• 제목/요약/키워드: Pinacol

검색결과 5건 처리시간 0.019초

Reaction Conditions and Mechanism of Electrolytic Reduction of Dibenzoylmethane$^\dag$

  • Kang, Sung-Chul;Chon, Jung-Kyoon
    • Bulletin of the Korean Chemical Society
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    • 제8권5호
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    • pp.414-418
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    • 1987
  • Electrochemical reduction of dibenzoylmethane was studied on mercury electrode by means of cyclic voltammetry, polarography and potentiostatic measurements in ethanol-water system. In acidic solutions monomeric pinacol was produced by irreversible two-electron process while monomeric and dimeric pinacol were competitively produced by the same process in neutral solution. However, in basic solution the dimeric pinacol was mostly produced through radical by irreversible one-electron transfer process. Mechanisms of the reduction of dibenzoylmethane are deduced from Tafel slope, pH dependance and reaction order with respect to the concentration of dibenzoylmethane in the solution of various pH.

Mechanistic Study of Half-titanocene-based Reductive Pinacol Coupling Reaction

  • Kim, Young-Jo;Do, Young-Kyu;Park, Sung-Jin
    • Bulletin of the Korean Chemical Society
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    • 제32권11호
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    • pp.3973-3978
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    • 2011
  • The reductive pinacol coupling reaction of aldehydes or ketones creating a new C-C bond has been a major tool to produce 1,2-diol compounds. The reaction mechanism is known to be composed of sequential three steps (activation, coupling, and dissociation). In this work, we studied the dissociation step of half-titanocene-based catalytic systems. Cp and $Cp^*$ derivatives of the pinacolato-bridged dinuclear complex were synthesized and evaluated as possible models for intermediates from the coupling step. We monitored $^1H$-NMR spectra of the reaction between the metalla-pinacol intermediates and $D_2O$. New reaction routes of the dissociation step including oxo- and pinacolato-dibridged dinuclear complexes and oxo-bridged multinuclear complexes have been suggested.

페닐기 및 메틸기를 포함하는 새로운 lactone의 합성 (Syntheses of New Lactones Containing Phenyl or Methyl Groups)

  • 장승현;문상칠;김학희;이갑득;정광보
    • 공업화학
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    • 제9권6호
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    • pp.842-845
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    • 1998
  • 디히드록시 화합물과 oxalyl chloride의 반응에 의해 4가지 새로운 lactone류와 ${\alpha}$,${\omega}$-dibromo 화합물과의 반응에 의해 dibenzo crown ether를 합성하였다. 5,6,11,12- Tetracarbonyl-2,2,3,3,8,8,9,9-octaphenyl-1,4,7,10-tetraoxacyclododecane(1), 5,6,11,12- tetracarbonyl-2,2,3,3,8,8,9,9-octamethyl-1,4,7,10-tetraoxacyclododecane(2), 7,8,15,16- tetracarbonyl-1,6,9,14-tetraoxacylclohexadecane(3), 5,6,11,12-tetracarbonyl-2,3,8,9- tetraphenyl-1,4,7,10-tetraoxacyclododecane(4)는 pyridine 존재 하에서 각각 benzopinacol, pinacol, 2,2'-dihydroxybiphenyl, hydrobenzoin과 oxalyl chloride의 반응에 의해 합성하였다. Dibenzo-13-crown-4(5)는 catechol과 1,3-dibromopropane/1,2-dibromoethane의 반응에 의해 각각 25%, 12%, 20%, 75%, 25%의 수율로 합성하였다.

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