• Title/Summary/Keyword: Asymmetric catalyst

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About the Shape Optimization of Ex-Manifold Diffuser (배기 매니폴드 확관부 형상 최적화에 관하여)

  • Jo, Sok-Hyun
    • Transactions of the Korean Society of Mechanical Engineers B
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    • v.28 no.9
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    • pp.1133-1138
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    • 2004

  • Shape optimization method was coupled with a conventional CFD analysis to find the optimal shape of ex-manifold diffuser which decreases the maldistribution of flow above the catalyst. Shape optimization results show that flow uniformity above the catalyst was increased about 28% fur the axi-symmetric case and about 18% for the asymmetric case. The axi-symmetric type can be applied to the diffuser of under floor catalyst and the asymmetric type can be applied to the diffuser of close coupled catalyst.

  • https://doi.org/10.3795/KSME-B.2004.28.9.1133 인용 PDF KSCI

Asymmetric Michael Addition of Ketones to Nitroolefins Catalyzed by a New Chiral Catalyst

  • Wang, Lian-Jun;Hu, Feng-Feng
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1280-1282
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    • 2010

  • A new chiral catalyst was synthesized and found that it could catalyzed the asymmetric Michael reaction of ketones with nitroolefins smoothly at room temperature, giving the desired adducts in 71 - 92% yields with excellent diastereoselectivities and high enantioselectivities (up to 95% ee).

  • https://doi.org/10.5012/bkcs.2010.31.5.1280 인용 PDF KSCI

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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    • v.31 no.3
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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.

  • https://doi.org/10.5012/bkcs.2010.31.03.635 인용 PDF KSCI

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

  • Yun, In-Gwon;Kim, Hwan-Cheol
    • The Journal of Natural Sciences
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    • v.7
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    • pp.47-51
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    • 1995

  • In order to develope new asymmetric catalyst, we synthesized the following new sulfonamide derivatives start from S-Indoline-2-Carboxylic Acid via the following 5 steps. Hydroxy methyl derivative(1) was thus treated with methane sulfonyl chloride in the presence of triethylamine as base to give mesylated derivative(2) in 85% of isolated yield. The mesylate compound (2) was treated with excess sodium azide to give Azido derivative (4) in 95% isolated yield. Azido compound (3) was then reduced to the corresponding amino derivative in near quntitative yield by the hydrogenation under hydrogen atmospere in the presence of catalytic amount of Pd-C. The amino derivative (4) was converted to its sulfonamide derivatives by the treatment of compound(4) with triisopropyl benzene sulfonyl chloride in the presence of triethyl amine as base. Finally t-BOC group of the compound(5) was removed by the treatement of excess Trifluoro-acetic acid in near quantitative yield to give the target sulfonamide derivative (7) .in this paper we prepared compound(6) in 49% overall yield via the 5 steps of synthesis starting from t-Boc- 2-hydroxy methyl indoline(1) which cab be easily prepared from commercial available S-indoline-2-carboxylic acid by known methods. we plan to apply this new catalyst for the asymmetric reduction , diels-alder reaction, aldolcondensation reaction in due courses.

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Synthesis of New Bimetallic Chiral Salen Catalyst Bearing Co(BF4)2 Salt and Its Application in Asymmetric Ring Opening of Epoxide

  • Kim, Yong-Suk;Lee, Choong-Young;Kim, Geon-Joong
    • Bulletin of the Korean Chemical Society
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    • v.31 no.10
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    • pp.2973-2979
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    • 2010

  • The newly synthesized homogeneous chiral Co(III) salen complexes were anchored non-covalently on the acidic sites of mesoporous Al-SBA-15. The Bronsted and Lewis acidic sites are attributed to the immobilization of fluorine functionalized chiral salen complexes on the supports. XRD, BET, TEM, FT-IR and ESCA (XPS) analyses were performed to characterize the property of support, and the structure of new homogeneous and heterogeneous chiral Co salen catalyst. The homogeneous and heterogeneous catalysts could be applied in asymmetric ring opening of epichlorohydrine (ECH) by water. They showed very high enantioselectivity and a good yield up to 99% in the catalytic synthesis of optically active products.

  • https://doi.org/10.5012/bkcs.2010.31.10.2973 인용 PDF KSCI