• 대한화학회지
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• 제52권1호
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• pp.52-56
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• 2008

제법을 위한 쉽고 효과적인 이 방법은 solvent-free하에서 H3PMo12O40 촉매를 사용해서 개선되었다. 이 방법의 큰 이점은 조작의 간편성, 더 작은 촉매량, 선택성, 온화한 반응조건,짧은 반응 시간 그리고 높은 수율이다. 재생된 촉매는 어떤 정제도 없이 다시 사용되어질 수 있다.

• Bulletin of the Korean Chemical Society
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• 제29권7호
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• pp.1332-1334
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• 2008

Stable crystalline 1-Benzyl-4-aza-1-azonia-bicyclo[2.2.2]octane tribromide (BABOT), can be readily synthesized from the reaction of the corresponding bromide with $HNO_3$ and aqueous KBr. Selective Oxidation of a variety of dialkyl and alkyl Aryl sulfides to the corresponding sulfoxides in high yield was achieved by this reagent in solution ($CH_3CN/H_2O$) and solvent free conditions. The reaction proceeds under neutral and mild conditions and can be carried out easily at room temperature with regeneration of BABOT. In this method purification of products is straightforward and no over oxidation to sulfone was noted.

• Archives of Pharmacal Research
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• 제20권2호
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• pp.176-179
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• 1997

Purine nucleosides were chlorinated by the reaction of acyl chloride in DMF with MCPBA under mild conditions with moderate yields. And, satisfactory method for the synthesis of ribonucleoside-$3^{I},5^{I}$-cyclic phosphates and its characterization by$^{1}H$ and $^{13}C$ nmr spectroscopy is described.

• Bulletin of the Korean Chemical Society
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• 제30권8호
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• pp.1711-1714
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• 2009

We have described an efficient synthesis of quino[2,3-b][1,5]benzoxazepine α-aminophosphonate derivatives by the nucleophilic addition of triethyl phosphite to substituted quino[2,3-b][1,5]benzoxazepines promoted by easily available, inexpensive and mild catalyst KAl(S$O_4)_2{\cdot}12H_2$O(alum). The reactions proceed smoothly at room temperature under solvent-free reaction conditions and providing high yield of product in very short reaction time.

• Bulletin of the Korean Chemical Society
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• 제31권10호
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• pp.2776-2782
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• 2010

Newly developed Horner-Wadsworth-Emmons (HWE) reagents 5 having triphenylphosphorane ylide subunits readily condensed with various carbonyl compounds under mild reaction conditions to afford $\beta,\gamma$-unsaturated $\alpha$-keto triphenylphorane ylides in good to excellent yields, which were hydrogenated over Pd-C (10%)/$H_2$ (1 atm) to give the corresponding $\alpha$-keto triphenylphorane ylides in quasi-quantitative yields. These triphenyphosphorane ylides have been utilized as the precursors to $\alpha$-keto amide/ester and vicinal tricarbonyl units in Wasserman's synthetic protocols, and have previously been prepared only from carboxylic acids/acid chlorides. Our new approaches provide excellent alternatives for the synthesis of triphenylphosphorane ylide precursors to $\alpha$-keto amide/ester and vicinal tricarbonyl units directly from carbonyl compounds in good to excellent yields.

• Bulletin of the Korean Chemical Society
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• 제33권12호
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• pp.4047-4051
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• 2012

A new and facile protocol for the synthesis of dithiocarabamate in EtOH/$H_2O$ is described. Reaction of aromatic and aliphatic amines with $CS_2$ and 3,4-dihydro-2H-pyran in the presence of N,N,N',N'-tetrabromobenzene-1,3-disulfonamide [TBBDA] and poly(N-bromo-N-ethylbenzene-1,3-disulfonamide) [PBBS] gives the corresponding dithiocarbamates in good to high yields.

• 대한화학회지
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• 제57권1호
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• pp.73-80
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• 2013

An efficient synthesis of quinoxalines derivatives is described using magnetic material separated from coal fly ash. Coal fly ash is a waste material generated in huge amount by burning of coal for the generation of electricity in thermal power station. It contains $SiO_2$, $Al_2O_3$ and magnetic material in significant amounts, from which magnetic material was separated by using magnetic separation method. These separated magnetic material further characterized by XPS, XRD, EDS, FTIR, SEM, TEM and BET techniques. The merits of present method are mild reaction conditions, and also excellent yields and short reaction times.

• Journal of Microbiology and Biotechnology
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• 제18권4호
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• pp.718-724
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• 2008

Dissolved oxygen (DO) and shear stress have pronounced effects on hyaluronic acid (HA) production, yet various views persist about their effects on the molecular weight of HA. Accordingly, this study investigated the effects of DO and shear stress during HA fermentation. The results showed that both cell growth and HA synthesis were suppressed under anaerobic conditions, and the HA molecular mass was only $(1.22{\pm}0.02){\times}10^6 Da$. Under aerobic conditions, although the DO level produced no change in the biomass or HA yield, a high DO level favored the HA molecular mass, which reached a maximum value of $(2.19{\pm}0.05){\times}10^6 Da$ at 50% DO. Furthermore, a high shear stress delayed the rate of HA synthesis and decreased the HA molecular weight, yet had no clear effect on the HA yield. Therefore, a high DO concentration and mild shear environment would appear to be essential to enhance the HA molecular weight.

• Bulletin of the Korean Chemical Society
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• 제33권2호
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• pp.453-458
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• 2012

Reactions of (N-isocyanimino)triphenylphosphorane with (1R)-(-)-campherchinon in the presence of aromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.

• Bulletin of the Korean Chemical Society
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• 제34권10호
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• pp.2953-2958
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• 2013

A noble phenylsulfonyl reagent 8 having ${\alpha}$-oxo (cyanomethylene)triphenylphosphorane ylide subunit readily condensed with various alkyl halides under basic conditions to afford ${\beta}$-alkyl-${\alpha}$-oxo-${\beta}$-phenylsulfonyl (cyanomethylene)triphenylphosphorane ylides 9 in excellent yields. These sulfonyl ylides 9 were then reductively desulfonylated with $Na(Hg)/Na_2HPO_4$ in the presence of methanol to provide ${\alpha}$-keto (cyanomethylene)-triphenylphosphorane ylides 2' in good to excellent yields. Our new synthetic approach offers an expeditious access to various ${\alpha}$-keto (cyanomethylene)triphenylphosphorane ylides from alkyl halides utilizing a new phenylsulfonyl reagent as the key reagent under mild reaction conditions in good overall yields.