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Radomir Jasiński - One of the best experts on this subject based on the ideXlab platform.
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A DFT study on the molecular mechanism of the conjugated nitroalkenes polymerization process initiated by selected unsaturated nucleophiles
Theoretical Chemistry Accounts, 2020Co-Authors: Agnieszka Kącka-zych, Radomir JasińskiAbstract:The participation of the Nitroethene and its α-substituted analogs as model nitrofunctionalized monomers, and (Z)-C,N-diphenylnitrone and methyl vinyl ether as initiators in the polymerization reactions, has been analyzed in the framework of the density functional theory calculations at the M06-2X(PCM)/6-311 + G(d) level. Our computational study suggests the zwitterionic mechanism of the polymerization process. The exploration of the nature of critical structures shows that the first reaction stage exhibits evidently polar nature, whereas additions of further nitroalkene molecules to the polynitroalkyl molecular system formed should be considered as moderate polar processes. The more detailed view on the molecular transformations gives analysis based on the bonding evolution theory. This study shows that the case of polymerization reaction between Nitroethene and (Z)-C,N-diphenylnitrone allows for distinguishing eleven topologically different phases, while, in the case of polymerization reaction Nitroethene and methyl vinyl ether, we can distinguish nine different phases.
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Selenyl analog of the (Z)-C,N-diphenylnitrone as the TAC in [3 + 2] cycloaddition with Nitroethene: A DFT computational study
Phosphorus Sulfur and Silicon and the Related Elements, 2020Co-Authors: Radomir JasińskiAbstract:The molecular mechanism of [3 + 2] cycloaddition (32CA) process between selenyl analog of the (Z)-C,N-diphenylnitrone and Nitroethene was examined on the basis of the M06-2X/6-311 + G(d)(PCM) calcu...
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selenyl analog of the z c n diphenylnitrone as the tac in 3 2 cycloaddition with Nitroethene a dft computational study
Phosphorus Sulfur and Silicon and The Related Elements, 2020Co-Authors: Radomir JasińskiAbstract:The molecular mechanism of [3 + 2] cycloaddition (32CA) process between selenyl analog of the (Z)-C,N-diphenylnitrone and Nitroethene was examined on the basis of the M06-2X/6-311 + G(d)(PCM) calcu...
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Competition between [2 + 1]- and [4 + 1]-cycloaddition mechanisms in reactions of conjugated nitroalkenes with dichlorocarbene in the light of a DFT computational study
Journal of Molecular Modeling, 2019Co-Authors: Radwan A. Alnajjar, Radomir JasińskiAbstract:The competition between [2 + 1] and [4 + 1] channels regarding reactions of conjugated nitroalkenes with dichlorocarbene was explored based on B3LYP/6-31G(d) calculations. It was found that, in the case of cycloadditions involving parent Nitroethene and its 1-substituted analogs, the [2 + 1] scheme should be treated as possible only from the kinetic process point of view. On the other hand, in similar reactions involving 2-substituted Nitroethenes, both channels considered may compete. Additionally, mechanistic aspects of all cycloadditions were analyzed. It was found that the considered [2 + 1]-cycloadditions proceed via a non-polar mechanism with a biradicaloidal transition state (TS), whereas [4 + 1]-cycloadditions proceed via a polar mechanism with a zwitterionic TS.
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Competition between [2 + 1]- and [4 + 1]-cycloaddition mechanisms in reactions of conjugated nitroalkenes with dichlorocarbene in the light of a DFT computational study
Journal of molecular modeling, 2019Co-Authors: Radwan Alnajjar, Radomir JasińskiAbstract:The competition between [2 + 1] and [4 + 1] channels regarding reactions of conjugated nitroalkenes with dichlorocarbene was explored based on B3LYP/6-31G(d) calculations. It was found that, in the case of cycloadditions involving parent Nitroethene and its 1-substituted analogs, the [2 + 1] scheme should be treated as possible only from the kinetic process point of view. On the other hand, in similar reactions involving 2-substituted Nitroethenes, both channels considered may compete. Additionally, mechanistic aspects of all cycloadditions were analyzed. It was found that the considered [2 + 1]-cycloadditions proceed via a non-polar mechanism with a biradicaloidal transition state (TS), whereas [4 + 1]-cycloadditions proceed via a polar mechanism with a zwitterionic TS.
V. M. Berestovitskaya - One of the best experts on this subject based on the ideXlab platform.
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Dipole moments and quantum chemical study of the structure of furan-containing gem-bromoNitroethenes
Russian Journal of Organic Chemistry, 2015Co-Authors: Ya. A. Vereshchagina, D. V. Chachkov, R. R. Khanafieva, A. Z. Alimova, V. M. Berestovitskaya, S. V. Makarenko, S. S. EliseenkoAbstract:As shown by the dipole moment method and quantum chemical calculations, 1-(furan-2-yl)-2-Nitroethene and 1-nitro-2-(5-nitrofuran-2-yl)ethenes exist in solution as E - s - trans isomers while 1-bromo-2- (5-bromofuran-2-yl)-1-Nitroethene and 1-bromo-1-nitro-2-(5-nitrofuran-2-yl)ethene have Z - s - cis configuration.
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Polarity and structure of 2-(1-methylbenzimidazol-2-yl)-1-phenyl- and -1,2-diphenyl-1-Nitroethenes
Russian Journal of General Chemistry, 2012Co-Authors: E. A. Ishmaeva, Ya. A. Vereshchagina, D. V. Chachkov, A. Z. Alimova, I. A. Litvinov, E. S. Ostroglyadov, O. S. Vasil’eva, A. A. Nikonorov, D. B. Krivolapov, V. M. BerestovitskayaAbstract:Polarity of 2-(1-methylbenzimidazol-2-yl)-1-phenyl- and -1,2-diphenyl-1-Nitroethenes was determined and their structure was studied using electronic and ^1H, ^13C NMR spectroscopy, dipole moments measuring, XRD analysis, and quantum-chemical calculations. It was shown that the 2-(1-methylbenzimidazol-2-yl)-1-nitro-1-phenylethene has Z -configuration both in crystal and solution. The nitro group and benzimidazole substituent in its molecule are removed from the plane of the double bond. For 1,2-diphenyl-1-Nitroethene E -structure is typical.
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α-Nitro chalcones: Structure and reaction with pyrrole
Russian Journal of General Chemistry, 2009Co-Authors: V. M. Berestovitskaya, R. I. Baichurin, N. I. Aboskalova, K. A. Lysenko, G. A. Berkova, A. V. Fel’gendlerAbstract:According to the ^1H NMR, IR, and electronic absorption spectra and X-ray diffraction data, 2-aryl-1-benzoyl-1-Nitroethenes have E configuration with predominant s-cis conformation, where the nitro group lies in the plane of the double carbon-carbon bond, while the carbonyl group deviates from that plane. Reactions of 2-aryl-1-benzoyl-1-Nitroethenes with pyrrole and N -methylpyrrole gave the corresponding alkylation products at the C^2 atom in the heteroring.
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Fourier transform IR spectra and structure of 2-substituted 1-nitro- and 1-bromo-1-Nitroethenes
Russian Journal of General Chemistry, 2007Co-Authors: A. A. Gazizova, Ya. A. Vereshchagina, D. V. Chachkov, R. R. Shagidullin, Alla V. Chernova, Eleonora A. Ishmaeva, V. M. BerestovitskayaAbstract:Molecular structure and vibrational spectra of 2-trichloromethyl(ethoxycarbonyl)-1-Nitroethenes and 2-trichloromethyl(ethoxycarbonyl)-1-bromo-1-Nitroethenes were calculated in terms of the density functional theory (B3LYP/6-31G*). The experimental FTIR spectra of these compounds in the range from 4000 to 400 cm−1 were interpreted in detail on the basis of the calculation data. 2-Substituted 1-nitro- and 1-bromo-1-Nitroethenes were assigned the structure with trans orientation of the nitro and trichloromethyl (or ethoxycarbonyl) groups, and the ethoxycarbonyl derivatives were assumed to exist in equilibrium between s-cis and s-trans conformers.
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Synthesis and Structure of Indole-, Pyridine-, and Benzimidazole-Containing Nitroethenes
Russian Journal of General Chemistry, 2004Co-Authors: V. M. Berestovitskaya, Ya. A. Vereshchagina, E. A. Ishmaeva, I. A. Litvinov, O. S. Vasil'eva, E. S. Ostroglyadov, G. R. Fattakhova, D. V. Beskrovnyi, S. M. AleksandrovaAbstract:Previously unknown 2-(1,2-dimethylindol-3-yl)-1-Nitroethene was synthesized, and procedures for preparing 2-(1-methylbenzimidazol-2-yl)- and 2-(3-pyridyl)-1-nitroethens were improved. The structures of the products were determined by spectroscopic methods and from their dipole moments. According to single crystal X-ray diffraction data, the ( E )-2-(1-methylbenzimidazol-2-yl)-1-Nitroethene molecules are virtually planar and are packed in stacks in the crystal lattice, with appreciable stacking interaction.
Dieter E Kaufmann - One of the best experts on this subject based on the ideXlab platform.
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reinvestigation of the nitration of tri chloroethene subsequent reactions of the products and evaluation of their anti microbial and antifungal activity
European Journal of Organic Chemistry, 2015Co-Authors: Viktor A Zapolskii, Jan C Namyslo, Galina Sergeev, Mark Bronstrup, Mimoza Gjikaj, Dieter E KaufmannAbstract:The nitration reaction of trichloroethene (1) to main products trichloroNitroethene (TCNiE 2, up to 60.8 %, by GC), 1,1,2,2-tetrachloro-1-nitroethane (8, up to 25.1 %, by GC), and 1,2,2-trichloro-2-nitroethyl [chloro(nitro)methylene]azinate (9, up to 8.0 %, by GC) was comprehensively investigated and optimized. Different 1,1-diamino-2-chloro-2-Nitroethenes, 2-nitroethoxyguanidines, and rare O-(1,2,2-trichloro-2-nitroethyl) oximes and carbimidoyl halides with unique formulas R–O–N=C(NO2)NRR1 and R–O–N=C(Hal)NRR1, respectively, were obtained from these nitration products in yields up to 91 %. The structure of (E)-morpholino(nitro)methanone O-(1,2,2-trichloro-2-nitroethyl) oxime (19) was proven by single-crystal X-ray diffraction analysis. In addition, the antimicrobial and antifungal activity of the synthesized compounds was examined. Notably, N-(1,2,2-trichloro-2-nitroethoxy)-3,4-dihydroisoquinoline-2(1H)carbimidoyl chloride (27) inhibited the growth of methicillin-resistant and sensitive Staphylococcus aureus with minimum inhibitory concentrations of 1.3 μg mL–1, and reduced the viability of the MCF-7 cancer cell line with an IC50 of 0.2 μg/mL.
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Chemistry of HaloNitroethenes,1: First Synthesis of Functionalized 3-Chloroquinoxalin-2(1H)-one 4-Oxides
Synthesis, 2008Co-Authors: Christian Meyer, Viktor A. Zapol'skii, Arnold Adam, Dieter E KaufmannAbstract:A one-pot annulation reaction of aniline and its ring-sub- stituted derivatives with 1,1,2-trichloro-2-Nitroethene (TCNiE) was developed delivering 3-chloroquinoxalin-2(1H)-one 4-oxides, ex- clusively, in good yields. The structure was proved by X-ray analy- sis. The C-N cyclization, a competing reaction to the double SNVin reaction of 1,1,2-trichloro-2-Nitroethene with amines, can be con- trolled by the mode of addition. Some of the resulting quinoxalin- ones are promising candidates with respect to their prospective biological, especially pharmacological, activity.
David J. Nisbet - One of the best experts on this subject based on the ideXlab platform.
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Effects of oral nitroethane administration on enteric methane emissions and ruminal fermentation in cattle
Animal Feed Science and Technology, 2011Co-Authors: Erin G. Brown, Héctor Gutiérrez-bañuelos, Robin C. Anderson, Gordon E Carstens, Lisa J. Slay, Todd R. Callaway, Jackson L. Mcreynolds, David J. NisbetAbstract:Abstract Methane is a potent greenhouse gas and its release to the atmosphere is widely believed to contribute to global warming. Ruminal enteric CH4 production represents a loss of 2–15% of the animal's gross energy (GE) intake and contributes nearly 20% of US CH4 emissions. Studies have evaluated the CH4 inhibiting potential of select short chain nitrocompounds, such as nitroethane, but results demonstrating their effects on ruminant exhaled CH4 emissions are lacking. Our study determined effects of oral nitroethane administration on CH4 emissions, accumulations of volatile fatty acids (VFA) and on ruminal CH4 producing activity in steers fed a forage based diet containing 8.8 MJ/kg of metabolizable energy on a dry matter (DM) basis. Effects of nitroethane administration on ruminal nitroethane reducing activity were also determined. Holstein steers (n = 24) of 317 ± 6.5 kg body weight (BW) were assigned to 4 treatments that included: 0, 30, 60 and 120 mg nitroethane/kg BW/d. Treatments were administered via oral gavage twice daily at 08:00 and 16:00 h for 8 d. DM intake decreased quadratically as level of nitroethane increased with steers administered 60 and 120 mg nitroethane/kg BW consuming 14 and 7% lower DM, respectively, than steers administered 0 or 30 mg nitroethane/kg BW. Methane emissions as a proportion of GE intake and ruminal CH4 producing activity both decreased linearly (P This paper is part of the special issue entitled: Greenhouse Gases in Animal Agriculture – Finding a Balance between Food and Emissions, Guest Edited by T.A. McAllister, Section Guest Editors: K.A. Beauchemin, X. Hao, S. McGinn and Editor for Animal Feed Science and Technology, P.H. Robinson.
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Effects of nitroethane and monensin on ruminal fluid fermentation characteristics and nitrocompound-metabolizing bacterial populations.
Journal of agricultural and food chemistry, 2008Co-Authors: Héctor Gutiérrez-bañuelos, Robin C. Anderson, Gordon E Carstens, Todd R. Callaway, Luis O Tedeschi, William E. Pinchak, Elisa Cabrera-diaz, Nathan A. Krueger, David J. NisbetAbstract:Nitroethane is a potent inhibitor of ruminal CH4 production, a digestive inefficiency resulting in the loss of 2-15% of a ruminant’s gross energy intake and an important emission source of this greenhouse gas. To assess the effect of nitroethane on methanogenesis and characterize ruminal adaptation observed with low treatment doses to this inhibitor, ruminal microbes were cultured in vitro with supplements of water (controls), 4.5 and 9 mM nitroethane, and 0.09 mM monensin, with or without 9 mM nitroethane. All treatments decreased CH4 production >78% compared to controls; however, differential effects of treatments were observed on CO2, butyrate isobutyrate, and valerate production. Treatments did not affect H2 accumulation or acetate and propionate production. Most probable numbers of nitrometabolizing bacteria were increased with 4.5 and 9 mM nitroethane compared to numbers recovered from controls or monensin-containing treatments, which may explain ruminal adaptation to lower nitroethane treatments.
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Zoonotic bacterial populations, gut fermentation characteristics and methane production in feedlot steers during oral nitroethane treatment and after the feeding of an experimental chlorate product.
Anaerobe, 2007Co-Authors: Héctor Gutiérrez-bañuelos, Robin C. Anderson, Gordon E Carstens, Lisa J. Slay, N. Ramlachan, Shane M. Horrocks, Todd R. Callaway, Thomas S. Edrington, David J. NisbetAbstract:Abstract Nitroethane inhibits the growth of certain zoonotic pathogens such as Campylobacter and Salmonella spp., foodborne pathogens estimated to cause millions of human infections each year, and enhances the Salmonella- and Escherichia coli-killing effect of an experimental chlorate product being developed as a feed additive to kill these bacteria immediately pre-harvest. Limited studies have shown that nitroethane inhibits ruminal methane production, which represents a loss of 2–12% of the host's gross energy intake and contributes to global warming and destruction of the ozone layer. The present study was conducted to assess the effects of 14-day oral nitroethane administration, 0 (0X), 80 (1X) or 160 (2X) mg nitroethane/kg body weight per day on ruminal and fecal E. coli and Campylobacter, ruminal and fecal methane-producing and nitroethane-reducing activity, whole animal methane emissions, and ruminal and fecal fermentation balance in Holstein steers ( n = 6 per treatment) averaging 403±26 (SD) kg BW. An experimental chlorate product was fed the day following the last nitroethane administration to determine effects on E. coli and Campylobacter. The experimental chlorate product decreased ( P 0.001 ) fecal, but not ruminal ( P > 0.05 ) E. coli concentrations by 1000- and 10-fold by 24 and 48 h, respectively, after chlorate feeding when compared to pre-treatment concentrations (>5.7 log10 colony forming units/g). No effects ( P > 0.05 ) of nitroethane or the experimental chlorate product were observed on fecal Campylobacter concentrations; Campylobacter were not recovered from ruminal contents. Nitroethane treatment decreased ( P 0.01 ) ruminal (8.46, 7.91 and 4.74±0.78 μmol/g/h) and fecal (3.90, 1.36 and 1.38±0.50 μmol/g/h) methane-producing activity for treatments 0X, 1X and 2X, respectively. Administration of nitroethane increased ( P 0.001 ) nitroethane-reducing activity in ruminal, but not fecal samples. Day of study affected ruminal ( P 0.0001 ) but not fecal ( P > 0.05 ) methane-producing and nitroethane-reducing activities ( P 0.01 ); treatment by day interactions were not observed ( P > 0.05 ). Ruminal accumulations of acetate decreased ( P 0.05 ) in 2X-treated steers when compared with 0X- and 1X-treated steers, but no effect ( P > 0.05 ) of nitroethane was observed on propionate, butyrate or the acetate to propionate ratio. Whole animal methane emissions, expressed as L/day or as a proportion of gross energy intake (%GEI), were unaffected by nitroethane treatment ( P > 0.05 ), and were not correlated ( P > 0.05 ) with ruminal methane-producing activity. These results demonstrate that oral nitroethane administration reduces ruminal methane-producing activity but suggest that a microbial adaptation, likely due to an in situ enrichment of ruminal nitroethane-reducing bacteria, may cause depletion of nitroethane, at least at the 1X administration dose, to concentrations too low to be effective. Further research is warranted to determine if the optimization of dosage of nitroethane or related nitrocompouds can maintain the enteropathogen control and anti-methanogen effect in fed steers.
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Effect of oral nitroethane and 2-nitropropanol administration on methane-producing activity and volatile fatty acid production in the ovine rumen.
Bioresource technology, 2005Co-Authors: Robin C. Anderson, Gordon E Carstens, Todd R. Callaway, Thomas S. Edrington, R.k. Miller, C.l. Schultz, Roger B. Harvey, David J. NisbetAbstract:Strategies are sought to reduce economic and environmental costs associated with ruminant methane emissions. The effect of oral nitroethane or 2-nitropropanol administration on ruminal methane-producing activity and volatile fatty acid production was evaluated in mature ewes. Daily administration of 24 and 72 mg nitroethane/kg body weight reduced (P < 0.05) methane-producing activity by as much as 45% and 69% respectively, when compared to control animals given no nitroethane. A daily dose of 120 mg 2-nitropropanol/kg body weight was needed to reduce (P < 0.05) methane-producing activity by 37% from that of untreated control animals. Reductions in methane-producing activity may have been diminished by the last day (day 5) of treatment, presumably due to ruminal adaptation. Oral administration of nitroethane or 2-nitropropanol had little or no effect on accumulations or molar proportions of volatile fatty acids in ruminal contents collected from the sheep. These results demonstrate that nitroethane was superior to 2-nitropropanol as a methane inhibitor and that both nitrocompounds reduced ruminal methanogenesis in vivo without redirecting the flow of reductant generated during fermentation to propionate and butyrate.
Ladislav Petruš - One of the best experts on this subject based on the ideXlab platform.
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A straightforward route to N-acetyl-d-glucosamine-derived C-β-D-Glycosyl synthons
Tetrahedron Letters, 1996Co-Authors: Mária Petrušová, James N. Bemiller, Ladislav PetrušAbstract:Abstract A practical synthesis of formaldehyde, Nitroethene, and nitroethane C -glycosylated with a 2-acetamido-2-deoxy-β- d -glucopyranosyl group is described. Synthesis follows the nitromethane route and involves an unusual, intramolecularly catalyzed β-elimination of acetic acid and pH-controlled ozonolysis of nitronate salts.
