• Title/Summary/Keyword: Benzylic Alcohol

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Selective Tandem Synthesis of Oximes from Benzylic Alcohols Catalyzed with 2, 3-Dichloro-5, 6-dicyanobenzoquinone

  • Aghapour, Ghasem;Mohamadian, Samaneh
    • Bulletin of the Korean Chemical Society
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    • v.33 no.4
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    • pp.1209-1212
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    • 2012
  • In spite of many reports in the literature concerning with oxidation of benzylic alcohols to carbonyl compounds with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in stoichiometric amounts or even more, we surprisingly found that benzylic alcohols are directly oxidized to oximes using a catalytic amount of DDQ in the presence of hydroxylamine hydrochloride under solvent-free conditions. The present tandem catalytic method can be efficiently used for preparation of oximes in the presence of some other functional groups with excellent chemoselectivity.

A Study for Kinetics and Oxidation Reaction and Alcohols by (C4H4N2H)2Cr3O10 ((C4H4N2H)2Cr3O10에 의한 알코올들의 산화반응과 반응속도 연구)

  • Young-Cho Park;Jae-Ho Sim
    • The Journal of the Convergence on Culture Technology
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    • v.10 no.6
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    • pp.781-788
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    • 2024
  • (C4H4N2H)2Cr3O10 has been prepared by the reaction of C4H4N2 with CrO3 in water. (C4H4N2H)2Cr3O10 was identified by elemental analysis, IR, UV-Vis and TG-DTA-TMA system. The oxidation of benzyl alcohol by (C4H4N2H)2Cr3O10 in organic solvents showed that the reactivity increased with the increase of the dielectric constant. The oxidation of alcohols was examined by (C4H4N2H)2Cr3O10 in CH2Cl2. As a resuit, (C4H4N2H)2Cr3O10 was found as efficient oxidizing agent that converted benzylic alcohol, allylic alcohol, saturated primary alcohol, secondary alcohols to the corresponding aldehydes or ketones(70%~96%). The selective oxidation of alcohols was also examined by (C4H4N2H)2Cr3O10 in CH2Cl2. (C4H4N2H)2Cr3O10 was selective oxidizing agent(10%~96%) of benzylic alcohol, allylic alcohol, saturated primary alcohols in the presence of secondary ones. In the presence of DMF. solvent with acidic catalyst such as HCl. (C4H4N2H)2Cr3O10 oxidized benzyl alcohol and its derivatives. The Hammett reaction constant was -0.70(303K). The observed experimental data were used to rationalize the hydride ion transfer in the rate determining step.

Identification of the chromophoric structure in alkali model lignin by 13C-NMR (13C-NMR에 의(依)한 알카리 모델리그닌의 착색구조(着色構造)에 관(關)한 연구(硏究))

  • Yoon, Byung Ho
    • Journal of Korean Society of Forest Science
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    • v.43 no.1
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    • pp.14-19
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    • 1979
  • On treatment with sodium hydroxide at $165^{\circ}$ for 1.5~3hr followed by air oxidation. vanillyl alcohol afforded colored materials. $^{13}C$-NMR spectrum of the material did not show any absorptions assigned to the carbons of chromophoric structures, but gave the valuable information on the chemical structures of the condensation products. On the other hand, the colored material specifically labelled by $^{13}C$ at the benzylic position was prepared by alkali treatment of vanillyl alcohol-[carbinol-$^{13}C$] followed by air oxidation, and $^{13}C$-NMR spectra of the material exhibited absorptions at 101.7 and 104.6 ppm due to the carbons of a quinonemethide structure, indicating that the quinomethide unit would be one of the important types of chromophores in which benzylic carbon of vanillyl alcohol was included.

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