• 제목/요약/키워드: Asymmetric hydrogenation

검색결과 9건 처리시간 0.023초

Carbon-silica composites supported Pt as catalyst for asymmetric hydrogenation of ethyl 2-oxo-4-phenylbutyrate

  • Mao, Cong;Zhang, Jie;Xiao, Meitian;Liu, Yongjun;Zhang, Xueqin
    • Current Applied Physics
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    • 제18권12호
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    • pp.1480-1485
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    • 2018
  • Mesoporous carbon-silica composites supported Pt nanoparticle catalysts (Pt/MCS) were firstly applied to the heterogeneous asymmetric hydrogenation of ethyl 2-oxo-4-phenylbutyrate (EOPB). A series of different silica contents were investigated in the fabrication of this mesoporous material. When the volume of added tetraethyl orthosilicate (TEOS) during the preparation of composites is 8 mL, Pt/MCS-8 holds carbon and silica as the main components and possesses relatively strong acidity, mesoporous structures with micropores, appropriate Pt nanoparticle size and high dispersibility showing by XRD, XPS, TPD, $N_2$ sorption and TEM. These properties cause its good catalytic performance in the heterogeneous asymmetric hydrogenation of EOPB with the enantiomeric excess value and conversion up to 85.6% and 97.8%, respectively.

Highly Enantioselective Rh-catalyzed Transfer Hydrogenation of α-Functionalized Arylketones

  • Lee, Do-Min;Kwak, Se-Hun;Lee, Kee-In
    • Bulletin of the Korean Chemical Society
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    • 제30권6호
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    • pp.1317-1324
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    • 2009
  • Asymmetric transfer hydrogenation of α-functionalized arylketones has been studied. The chiral Rh-catalyst effectively performed in transfer hydrogenation of $\alpha$-mesyloxyketones with an azeotropic mixture of formic acid/triethylamine to produce optically active 1-arylethandiols with excellent enantioselectivity.

A New Approch for Catalyst Optimization: Host/Guest Complexes of Chiral Bisphosphine Bearing Imidazolidinone and Their Application in Rh-Catalyzed Asymmetric Hydrogenation

  • Park, Jung-Hwan;Shin, Hyun-Ik;Park, Doo-Han;Lee, Sang-Gi
    • Bulletin of the Korean Chemical Society
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    • 제31권3호
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    • pp.635-638
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    • 2010
  • As a new strategy for the optimization of a chiral catalyst, the catalytic activity of the host-guest complexes of chiral bisphosphine bearing imidazolidinone was investigated in Rh-catalyzed asymmetric hydrogenation of enamide. Marginal enhancement in enantioselectivity was observed and the nature of interaction between host-guest was experimentally elucidated.

Dihydrocinchonidine으로 개질된 Rh-Pt/Al2O3 이원금속 촉매를 이용한 Ethyl Pyruvate의 비대칭 수소화 (Asymmetric Hydrogenation of Ethyl Pyruvate over Bimetallic Rh-Pt/Al2O3 Catalysts Modified with Dihydrocinchonidine)

  • 조홍백;강준석;박융호
    • 공업화학
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    • 제17권4호
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    • pp.369-374
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    • 2006
  • Ethyl pyruvate의 비대칭 수소화 반응에 $Rh-Pt/Al_{2}O_{3}$ 이원금속 촉매를 처음으로 적용하고 그 반응특성을 조사하였다. $Rh-Pt/Al_{2}O_{3}$ 촉매는 상용 $Pt/Al_{2}O_{3}$에 Rh을 담지하거나 $Al_{2}O_{3}$에 Pt와 Rh을 연속적으로 함침시켜 제조하여, 촉매제법, Rh 함량 및 환원온도에 따라 반응속도, 광학선택도(ee%)가 변화하는 경향을 비교하였으며, XRD, TEM을 통하여 촉매의 물리적 특성을 분석하였다. $Rh-Pt/Al_{2}O_{3}$ 이원금속 촉매는 환원온도가 증가함에 따라 반응속도와 광학순도가 향상되었다(63.6 ee%). 또한 Rh의 함량에 따라서도 촉매 반응속도의 큰 변화를 보여주었는데, 그 변화 경향은 촉매 제조과정에 따라 달랐으나 광학선택도는 모든 이원촉매가 단일촉매에 비해 떨어지는 결과(56~60 ee%)를 나타내었다.

Total synthesis of Antofine by using Intramolecular 1.3-dipolar cycloaddition of Azidealkene

  • Lee, Jae-Kwang;Lee, Tae-Ho;Song , So-Young
    • 대한약학회:학술대회논문집
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    • 대한약학회 2002년도 Proceedings of the Convention of the Pharmaceutical Society of Korea Vol.2
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    • pp.362.2-362.2
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    • 2002
  • Antofine belongs to the Phenathroindolizidine group of alkaloids. This natural products exhibit interesting biological properties such as antitumour activity. and anti-inflammentory. Wittig reaction of phenathrenealdehyde with the phosponium salt provided the phenathreneazidealkene in good yield. Intramolecular 1.3-dipolar cycloaddition of the resulting azidealkent in refluxing benzene proceeded the imine. It was reduced with cyanoborohydride of Noyori's Asymmetric Hydrogenation. (omitted)

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새로운 술폰아미드계의 촉매의 합성 (Synthesis of Indoline tri-isopropyl benzene sulfonamide as a potential new asymmetric catalyst)

  • 윤인권;김환철
    • 자연과학논문집
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    • 제7권
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    • pp.47-51
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    • 1995
  • 입체 이성질체를 합성하는 방법으로 최근에 알려진 입체선택성 촉매를 이용한 유기반응을 연구 하기 위하여 비천연 아미노산인 인돌린-2- 카르본산으로 부터카르본산그룹의 환원,2차아민기의 보호화,메실화,아지도치환,환원에 의한 아민기로의 전환, 술폰화, 보호기제거등의 총 5단계의 합성과정을 거쳐 목적하는 술폰아미드를 합성하였다. 각 생성물은 관 크로마토그래피에 의하여 분리 정제후 핵자기공명스펙트럼($^1H,^13C $ NMR) 적외선 스펙트럼 등에 의하여 구조를 확인 하였다.

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