• Bulletin of the Korean Chemical Society
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• v.31 no.4
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• pp.1047-1050
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• 2010

• Bulletin of the Korean Chemical Society
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• v.25 no.1
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• pp.35-36
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• 2004

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4408-4410
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• 2011

• Bulletin of the Korean Chemical Society
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• v.26 no.4
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• pp.515-522
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• 2005

Enzyme-metal combo catalysis is described as a useful methodology for the synthesis of optically active compounds. The key point of the method is the use of enzyme and metal in combination as the catalysts for the complete transformation of racemic substrates to single enantiomeric products through dynamic kinetic resolution (DKR). In this approach, enzyme acts as an enantioselective resolving catalyst and metal does as a racemizing catalyst for the efficient DKR. Three kinds of enzyme-metal combinations - lipase-ruthenium, subtilisin-ruthenium, and lipase-palladium –have been developed as the catalysts for the DKRs of racemic alcohols, esters, and amines. The scope of the combination catalysts can be extended to the asymmetric transformations of ketones, enol acetates, and ketoximes via the DKRs. In most cases studied, enzyme-metal combo catalysis provided enantiomerically-enriched products in high yields.

• Korean Chemical Engineering Research
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• v.46 no.4
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• pp.752-755
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• 2008

Mesoporous SBA-15 silica-supported TsCHDA and TsDPEN ligands have been prepared by reaction of SBA-15 silica with (1R,2R)-N-(trimethoxysilylpropyl-N-sulfonyl)-1,2-cyclohaxanediamine or (1R,2R)-N-(trimethoxysilylpropyl-N-sulfonyl)-1,2-diphenylethylenediamine-1,2-diphenylethylenediamine, respectively. The Ru complexes exhibited excellent catalytic activity and satisfactory enantioselectivity in the asymmetric hydrogen transfer of ketones under microwave conditions. The heterogeneous Ru catalyst was reusable as well as air-stable to allow easy use. Microwave-assisted efficient procedure has been developed for asymmetric hydrogen transfer.

• Bulletin of the Korean Chemical Society
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• v.27 no.6
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• pp.857-862
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• 2006

The catalytic enantioselective Michael reaction promoted by quaternary ammonium salts from Cinchona alkaloids as a phase-transfer catalyst is described. Treatment of malonates with $\alpha$,$\beta$-unsaturated ketones under mild reaction conditions afforded the corresponding Michael adducts in good yields with good to moderate enantiomeric excesses.

• Bulletin of the Korean Chemical Society
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• v.26 no.11
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• pp.1839-1842
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• 2005

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.199-199
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• 2011

The addition of a carbanion to ${\yen}{\acute{a}}{\yen}{\hat{a}}$-unsaturated carbonyl compounds is of importance in the C-C bond formation reactions for modern pharmaceuticals and organic synthesis. Recently, heterogeneous asymmetric catalysis became more attractive area of research because of the easy recovery and separation of the catalyst from the reaction system. Most of synthetic methods for heterogeneous catalysts were grafting or immobilization of homogeneous catalyst onto the solid supports. Trans-1,2-Diaminocyclohexane(DACH) and L-proline ligands have been enormously used as chiral ligands in several catalytic transformation under homogenous conditions. Our group prepared l-proline functionalized mesoporous silica was synthesized under acidic condition using a poly(ethylene oxide)-poly(propylene oxide)-poly(ethylene oxide) triblock copolymer template (EO20PO70EO20, Pluronic P-123, BASF). Furthermore, we successfully directly synthesized trans-1,2 diaminocyclohexane functionalized mesoporous silica by using microwave method. The direct functionalization of chiral ligand into the framework of mesoporous materials is expected to be useful for the heterogeneous asymmetric catalysis. So, we adopt the direct synthesis of chiral ligand functionalized mesoporous silica by using thermal and microwave irradiation. Then, chiral ligand functionalized mesoporous silicas were applied to enantioselective asymmetric catalytic reactions.

• Bulletin of the Korean Chemical Society
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• v.18 no.5
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• pp.471-473
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• 1997

• Current Applied Physics
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• v.18 no.12
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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.