods
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Alexander F. Schmidt, E. V. Yarosh, A. A. Kurokhtina, and E. V. Larina
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Reaction mechanism ,010405 organic chemistry ,Chemistry ,Process Chemistry and Technology ,Sonogashira coupling ,010402 general chemistry ,Photochemistry ,01 natural sciences ,Combinatorial chemistry ,Catalysis ,Coupling reaction ,0104 chemical sciences ,Catalytic cycle ,Heck reaction ,Elementary reaction ,Stepwise reaction ,Physical and Theoretical Chemistry ,Reaction progress kinetic analysis - Abstract
Investigating the mechanism of a complex catalytic reaction is usually quite complicated because many processes, such as active catalyst formation and deactivation, are linked to the main catalytic cycle. Using artificial multi-route reactions with similar competing substrates is a unique way to elucidate the fine details of a reaction mechanism. Applying such multi-route reaction-based methods to the cross-coupling of alkynes with aryl halides (Cu-free Sonogashira reaction) and alkenes with aromatic carboxylic anhydrides (modified Heck reaction) catalysed by ligand-free Pd allowed us to elucidate the fast, reversible, and rate-determining steps involved in the relevant catalytic cycles.
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- 2016
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9. Formation of polyaromatic compounds by coupling of aryl iodides with arylacetylenes in the presence of palladium-based ligand-free catalytic systems
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Alexander F. Schmidt, A. A. Kurokhtina, N. A. Lagoda, E. V. Yarosh, and E. V. Larina
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010405 organic chemistry ,Chemistry ,Ligand ,Aryl ,Organic Chemistry ,chemistry.chemical_element ,010402 general chemistry ,Photochemistry ,01 natural sciences ,0104 chemical sciences ,Catalysis ,Coupling (electronics) ,chemistry.chemical_compound ,Palladium - Published
- 2016
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10. Consideration of structural defects in modified synthetic fibres in determining their physicomechanical properties
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E. V. Yarosh, A. V. Artemov, and S. V. Frolov
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Synthetic fiber ,Materials science ,Chemical engineering ,General Chemical Engineering ,General Materials Science ,General Chemistry - Published
- 2000
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11. Methodology for Assessing the Risks of Information Enterprise Security Using Case Technologies
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А. V. Gavrilov, V. A. Sizov, and E. V. Yaroshenko
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information security ,risks ,case technologies ,business process ,idef0. ,Special aspects of education ,LC8-6691 - Abstract
Purpose of the study. Creating an effective information security system of an enterprise is impossible without an adequate assessment of the risks to which its assets are exposed. The results of such an assessment should become the basis for making decisions in the field of information security of the enterprise. Identification of information assets and assessment of their value, determination of the level of threats to the security of assets allow planning measures to create an enterprise information security system.This paper discusses a methodology for assessing the risks of information security of an enterprise, a distinctive feature and novelty of which is the use of modern tools and methods for constructing and analyzing business processes in order to identify the information assets of an enterprise to be protected.Materials and methods. It is proposed to identify information assets based on the model of business processes of the enterprise, performed using the IDEF0 methodology. Modeling of business processes was carried out in the Business Studio environment of the “Modern Management Technologies” company.The activity of a typical IT-industry company was considered as an example for the risk analysis.Results. The methodology for assessing the risks of information security of an enterprise described in the article has been successfully tested in the educational process. Its use in conducting laboratory classes in the discipline “Designing the information security system of enterprises and organizations” for masters studying in the direction of “Information security” allowed, according to the authors of the article, to increase the effectiveness of the formation of students’ professional competencies.Conclusion. The paper proposes a methodology for assessing information security risks for objects of an enterprise’s information infrastructure, which makes it possible to identify priority areas of information security at an enterprise. As a result of the application of the technique, a loss matrix is formed, showing the problem areas in the organization of information protection, which should be given priority attention when planning information security measures. Based on the data obtained, it is possible to form an economically justified strategy and tactics for the development of an enterprise information security system.
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- 2021
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12. Application of Data Mining Methods in the Design and Creation of New Products and Services
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A. A. Bryzgalov and E. V. Yaroshenko
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data mining methods ,kohonen self-organizing map ,consumer needs ,data analysis ,innovative design processes ,Special aspects of education ,LC8-6691 - Abstract
The purpose of research is to substantiate the need to use knowledge extraction methods in the design and creation of new products and services and the feasibility of using the Kohonen self-organizing map method through its formation. Such a map helps to identify previously unknown groups, in particular, as in the case of this article – consumer groups, and their analysis will make it possible to form new tariffs for the services of the mobile operator’s billing system. The main reason for the research is to show organizations the ability to design and create innovative products.Research methods are empirical in nature, based on the collection and accumulation of data on consumer behavior in the market and their subsequent analysis. In order to analyze the collected data, Data Mining methods are used, in particular, the Kohonen self-organizing map method, which allows to obtain automatic clustering of consumers in the market by various characteristics. Clustering was performed using the Kohonen self-organizing map algorithm implemented in the BaseGroup Labs Deductor Studio analytical platform. The choice of this software product is explained by a clear interface and the availability of the required functionality. The study was based on data provided by the mobile operator’s billing system. This is a fairly large amount of data showing the completed operations of mobile operator subscribers.Results. The article provides an overview of sources that offer possible methods for extracting knowledge and ways to process it. The Kohonen map is also built, which allows you to get information about the current situation for mobile subscribers from various independently selected areas. After analyzing this information, the revealed knowledge is applied in the formation of new tariffs and services of the mobile operator. This method of extracting knowledge can also be applied to other large volumes of data from various fields of activity. However, there is a limitation when using this type of knowledge extraction, which is that the data must be structured. If you use unstructured data, you can consider other methods for extracting knowledge described in this article.Conclusion. The article considers the stage of knowledge extraction when designing and creating new products and services based on Data Mining methods, in particular the self-organizing Kohonen map. Innovation in the design and creation of products and services is emphasized by the variability of data in accordance with the dynamic behavior of consumers in the market, which causes the need to periodically review the requirements and concepts of products and services brought to the market.
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- 2020
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13. Constructing network enterprise structure to create innovative products
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Yu. F. Telnov, V. M. Trembach, A. V. Danilov, E. V. Yaroshenko, V. A. Kazakov, and O. A. Kozlova
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network enterprise ,innovative product ,model-based enterprise ,reference architectural model for industrie 4.0 (rami) ,network enterprise ontology ,qfd ,quality function deployment ,fmea ,failure mode and effects analysis ,Special aspects of education ,LC8-6691 - Abstract
The subject of the study is the formation of the structure of a network enterprise, considered as a set of interacting enterprises in a networked Internet environment that implements a value chain. To build the structure of the network enterprise, it is proposed to use and support the ontology of the network enterprise, which conceptually reflects the models of products and related production and business processes throughout the life cycle. At the same time, the focus is on the implementation of flexible processes for creating innovative products using intelligent model-oriented technologies.The purpose of the study is to build an algorithm for forming the structure of a network enterprise that would ensure the best implementation of the value chain with minimal risks of mismatch of designs and production processes with qualitative value characteristics and requirements for an innovative product. The construction of an algorithm for forming the structure of a network enterprise involves solving the problems of modeling the structure of an innovative product based on an analysis of qualitative value characteristics and requirements for product components, its creation processes, distribution of roles of enterprise participants and analysis of their capabilities.Methods. As the main research method is the method of constructing a model of “digital thread” of creating an innovative product. The most complete application of this method is carried out as part of the reference model of enterprise architecture for Industrie 4.0 (RAMI). The resulting conceptual model of an innovative product and related production and business processes is implemented using an ontological approach. It is proposed to use a combination of QFD (Quality Function Deployment) methods for deploying the structure of a network enterprise and analyzing the types and consequences of potential FMEA (Failure Mode and Effects Analysis) inconsistencies.The main results of the study are ontology and the algorithm for forming the structure of the network enterprise. A distinctive feature of the proposed ontology of the network enterprise is a clear separation of the valuable qualitative characteristics of the product and the requirements for its creation, as well as the allocation of the abilities of participants in enterprises to implement the necessary processes. The novelty of the presented algorithm for the formation of the structure of a network enterprise lies in the combined application of the QFD and FMEA methods, as well as in the iteration of modeling the structure of an innovative product from the position of the best implementation of quality value characteristics and functional requirements.Conclusions, prospects. The proposed algorithm for creating the structure of a network enterprise allows you to get the best decisions on the criterion for assessing the highest rating for the implementation of quality characteristics and requirements for the components of the value chain and its participants, provided that minimal risk assessments of the mismatch between the designs and processes of creating innovative products are obtained. The developed ontology and the algorithm for forming the structure of the network enterprise is of practical importance for creating an intelligent system for supporting the adoption of innovative decisions for the dynamic construction of network enterprises in the Internet environment.
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- 2019
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14. Development of a prototype of multi-agent system of network interaction of educational institutions
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Yu. F. Telnov, A. V. Danilov, R. I. Diveev, V. A. Kazakov, and E. V. Yaroshenko
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information and educational space ,educational programs ,network interaction ,multi-agent system ,ontology ,agent interaction protocols ,Special aspects of education ,LC8-6691 - Abstract
The aim of the research is to develop a prototype of the intelligent multi-agent system for dynamic interaction of the intelligent agents in the integrated information and educational space to solve the problem of formation of joint educational programs by several educational institutions. Materials and methods. In modern conditions of digital transformation of education the organization of network training of students on dynamically formed educational programs in accordance with the needs of the labor market and the individual requirements of students is becoming increasingly important. It is proposed to develop a software platform based on intelligent multi-agent technology for flexible integration of educational resources and implementation of joint educational programs by several interacting educational institutions. As a basis for the development of the software prototype architecture, the specifications of the developer community for the standardization of agent technologies FIPA (the Foundation for Intelligent Physical Agents), and the software tool environment – JADE framework (Java Agent Development Network) were chosen.Results. The paper presents the architecture of intelligent multi-agent system for network interaction of educational institutions in the integrated information and educational space, which allows to dynamically forming educational programs in accordance with the requested professional competencies. The structure of the ontology of information and educational space, providing the interaction of intelligent agents, is justified, and the mechanism of its display from the OWL format to the format of the tool environment JADE, using the plugin Protege is described. The description of the software prototype, the structure of intelligent agents in the JADE format and the technology of agent interaction, based on the FIPA protocols in the process of educational programs formation is presented.Conclusion. The implementation of the multi-agent system prototype for network interaction of educational institutions allows you to quickly create educational programs in accordance with individual and group learning trajectories under the specific formed professional competence. The presented software prototype with some modification can be used for other subject areas of the digital economy, involving the dynamic formation of network structures of interaction for business partners.
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- 2019
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