• 제목/요약/키워드: Hydrogenolysis

검색결과 29건 처리시간 0.02초

Catalytic Hydrogenation of Aromatic Nitro Compounds over Borohydride Exchange Resin Supported Pd (BER-Pd) Catalyst

  • Yoon, Nung-Min;Lee, Hyang-Won;Choi, Jae-Sung;Lee, Hyun-Ju
    • Bulletin of the Korean Chemical Society
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    • 제14권2호
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    • pp.281-283
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    • 1993
  • Aromatic nitro compounds are selectively hydrogenated to the corresponding amines in high yields at room temperature and atmospheric pressure using BER-Pd catalyst without affecting ketone, ether, ester, nitrile or chloro groups also present. Especially the nitro group in 4-nitrobenzyl alcohol, methyl 4-nitrobenzyl ether and N-N-dimethyl 4-nitrobenzylamine is selectively hydrogenated with this catalyst to give the corresponding amines without hydrogenolysis of benzylic groups. And aromatic nitro compound can be reduced selectively in the presence of aliphatic nitro compound.

Direct Conversion of Cellulose into Polyols over Pt/CsxH3-xPW12O40

  • You, Su Jin;Baek, In Gu;Park, Eun Duck
    • 청정기술
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    • 제19권1호
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    • pp.13-21
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    • 2013
  • 다른 분율의 Cs이 포함된 Pt/$Cs_xH_{3-x}PW_{12}O_{40}$ 촉매를 제조하여 셀룰로우스의 폴리올로의 수소화분해반응를 수행하였다. 촉매의 비표면적과 Pt의 분산도는 Pt/$Cs_xH_{3-x}PW_{12}O_{40}$ 촉매의 Cs 함량이 증가함에 따라 증가하였다. 그러나 Pt/$Cs_xH_{3-x}PW_{12}O_{40}$ 촉매의 Cs의 함량이 변함에도 불구하고 비슷한 폴리올 수득률을 보였다. Pt/$Cs_xH_{3-x}PW_{12}O_{40}$ 촉매의 반응 활성은 Ni/W/SBA-15와 두 가지의 복합촉매(Pt/AC+$H_3PW_{12}O_{40}$과 Pt/AC+$Cs_{3.0}PW_{12}O_{40}$)와 비슷하였다. 이 반응을 진행하는 동안 Pt/$Cs_xH_{3-x}PW_{12}O_{40}$ 촉매로부터 헤테로폴리 음이온이 침출되는 것을 확인하였다.

Solid-Phase Synthesis of Unfunctionalized Arenes Via the Traceless Cleavage of Sulfonate Linkers

  • Kim, Chul-Bae;Cho, Chul-Hee;Jo, Min-Jy;Park, Kwang-Yong
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3655-3659
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    • 2011
  • The hydrogenolysis of polymer-bound arenesulfonates by 2-propylmagnesium chloride was performed through reductive cleavage of the C-S bond in the presence of a nickel catalyst. The reaction underwent in the highest efficiency by adding 15 equiv of the nucleophile in two additions with $dppfNiCl_2$ in THF. Various unfunctionalized naphthalene, biphenyl, and stilbene derivatives were produced in good yields by the traceless sulfonate linker system at room temperature.

Catalytic deoxygenation of vanillin over layered double hydroxide supported Pd catalyst

  • Liao, Chanjuan;Liu, Xixi;Ren, Yongshen;Gong, Daoxin;Zhang, Zehui
    • Journal of Industrial and Engineering Chemistry
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    • 제68권
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    • pp.380-386
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    • 2018
  • A sustainable method was developed for the upgrade of biomass derived vanillin (a typical model compound of lignin) into the potential liquid biofuels over a layered double hydroxide supported Pd catalyst (abbreviated as CoAl-LDH/Pd). The CoAl-LDH/Pd catalyst showed high catalytic activity towards the hydrodeoxygenation of vanillin into 2-methoxy-4-methylphenol (MMP) under mild conditions in aqueous media. High MMP yield up to 86% was produced at $120^{\circ}C$ after 4 h. Kinetic studies revealed that the rate-determining step for the hydrodeoxygenation of vanillin was the hydrogenolysis of vanillyl alcohol. More importantly, the CoAl-LDH/Pd catalyst was highly stable without the loss of activity.

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 $H_2O$.

Hydrogenation of Arenes with Metallic Iridium and Rhodium Powders Prepared from Iridium(Ⅰ) and Phodium(Ⅰ)-COD Complexes under Mild Conditions

  • 진종식;이병노;문지중;송중호;박용선
    • Bulletin of the Korean Chemical Society
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    • 제16권6호
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    • pp.528-533
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    • 1995
  • Metallic iridium and rhodium powders prepared from the reactions of [M(COD)(PhCN)2]ClO4 (M=Ir(1), Rh(2); COD=1,5-cyclooctadiene) with hydrogen at room temperature in methylene chloride show catalytic activities for hydrogenation of arenes at room temperature under atmospheric pressure of hydrogen. Most substituents (CH3, COOH, NO2, CH2OH, CHO, OPh, OCH3, C=C, halogens and CH2Cl) on aromatic ring suppress the rate of the hydrogenation of the aromatic ring while the aromatic ring hydrogenation of phenol and 1,4-dihydroxobenzene is faster than that of benzene over these metallic powders. Hydrogenation of benzoic acid occurs only at the aromatic ring leaving the COOH group intact over iridium metal powders while benzoic acid is not hydrogenated at all over rhodium metal powders. Carbonyl, nitro, acetylenic and olefinic groups on an aromatic ring are hydrogenated prior to the aromatic ring hydrogenation. Hydrogenolysis of OH groups of phenol, benzyl alcohol and 1,4-dihydroxobenzene, and hydrodehalogenation of halobenzenes, benzyl halides and cinnamyl chloride also occur along with the hydrogenation of aromatic ring.

수소첨가를 통한 폐플라스틱 분해 기술 동향 (Recent Research Trend in Plastic Waste Upcycling via Hydrocracking Using Heterogeneous Catalysts)

  • 노인수
    • 공업화학전망
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    • 제24권2호
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    • pp.1-9
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    • 2021
  • 플라스틱은 가볍고 물성이 뛰어나며 가공이 용이하면서도 낮은 가격 때문에 우리의 실생활에서 매일 사용되고 있다. 동시에 썩지 않는 특성 탓에 폐플라스틱에 의한 환경오염의 문제가 심해짐에 따라 전 세계적으로 일회용 포장재 및 용기에 사용되는 플라스틱의 사용을 금지하는 규제 및 폐플라스틱을 재활용하려는 시도가 늘어나고 있다. 하지만 인류가 지난 수십 년간 생산한 플라스틱은 약 83억 톤이지만 이중 약 10%정도만 재활용 되었을 정도로 폐플라스틱의 재활용 비율은 미비하다. 특히, 최근 코로나 팬데믹으로 인해 택배 및 배달음식 주문량이 늘어남에 따라 플라스틱의 사용량이 급증하여 폐플라스틱의 재활용 필요성은 더욱더 커지고 있다. 본 기고문에서는 불균일 촉매를 이용한 수소첨가 폐플라스틱의 분해에 관한 최신 연구동향을 다루고자 한다. 안정적이고 반응성 및 선택성이 뛰어난 촉매 개발은 폐플라스틱의 효과적인 분해를 위해서 매우 중요하다.

리그닌 이양체(二量體) 모델화합물(化合物)의 합성(合成) - Veratrylglycerol-β-vanillylalcohol ether 화합물(化合物) - (Synthesis of Dimeric Lignin Model Compounds - Veratrylglycerol-β-vanillylalcohol ether compounds -)

  • 조국란;황병호
    • Journal of Forest and Environmental Science
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    • 제12권1호
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    • pp.37-44
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    • 1996
  • Veratrylglycerol-${\beta}$-vanillylalcohol ether 결합 (${\beta}$-O-4 linkage)을 갖는 이양체(二量體) 리그닌 모델화합물(化合物)의 합성(合成)하여 각종 리그닌 반응(反應)의 시료(試料)로서 활용(活用)하고자 3,5-dimethoxyacetophenone을 출발물질(出發物質)로 하여 ${\beta}$-ring에 측소(側銷)를 갖는 이양체(二量體) 리그닌 모델화합물(化合物)(I-IV)을 합성(合成)하였고, 융점측정, $^1H(^{13}C)$-NMR 및 Mass 스펙트라에 의하여 그 화학구조(化學構造)를 동정(同定)하였다. 이 합성화합물(合成化合物)중에서 1-(3,4-dimethoxyphenyl)-2-(2'-methoxy-4'-hydroxymethylphenoxy)ropanediol-1,3[IV]는 매우 중요한 리그닌 이양체(二量體) 화합물(化合物)이다. 이러한 리그닌 합성연구(合成硏究)는 기초적(基礎的)인 연구(硏究)의 중요성(重要性) 뿐만아니라 응용면(應用面)에서도 그 활용도(活用度)가 높을 것이다.

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