• 제목/요약/키워드: Benzyl alcohols

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Carbonylation of Benzyl Alcohols and Benzyl Bromide to Phenylacetic Acids with Rhodium(Ⅰ) and Iridium(Ⅰ) Complexes

  • Chin Chong Shik;Jung Ho Jin;Hong Seung-gweon
    • Bulletin of the Korean Chemical Society
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    • 제13권4호
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    • pp.391-395
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    • 1992
  • Rhodium(I) and iridium(II) complexes, M(Cl$O_4$)(CO)$(PPh_3)_2$ and [M(CO)$(PPh_3)_3$]Cl$O_4$ (M = Rh, Ir), and RhX(CO)$(PPh_3)_2$ (X = Cl, Br, OH) catalyze the carbonylation of benzyl alcohols to produce phenylacetic acids under 6 atm of CO at $110^{\circ}C$ in deuterated chloroform. Benzyl alcohols initially undergo dehydration to give dibenzyl ethers which are then carbonylated to benzyl phenylacetates, and the hydrolysis of benzyl phenylacetate produces phenylacetic acids and benzyl alcohols. The carbonylation is accompanied with dehydrogenation followed by hydrogenolysis of benzyl alcohols giving benzaldehydes and methylbenzenes which are also produced by CO2 elimination of phenylacetic acids. Phenylacetic acid is also produced in the reactions of benzyl bromide with CO catalytically in the presence of Rh(Cl$O_4$)(CO)$(PPh_3)_2$ and $H_2O$, and stoichiometrically with Rh(OH)(CO)$(PPh_3)_2$ in the absence of $H_2O$.

브롬화벤젠의 알코올에 의한 용매분해에 관한 반응속도론적 연구 (Kinetics of the Solvolysis of Benzyl Bromides in Alcohols)

  • 임용진;여수동;홍순영
    • 대한화학회지
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    • 제15권5호
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    • pp.219-222
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    • 1971
  • The kinetics of the solvolysis of benzyl and p-or m-substituted benzyl bromides in various alcohols have been determined by an electric conductivity method. From these reactions, a curved Hammett plot is obtained and a mechanism is proposed to account for the nonlinear behavior observed. In addition, effects of solvent polarity on the activation parameters for the solvolysis of benzyl bromides are discussed.

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Oxidation of Benzyl Alcohols with Extraordinarily High Kinetic Isotope Effects

  • Jo, Myeong-Ran;Seok, Won-K.
    • Bulletin of the Korean Chemical Society
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    • 제32권spc8호
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    • pp.3003-3008
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    • 2011
  • Reactions of benzyl alcohol and its derivatives by [Ru$^{IV}$(tpy)(dcbpy)(O)]$^{2+}$ (tpy = 2,2':6',2"-terpyridine; dcbpy = 4,4'-dicarboxy-2,2'-bipyridine) leading to the corresponding benzaldehydes in acetonitrile and water have been studied. Kinetic studies show that the reaction is first-order in both alcohol and oxidant, with k = 1.65 (${\pm}$ 0.1) $M^{-1}s^{-1}$ at $20^{\circ}C$, ${\Delta}H^{\ddag}$ = 4.3 (${\pm}$ 0.1) kcal/mol, ${\Delta}S^{\ddag}$ = -22 (${\pm}$ 1) eu, and $E_a$ = 4.9 (${\pm}$ 0.1) kcal/mol. High ${\alpha}$ C-H kinetic isotope effects are observed, but O-H solvent isotope effects are negligible. Spectral evidences with the isotope effects suggest that oxidation of benzyl alcohols occurs by a two-electron, hydride transfer. The catalytic cycles of aerobic benzyl alcohol oxidation are employed.

Convenient One-Pot Synthesis of 2,4,5-Triaryl-1H-imidazoles from Arylaldehydes, Benzyl Alcohols, or Benzyl Halides with HMDS in the Presence of Molecular Iodine

  • Veisi, Hojat;Khazaei, Ardashir;Heshmati, Leila;Hemmati, Saba
    • Bulletin of the Korean Chemical Society
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    • 제33권4호
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    • pp.1231-1234
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    • 2012
  • A one-pot efficient procedure for the synthesis of 2,4,5-triaryl-1H-imidazole derivatives in good to excellent yields by reaction between hexamethyldisilazane and arylaldehydes, benzyl alcohols, benzyl halides in the presence of molecular iodine has been developed. The remarkable advantages of this method are the simple workup procedure, high yields of products, and the availability of reagents.

효소적 방법에 의한 방향족 알코올류 및 Monoterpene Alcohol류의 배당체 합성 (Enzymatic Synthesis of $\beta$ -Glucosides of Aromatic Alcohols and Monoterpene Alcohols)

  • 김영회;김삼곤;김근수;나도영
    • 한국연초학회지
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    • 제25권1호
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    • pp.70-79
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    • 2003
  • $\beta$ -Glucosidase-catalysed synthesis of glucosides with aromatic alcohols and monoterpene alcohols as accepters and cellobiose as a donor in the presence of various commercial $\beta$ -glucosidases were described. $\beta$ -Glucosidases from Aspergillus niger spp,. Trichoderma spp., Penicillium sup. and bitter almond have been shown to catalyze synthesis of $\beta$ -glucosides of benzyl alcohol, 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, 2-phenylethyl alcohol, geraniol and citronellol in the presence of cellobiose as sugar donor. Among enzyme preparations tested, each $\beta$ -glucosides prepared from Aspergillus niger were isolated in the pure state by Diaion HP-20 and silica gel column chromatography. The products were identified as $\beta$ -glucosyl products of benzyl alcohol, 2-hydroxyhenzyl alcohol, 4-hydroxybenzyl alcohol, 2-phenyl ethyl alcohol, geraniol and citronellol by spectrometry (UV, IR, $^1$H-NMR, $^{13}$ C-NMR) and enzymatic hydrolysis with $\beta$ - glucosidase. Monoterpene alcohols with a sterically hindered hydroxyl group, such as linalool, $\ell$-menthol and $\alpha$-terpineol were not used as acceptors in transglycosylation reaction.

덴드리틱 벤질 클로라이드의 효율적인 합성 (Facile Synthesis of Dendritic Benzyl Chlorides from Their Alcohols with Methanesulfonyl Chloride/$Et_3N$)

  • 이재욱;한승철;김희주;김정환;이언엽;김병기;성새름;강화신;김지현;허도성
    • 폴리머
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    • 제31권5호
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    • pp.417-421
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    • 2007
  • 덴드리틱 벤질 알코올을 트리에틸아민과 메탄술포닐클로라이드와 반응시켜서, 덴드리틱 벤질 클로라이드의 효율적인 합성이 이루어졌다. 이 반응은 히드록시기의 메실화 반응과 염소화 반응의 2단계 반응으로 이루어지는데, 중간체의 분리없이 한 반응 용기내에서 반응이 진행되는 경제적인 방법이다.

크롬(VI)-퀴놀린 화합물에 의한 알코올류의 산화반응에 대한 반응속도론적 연구 (Kinetic Study on the Oxidation Reaction of Alcohols by Cr(VI)-Quinoline Compound)

  • 박영조;김수종
    • 융합정보논문지
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    • 제11권9호
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    • pp.109-114
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    • 2021
  • 유기공업 화학에서 알코올류의 산화제에 대해 연구가 많이 진행 되고 있으며, 그중에서도 크롬(VI)-계열의 시약들이 산화제로 널리 이용되어 왔다. 그리고 일차알코올을 알데히드로만 산화시키는 산화제와 메카니즘 규명이 필요하게 되었다. 이러한 연구의 일환으로 본 연구에서는 퀴놀린과 chromium(VI) trioxide을 반응시켜 크롬(VI)-퀴놀린 화합물[(C9H7NH)2Cr2O7]을 합성하여, FT-IR 및 원소분석에서 구조를 확인하였다. 여러 가지 유기용매를 사용하여 크롬(VI)-퀴놀린 화합물에 의한 벤질 알코올의 산화반응은 유전상수 값이 큰 유기용매인 N,N'-dimethylformamide에서 높은 산화반응성을 보였다. N,N'-dimethylformamide 용매를 사용하여 크롬(VI)-퀴놀린 화합물은 치환 벤질 알코올류를 효율적으로 산화시켰고, Hammett 반응상수(ρ)=-0.69(303 K) 이였다. 본 실험에서 알코올의 산화반응 과정은 chromate ester 형성과정과, 속도결정단계에서 수소화 전이가 일어나는 반응경로임을 알 수 있었다. 결과적으로 크롬(VI)-퀴놀린 화합물은 벤질알코올, 알릴알코올, 일차알코올 및 이차알코올류를 알데히드나 케톤으로 전환시키는 효율적인 산화제로, 이차알코올류 존재 하에서 벤질알코올, 알릴알코올, 일차알코올의 선택적인 산화제로 사용할 수 있다.