• Bulletin of the Korean Chemical Society
• /
• 제35권7호
• /
• pp.2029-2032
• /
• 2014

Magnetically nano-$CoFe_2O_4$ efficiently catalyzes oxidation of primary and secondary benzylic and aliphatic alcohols to give the corresponding carbonyl products in good yields. The reactions were carried out in an aqueous medium at room temperature in the presence of oxone (potassium hydrogen monopersulfate) as an oxidant. In addition, the catalysts could be reused up to 6 runs without significant loss of activities. Catalyst was characterized by SEM, XRD and IR.

• Bulletin of the Korean Chemical Society
• /
• 제31권4호
• /
• pp.949-952
• /
• 2010

A new and efficient reagent for the conversion of primary and secondary alcohols into their corresponding aldehydes and ketones is introduced. The reagent was easily prepared from the reaction of DBU with molecular bromine in $CHCl_3$. The structure of the reagent as $DBUH^+{Br_3}^-$ was determined by single crystal X-ray diffraction analysis.

• 대한화학회지
• /
• 제41권10호
• /
• pp.535-540
• /
• 1997

탄산칼륨 존재하에서 사염화규소는 1차, 2차, 3차 및 벤질알코올 유도체 뿐 만 아니라 시클로헥산올과 같은 고리형 알코올, 알릴 알코올등의 염소화반응에 효과적임을 알 수 있었다. 탄산칼륨이 사염화규소의 반응성이 큰 규소-염소 결합과 반응하여 생성될 수 있는 불안정한 중간체인 Trichlorosilyloxy carbonylchloride 혹은 최종적으로 평형농도 만큼 소량씩 생성되리라 예상되는 Phosgene은 모두 반응메카니즘적으로 알코올의 염소화반응에 관여할 수 있음을 알았다.

• Journal of Electrochemical Science and Technology
• /
• 제9권4호
• /
• pp.339-344
• /
• 2018

The gelling agent used in Zn-air cells plays a role in improving battery life. It prevents the evaporation of water and diffusion of $Zn^{2+}$ ions away from the current collector. Additional functionality was incorporated by replacing some of the gelling agents with new materials. Alcohols with moderate viscosity, namely maltose, sucrose, poly ethylene glycol 600, and 2-hydroxyethyl cellulose, were used to replace some gelling agents in this work. Among these alcohols, poly ethylene glycol 600 and 2-hydroxyethyl cellulose improved the cycle life of full cells. This improved cycle life was attributed to the inhibition of water electrolysis and the improved cycle life of the anode.

• Bulletin of the Korean Chemical Society
• /
• 제32권spc8호
• /
• pp.3179-3182
• /
• 2011

• Bulletin of the Korean Chemical Society
• /
• 제17권12호
• /
• pp.1135-1142
• /
• 1996

Reaction of diethylzinc with α-branched aldehydes in the presence of a catalytic amount (5 mol %) of various β-amino thiols in toluene or ether provided the corresponding secondary alcohols in outstanding ee. Detailed preparative procedure for the β-amino thiols are presented.

• Bulletin of the Korean Chemical Society
• /
• 제10권4호
• /
• pp.382-388
• /
• 1989

The approximate rates and stoichiometry of the reaction of excess potassium tri-sec-butylborohydride ($K_s-Bu_3BH$) with selected organic compounds containing representative functional groups were determined under the standard conditions (0$^{\circ}C$, THF) in order to define the characteristics of the reagent for selective reductions. Primary alcohols evolve hydrogen in 1 h, but secondary and tertiary alcohols and amines are inert to this reagent. On the other hand, phenols and thiols evolve hydrogen rapidly. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of norcamphor gives 99.3% endo- and 0.7% exo-isomer of norboneols. The reagent rapidly reduces cinnamaldehyde to the cinamyl alcohol stage and shows no further uptake of hydride. p-Benzoquinone takes up one hydride rapidly with 0.32 equiv hydrogen evolution and anthraquinone is cleanly reduced to the 9,10-dihydoxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively, however further reduction does not occur. Anhydrides utilize 2 equiv of hydride and acyl chlorides are reduced to the corresponding alcohols rapidly. Lactones are reduced to the diol stage rapidly, whereas esters are reduced moderately (3-6 h). Terminal epoxides are rapidly reduced to the more substituted alcohols, but internal epoxides are reduced slowly. Primary and tertiary amides are inert to this reagent and nitriles are reduced very slowly. 1-Nitropropane evolves hydrogen rapidly without reduction and nitrobenzene is reduced to the azoxybenzene stage, whereas azobenzene and azoxybenzene are inert. Cyclohexanone oxime evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine and quinoline are reduced slowly, however pyridine N-oxide takes up 1.5 equiv of hydride in 1 hr. Disulfides are rapidly reduced to the thiol stage, whereas sulfide, sulfoxide, sulfonic acid and sulfone are practically inert to this reagent. Primary alkyl bromide and iodide are reduced rapidly, but primary alkyl chloride, cyclohexyl bromide and cyclohexyl tosylate are reduced slowly.

• Bulletin of the Korean Chemical Society
• /
• 제8권4호
• /
• pp.285-291
• /
• 1987

The approximate rates, stoichiometries and products of the reaction of potassium triethylborohydride $(KEt_3BH)$ with selected organic compounds containing representative functional groups under the standard condition $(0^{\circ}C,$ THF) were examined in order to explore the reducing characteristics of this reagent as a selective reducing agent. Primary alcohols, phenols and thiols evolve hydrogen rapidly whereas secondary and tertiary alcohols evolve very slowly. n-Hexylamine is inert to this reagent. Aldehydes and ketones are reduced rapidly and quantitatively to the corresponding alcohols. Reduction of noncamphor gives 3% exo- and 97% endo-norboneol. Anthraquinone is cleanly reduced to 9,10-dihydro-9,10-dihydroxyanthracene stage. Carboxylic acids liberate hydrogen rapidly and quantitatively but further reduction does not occur. Anhydrides utilize 2 equiv of hydride to give an equimolar mixture of acid and alcohol. Acid chlorides, esters and lactones are rapidly and quantitatively reduced to the corresponding alcohols. Epoxides are reduced at moderate rates with Markovnikov ring opening to give the more substituted alcohols. Primary amides liberate 1 equiv of hydrogen rapidly. Further reduction of caproamide is slow whereas benzamide is not reduced. Tertiary amides are reduced slowly. Benzonitrile utilizes 2 equiv of hydride in 3 h to go to the amine stage whereas capronitrile takes only 1 equiv. The reaction of nitro compounds undergo rapidly whereas azobenzene and azoxybenzene are reduced slowly. Cyclohexanone oxime rapidly evolves hydrogen without reduction. Phenyl isocyanate utilizes 1 equiv of hydride to proceed to formanilide stage. Pyridine N-oxide and pyridine is reduced rapidly. Disulfides are rapidly reduced to the thiol stage whereas sulfoxide, sulfonic acid are practically inert to this reagent. Sulfones and cyclohexyl tosylate are slowly reduced. Octyl bromide is reduced rapidly but octyl chloride and cyclohexyl bromide are reduced slowly.

• 대한화학회지
• /
• 제34권6호
• /
• pp.534-538
• /
• 1990

H$_2$O을 용매로 하여 헤테로고리 염기인 이소퀴놀린과 CrO$_3$를 반응시켜 Cr(Ⅵ)화합물인 [$C_9H_7$NH]$_2Cr_2O_7$을 얻었다. 이 화합물은 비흡수성이면서 물에 잘 녹았다. 그리고 원소분석, 적외선 분광법으로 이 화합물의 구조가 [$C_9H_7$NH]$_2Cr_2O_7$임을 확인하였다. 또한, 이 화합물이 여러 가지 알코올을 알데히드나 케톤으로 전환시킬 수 있는 산화제로 작용하는가를 알아보기 위하여 알릴, 일차, 이차 알코올을 각각 산화반응에 이용한 결과 알코올들에 대해 효율적인 산화제로 작용하였다.

• 대한화학회지
• /
• 제41권10호
• /
• pp.541-546
• /
• 1997

이산화망간 존재하에서 사염화규소는 1차, 2차, 3차 및 벤질알코올 유도체 뿐 만 아니라 시클로헥산올과 같은 고리형 알코올, 알릴 알코올 등의 염소화반응을 정량적으로 수행할 수 있음을 발견하였다. 먼저 이산화망간이 사염화규소의 반응성이 큰 규소-염소 결합에 삽입되어 불안정한 중간체인 Manganese(IV) oxodichloride를 생성하고 이 중간체는 계속하여 사염화규소와 반응하여 최종적으로 사염화망간을 생성하리라 예상된다. 이렇게 생성되리라 예상되는 화학종들은 모두 반응메카니즘적으로 알코올의 염소화반응에 관여할 수 있음을 알았다. 이 반응은 Thionyl chloride나 삼염화인등을 사용한 고전적인 알코올의 염소화반응에 비하여 많은 장점을 가짐을 알 수 있었다.