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Journal articles on the topic 'Alkenes Benzene'

Author: Grafiati

Published: 4 June 2021

Last updated: 15 February 2022

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1

Zhang, Pengfei, and Zhenchu Chen. "Hypervalent Iodine in Synthesis 74: Synthesis and Reactivity of New Functionalised Alkenyliodonium Salts1." Journal of Chemical Research 2003, no. 9 (September 2003): 570–71. http://dx.doi.org/10.3184/030823403322597342.

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β-Amino substituted α,β-unsaturated ketones react with [hydroxy(tosyloxy)iodo]benzene to afford the corresponding alkenyl(phenyl)iodonium tosylates; these new α-acyl-β-aminoalkenyl(phenyl)iodonium tosylates offer an easy access to highly functionalised alkenes upon reaction with verious nucleophiles

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2

Rajapakse, Nimal, Brian R. James, and David Dolphin. "Alkyne and alkene complexes of (tetramesitylporphyrinato)ruthenium(II)." Canadian Journal of Chemistry 68, no. 12 (December 1, 1990): 2274–77. http://dx.doi.org/10.1139/v90-350.

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The reactions of benzene or toluene solutions of RuII(TMP), where TMP is the dianion of 5,10,15,20–tetramesitylporphyrin, with some acetylenes and alkenes are reported. Acetylene yields the isolable [Ru(TMP)]2(μ-C2H2) species; while with phenylacetylene or diphenylacetylene, 1:1 π-complexes are formed. The π-complexes Ru(TMP)(C2H4) and Ru(TMP)-(C2H4)(iPrOH)•iPrOH are isolated from reactions with ethylene, and a similar cyclohexene species is characterized insitu. The findings are relevant to O2-epoxidation of alkenes catalyzed by the trans-Ru(TMP)(O)2 complex. Keywords: ruthenium, porphyrin (tetramesityl), alkene complexes, alkyne complexes.

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3

Hoffmann, Norbert. "Photochemical Cycloaddition between Benzene Derivatives and Alkenes." Synthesis, no. 4 (2004): 481–95. http://dx.doi.org/10.1055/s-2004-815973.

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4

Huang, Jiuzhong, Wuxin Yan, Chaowei Tan, Wanqing Wu, and Huanfeng Jiang. "Palladium-catalyzed regioselective hydroboration of aryl alkenes with B2pin2." Chemical Communications 54, no. 14 (2018): 1770–73. http://dx.doi.org/10.1039/c7cc09432a.

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5

Meyer, Lars, Nacira Alouane, Kerstin Schmidt, and Paul Margaretha. "Photocycloaddition of cyclohex-2-enones to acrylonitrile." Canadian Journal of Chemistry 81, no. 6 (June 1, 2003): 417–22. http://dx.doi.org/10.1139/v03-016.

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The photocycloaddition of cyclohex-2-enones 1a, 1b, and 5a5c to acrylonitrile (2) in benzene has been studied. The reactions proceed with moderate regioselectivity and with preferential formation of diastereomeric mixtures of endo- and exo-5-oxobicyclo[4.2.0]octane-7-carbonitriles 3, 4, and 68. Very similar relative rates of conversion to products are observed in the photocycloadditions of 1b, 5a, and 5b to 2 and methacrylonitrile (9), respectively. In contrast, 5,5-dimethylcyclohex-2-enone (1b) forms cycloadducts with 2,3-dimethylbut-2-ene (12) as efficiently as with the unsaturated nitriles, but the 2,5,5-trialkylcyclohex-2-enones 5a and 5b do not react with this alkene at measurable rates of conversion. A dual path mechanism is presented that involves either exciplex formation between triplet-excited cyclohexenones and electron-rich alkenes or radical addition of the former to electron-deficient alkenes bearing a substituent, exercising a resonance effect.Key words: [2+2]-photocycloaddition, cyclobutane, cyclobutanecarbonitrile, radical addition to unsaturated nitriles.

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6

Lin, Zhiyang, Youxiang Jin, Weitao Hu, and Chuan Wang. "Nickel-catalyzed asymmetric reductive aryl-allylation of unactivated alkenes." Chemical Science 12, no. 19 (2021): 6712–18. http://dx.doi.org/10.1039/d1sc01115d.

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A nickel-catalyzed reductive asymmetric aryl-allylation of tethered unactivated alkenes has been developed, providing diverse benzene-annulated cyclic compounds bearing a quaternary stereocenter with high regio-, E/Z- and enantio-selectivity.

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7

Jin, Youxiang, and Chuan Wang. "Ni-catalysed reductive arylalkylation of unactivated alkenes." Chemical Science 10, no. 6 (2019): 1780–85. http://dx.doi.org/10.1039/c8sc04279a.

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8

Zhang, Zhipeng, Ying-jun Zhou, and Xiao-Wei Liang. "Total synthesis of natural products using photocycloaddition reactions of arenes." Organic & Biomolecular Chemistry 18, no. 29 (2020): 5558–66. http://dx.doi.org/10.1039/d0ob01204a.

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The photocycloaddition reaction of benzene with alkenes has become a significant approach for organic chemists and thus has been frequently utilized as a key step in the total synthesis of natural products.

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9

Trinh, Khang H., Son H. Doan, Tien V. Huynh, Phuong H. Tran, Diep N. Pham, Minh-Vien Le, Tung T. Nguyen, and Nam T. S. Phan. "Alternative pathways to α,β-unsaturated ketones via direct oxidative coupling transformation using Sr-doped LaCoO 3 perovskite catalyst." Royal Society Open Science 6, no. 11 (November 2019): 191313. http://dx.doi.org/10.1098/rsos.191313.

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A strontium-doped lanthanum cobaltite perovskite material was prepared, and used as a recyclable and effective heterogeneous catalyst for the direct oxidative coupling of alkenes with aromatic aldehydes to produce α,β-unsaturated ketones. The reaction afforded high yields in the presence of di- tert -butylperoxide as oxidant. Single oxides or salts of strontium, lanthanum and cobalt, and the undoped perovskite offered a lower catalytic activity than the strontium-doped perovskite. Benzaldehyde could be replaced by benzyl alcohol, dibenzyl ether, 2-oxo-2-phenylacetaldehyde, 2-bromoacetophenone or (dimethoxymethyl) benzene in the oxidative coupling reaction with alkenes. To our best knowledge, reactions between these starting materials with alkenes are new and unknown in the literature.

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10

Śliwak, Agata, Stanisław Gryglewicz, Józef Hoffmann, and Grażyna Gryglewicz. "Precursors of volatile organic compounds emitted during phosphorite processing." Polish Journal of Chemical Technology 14, no. 2 (January 1, 2012): 62–69. http://dx.doi.org/10.2478/v10026-012-0072-7.

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Precursors of volatile organic compounds emitted during phosphorite processing The composition of solvent-soluble organic matter of phosphorite, which is a precursor of volatile organic compounds emitted by the fertilizer industry, was studied. A benzene-methanol mixture and chloroform were used for the extraction of free and bound bitumen from phosphorites, respectively. The separated bitumen fractions were characterized qualitatively by GC-MS and quantitatively by GC-FID. n-Alkanes, n-alkenes, fatty acids and isoprenoids were identified in the extracts. The main components were n-alkanes and n-alkenes, constituting over 80% of the total bitumen determined. An unexpected presence of n-alkenes only in the free bitumen fraction was found. The possible source of ill-smelling substances evolved during treatment of phosphorite with H2SO4 was discussed.

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11

AlJunaibi, Fatima, Hanan Aldhanhani, Halima Alawani, Amnah Al Hmoudi, Abdullah Al-Hemyari, and Thies Thiemann. "Deuteration of Alkenes with NaBD4/AcOD in Pre-Sence of Pd on Carbon." Proceedings 41, no. 1 (November 14, 2019): 6. http://dx.doi.org/10.3390/ecsoc-23-06461.

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Activated alkenes such as cinnamates and chalcones can easily be converted to 2,3-dideuterio-arylpropionates and dideuteriochalcones, respectively, by the action of NaBD4, AcOD in the presence of Pd on carbon. Toluene or benzene was used as solvent. It was shown that Pd on carbon was necessary for the reaction to proceed. Deuterium addition experiments were also carried out with NaBD4, AcOD, D2O in the presence of Pd on carbon.

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12

McIntosh, John M., and Randy K. Leavitt. "A brief survey of the use of the Pummerer rearrangement for the alkylation of 1,3-oxathiolan-5-ones and 1,3-thiazolidin-4-ones." Canadian Journal of Chemistry 63, no. 12 (December 1, 1985): 3312–16. http://dx.doi.org/10.1139/v85-548.

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Oxidation of 1,3-oxathiolan-5-ones (1) gives acceptable yields of sulfoxides only when C4 is unsubstituted. Sulfoxides derived from 1,3-thiazolidine-4-ones (8) are easily prepared. Acid-catalyzed rearrangement in the presence of 1-alkenes or benzene leads to alkylation (arylation) at C5. Alkylation of 8c may be generally more effective than that of 1. An aldol condensation of 8c shows little stereoselectivity.

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13

Chen, Weiqiang, Hui-Jing Li, Qin-Ying Li, and Yan-Chao Wu. "Direct oxidative coupling of N-acyl pyrroles with alkenes by ruthenium(ii)-catalyzed regioselective C2-alkenylation." Organic & Biomolecular Chemistry 18, no. 3 (2020): 500–513. http://dx.doi.org/10.1039/c9ob02421b.

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14

Barteková, Elena, and Martin Bajus. "Pyrolysis of Hexadecane." Collection of Czechoslovak Chemical Communications 62, no. 7 (1997): 1057–69. http://dx.doi.org/10.1135/cccc19971057.

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The kinetics of thermal decomposition of hexadecane was studied in a flow tubular reactor from stainless steel. The experiments were performed in the temperature range of 700 to 780 °C for the mass ratio of steam to hydrocarbon 3 : 1. The hexadecane pyrolysis took place according to the first-order reaction with a frequency factor of 3.5 . 109 s-1 and an activation energy of 162 kJ mol-1. In the pyrolysis products there were above all 1-alkenes. From alkanes, methane and ethane and less propane were formed in a higher degree. The prevailing compounds are ethene and propene whose amount increases with increasing temperature and residence time. The content of 1-alkenes higher than 1-pentene decreases with increasing conversion which gives evidence of their decomposition owing to their lower stability in comparison with the lighter 1-alkenes. The formation of dienes (1,3-butadiene and propadiene) and benzene also confirmed the course of secondary reactions. The observed higher formation of hydrogen results from the reaction of steam with coke deposited on the walls of the reactor or with hydrocarbon radicals. The evidence of the coke formation is given also by the presence of carbon oxides whose amount grew with the pyrolysis severity. The high content of 1-hexene in comparison with the other higher 1-alkenes is probably caused by the isomerization of alkyl radicals by 1,5-hydrogen transfer.

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15

Pavlov, O. S., T. A. Chistyakova, and S. Yu Pavlov. "The processes of benzene alkylation with n-alkenes on the sulfocation exchangers." Russian Journal of Applied Chemistry 82, no. 4 (April 2009): 706–10. http://dx.doi.org/10.1134/s1070427209040338.

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16

Kavipriya, K., and M. Chandra. "FTIR and GCMS Analysis of Bioactive Phytocompounds in Methonalic Leaf Extract of Cassia Alata." Biomedical and Pharmacology Journal 11, no. 1 (March 25, 2018): 141–47. http://dx.doi.org/10.13005/bpj/1355.

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The methanolic extract of plant Cassia alata was prepared by using soxhlet apparatus. FTIR and GCMS analysis were done to this plant extract to find out the bioactive phytocompounds. The FTIR results of this plant extract showed 21 peaks indicate the presence of the bioactive compounds such as sulfates, sulfonamides, sulfones, sulfonyl chlorides, sulfates, sulfonamides, alkanes, aromatic, aromatic, alkenes, ester, alkenes, ketenes, isocyanates, isothiocyanates, acetylene, nitrile, phosphine, phosphine, aldehyde, alkane, amide, alcohol and alcohol. The GCMS results showed 13 peaks. The retention time (RT) of all these thirteen peaks indicate the presence of functional group such as 1-Butanol, 3-methyl-1,6-Anhydro-.beta.-D-glucopyranose (levoglucosan), 3-O-Methyl-d-glucose, Oxirane, 10-Methyl-E-11-tridecen-1-ol propionate, l-(+)-Ascorbic acid 2,6-dihexadecanoate, (R)-(-)-14-Methyl-8-hexadecyn-1-ol, Oleic Acid , Vitamin E acetate and 1,2-Bis(trimethylsilyl) benzene.

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17

Dockendorff, Chris, Eric Greve, and Jacob Porter. "DFT-Assisted Design and Evaluation of Bifunctional Amine/Pyridine-Oxazoline Metal Catalysts for Additions of Ketones to Unactivated Alkenes and Alkynes." Synthesis 51, no. 02 (October 2, 2018): 450–62. http://dx.doi.org/10.1055/s-0037-1610285.

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Bifunctional catalyst systems for the direct addition of ketones to unactivated alkenes/alkynes were designed and modeled by density functional theory (DFT). The designed catalysts possess bidentate ligands suitable for binding of pi-acidic group 10 metals capable of activating alkenes/alkynes, and a tethered organocatalyst amine to activate the ketone via formation of a nucleophilic enamine intermediate. The structures of the designed catalysts before and after C–C bond formation were optimized using DFT, and reaction steps involving group 10 metals were predicted to be significantly exergonic. A novel oxazoline precatalyst with a tethered amine separated by a meta-substituted benzene spacer was synthesized via a 10-step sequence that includes a key regioselective epoxide ring-opening step. It was combined with group 10 metal salts, including cationic Pd(II) and Pt(II), and screened for the direct addition of ketones to several alkenes and an internal alkyne. 1H NMR studies suggest that catalyst-catalyst interactions with this system via amine–metal coordination may preclude the desired addition reactions. The catalyst design approach disclosed here, and the promising calculations obtained with square planar group 10 metals, light a path for the discovery of novel bifunctional catalysts for C–C bond formation.

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18

Arata, Michiko, Teppei Miura, and Kazuhiro Chiba. "Electrocatalytic Formal [2+2] Cycloaddition Reactions between Anodically Activated Enyloxy Benzene and Alkenes." Organic Letters 9, no. 21 (October 2007): 4347–50. http://dx.doi.org/10.1021/ol7019845.

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19

Liu, Ningwei, Xiaolan Li, Wanhui Ren, Liguang Li, Congcong Su, and Chuang Wang. "Concentration Characteristics and Photochemical Reactivities of VOCs in Shenyang, China." Atmosphere 12, no. 10 (September 23, 2021): 1240. http://dx.doi.org/10.3390/atmos12101240.

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We investigated the seasonal and diurnal characteristics of volatile organic compound (VOC) concentrations in Shenyang, China, using the whole-year hourly data of 52 types of VOC at three sites over the year 2019. The photochemical reactivities of VOCs were also studied by analyzing the influence of VOCs on ozone and secondary organic aerosol (SOA) formation potential and the hydroxyl radical consumption rate. It is shown that the order of VOC concentrations from high to low is alkanes, alkynes, alkenes, and aromatic hydrocarbons. For various types of VOCs, the maximum appeared in the morning and at night, whereas the minimum appeared in the afternoon. The contributions of VOCs to ozone formation potential are highest for aromatic hydrocarbons with a value of 78%, followed by alkenes and alkanes, among which toluene and isoprene contributed the most. The contributions of VOCs to SOA formation potential are also highest for aromatic hydrocarbons with a value of 94%, followed by alkanes and alkenes, among which the contributions of toluene and benzene add up to over 70%. Being the most active type of VOCs in atmospheric chemical reactions, aromatic hydrocarbons are the dominant contributor to the formation of both ozone and SOA, and therefore being able to control of the use of a large number of solvents and vehicle exhaust emissions would be an effective way to regulate the formation of ozone and SOA in Shenyang.

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20

Park, Sang Won, Soong-Hyun Kim, Jaeyoung Song, Ga Young Park, Darong Kim, Tae-Gyu Nam, and Ki Bum Hong. "Hypervalent iodine-mediated Ritter-type amidation of terminal alkenes: The synthesis of isoxazoline and pyrazoline cores." Beilstein Journal of Organic Chemistry 14 (May 11, 2018): 1028–33. http://dx.doi.org/10.3762/bjoc.14.89.

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Hypervalent iodine-mediated olefin functionalization provides a rapid gateway towards accessing both various heterocyclic cores and functional groups. In this regard, we have developed a Ritter-type alkene functionalization utilizing a PhI(OAc)2 ((diacetoxyiodo)benzene, PIDA)/Lewis acid combination in order to access isoxazoline and pyrazoline cores. Based on allyl ketone oximes and allyl ketone tosylhydrazones, we have developed an alkene oxyamidation and amido-amidation protocol en route to accessing both isoxazoline and pyrazoline cores. Additionally, acetonitrile serves as both the solvent and an amine source in the presence of this PIDA/Lewis acid combination. This operationally straightforward and metal-free protocol provides an easy access to isoxazoline and pyrazoline derivatives.

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21

Yang, Jun, Juntao Chen, Huitao Bi, Haiping Gu, Zhenling Liu, and Wanxi Peng. "Molecules and functions of rosewood: Pterocarpus indicus." Thermal Science 24, no. 3 Part A (2020): 1869–76. http://dx.doi.org/10.2298/tsci190608075y.

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Pterocarpus indicus was extracted by three organic solvents: ethanol, ethanol/ benzene (1:2), and ethanol/methanol (1:1). The extracts was analyzed by FT-IR, GC-MS, TG, Py-GC-MS, and TDS-GC-MS. Abundant bioactive ingredients in the Pterocarpus indicus extracts included alkanes, phenols, alcohols, esters, carboxylates, alkenes, acids, and aromatic compounds. The main active ingredients was Cinnamaldehyde, (E)-.This study of the chemical composition of Pterocarpus indicus provides a scientific basis for the development and utilization of the plant, with potential applications in the fields of biomedicine, the chemical industry, cosmetics, skin care products, and spices.

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22

Srinivas, B. T. V., Vikas S. Rawat, and Bojja Sreedhar. "Iron-Catalyzed Dioxygenation of Alkenes and Terminal Alkynes by using (Diacetoxyiodo)benzene as Oxidant." Advanced Synthesis & Catalysis 357, no. 16-17 (November 16, 2015): 3587–96. http://dx.doi.org/10.1002/adsc.201500681.

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23

Joly, J. F., and J. P. Boitiaux. "Modified zeolite HY catalysts for the preparation of phenylalkanes from linear alkenes and benzene." Zeolites 15, no. 8 (November 1995): 755. http://dx.doi.org/10.1016/0144-2449(95)96845-r.

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24

Nooi, J. R., J. J. Muller, M. C. Testa, and S. Willemse. "Isomerization reactions occurring on alkylation of benzene with some branched long-chain 1-alkenes." Recueil des Travaux Chimiques des Pays-Bas 88, no. 4 (September 2, 2010): 398–410. http://dx.doi.org/10.1002/recl.19690880403.

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25

Moulay, Saad. "C-Methylation of Organic Substrates: A Comprehensive Overview. Part I. Methane as a Methylating Agent." Mini-Reviews in Organic Chemistry 17, no. 7 (October 9, 2020): 805–13. http://dx.doi.org/10.2174/1570193x16666191023143652.

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A literature survey on C-methylation of organic substrates with methane as a methylating agent is analyzed. Of the substrates that undergo C-methylation are benzene, naphthalenes, toluene, alkanes, alkenes, acetonitrile, and other functionalized organic compounds. None of these methylation reactions occur in the absence of a catalyst. A direct introduction of a methyl group on the carbon sites of a molecule is concomitant with the formation of other products, as a result of either a possible rearrangement or a further reaction with methane. Mechanistically, the C-methylation with methane proceeds oxidatively. The products selectivities depend on several factors, mainly on the acid/ base character of the solid catalyst.

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26

Yusubov, M. S., R. J. Yusubova, V. D. Filimonov, and Ki‐Whan Chi. "(Dichloroiodo)benzene—An Easily Available Reagent for Chloro‐ and Iodoalkoxylation, Iodohydroxylation, and Iodochlorination of Alkenes." Synthetic Communications 34, no. 3 (December 31, 2004): 443–50. http://dx.doi.org/10.1081/scc-120027283.

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27

Marongiu, Bruno, Silvia Porcedda, Barbara Pittau, and Henry V. Kehiaian. "Thermodynamics of binary mixtures containing linear or cyclic alkenes. II. Mixtures with benzene or tetrachloromethane." Fluid Phase Equilibria 99 (August 1994): 185–98. http://dx.doi.org/10.1016/0378-3812(94)80030-8.

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28

Wu, Dan, and Donal F. O’Shea. "Potential for release of pulmonary toxic ketene from vaping pyrolysis of vitamin E acetate." Proceedings of the National Academy of Sciences 117, no. 12 (March 10, 2020): 6349–55. http://dx.doi.org/10.1073/pnas.1920925117.

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A combined analytical, theoretical, and experimental study has shown that the vaping of vitamin E acetate has the potential to produce exceptionally toxic ketene gas, which may be a contributing factor to the upsurge in pulmonary injuries associated with using e-cigarette/vaping products. Additionally, the pyrolysis of vitamin E acetate also produces carcinogen alkenes and benzene for which the negative long-term medical effects are well recognized. As temperatures reached in vaping devices can be equivalent to a laboratory pyrolysis apparatus, the potential for unexpected chemistries to take place on individual components within a vape mixture is high. Educational programs to inform of the danger are now required, as public perception has grown that vaping is not harmful.

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29

Nyquist, R. A. "Infrared Study of Solute/Solvent Interactions between Separate Chloroform Solutions of Alkanes, Cycloalkanes, Alkenes, Cycloalkenes, Cyclohexadienes, Benzene, and Carbon Tetrachloride." Applied Spectroscopy 47, no. 5 (May 1993): 560–65. http://dx.doi.org/10.1366/0003702934067315.

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The intermolecular deuteron bonds formed between Cl3CD and ClCCl3, are stronger than between Cl3CD and ClCCl2D, since the Cl atoms of CCl4, are more basic than Cl atoms for CDCl3. The n-alkanes act as a diluent for CDCl3 molecules, and the strength of the intermolecular proton bond in (Cl3CD:ClCCl2D) n complexes increases as n becomes larger. Solvent density also plays an important role in solute/solvent interaction. Increased solvent density causes the CD:Cl or CD:π (of C=C group) intermolecular bond distance to decrease, causing the bond to be stronger. A repulsion exists between the intermolecular π electron system of benzene, 1,3-cyclohexadiene, or 1,4-cyclohexadiene and the chlorine atom δ electrons of CDCl3, and this repulsive effect is a factor in establishing the equilibrium intermolecular bond distance formed between the CD:π bonds of benzene (or cyclohexadienes) and the proton of CDCl3. These conclusions are based on the study of the vCD, vC=C, and v(C=C)2 frequencies vs. mole % CDCl3 (or CHCl3)/solvent system.

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30

Shu, Xing-Zhong, Shu-Chun Zhao, Ke-Gong Ji, Zhao-Jing Zheng, Xue-Yuan Liu, and Yong-Min Liang. "Platinum-Catalyzed Cyclization of o-Alkynyl(oxo)benzenes with Alkenes by 1,2-Migration of Benzene: Synthesis of 8-Oxabicyclo[3.2.1]octane Derivatives." European Journal of Organic Chemistry 2009, no. 1 (November 12, 2008): 117–22. http://dx.doi.org/10.1002/ejoc.200800888.

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31

Zhang, Xiaoxiao, Xiang Ding, Xinming Wang, Dilinuer Talifu, Guo Wang, Yanli Zhang, and Abulikemu Abulizi. "Volatile Organic Compounds in a Petrochemical Region in Arid of NW China: Chemical Reactivity and Source Apportionment." Atmosphere 10, no. 11 (October 24, 2019): 641. http://dx.doi.org/10.3390/atmos10110641.

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We measured volatile organic compounds (VOCs) during the heating, non-heating, and sandstorm periods in the air of the Dushanzi district in NW China and investigated their concentrations, chemical reactivity, and sources. The observed concentrations of total VOCs (TVOCs) were 22.35 ± 17.60, 33.20 ± 34.15, and 17.05 ± 13.61 ppbv in non-heating, heating, and sandstorm periods, respectively. C2-C5 alkanes, C2-C3 alkenes, benzene, and toluene were the most abundant species, contributing more than 60% of the TVOCs. Among these VOCs, alkenes such as propene had the highest chemical reactivity, accounting for more than 60% of total hydroxyl radical loss rate (LOH) and ozone formation potential (OFP). Chemical reactivity was the highest in the heating period. The average reaction rate constant (KOH-avg) and average maximum incremental reactivity coefficient (MIR-avg) of the total observed VOCs were (8.72 ± 1.42) × 10−12 cm3/mol∙s and 2.42 ± 0.16 mol/mol, respectively. The results of the source apportionment via the Positive Matrix Factorization (PMF) model showed that coal combustion (43.08%) and industrial processes (38.86%) were the major sources of VOCs in the air of the Dushanzi district. The contribution of coal combustion to VOCs was the highest in the heating period, while that of industrial solvents and oil volatilization was the lowest.

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32

Whitehill, Andrew R., Ingrid George, Russell Long, Kirk R. Baker, and Matthew Landis. "Volatile Organic Compound Emissions from Prescribed Burning in Tallgrass Prairie Ecosystems." Atmosphere 10, no. 8 (August 14, 2019): 464. http://dx.doi.org/10.3390/atmos10080464.

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Prescribed pasture burning plays a critical role in ecosystem maintenance in tallgrass prairie ecosystems and may contribute to agricultural productivity but can also have negative impacts on air quality. Volatile organic compound (VOC) concentrations were measured immediately downwind of prescribed tallgrass prairie fires in the Flint Hills region of Kansas, United States. The VOC mixture is dominated by alkenes and oxygenated VOCs, which are highly reactive and can drive photochemical production of ozone downwind of the fires. The computed emission factors are comparable to those previous measured from pasture maintenance fires in Brazil. In addition to the emission of large amounts of particulate matter, hazardous air pollutants such as benzene and acrolein are emitted in significant amounts and could contribute to adverse health effects in exposed populations.

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33

Ali, Muhammad Shaiq, Tomoya Kitazume, and Viqar Uddin Ahmad. "Enzymatic Racemic Resolution of a Fluorinated Substrate and Syntheses of E and Z Alkenes as Precursors for Some Biologically Active Fluorohexoses." Zeitschrift für Naturforschung B 52, no. 3 (March 1, 1997): 413–18. http://dx.doi.org/10.1515/znb-1997-0320.

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Abstract A fluorinated substrate 6 was prepared and then the enantiomers (6a and 7a) were separated by an enzyme in presence of an acetylating agent. The optical purity of 6a and 7a were determined by derivatising them into their MTPA -esters and then by taking their 19F NMR spectra. It was observed that, PL 266 (enzyme), benzene (solvent), 24 h (time), 40 °C (temp.) and vinyl acetate (acetylating agent) were the ideal conditions for racemic resolution. The optical purity was further improved by changing the solvent (hexane), amount of enzyme (PL 266; 3000 units), reaction time (12 h) and amount of acetylating agent (vinyl acetate; two molar). The optically pure species was used for the preparation of E and Z alkenes.

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34

Srinivas, B. T. V., Vikas S. Rawat, and Bojja Sreedhar. "ChemInform Abstract: Iron-Catalyzed Dioxygenation of Alkenes and Terminal Alkynes by Using (Diacetoxyiodo)benzene as Oxidant." ChemInform 47, no. 13 (March 2016): no. http://dx.doi.org/10.1002/chin.201613042.

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35

Villamañan, Miguel A., and Henry V. Kehiaian. "Prediction of thermodynamic properties of ternary hydrocarbon mixtures containing olefins. I. 1-Alkenes + benzene + n-alkanes." Fluid Phase Equilibria 42 (January 1988): 165–72. http://dx.doi.org/10.1016/0378-3812(88)80056-6.

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36

Bryce-Smith, Derek, Michael G. B. Drew, Gary A. Fenton, Andrew Gilbert, and Andrew D. Proctor. "Stereochemical control in meta photocycloaddition of alkenes to the benzene ring: the anomalous behaviour of cyclohexene." Journal of the Chemical Society, Perkin Transactions 2, no. 5 (1991): 779. http://dx.doi.org/10.1039/p29910000779.

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37

Maxwell, James L., Mats Boman, Robert W. Springer, Jaikumar Narayan, and Saiprasanna Gnanavelu. "Hyperbaric Laser Chemical Vapor Deposition of Carbon Fibers from the 1-Alkenes, 1-Alkynes, and Benzene." Journal of the American Chemical Society 128, no. 13 (April 2006): 4405–13. http://dx.doi.org/10.1021/ja057666j.

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38

Stiner, Lawrence, and Larry J. Halverson. "Development and Characterization of a Green Fluorescent Protein-Based Bacterial Biosensor for Bioavailable Toluene and Related Compounds." Applied and Environmental Microbiology 68, no. 4 (April 2002): 1962–71. http://dx.doi.org/10.1128/aem.68.4.1962-1971.2002.

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ABSTRACT A green fluorescent protein-based Pseudomonas fluorescens strain A506 biosensor was constructed and characterized for its potential to measure benzene, toluene, ethylbenzene, and related compounds in aqueous solutions. The biosensor is based on a plasmid carrying the toluene-benzene utilization (tbu) pathway transcriptional activator TbuT from Ralstonia pickettii PKO1 and a transcriptional fusion of its promoter PtbuA1 with a promoterless gfp gene on a broad-host-range promoter probe vector. TbuT was not limiting, since it was constitutively expressed by being fused to the neomycin phosphotransferase (nptII) promoter. The biosensor cells were readily induced, and fluorescence emission after induction periods of 3 h correlated well with toluene, benzene, ethylbenzene, and trichloroethylene concentrations. Our experiments using flow cytometry show that intermediate levels of gfp expression in response to toluene reflect uniform induction of cells. As the toluene concentration increases, the level of gfp expression per cell increases until saturation kinetics of the TbuT-PtbuA1 system are observed. Each inducer had a unique minimum concentration that was necessary for induction, with K app values that ranged from 3.3 ± 1.8 μM for toluene to 35.6 ± 16.6 μM for trichloroethylene (means ± standard errors of the means), and maximal fluorescence response. The fluorescence response was specific for alkyl-substituted benzene derivatives and branched alkenes (di- and trichloroethylene, 2-methyl-2-butene). The biosensor responded in an additive fashion to the presence of multiple inducers and was unaffected by the presence of compounds that were not inducers, such as those present in gasoline. Flow cytometry revealed that, in response to toxic concentrations of gasoline, there was a small uninduced population and another larger fully induced population whose levels of fluorescence corresponded to the amount of effectors present in the sample. These results demonstrate the potential for green fluorescent protein-based bacterial biosensors to measure environmental contaminants.

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39

Zakumbaeva, G. D., N. Ph Toktabaeva, A. Zh Kubasheva, L. V. Gorbacheva, A. I. Lyashenko, and I. S. Chanysheva. "The Use of C2–C5 Hydrocarbons for Production of Gasoline Components." Eurasian Chemico-Technological Journal 6, no. 3 (July 13, 2017): 189. http://dx.doi.org/10.18321/ectj617.

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<p>A conversion of light hydrocarbons (C<sub>2</sub>–C<sub>5</sub>) over HZSM-zeolite-containing catalysts modified by the VA Group metals was studied. The process was carried out in a flow reactor at varying temperature from 350 to 400 °C, pressure – 0.1-0.5 MPa and space velocity – 100-300 hr<sup>-1</sup>. It was observed that catalysts had high activity in the process of interaction between pentane and ethylene at temperature 350-400 °C and P = 0.1 MPa. The conversion of pentane and ethylene at these conditions over the catalyst P-3 are > 98% and 99-100% respectively. The reaction products are C<sub>1</sub>–C<sub>4</sub> alkanes, C<sub>3</sub>–C<sub>4</sub> alkenes and C<sub>5</sub><sup>+</sup> hydrocarbons of normal and iso-structure, benzene, ethyl-benzene, xylene, toluene. Maximum yield of C<sub>5</sub>–C<sub>7</sub> alkanes is 91.6% over P-2 and ethyl-benzene is 36.6% over P-3 catalyst observed at mild conditions T = 350 °C and P = 0.1 MPa. Yield of benzene is 1.3-1.4% that meets to environmental requirements. The composition of alkylation gasoline depends on the catalyst nature. Studied zeolite-containing catalysts are polyfunctional and carry out the reactions of dehydrogenation, isomerization, cyclization, alkylation and partly cracking of hydrocarbons by one step. The process scheme is presented.</p>

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40

Cai, H., and S. D. Xie. "Tempo-spatial variation of emission inventories of speciated volatile organic compounds from on-road vehicles in China." Atmospheric Chemistry and Physics 9, no. 18 (September 22, 2009): 6983–7002. http://dx.doi.org/10.5194/acp-9-6983-2009.

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Abstract. Emission inventories of sixty-seven speciated non-methane volatile organic compounds (NMVOC) from on-road vehicles in China were estimated for the period of 1980–2005, using seven NMVOC emission profiles, which were summarized based on local and international measurements from published literatures dealing with specific vehicle categories running under particular modes. Results show an exponential growth trend of China's historical emissions of alkanes, alkenes, alkines, aromatics and carbonyls during the period of 1980–2005, increasing from 63.9, 39.3, 6.9, 36.8 and 24.1 thousand tons, respectively, in 1980 to 2778.2, 1244.5, 178.7, 1351.7 and 406.0 thousand tons, respectively, in 2005, which coincided well with China's economic growth. Emission inventories of alkenes, aromatics and carbonyls were gridded at a high resolution of 40 km×40 km for air quality simulation and health risk evaluation, using the geographic information system (GIS) methodology. Spatial distribution of speciated NMVOC emissions shows a clear difference in emission densities between developed eastern and relatively underdeveloped western and inland China. Besides, the appearance and expansion of high-emission areas was another notable characteristic of spatial distribution of speciated NMVOC emissions during the period. Emission contributions of vehicle categories to speciated NMVOC groups showed annual variation, due to the variance in the provincial emissions and in the relative fractions of the seven emission profiles adopted at the provincial level. Highly reactive and toxic compounds accounted for high proportions of emissions of speciated NMVOC groups. The most abundant compounds were isopentane, pentane and butane from alkanes; ethene, propene, 2-methyl-2-butene and ethyne from alkenes and alkines; benzene, toluene, ethylbenzene, o-xylene, and m,p-xylene (BTEX) and 1,2,4-trimethylbenzene from aromatics and formaldehyde, acetaldehyde, benzaldehyde and acetone from carbonyls.

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41

Cai, H., and S. D. Xie. "Tempo-spatial variation of emission inventories of speciated volatile organic compounds from on-road vehicles in China." Atmospheric Chemistry and Physics Discussions 9, no. 3 (May 5, 2009): 11051–85. http://dx.doi.org/10.5194/acpd-9-11051-2009.

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Abstract. Emission inventories of sixty-nine speciated non-methane volatile organic compounds (NMVOC) from on-road vehicles in China were estimated for the period of 1980–2005, using seven NMVOC emission profiles, which were summarized based on local and international measurements from published literatures dealing with specific vehicle categories running under particular modes. Results show an exponential growth trend of China's historical emissions of alkanes, alkenes, alkines, aromatics and carbonyls during the period of 1980–2005, increasing from 63.9, 39.3, 6.9, 36.8 and 24.1 thousand tons, respectively, in 1980 to 2781.4, 1244.9, 178.5, 1350.7 and 403.3 thousand tons, respectively, in 2005, which coincided well with China's economic growth. Emission inventories of alkenes, aromatics and carbonyls were gridded at a high resolution of 40 km×40 km for air quality simulation and health risk evaluation, using the geographic information system (GIS) methodology. Spatial distribution of speciated NMVOC emissions shows a clear difference in emission densities between developed eastern and relatively underdeveloped western and inland China. Besides, the appearance and expansion of high-emission areas was another notable characteristic of spatial distribution of speciated NMVOC emissions during the period. Emission contributions of vehicle categories to speciated NMVOC groups showed annual variation, due to the variance in the provincial emissions and in the relative fractions of the seven emission profiles adopted at the provincial level. Highly reactive and toxic compounds accounted for high proportions of emissions of speciated NMVOC groups. The most abundant compounds were isopentane, pentane and butane from alkanes; ethene, propene, 2-methyl-2-butene and ethyne from alkenes and alkines; benzene, toluene, ethylbenzene, o-xylene, and m,p-xylene (BTEX) and 1,2,4-trimethylbenzene from aromatics and formaldehyde, acetaldehyde, benzaldehyde, acetone and acrolein from carbonyls.

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42

Forte, Leonard, Min H. Lien, Alan C. Hopkinson, and Diethard K. Bohme. "Gas-phase measurements of the kinetics of BF2+-induced polymerization of olefinic monomers." Canadian Journal of Chemistry 67, no. 10 (October 1, 1989): 1576–83. http://dx.doi.org/10.1139/v89-240.

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The initial steps in the BF2+-induced polymerization of the monomers of ethylene, propylene, cis-2-butene, isobutene, and styrene have been observed in the gas phase at room temperature using the Selected-Ion Flow Tube (SIFT) technique. Rate constants and product distributions have been determined for the initiation of the polymerization in each case. All five initiation reactions were found to be rapid (k ≥ 5.0 × 10−10 cm3 molecule−1 s−1). The primary product ions that propagate polymerization have been identified and sequential addition reactions have been followed in all five systems. For ethylene the energetics of the initial steps have been followed using abinitio molecular orbital theory. Reactions of BF2+ with the vapours of water and benzene have also been characterized. Keywords: ion-induced polymerization, alkenes, kinetics, gas phase ion chemistry.

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43

Kominami, Hiroshi, Satoshi Yamamoto, Kazuya Imamura, Atsuhiro Tanaka, and Keiji Hashimoto. "Photocatalytic chemoselective reduction of epoxides to alkenes along with formation of ketones in alcoholic suspensions of silver-loaded titanium(iv) oxide at room temperature without the use of reducing gases." Chem. Commun. 50, no. 35 (2014): 4558–60. http://dx.doi.org/10.1039/c3cc49340g.

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44

Bryce-Smith, D., M. G. B. Drew, G. A. Fenton, and A. Gilbert. "Mechanism of photochemical meta-cycloaddition of alkenes to the benzene ring: a novel type of molecular interaction." Journal of the Chemical Society, Chemical Communications, no. 9 (1985): 607. http://dx.doi.org/10.1039/c39850000607.

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45

Venkatraman, Pitchaikannu, and C. S. Sureka. "ID: 1082 An in-vitro study to diagnose and distinguish breast and lung cancers using the PCB technology based nanodosimeter." Biomedical Research and Therapy 4, S (September 5, 2017): 169. http://dx.doi.org/10.15419/bmrat.v4is.356.

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Generally, in the modern field of nanodosimetry, the Printed Circuit Board (PCB) technology based 3D positive ion detector has been identified as a device to detect cancers in lungs and breast region. In the nano environment, these cancer cells have been diagnosed by the exhalation of specific volatile organic compounds (VOCs) which serves as eminent source biomarkers for cancer diagnosis. Earlier studies reported that lungs emit various VOCs include Benzene, Ethylbenzene, Cyclohexane, methanol, ethanol, dodecane and tridecane, and the breast emit alkanes, alkenes, ketones, halogenated hydrocarbons, aldehydes, alcohols, esters, unsaturated hydrocarbons, terpenes, siloxanes, and aromates. By employing VOCs exhalation, the field of nanodosimetry aids as a direct evidence that the diagnosis of critical organs like lungs and breast cancer cells without harming the patients is possible. In our present out, we carried out in diagnosing and to distinguishing the cancer tissues of breast and lung using PCB technology based nanodosimeter.

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46

BRYCE-SMITH, D., M. G. B. DREW, G. A. FENTON, A. GILBERT, and A. D. PROCTOR. "ChemInform Abstract: Stereochemical Control in meta Photocycloaddition of Alkenes to the Benzene Ring: The Anomalous Behaviour of Cyclohexene." ChemInform 22, no. 33 (August 22, 2010): no. http://dx.doi.org/10.1002/chin.199133096.

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47

Orazbayeva, Dina, Ulzhalgas Karatayeva, Kulzhan Beysembayeva, and Kulyash Meyramkulova. "Identification and quantification of organic pollutants in the air of the city of Astana using solid phase microextraction." Chemical Bulletin of Kazakh National University, no. 2 (June 30, 2017): 14–17. http://dx.doi.org/10.15328/cb826.

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Solid-phase microextraction in combination with gas chromatography and mass-spectrometry (GC-MS) was used for determination of benzene, toluene, ethylbenzene and o-xylene (BTEX), polycyclic aromatic hydrocarbons (PAH), and for identification of volatile organic compounds (VOCs) in ambient air of the city of Astana, Kazakhstan. The screening of the samples showed the presence of mono- and polycyclic aromatic hydrocarbons, alkanes, alkenes, phenols, and benzaldehydes. The concentrations of naphthalene were 5-7 times higher than the permissible value, it was detected in all studied air samples. Average concentration of naphthalene was 18.4 μg/m3, acenaphthylene – 0.54 μg/m3, acenaphthene – 1.63 μg/m3, fluorene – 0.79 μg/m3, anthracene – 3.27 μg/m3, phenanthrene – 0.22 μg/m3, fluorantene – 0.74 μg/m3, pyrene – 0.73 μg/m3. Average concentrations of BTEX in the studied samples were 31.1, 84.9, 10.8 and 11.6 μg/m3, respectively. Based on the statistical analysis of the concentrations of BTEX and PAH, the main source of city air pollution with them was assumed to be vehicle emissions.

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48

Siebert, Walter, Manfred Hildenbrand, Pia Hornbach, Gerhard Karger, and Hans Pritzkow. "1,2- und 1,1-Diborylalkene / 1,2- and 1,1-Diborylalkenes." Zeitschrift für Naturforschung B 44, no. 10 (October 1, 1989): 1179–86. http://dx.doi.org/10.1515/znb-1989-1006.

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Reactions of B2Cl4 with 3-hexyne, 2,2-dimethyl-3-butyne, and 2,2,5,5-tetramethyl-3-hexyne lead to the cis-bis(dichloroboryl)alkenes la—c; with bis(trimethylsilyl)acetylene geminai diborylation and Me3Si migration occurs to yield (Me3Si)2C=C(BCl2)2 (2a). On heating 2a in benzene a Cl/Me exchange with formation of 2b is observed. Me2C=C(BCl2)2 (4a) is obtained from Me2C=C(SnMe3)2 and BCl3. In 1a—c, e, 2a, and 4a reaction of one Cl of each BCl2 group with Me3Si—NMe2 or iPr2NH leads to the corresponding bis(chloro-dialkylaminoboryl)ethenes 5c, f—i, 5′a, b, e, 2d, e, and 4b, c, of which 5′a, b, e possess the 1-azonia-2-borata-5-borole structure via an intramolecular donor-acceptor N→B bond. 2,4-Bis(t-butyl)-1,3-bis(dimethylamino)-1,3-dihydro-1,3-diborete (6c) is cleaved with bromine to yield the cis-1,2-diborylethene derivative 5j, as established by an X-ray structure analysis.

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49

Weeks, Colin L., Aviva Levina, Ronald R. Fenton, and Peter A. Lay. "EXAFS and EPR Studies of the Alkene Oxidation Catalyst Species trans-[CrIII(bpb)(L)2]n+ and CrV Oxidation Products (bpb=N,N'-Bis(2-pyridinecarboxamido)-1,2-benzene)." Australian Journal of Chemistry 68, no. 4 (2015): 581. http://dx.doi.org/10.1071/ch14532.

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The structures of trans-[CrIII(bpb)(OH2)2]+ and trans-[CrIII(bpb)(OH2)Cl] (bpb = N,N′-bis(2-pyridinecarboxamido)-1,2-benzene) have been determined by multiple-scattering analysis of their extended X-ray absorption fine structure (EXAFS) spectra. This is the first reported structural characterizations of these complexes, which have been used as catalysts in the oxidation of alkenes and the industrially important coupling reaction of epoxides with CO2. The formation of CrV species, which are likely catalytic intermediates, was observed when trans-[CrIII(bpb)(OH2)Cl] was treated with oxidants: PbO2, iodosylbenzene, or tert-butylhydroperoxide. The intermediates in these reactions were studied using X-band and Q-band electron paramagnetic resonance (EPR) spectroscopy to probe the ability of the bpb ligand to stabilize CrV–oxido complexes. Several CrV species were generated in such oxidation reactions that may be the reason for the lack of selectivity when the CrIII species are used as oxidation catalysts in the presence of oxidants.

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50

Asaftei, Iuliean V., Ion Sandu, Nicolae Bilba, Neculai Catalin Lungu, Maria Ignat, and Elvira Mahu. "Oligo-Aromatization of Light Hydrocarbons from Petroleum Refining Processes Over ZnO/MFI Microporous Material." Revista de Chimie 71, no. 2 (March 3, 2020): 403–12. http://dx.doi.org/10.37358/rc.20.2.7943.

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The conversion of light hydrocarbons resulted as by-product of petroleum refining (mixtures of (n + i) butanes, 52.28 � 63.20 vol.%, (1-, cis-, trans-, 2-) butenes, 28.64 � 36.43 vol.% and propane � propylene, 4.79 � 14.64 vol.%) over bifunctional 5% ZnO/HZSM-5 co-catalyst in a fixed-bed stainless-steel reactor (Twin Reactor System Naky) at 450�C, 4 atm. total pressure and at a space velocity (WHSV) of 1 h-1 have been investigated. The results indicate that the selectivity to light aromatics � benzene, toluene and xylenes (BTX) � and to both the gaseous C1, C2 - C4 hydrocarbons and liquid (i + n) C5 � C10 aliphatic hydrocarbons depends on the time on stream of the process. This is a result of coke deposition (polyunsaturated compounds) and catalyst deactivation. The aromatics BTX represent 59-60 wt% in the liquid product during the first 24-36 hours time-on-stream and only 20-30 wt% after 40 hours of reaction when the aliphatic hydrocarbon C5 � C10 (mostly iso) and ]C10 (denoted �oligo�) reach to 70 � 80 wt%. The aromatic products were principally toluene, xylenes and benzene, theirs concentration varying with the time on stream of the process. The initial aromatization process described as dehydrocyclodimerization of alkanes and alkenes, principally to aromatics BTX and molecular hydrogen is accompanied by an oligomerization, isomerisation, cracking and alkylation process to form finally in the liquid product an excessively mixture of iso- and normal- C5 � C10 aliphatic hydrocarbons and ] C10.

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