• Bulletin of the Korean Chemical Society
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• v.28 no.12
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• pp.2435-2441
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• 2007

The catalytic enantioselective electrophilic fluorinations of active methane compounds promoted chiral palladium complexes have been developed. Treatment of α-cyano acetates and α-cyanoalkylphosphonates with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding α-cyano-α-fluorinated adducts in high yields with excellent enantiomeric excesses (up to 99% ee). These reactions can be conducted in alcoholic solvents without any precaution to exclude water and moisture.

• Bulletin of the Korean Chemical Society
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• v.30 no.4
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• pp.829-836
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• 2009

The catalytic enantioselective electrophilic fluorinations of active methine compounds promoted chiral palladium complexes have been developed. Treatment of $\beta$-keto phosphonates and $\beta$-ketoesters with N-fluorobenzenesulfonimide as the fluorine source under mild reaction conditions afforded the corresponding $\alpha$-fluorinated adducts in high yields with excellent enantiomeric excesses (up to 99% ee). These reactions can be conducted in alcoholic solvents without any precaution to exclude water and moisture.

• Bulletin of the Korean Chemical Society
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• v.31 no.3
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• pp.727-730
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• 2010

• Bulletin of the Korean Chemical Society
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• v.32 no.4
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• pp.1195-1200
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• 2011

The catalytic enantioselective Mannich-type reaction promoted by chiral binaphthyl-modified bifunctional organocatalysts is described. The treatment of ${\alpha}$-fluoro-${\beta}$-ketoesters with N-Boc imines under mild reaction conditions afforded the corresponding ${\beta}$-aminated ${\alpha}$-fluoro-${\beta}$-ketoesters with excellent enantioselectivities (up to 98% ee).

• Bulletin of the Korean Chemical Society
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• v.31 no.9
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• pp.2449-2450
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• 2010

• Bulletin of the Korean Chemical Society
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• v.35 no.1
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• pp.98-102
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• 2014

The organocatalytic enantioselective Michael addition reaction promoted by chiral binaphthyl-modified squaramide catalyst have been developed, allowing facile synthesis of the corresponding chiral 2-amino-4H-chromenes derivatives with excellent enantioselectivity (up to 99% ee). The method reported represents a practical entry for the preparation of chiral 2-amino-4H-chromenes derivatives.

• KSBB Journal
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• v.17 no.4
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• pp.321-325
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• 2002

Chiral epoxides are valuable intermediates for the asymmetric synthesis of enantiopure bioactive compounds. Microbial epoxide hydrolases (EHs) are newly discovered enzymes and versatile biocatalysts for the preparation of chiral epoxides by enantioselective hydrolysis of cheap and easily available racemic epoxide substrates. EHs are commercially potential biocatalysts due to their characteristics such as high enantioselectivity, cofactor-independent catalysis, and easy-to-Prepare catalysts. In this Paper, recent progresses in biochemistry and molecular biology of EH and developments of novel reaction systems are reviewed to evaluate the commercial feasibility of EH-catalyzed hydrolytic kinetic resolution for the production of chiral epoxides.

• Journal of Life Science
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• v.16 no.1
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• pp.168-174
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• 2006

Enantiopure epoxides are valuable intermediates for the asymmetric synthesis of enantiopure bioactive compounds. Microbial epoxide hydrolases (EHs) are versatile biocatalysts for the preparation of enantiopure epoxides by enantioselective hydrolysis of cheap and easily available racemic epoxide substrates. EHs are commercially potential biocatalysts due to their characteristics such as high enantioselectivity, cofactor-independent catalysis, and easy-to-prepare catalysts. In this paper, recent progresses In molecular engineering of EHs are reviewed to evaluate the commercial feasibility of EH-catalyzed hydrolytic kinetic resolution for the production of enantiopure epoxides.

• Bulletin of the Korean Chemical Society
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• v.10 no.2
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• pp.172-177
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• 1989

Stereoselective solvolyses of optically active activated esters in the aggregate system of optically active polymeric surfactants containing imidazole and benzene moieties were performed. The catalyst polymers employed were copolymers of N-methacryloyl-L-histidine methyl ester (MHis) with N,N-dimethyl-N-hexadecyl-N-[10-(p-methacryloylo xyphenoxycarbonyl)-decyl]ammonium bromide(DEMAB). In the solvolyses of N-carbobenzoxy-D- and L-phenylalanine p-nitrophenyl esters (D-NBP and L-NBP) by polymeric catalysts, copoly(MHis-DEMAB) exhibited not only increased catalytic activity but also enhanced enantioselectivity as the mole ${\%}$ of surfactant monomers in the copolymers increased. The polymeric catalysts showed noticeable enantioselective solvolyses toward D- and L-NBP of the substrates employed. As the reaction temperature was lowered for the solvolyses of D- and L-NBP with the catalyst polymer containing 3.5 mole ${\%}$ of MHis, the increased reaction rate and enhanced enantioselectivity were observed. The coaggregative systems of the polymer and monomeric surfactants were also investigated. In the case of coaggregate system consisted of 70 mole ${\%}$ of cetyldimethylethylammonium bromide with polymeric catalyst showed maximum enantioselective catalysis, viz., $k_{cat}(L)/k_{cat}(D)$ = 2.85. The catalyst polymers in the sonicated solvolytic solutions were confirmed to form large aggregate structure by electron microscopic observation.

• Proceedings of the Korean Vacuum Society Conference
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• 2011.08a
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• pp.198-198
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• 2011

Organocatalysis is a relatively new and popular area within the field of chiral molecule synthesis. It is one of the main branches of enantioselective synthesis with enzymatic and organometallic catalysis. In recent years, immense high quality studies on catalysis by chiral secondary amines were reported. These progresses instantly led to different organocatalytic activation concepts, so thousands of researchers from academia and the chemical industry are currently involved in this field and new ideas, new approaches, and creative thinking have been rapidly emerged. Organocatalysts, some of which are natural products, appear to solve the problems of metal catalysts. Compared to metal-based catalysis, they have many advantages including savings in cost, time, and energy, easier experimental procedure, and reduction of chemical waste. These benefits originate from the following factors. First, organocatalysts are generally stable in oxygen and water in the atmosphere, there is no need for special equipments or experimental techniques to operate under anhydrous or anaerobic conditions. Second, organic reagents are naturally available from biological materials as single enantiomers that they are easy and cheap to prepare which makes them suitable for small-scale to industrial-scale reactions. Third, in terms of safety related catalysis, small organic molecules are non-toxic and environmentally friendly. Therefore, the purpose of this research is to develop novel synthetic methods and design for various organocatalyst. Furthermore, it is expected that these organocatalysts can be applied to a variety of asymmetric reactions and study the transition state of these reactions using a metal sulface. Here, we report the synthesis of unprecedented organocatalysts, proline and pyrrolidine derivatives with quaternary carbon center.