• Title/Summary/Keyword: [2+2] Cycloaddition

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Kinetics and Mechanism of 1,3-Cycloaddition of 3.4.5.6-Tetrachlorobenzene-2-Diazo-1-Oxide (3.4.5.6-Tetrachlorobenzene-2-Diazo-1-Oxide의 1,3-환상부가에 대한 반응 속도론적 및 반응 메카니즘에 관한 연구)

  • Hong, Soon-Yung
    • Journal of the Korean Chemical Society
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    • v.14 no.3
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    • pp.271-275
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    • 1970
  • The effect of dimethyl maleate on the rate of thermolysis of 3,4,5,6-Tetrachlorobenzene-2-Diazo-1-Oxide in 1-chloronaphthalene at $130.2^{\circ}$ was investigated: In a separate experiment, the effect of dimethyl fumarate upon the same reaction at the same temperature was investigated. The rate of thermolysis was decreased by dimethyl maleate, while dimethyl fumarate accelerated the reaction. Some kinetic parameters of the thermolysis of 3,4,5,6-Tetrachlorobenzene-2-Diazo-1-Oxide were calculated. A mechanism of isomerization of dimethyl maleate to dimethyl fumarate by 3,4,5,6-Tetrachlorobenzene-2-Diazo-1-Oxide was proposed.

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1,2,4-Triazole Fused Heterocycles; Part 3. Preparation of 1-(1-Phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles and 4H-1,2,4-Triazolo[1,5-c][1,3,5]oxadiazines

  • 이기정;이유석;송동혁
    • Bulletin of the Korean Chemical Society
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    • v.16 no.11
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    • pp.1037-1042
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    • 1995
  • The reaction of acetophenone 1-ureidoethylidenehydrazones 6 with a mixture of triphenylphosphine, carbon tetrachloride, and triethylamine in dichloromethane provides a general route to 1-(1-phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles 11 via the electrocyclization of the expected azino carbodiimide intermediates 9 to give the resonance stabilized azomethine imine 10a followed by a proton abstraction from the methyl group by amide anion. However, the same reaction of benzaldehyde 1-ureidoethylidenehydrazones 5 was unsuccessful. Under the same conditions, the reactions of benzaldehyde 1-N-acylureidoethylidenehydrazones 7 or acetophenone 1-N-acylureidoethylidenehydrazones 8 afforded 4H-1,2,4-triazolo[1,5-c][1,3,5]oxadiazines 16 or 17 via the zwitterionic species 15, or a [4+2] intramolecular cycloaddition from the carbodiimide intermediates 14, respectively.

Cycloaddition of Carbon Dioxide to Allyl Glycidyl Ether Using Silica-supported Ionic Liquid as a Catalyst (실리카에 고정화된 이온성액체를 촉매로 이용한 알릴글리시딜에테르와 이산화탄소의 부가반응)

  • Shim, Hye-Lim;Lee, Mi-Kyung;Yu, Jeong-In;Park, Dae-Won
    • Clean Technology
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    • v.14 no.3
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    • pp.166-170
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    • 2008
  • In this study, imidazolium salt ionic liquid on amorphous silica was prepared and its catalytic performance in the cycloaddition of $CO_2$ with allyl glycidyl ether (AGE) to produce heterocyclic carbonate was investigated. The ionic liquid was generated on chloropropyl functionalized silica through the immobilization of imidazole. The prepared catalyst was characterized using a number of instrumental analysis including XRD, BET, $^{29}Si$ MAS-NMR and SEM. $^{29}Si$ MAS-NMR showed that the ionic liquid formed adduct with the chloropropyl groups attached to the silica surface. The immobilized ionic liquid showed very good catalytic activity for the cycloaddition of $CO_2$ with AGE, showing 55-61% of AGE conversion with over 85% of the carbonate selectivity at $80-120^{\circ}C$. Its AGE conversion and selectivity to the carbonate were even higher than the homogeneous analog, 1-n-butyl-3-methyl imidazolium bromide (BMImBr).

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Synthesis and herbicidal activity of 3-aryltetrahydro-1,2-benzisoxazolin-4-one derivatives (3-Aryltetrahydro-1,2-benzisoxazolin-4-one 유도체의 합성 및 제초 활성)

  • Kim, Hyoung-Rae;Song, Jong-Hwan;Jeon, Dong-Ju;Hong, Kyung-Sik;Ryu, Eung-K.
    • The Korean Journal of Pesticide Science
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    • v.2 no.1
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    • pp.104-106
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    • 1998
  • 3-Aryltetrahydro-1,2-benzisoxazolin-4-one derivatives were prepared by regioselective 1,3-dipolar cycloaddition reactions of various aryl nitrile oxides with 2-cyclohexen-1-one. The structures of these compounds were designed as a modifications of triketone herbicides and showed good herbicidal activity.

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Azide/Alkyne Resins for Quick Preparation of 1,4-Disubstituted 1,2,3-Triazoles

  • Sirion, Uthaiwan;Lee, Jae-Hak;Bae, Yu-Jin;Kim, Hee-Jun;Lee, Byoung-Se;Chi, Dae-Yoon
    • Bulletin of the Korean Chemical Society
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    • v.31 no.7
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    • pp.1843-1847
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    • 2010
  • An efficient method for the preparation of 1,4-disubstituted 1,2,3-triazole compounds is described using polymeric quaternary ammonium salts having azide or alkyne functionality to remove unreacted excess starting molecules (azide/alkyne). Copper metal could easily be removed by simple filtration with a short $Na_2SO_4$/silica cartridge, affording highly regioselective products in high yield and excellent purity without the need for work-up, extraction and chromatographic purification.

A Synthetic Approach to 11-Oxabicyclo[6.2.1]undecyl Bicyclics

  • 정희선;김훈;강호정
    • Bulletin of the Korean Chemical Society
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    • v.18 no.7
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    • pp.754-760
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    • 1997
  • Through a sequence of reactions including Diels-Alder cycloaddition of a furan diene as the key step, 11-oxatricyclo[6.2.1.01,6]undecyl rings were synthesized from 5-methylfurfural with the goal of developing a synthetic protocol to 11-oxabicyclo[6.2.1]undecyl system. The strategy to incorporate an oxygen atom at C6 carbon of tricyclic 11 or 16 by Baeyer-Villiger oxidation was unsuccessful, implicating that there is too much steric congestion around the carbonyl ketone. As an alternative approach, bicyclic 23 and 24 were prepared from 2-methylfuran via known tricyclic 20. Cyclization of bicyclic 23 and 24 under several reaction conditions also failed to produce hydroxylated product 25 and 26.

Development of Click Chemistry in Polymerization and Applications of Click Polymer

  • Karim, Md. Anwarul
    • Rubber Technology
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    • v.13 no.1
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    • pp.1-9
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    • 2012
  • Click chemistry had enjoyed a wealthy decade after it was introduced by K.B.Sharpless and his co-worker on 2001. Since there is no optimized method for synthesis of click polymer, therefore, this paper introduced three click reaction methods such as catalyst, non-catalyst and azide-end capping for fluorene-based functional click polymers. The obtained polymers have reasonable molecular weight with narrow PDI. The polymers are thermally stable and almost emitted blue light emission. The synthesized fluorene-based functional click polymers were characterized to compare the effect of click reaction methods on polymer electro-optical properties as well as device performance on quasi-solid-state dye sensitized solar cells (DSSCs) applications. The DSSCs with configuration of $SnO_2:F/TiO_2/N719$ dye/quasi-solid-state electrolyte/Pt devices were fabricated using these click polymers as a solid-state electrolyte components. Among the devices, the catalyzed click polymer composed device exhibited a high power conversion efficiency of 4.62% under AM 1.5G illumination ($100mW/cm^2$).These click polymers are promising materials in device application and $Cu^I$-catalyst 1, 3-dipolar cycloaddition click reaction is an efficient synthetic methodology.

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Ring-Opening Polymerization of Substituted 3,4-Dihydro-2H-pyrans. Syntheses of Alternating Vinyl Copolymers of Dimethyl Dicyanofumarate and Electron-Rich Olefins

  • Lee, Ju-Yeon;Cho, I-Whan
    • Bulletin of the Korean Chemical Society
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    • v.7 no.5
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    • pp.372-376
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    • 1986
  • Substituted 3,4-dihydro-2H-pyrans ($1_{a-e}$) were prepared by (4 + 2) cycloaddition reaction of dimethyl dicyanofumarate with the corresponding electron-rich olefins. The compounds $1_{a-e}$ were ring-open polymerized by cationic initiators to obtain polymers of 1:1 alternating sequence. Polymerizations were carried out with boron trifluoride etherate in methylene chloride at $-78^{\circ}C$. All the polymers obtained were soluble in common solvents and were reprecipitated by pouring its chloroform solution into diethyl ether. All the compounds $1_{a-e}$ were not as reactive as the corresponding pyrans derived from ${\alpha}$ -cyanoacrylate.