• 대한화학회지
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• 제9권3호
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• pp.148-151
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• 1965

Benzyl chloride 및 bromide와 chloride 및 bromide ion 간의 반응을 90% ethanol 용액에서반응속도론적으로 연구하였다. 반 정량적인 결과의 해석은 bond-formation 이 bond-breaking보다 더 중요하고 또 결합형성 과정에서는 형성으로 얻은 energy보다는 nucleophile의 electron affinity의 증가로 인한 차이가 더 중요함을 보여주고 있다.

• Bulletin of the Korean Chemical Society
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• 제28권9호
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• pp.1553-1561
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• 2007

The new type of heterometallic chiral polymer salen complexes have been synthesized and it has been found that group 13 metal salts (AlCl3, GaCl3 and InCl3) combined to cobalt salen unit played the crucial role in the asymmetric kinetic resolution of racemic epoxides. Polymeric salen catalysts showed very high reactivity and enantioselectivity for the asymmetric ring opening of terminal epoxide with diverse nucleophiles. They provide the enantiopure useful chiral intermediates such as chiral terminal epoxides and α -aryloxy alcohols in one-step process. An efficient methodology for providing very high enantioselectivity can be achieved in the synthesis of valuable chiral building blocks via our catalytic system by combination of various asymmetric ring opening reactions.

• 약학회지
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• 제26권2호
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• pp.91-96
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• 1982

In an attempt to design prodrugs for the Derivatives of the Isothiocyanates R-N=C=S were synthesized eleven novel bis-dithiocarbamates. The best way of preparing the dithiocarbamates was the formation of the dithiocarbonates followed by the reaction of the dithiocarbonates with amines. Thus, the treatment of the diols with carbon disulfide in the presense of potassium hydroxide afforded the potassium salts of the ditniocarbonic acids. The potassium salts were then reacted with alkyl halides to give the dithiocarbonates, which upon treatment with amines produces the dithiocarbamates. In case of vicinal diol (n=o in the above formula), only one of the hydroxy groups was reacted to give the mono-dithiocarbonate. The dithiocarbonates failed to react with amides and aromatic amines. Dithiocarbonates of the different types were obtained when the active double bonds, such as $CH_{2}=CH-Z$ , (Z are electron withdrawing groups), were allowed to react with the free dithiocarbonic acids produced in situ by carefully neutralizing the Potassium salts of the corresponding acids. These compounds are considered to be of some value as prodrugs for the active double bonds.

• 약학회지
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• 제40권3호
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• pp.300-305
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• 1996

The base-induced elimination of N-protected 2-(bromomethyl)pyrrolidines 12a-c with KHMDS in THF at -78$^{\circ}C$ for 1h gave exocyclic enamines 13a-c. The acidic catalyzed pr otonation on ${\beta}$-carbon atom of 2-(methylene)pyrrolidines 13a-c with $H_3PO_4$ formed endocyclic N-iminium intermediates 14(or 15). Nucleophilic attack of alpha-carbon atom and hydrolysis of N-iminium ion gave carbocationic adduct (aminoalcohol) 16 from which 5-amino-2-pentanones 17a-c were formed after deprotonation.

• 대한화학회지
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• 제6권1호
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• pp.73-77
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• 1962

Yields of hydrogen, methane, carbon monoxide, formaldehyde and ethylene glycol by gamma-radiolysis of methanol have been determined at room temperature and compared with values reported in the literature. The G-values obtained by the present studies are as follows: $G(H_2)=4.98,\;G(CH_4)=0.28,\;G(CO)=0.09,\;G(HCHO)=2.14\;and\;G(C_2H_6O_2)=3.07.$ The effects of water, methyl borate and alkali halides added to methanol prior to radiolysis have also been investigated. It is observed that alkali iodides and bromides affect the G-values, particularly, of hydrogen, formaldehyde and/or ethylene glycol, whereas alkali chlorides and fluorides have less pronounced effects.

• 대한화학회지
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• 제9권4호
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• pp.211-214
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• 1965

H.Eyring과 그의 공동 연구자들이 발전시킨 액체이론$^{(1-3)}$에 따라서 할로겐화 메틸의 분배함수를 구하였으며 이에 포함된 parameters은 장세헌과 그의 공동 연구자들이 개정한 방법$^{(4)}$에 따라서 구하였다. 이 분배함수로부터 여러가지 열역학적 양들을 계산하여 실험치와 비교하여 본 결과 매우 잘 맞었다.

• Bulletin of the Korean Chemical Society
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• 제30권2호
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• pp.496-498
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• 2009

• 대한화학회지
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• 제17권4호
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• pp.286-297
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• 1973

폴리플루오로알켄닐리튬 化合物들이 1,2-dihalopolyfluorocycloalkenes와 알킬리튬試藥과의 交換反應에 依하여 合成되었다. 수은, 비소와 디메틸게르마늄할로겐화물과의 여러 가지 反應이 著述되어 있고 또 이 化合物들의 化學的性質에 대하여 考察하였다.

• 열처리공학회지
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• 제8권2호
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• pp.127-136
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• 1995

The simultaneous addition of Al and Cr to the surface of Ni-and Fe-base alloy provides enhanced resistance to oxidation and corrosion in high temperatures. However, because of the large differences in thermodynamic stabilities of the volatile halides of Al and Cr, the codeposition of Al and Cr by halideactivated pack cementation is only possible for very specific, limited combinations of conditions. In this study, the experiments on the combinations of various metallic source powders and activators were conducted in order to obtain codeposition layers of Al and Cr on Ni with adequate composition by pack cementation. When Cr-Al masteralloy was used as a source powder, it was not easy to control Al and Cr content sensitively in the coating layers. On the other hand, when pure Cr and Al powder was used, ${\beta}$-NiAl layer containing about 20wt % Cr was obtained.

• Bulletin of the Korean Chemical Society
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• 제10권1호
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• pp.80-84
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• 1989

Two properties of sodium naphthalenide (2), i.e. a strong base and a good electron donor were utilized for one pot synthesis: 2-alkylthiobenzimidazoles were synthesized in excellent yields from the reactions of benzimidazoline-2-thione (1) with an equimolar amount of alkyl halides in the presence of 2. Continuous addition of a different alkyl halide without the isolation of 2-alkylthiobenzimidazoles afforded 1-alkyl-2-alkylthiobenzimidazoles having different alkyl groups at N and S atoms in excellent yields. Further addition of 2 to 1-alkyl-2-alkylthiobenzimidazoles gave excellent yields of 1-alkylbenzimidazoline-2-thiones. When 2 in THF was added to a suspension of 1-alkyl-2-alkylthiobenzimidazoles in THF, a bond cleavage between N and C of alkyl group as well as S and C of alkyl group occurred. This is in contrast to the observation in which only cleavage between S and C of alkyl group takes place in the homogeneous solution.