Agnieszka Kącka-Zych

Cracow University of Technology | PK · Institute of Organic Chemistry and Technology

In the present work, the electronic structure and stability of acyclic nitronic acids were studied. Depending on the different substituents, the analyzed compounds can be classified as pseudo(mono)radical or zwitterionic nitronic acids. ELF topological analysis of the electron density of nitronic acids containing in their structure EWG substituent...

The Diels-Alder (DA) reaction between hexachlorocyclopentadiene and 1,2-dichloroethylene has been studied using the Molecular Electron Density Theory (MEDT) through Density Functional Theory (DFT) calculations at the B3LYP/6-31G(d) level. The electronics structure of the reagents has been characterized through the Electron Localization Function (EL...

Hetero Diels-Alder (HDA) reactions with the participation of E-2-aryl-1-cyano-1-nitroethenes (1a-g) and methylenecyclopentane (2) were evaluated on the basis of experimental as well as quantumchemical data [1]. It was found that contrary to most known HDA reactions, title processes are realised under non-catalytic conditions and with full regiocont...

Hetero Diels-Alder (HDA) reactions with the participation of E-2-aryl-1-cyano-1-nitroethenes and methylenecyclopentane were evaluated on the basis of experimental as well as quantumchemical data. It was found that contrary to most known HDA reactions, title processes are realised under non-catalytic conditions and with full regiocontrol. The DFT st...

[3+2] cycloaddition reactions of -COOMe and -CN trans-substituted nitroethenes with (Z)-C,N-diphenylimine N-oxide were tested. For the contrast to most known nitroalkene/nitrone cycloaditions, the reactions studied realized with the formation of 5-nitroisoxazolidines

The density functional theory computational study indicates the possibility of the synthesis of seven‐membered internal nitronates via cycloaddition reactions involving Z‐C‐aryl‐N‐methylnitrones and E‐2‐aryl‐1‐cyano‐1‐nitroethenes. The detailed exploration of the reaction paths indicates a polar, stepwise reaction mechanism through the zwitterionic...

In the framework of this paper we describe a new, green procedure for the synthesis of a series of 1,2-oxazine N-oxide moieties via Hetero Diels-Alder (HDA) reaction with the participation of (2E)-3-aryl-2-nitroprop-2-enenitriles. For the contrast of most known HDA reactions, the described process is realized without presence of Lewis acid-type cat...

The question of the reactivity of different substituted nitrylimine-type three atom components (TACs) in [3+2] cycloaddition (32CAs) reactions with electrophilically activated nitroethenes was explored within the Molecular Electron Density Theory (MEDT). In the course of parallel research, the molecular mechanism of considered transformation was ex...

In the present work, the formation of the four-membered cyclic nitronates and the retro (3+2) cycloaddition (retro-32CA) reaction of the 4H-[1,2]oxazete 2-oxide were studied using density func-tional theory method at the MPWB1K/6-311G(d,p) theoretical level. The electronic structure of 3-tert-butyl-4,4-dimethyl-1,2-dinitro-pent-2-ene was known thro...

Conversion of N-trialkylsilyloxy nitronates into bicyclic isoxazoline derivatives has been explored using Density Functional Theory (DFT) method within the context of the Molecular Electron Density Theory (MEDT) at the wB97XD(PCM)/6-311G(d,p) theoretical level. The obtained results clearly indicated that this reaction proceeds via a domino process,...

The reactions of -dehydronitration of furaxanenitrolic acids have been studied within the Density Functional Theory (DFT) using Molecular Electron Density Theory (MEDT) scheme at the MPWB1K(PCM)/6-311G(d,p) level of theory. The alteration of bonding along the course of the reaction is studied in the topology of the Electron Density Functional with...

The large and significant increase in carbon dioxide concentration in the Earth's atmosphere is a serious problem for humanity. The amount of CO2 is increasing steadily which causes a harmful greenhouse effect that damages the Earth's climate. Therefore, one of the current trends in modern chemistry and chemical technology are issues related to its...

The present paper is a continuation of comprehensive study regarding to synthesis and properties of pyrazoles and their derivatives. In its framework an experimental and theoretical studies of thermal decomposition of the 3,3-diphenyl-4-(trichloromethyl)-5-nitropyrazoline were performed. It was found, that the decompositions of the mentioned pyrazo...

The “green” and selective methodology for the preparation of precursors of cyclopropene-type inhibitors for the maturation of fruits or vegetables was described. It was found out that 2-nitroprop-1-ene undergoing reactions with diaryldiazomethanes under mild conditions yields 3,3-diphenyl-5-methyl-5-nitro-Δ1-pyrazolines. Under the applied condition...

The mechanism of the Diels-Alder reactions between perfluorobicyclo[2.2.0]hex-1(4)-ene (1a) and bicyclo[2.2.0]hex-1(4)-ene (1b) with benzene (2a) and naphthalene (2b) have been studied within the Density Functional Theory at the MPWB1K/6-311G(d,p) level. The bonding pattern in these reactions is analysed in the topology of the Electron Localization...

The structure and the contribution of the bis(2-chloroethyl) 2-nitro 1a and 2-bromo- 2-nitroethenylphosphonates 1b with anthracene 2 in the Diels–Alder (DA) reactions have been studied within the Molecular Electron Density Theory (MEDT) at the B3LYP functional together with 6-31G(d), 6-31+G(d) and 6-31+G(d,p) basic sets. Analysis of the Conceptual...

The [4+1] cycloaddition (41CA) and [2+1] cycloaddition (21CA) reactions of the α-halogeno-nitroalkenes with carbene have been studied using the Molecular Electron Density Theory (MEDT) through DFT calculations at the MPWB1K(PCM)/6-311G(d,p) computational level. The 41CA reaction take place through a polar two-step mechanism involving the formation...

The participation of the nitroethene and its α-substituted analogues as model nitrofunctionalyzed monomers, and (Z)-C,N-diphenylnitrone and methyl vinyl ether as initiators in the polymerisation reactions, has been analysed in the framework of the DensityFunctional Theory (DFT) calculations at the M06-2X(PCM)/6-311+G(d) level. Our computational stu...

The domino sequence of pseudocyclic reactions involving 4-methoxybenzonitrile N-oxide and trans-2-phenyl-1-cyano-1-nitroethene proceeding in mild (r.t.; atm. pressure) non-catalytic (without participation of palladium or other transition metals (TM)) conditions yielded a bis-heterobiarylic molecular system containing an oxadiazole moiety with an al...

The participation of different diaryldiazomethanes as three-atom components (TACs) in [3+2] cycloaddition reactions with (E)-3,3,3-trichloro-1-nitroprop-1-ene was analysed. All of the examined reactions occur with full regioselectivity, leading to respective 3,3-diaryl-4-trichloromethyl-5-nitro-Δ1-pyrazolines. Contrary to other known nitro-Δ1-pyraz...

The structure and the participation of the N-methoxy-N-[bis(methoxycarbonyl)methylene]amine N-oxide as model push-pull nitronate 1 with nitroethylene 2 in [3+2] cycloaddition (32CA) reaction have been analyzed within the Molecular Electron Density Theory (MEDT) using Density Functional Theory (DFT) calculations at the B3LYP(PCM)/6-31G(d) level. Top...

The molecular mechanism of elimination of the trimethylsilyl bromide (2) from 2-(trimethylsilyloxy)-3-bromo-3-methyl-isoxazolidines (1a-d) have been analysed within the Molecular Electron Density Theory (MEDT) using Density Functional Theory (DFT) calculations at the M06-2X(PCM)/6-31+G(d) computational level. These elimination reactions take place...

Reaction of 3-nitroisoxazoline-2-oxide with monosubstituted ethenes, first time documented fifty years ago, have been reviewed. Structures of phenyl and cyano derivatives of 1-aza-2,8-dioxabicyclo[3.3.0]octane produced in [3+2] cycloaddition (32CA) between styrene and acrylonitrile with 3-nitroisoxazoline-2-oxide were determined through single crys...

The characterization of the structure of nitronic ester and their rearrangement into nitronorbornene reactions has been analyzed within the Molecular Electron Density Theory (MEDT) using Density Functional Theory (DFT) calculations at the B3LYP/6-31G(d) computational level. Quantum-chemical calculations indicate that this rearrangement takes place...

The molecular mechanism of the decomposition reaction of nitroethyl benzoate (NEB-1) catalyzed by Lewis acids (LAs) based on aluminium metal, AlMe3 and AlCl3, in N,N-dimethylacetamide, has been analyzed within the molecular electron density theory (MEDT) using calculations at the B3LYP(PCM)/6-31+G(d) computational level. These LA catalyzed decompos...

In this review we present recent progress in the cycloaddition reactions of conjugated nitroalkenes with alkenes, conjugated 1,3-dienes or three atoms components (eg. nitrones, azides, diazocompounds, azomethine imines and ylides).

Theoretically possible reaction paths of [3+2] cycloaddition (32CA) between homogenous group of (Z)-C-aryl-N-phenylnitrones and 2-methyl-1-nitroprop-1-ene were explored in detail using B3LYP/6-31G(d) level of theory. All the considered 32CA processes are initiated by attack of the most nucleophilic oxygen atom in nitrone molecule to the most electr...

Reaction paths of [3+2] cycloaddition (32CA) between 2-methyl-1-nitroprop-1-ene and (Z)- C-aryl-N-phenylnitrones were explored in detail using B3LYP/6-31G(d) level of theory. All the considered 32CA processes are initiated by attack of the most nucleophilic oxygen atom in nitrone molecule to the most electrophilic beta-carbon atom in nitroethylene...

5-(Nitromethyl)-3-phenyl-4,5-dihydroisoxazole was obtained as a product of a high-yielding [3 + 2] cycloaddition reaction of in situ-generated benzonitrile N-oxide and 3-nitroprop-1-ene. For the first time, the regiochemistry of this reaction was unambiguously proven by X-ray structural analysis. The quantum-chemical calculation performed at the M0...

The molecular mechanisms of the decomposition reactions of nitroethyl benzoates catalyzed by Lewis acids based on boron element – BH3 and BF3 – was studied using density functional theory methods. These reactions take place much faster than the uncatalyzed process. However, the presence of fluorinated Lewis acids has a unique influence on the molec...

This work is a continuation of our study on the chemistry of 2-aryl-1-cyano-1-nitroethenes. In this paper, we have described the reactivity of 2-aryl-1-cyano-1-nitroethenes as a key component in [2+3] and [2+4] cycloaddition reactions, and in other transformations.

Triethylsulfonium and triethylphosphonium cations as novel catalysts for the decomposition process of nitroethyl benzoates All authors Agnieszka Kącka & Radomir Jasiński DOI http://dx.doi.org/10.1080/10426507.2017.1290626 Published online 13 February 2017 PowerPoint slideOriginal jpg (72.00KB)Display full size

The molecular mechanism of the decomposition reaction of nitroethyl benzoate (NEB) 1 yielding nitroethylene 2 and benzoic acid 3 has been studied within the Molecular Electron Density Theory (MEDT) using DFT methods at the B3LYP/6-31G(d) computational level. This decomposition reaction takes place through a one-step mechanism. Bonding Evolution The...

Reactions between (E)-2-aryl-1-cyano-1-nitroethenes and diazafluorene lead to acyclic 2,3-diazabuta-1,3-diene derivatives, instead of the expected pyrazoline systems. DFT calculations suggest that this is a consequence of formation of zwitterionic structure in the first stage of the reaction. It must be noted that this is a specific property of the...

DFT calculations at different theory levels, indicate consistently, that in the presence of ethylammonium cation, a nitroethyl benzoates decomposition process is expected to take place much faster than under “conventional” (non-catalyzed) conditions. The one-step mechanism being replaced by a two-step mechanism involving a zwitterionic intermediate...

DFT calculations indicate that the decomposition reaction of nitroethyl benzoates in the presence of 1,3-dimethylimidazolium cation takes place much faster than in the case of the non-catalyzed process. Additionally, our calculations suggest one-step, polar mechanism of title reaction

A review of processes for prepn. of aliph. nitrocomps. by nucleophilic substitution involving the nitrite anion. Several reactions carried out via green protocol under mild conditions were also included.

Quantum"chemical study of thermal decomposition reactions of model nitroethyl carboxylates were studied using various DFT theory levels. It was found that conversion esters into nitroalkenes demean according to one"step mechanism. However, it is not expected “pericyclic” mechanism but “one"step two" stage” process. Subsequently, also nitrous acid e...

1,3-Dipolar cycloaddition reactions between ketonitrones (1a-e) and β-substituted nitroalkenes (2a-d) proceed under mild conditions, with complete regioselectivity, and lead with high yields to sterically crowded 2,3,3,5-tetrasubstituted-4-nitroisoxazolidines (3a-f). Reaction course may be interpreted on the basis of nature of local, nucleophile-el...

The utilization of chiral phosphorus ligands in atroposelective cross-coupling reactionsAll authorsOleg M. Demchuka*, Katarzyna Kapłona, Agnieszka Kąckab & K. Michał PietrusiewiczaDOI:http://dx.doi.org/10.1080/10426507.2015.1079197Published online:06 February 2016PowerPoint slideOriginal jpg (171.00KB)Display full sizeAtroposelective synthesis of a...

1,3-Dipolar cycloaddition reactions between ketonitrones and 2-EWG-substituted nitroethenes proceed under mild conditions, with complete regioselectivity, and lead with high yields to sterically crowded 2,3,3,5-tetrasubstituted-4-nitroisoxazolidines. Subsequently we have performed a study about reaction course in ionic liquid instead of “convention...

Cycloaddition reactions involving conjugated dienes and their heteroanalogs of 2π-electron systems (Diels-Alder reactions – DAR) are the most versatile, stereo controlled method of synthesis of six-carbon or heterocyclic rings. The concept of concerted perfectly pericyclic mechanism of these reactions, however, still lingers in some academic textbo...

Using DFT calculations at various theory levels, quantum-chemical simulations of decomposition paths were performed for a series of nitroalkyl benzoates. It was discovered, that these reactions proceed via polar, but one-step mechanism. It turned out that depending on the nature of the substituent in the ester molecule and on medium polarity, the s...

Analysis of addent interactions with respect to the theory of electrophilicity and nucleophilicity indexes and kinetic studies shows the polar nature of [2+3] cycloaddition of (Z)-C-(m,m,p-trimethoxyphenyl)-N-(p-methylphenyl)-nitrone to (E)-3,3,3-trichloro-1-nitroprop-1-ene. However, PES exploration results do not confirm any zwitterion on the reac...

The mechanistic aspects of the hetero Diels-Alder (HDA) reactions between between strongly electrophilic (E)-2-aryl-1-cyano-1-nitroethenes and ethyl vinyl ether has been analyzed on the basis of kinetic experimental results as well as quantum chemical simulations of reaction paths. These reactions may theoretically proceed via one step or stepwise,...