• Bulletin of the Korean Chemical Society
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• v.34 no.8
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• pp.2531-2534
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• 2013

• Bulletin of the Korean Chemical Society
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• v.24 no.11
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• pp.1632-1636
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• 2003

Palladium-catalyzed cross-coupling reactions of neopentyloxysulfonylphenyl bromides with arylboronic acids provided a variety of neopentyl biphenylsulfonates in good yields. 2-Bromo- and 4-bromobenzenesulfonates underwent the coupling reaction more rapidly than 3-bromobenzenesulfonate, while chlorobenzenesulfonate did not produce the coupling product under the standard reaction conditions.

• YAKHAK HOEJI
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• v.47 no.5
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• pp.288-292
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• 2003

The synthesis of new 6-exomethylene penams with substituted triazole ring was described. The 6,6-dibromopenam 5 was reacted with $CH_3$MgBr and substituted triazole 4 to afford the 6-bromo penicillanate 6, which was treated with acetic anhydride to give acetoxy compound 7. The deacetobromination of acetoxy compound 7 with zinc and acetic acid gave 6-exomethylene penams 8, which was oxidized to sulfones 9 by m-CPBA. The p-methoxybenzyl compounds 6∼9 were deprotected by AlCl$_3$ and neutralized to give the sodium salts 10∼13.

• Bulletin of the Korean Chemical Society
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• v.10 no.1
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• pp.104-106
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• 1989

Halopyrimidines such as 2-chloro-, 5-bromo, and 4,6-dichloro-5-nitropyrimidine undergo substitution reactions with superoxide anion radical (superoxide) to give the corresponding hydroxypyrimidines under suitable conditions. Parallel experiments employing hydroxide instead of superoxide strongly indicate that the reactivity of superoxide is comparable to that of the hydroxide in the reaction with halopyrimidines. The results seem to provide a piece of information in favor of the nucleophilic substitution rather than electron-transfer mechanism in the title reaction.

• Bulletin of the Korean Chemical Society
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• v.22 no.4
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• pp.375-378
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• 2001

The palladium catalyzed dehalogenative homocoupling of haloarylsulfonates under reductive conditions has proceeded selectively depending on the type of the halogen. Thus, an iodo or a bromo leaving group of haloarylsulfonates was homocoupled to gi ve symmetrical biaryls in good yields with the sulfonate group intact, whereas a chloro leaving group gave no reaction under the conditions used. When the more reactive nickel catalyst was employed instead of the palladium catalyst in the reaction, both dehalogenative and desulfonative homocouplings of haloarylsulfonates occurred regardless of the type of the halogen used.

• YAKHAK HOEJI
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• v.44 no.2
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• pp.128-134
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• 2000

The synthesis of new 6-exomethylene penams with triazole ring was described. The 6,6-dibromopenam 5 was treated with $CH_3$MgBr and carbaldehyde 4 to afford the 6-bromo-6-(1-hydroxy-1-methyl)penicillanate 6, which was reacted with acetic anhydride to give acetoxy compound 7. The deacetobromination of 7 with zinc and acetic acid gave 6-exomethylenpenams, Z-isomer 8 and E-isomer 9, which were oxidized to sulfones 10 and 11 by m-CPBA. The p-methoxybenzyl compounds 6~11 were deprotected by AlCl$_3$ and neutralized to give the sodium salts 12~17.

• YAKHAK HOEJI
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• v.48 no.5
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• pp.303-308
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• 2004

The synthesis of new 6-triazole exomethylenepenams was described. The 6,6-dibromopenam 5 was reacted with $CH_3$MgBr and substituted triazole 4 to afford the 6-bromo penicillanate 6, which was treated with acetic anhydride to give acetoxy compound 7. The deacetobromination of acetoxy compound 7 with zinc and acetic acid gave 6-exomethylene penams 8 and 9, which were oxidized to sulfones 10 and 11 by m-CPBA. The p-methoxybenzyl compounds 6-11 were deprotected by AlCl$_3$ and neutralized to give the sodium salts 12-17.

• Bulletin of the Korean Chemical Society
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• v.16 no.4
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• pp.349-355
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• 1995

Bromo-and chlorotrimethylsilane react with selenium dioxide in halocarbon solvents and generate selenium oxybromide and oxychloride, respectively. These in-situ generated oxyhalides turned out to be very efficient for selective bromination and chlorination of aldehydes and ketones. Under carefully controlled reaction conditions, second and third introduction of halogens into carbonyl compounds can be greatly suppressed, and high yields of monohalo compounds were obtained. The product ratios of this halogenation reactions can be best explained if the reactions are assumed to involve intermediate β-ketoselenenyl chlorides.

• The Korean Journal of Pesticide Science
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• v.5 no.3
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• pp.36-40
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• 2001

A series of new 2-N-benzyl-5-phenoxy-3-isothiazolone derivatives were synthesized and their in vitro antifungal activities against resistant Phytophthora capsici (RPC) & sensitive Phytophthora capsici (SPC) with metalaxyl fungicide have been measured. In addition, influence of substituted 5-phenoxy group on the -antifungal activities ($pI_{50}$) and the reactivity of substrates were investigated. From the results, reactivity of none substituted substrate showed tendency displaying orbital-controlled reaction. The substituents on the 5-phenoxy ring showed selective fungicidal activity between SPC and RPC. Especially, the 4-fluoro substituent, 6 in the RPC and 4-nitro substituent, 3 in SPC exhibited strongly selective antifungal activity among them. The activities on the SPC would depend largely on the optimal molar refractivity ($MR_{(opt.)}=7.37cm^3/mol$) whereas the activities on the RPC would depend largely on the optimal highest occupied molecular orbital energy ($HOMO_{(opt.)}=-9.2137e.v.$) and weak electron donating (${\sigma}<0$) group. And Free-Wilson analyses revealed that the antifungal activity against RPC depends on the methoxy and bromo-substituent and all of the substituents contribute to antifungal activities against SPC.

• Journal of Physiology & Pathology in Korean Medicine
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• v.16 no.1
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• pp.192-196
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• 2002

Traditionally, aqueous extracts of Puerariae radix had been used for the treatment of alcohol-related problems. In the present study, the effect of Puerariae radix on cell proliferation and expression of nitric oxide synthase (NOS) in the dentate gyrus of alcohol-intoxicated rats were investigated via 5-bromo-2' -deoxyuridine (BrdU) immunohistochemistry and nicotinamide adenine dinucleotide phosphate-diaphorase (NADPH-d) histochemistry, respectively. Sprague-Dawley rats weighing 150 ± 10 g were divided into four groups: the control group, the Puerarias radix-treated group, the alcohol-treated group, and the alcohol- and Puerariae radix-treated group. The numbers of both BrdU-positive and NADPH-d-positive cells in the dentate gyrus were inhibited significantly by alcohol administration, while Puerariae radix treatment was shown to increase those numbers. In this study, it was revealed that Puerariae radix possesses protective effect against alcohol-induced suppressed new cell formation and NOS expression in the dentate gyrus. Based on the results, it is possible that NO, which might play an important role in the regulation of cell proliferation, is a major target of the toxic effects of alcohol.