• Title/Summary/Keyword: [5+2] Cycloaddition

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Chemisorption and orientation of Selenopheneon Si(100)-$2{\times}1$

  • Lee, Han-Koo;Kim, Ki-Jeong;Kim, Hyeong-Do;Shin, Hyun-Joon;Kim, Bong-Soo
    • Proceedings of the Korean Vacuum Society Conference
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    • 2010.02a
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    • pp.372-372
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    • 2010
  • We have investigated adsorption of selenophene on Si(100) at room temperature using high resolution photoemission spectroscopy (HRPES) and near edge X-ray absorption fine structure (NEXAFS) in the partial electron yield (PEY) mode. The Si 2p, C 1s, Se 3d spectra of selenophene on Si(100) show that selenophene is nondissociatively chemisorbed on Si(100)-$2{\times}1$ through [2+2] cycloaddition. NEXAFS has been conducted to characterize the adsorption geometry of selenophene on Si(100). Since the $\pi^*$ orbital of C=C bond show good angular dependence in carbon K-edge NEXAFS spectra, the angle $53{\pm}5^{\circ}$ determined from NEXAFS spectra. This majority structure is consistent with the [2+2] cycloaddition of selenophene to the dimer of the Si(100)-$2{\times}1$ surface.

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Synthesis and Cycloaddition Reaction of C-(2-naphthoyl)-N-arylmethanohydrazonoylpyridinium Bromides

  • Hassaneen, Hamdi M.;Shawali, Ahmad S.;Elwan, Nehal M.;Abounada, Nada M.;Algharib, Mohammed S.
    • Archives of Pharmacal Research
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    • v.15 no.4
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    • pp.292-297
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    • 1992
  • Coupling of naphthacylpyridinium bromide 2 [1-(2-naphthyl) ethanone-2-pyridinium bromide] with N-nitrosoacetarylamides afforded C-(2-naphthoyl)-N-arylmethanohydrazonoylpyridinium bromides 3A-C. Treatment of 3A-C with base afforded the corresponding tetrazines 6A-C. Cycloaddition of nitrilimines 5A-C to N-arylmaleimides, acrylonitrile, ethyl acrylate, acrylamide, fumaronitrile, $\alpha$-cyanocinnamonitriles, ethyl $\alpha$-cyano-p-nitrocinnamates and $\alpha$-cyano-p-nitrocinnamamide afforded the corresponding cycloadducts 7-14, respectively. The cycloadducts 11-14 undergo a facile thermal elimination of hydrogen cyanide to give the corresponding pyrazoles 18-21 respectively.

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New Synthesis of Perhydrotriazolotriazoles Catalyzed by TiCl4 under Ambient Conditions

  • Safari, J.;Gandomi-Ravandi, S.;Ghotbinejad, M.
    • Journal of the Korean Chemical Society
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    • v.56 no.1
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    • pp.78-81
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    • 2012
  • Aromatic 2,3-diazabuta-1,3-dienes in glacial acetic acid with isothiocyanate in the presence of catalyst $TiCl_4$ at room temperature produced via criss-cross cycloaddition reactions the corresponding perhydro[1,2,4]triazolo[1,2-a][1,2,4] triazole-1,5-dithiones in relatively high yields and short reaction time.

Synthesis of Polymers Including Both Triazole and Tetrazole by Click Reaction

  • Shin, Jung-Ah;Lim, Yeong-Gweon;Lee, Kyung-Hee
    • Bulletin of the Korean Chemical Society
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    • v.32 no.2
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    • pp.547-552
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    • 2011
  • Azido contained polymers were treated with various substituted N-propargyl tetrazoles in $CH_2Cl_2/H_2O$ at room temperature by Cu-catalyzed [2+3] cycloaddition to afford high yields of the corresponding polymers, possessing both triazole and tetrazole moiety.

Microwave Assisted Reaction of Condensed Thiophenes With Electron Poor Olefins

  • Al-zaydi, Khadijah M.;Elnagdi , Mohamed H.
    • Journal of the Korean Chemical Society
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    • v.47 no.6
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    • pp.591-596
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    • 2003
  • Aminothienopyridazines 1a, b and aminothienocoumarin 2 condensed with DMFDMA to yield amidines 3a, b and 4. These compounds reacted with N-phenylmaleimide to yield 9 and 10. On the other hand reacting 3a, b, 4, 18, 19 and 20 with maleic anhydride afforded only the formylated derivatives 5a, b, 6, 21, 22 and 23 respectively. The reaction of 3a, b with diethyl fumarate afforded 11, formed most likely via hydrolysis of the amidine 14 during working up the reaction mixture. Irradiation of N-phenylmaleimide in microwave oven afforded [2+2] and [2+2+2] cycloaddition product.

Facile Synthesis of Fréchet Type Dendritic Benzyl Azides and Dendrimer via Cycloaddition Reaction with Tripodal Core

  • Lee, Jae-Wook;Kim, Byung-Ku;Kim, Jung-Hwan;Shin, Won-Suk;Jin, Sung-Ho
    • Bulletin of the Korean Chemical Society
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    • v.26 no.11
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    • pp.1790-1794
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    • 2005
  • Fréchet-type dendritic benzyl azides were efficiently synthesized using 5-(azidomethyl)-1,3-dihydroxybenzene as an azide focal point functionalized unit by adding a generation to the existing dendron and applied for the construction of dendrimers containing 1,2,3-triazole rings as connectors via click chemistry with a tripodal acetylene core.

Heterocyclization Reaction of 4-(2-Methylaziridin-1-yl)-3-ureidobenzotrifluorides under Appel's Conditions

  • Cho, Hyun-In;Lee, Kee-Jung
    • Bulletin of the Korean Chemical Society
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    • v.24 no.2
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    • pp.189-192
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    • 2003
  • The reaction of 4-(2-methylaziridin-1-yl)-3-ureidobenzotrifluorides 4 with triphenylphosphine, carbon tetrachloride, and triethylamine (Appel's condition) led to the corresponding carbodiimides 5, which underwent intramolecular cycloaddition reaction with aziridine under the reaction condition to give the benzimidazolefused heterocycles, 2,3-dihydro-1H-imidazo[1,2-a]benzimidazoles 8 and 12,13-dihydro-5H-benzimidazo[2,3-b] [1,3]benzodiazepines 9.