• Bulletin of the Korean Chemical Society
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• v.34 no.10
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• pp.2978-2982
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• 2013

A doubly tethered $N-CH_3$ amide chiral stationary phase (CSP 4) based on (+)-(18-crown-6)-2,3,11,12-tetracarboxylic acid was applied to the resolution of an antiarrythmic agent, tocainide, and its analogues and the chromatographic resolution results were compared with those on a singly tethered N-H amide CSP (CSP 1), a singly tethered $N-CH_3$ amide CSP (CSP 2) and a doubly tethered N-H amide CSP (CSP 3) under an identical aqueous mobile phase condition. CSP 4 was found to be generally better than other CSPs in terms of the separation factors (${\alpha}$) and resolutions (RS). The retention times of analytes denoted by the retention factors ($k_1$) on CSP 4 were quite long compared to those on other CSPs because of the improved lipophilicity of CSP 4. The long retention times of analytes on CSP 4 were successfully controlled by the addition of a small amount of ammonium acetate to aqueous mobile phase without hurting the chiral recognition efficiency. The variation of the content and type of organic and acidic modifier in aqueous mobile phase was found not to change the chiral recognition efficiency significantly.

• Bulletin of the Korean Chemical Society
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• v.26 no.10
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• pp.1549-1554
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• 2005

Chiral separation of arylalcohols such as 1-phenyl-1-propanol, 1-phenyl-2-propanol, and 2-phenyl-1-propanol by capillary electrophoresis was studied using sulfonated $\beta$-cyclodextrin (CD) as a chiral selector and Ag colloids as an additive. The optimum separation condition of arylalcohols was found to be the chiral selector concentration of 6.5 mM, applied voltage of 15 kV, and pH of 7.0. In order to improve chiral separation, an Ag colloid was mixed with a running buffer. The resolution in the Ag colloid-mixed running buffer was considerably superior to that obtained with the sulfonated $\beta$-CD alone. The molar ratio of sulfonated $\beta$-CD to Ag colloid, which is one of critical parameters affecting resolution, was found to be optimum at 65 : 1. In order to elucidate the resolution mechanism, an inclusion-complex of the arylalcohols with sulfonated $\beta$-CD was prepared by mixing and shaking in solution, and then characterized by cyclic voltammetry (CV). The inclusion mechanism was also discussed using experimental results.

• 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).

• Proceedings of the Optical Society of Korea Conference
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• 2009.02a
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• pp.233-234
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• 2009

The theoretical study of a surface-plasmon wave at a planar metal-chiral interface is presented in this communication. It is found that a surface-plasmon wave can be excited at the planar interface of a thin metal film and a structurally dielectric chiral medium, if the exciting plane wave is P-polarized.

• Bulletin of the Korean Chemical Society
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• v.27 no.10
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• pp.1638-1640
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• 2006

A variety of chiral cyanohydrins were readily prepared from aldehydes with TMSCN under the influence of chiral titanium complex formed in situ from $Ti(O^iPr)_4$/TADDOL(I) in the presence of $Ph_3PO$ as additive. The double activation method produces trimethylsilylethers in excellent yield (95%) with moderate enantiomeric excess.

• Journal of Photoscience
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• v.10 no.1
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• pp.21-35
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• 2003

The photoinitiated intramolecular ylide-olefin addition has been developed as an approach for the construction of one ring and two chiral centers, two rings and three chiral centers or three rings and six chiral centers in a single experimental operation from relatively simple starting materials. These investigations have uncovered several interesting and unusual reactions, which are sensitive to controls such as wavelength, temperature and solvent.

• Proceedings of the PSK Conference
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• 2002.10a
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• pp.163-164
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• 2002

In the past two decades, separations of enantiomers (optical isomers) by high-performance liquid chromatography (HPLC) have remarkably advanced ［1］. Among many commercially available chiral stationary phases (CSPs) for HPLC, polysaccharide-based CSPs are the most popular ones, which can cover the resolution of a wide range of the chiral compounds ［2, 3, 4］. Here, I will explain mainly the HPLC separation of enantiomers using these CSPs. (omitted)

• Bulletin of the Korean Chemical Society
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• v.32 no.12
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• pp.4423-4426
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• 2011

• Bulletin of the Korean Chemical Society
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• v.32 no.7
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• pp.2493-2496
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• 2011

• 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.