• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1554-1558
• /
• 2011

A novel and efficient method for the synthesis of 2,3-dihydrofurans bearing a variety of substituents on the dihydrofuran ring was achieved by the reaction of cyclic diazodicarbonyl compounds with styrene and vinyl acetate. The key strategy was AgBF$_4$/[Bmim]BF$_4$-catalyzed [3+2] cycloaddition. The synthesized dihydrofurans with an acetate group were further converted to the corresponding 3-acylfurans.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.5
• /
• pp.1662-1668
• /
• 2011

Steric and electronic parameters of 4'-substituents play significant roles in steering the conformation of nucleoside analogues. In order to investigate the relationship of 4'-substituent with antiviral enhancement, novel 4'-phenyl-5'-norcarbocyclic adenosine phosphonic acid analogues were racemically synthesized via de novo acyclic stereoselective route from propionaldehyde 5. The phenyl substituted cyclopentenols 15a and 15b as key intermediates were successfully constructed via reiterative carbonyl addition of Grignard reagents and ring-closing metathesis of corresponding divinyl 14. The synthesized nucleoside phosphonic acids analogues 19, 20, 21, and 23 were subjected to antiviral screening against HIV-1.

• Bulletin of the Korean Chemical Society
• /
• v.29 no.8
• /
• pp.1472-1478
• /
• 2008

The synthesis of a new series of 1$\beta$-methylcarbapenems having spiro[2,4]heptane moieties is described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents at the pyrrolidine ring was investigated. Most of the compounds were found to be more active compared to imipenem against Gram-negative bacteria. A particular compound (IIIc) having 7-oxo-5- azaspiro[2,4]heptane moiety showed the most potent antibacterial activity.

• Journal of the Korean Applied Science and Technology
• /
• v.34 no.1
• /
• pp.101-107
• /
• 2017

Anthracene has been a motive molecule for the blue-emitting materials in OLED. Since the blue emission needs big band gap between HOMO and LUMO, the blue-emitting materials are rare. In this paper, some anthracene derivatives containing simple aryl groups are synthesized and characterized. Regardless of the substituents the absorption and the emission bands are similar to each other and similar to the derivatives with the bulky silyl groups. The thermal and the CIE tests imply that among the tested 9-(2-naphthyl)-10-phenylanthracene is most promising for the diode. The material for the emission layer has to be investigated, which is simple to be prepared as well as good in the electrical and the thermal properties.

• Journal of the Korean Chemical Society
• /
• v.46 no.3
• /
• pp.225-228
• /
• 2002

Poly-o-toluidine (POT) was chemically and electrochemically synthesized for the study of the electronic and steric effect of methyl substituents. It was found that the steric effect was dominant in POT. The IP 4.95 eV, EA 3.24 eV, Eg 1.71 eV of POT were found by the CV (Cyclic Voltammetry) and CCPSA (Constant Current Potentiometric Stripping Analysis).

• Journal of the Korean Chemical Society
• /
• v.46 no.3
• /
• pp.229-232
• /
• 2002

Poly-o-toluidine (POT) was chemically and electrochemically synthesized for the study of electronic and steric effect of methyl substituents. The turn-on voltage of organic light emitting diode (OLED) was 9~14 V. ITO/POT/Al structured OLED were fabricated with various oxidation states of POT. PL, I-V characteristics and EL spectra were investigated.

• Bulletin of the Korean Chemical Society
• /
• v.27 no.5
• /
• pp.705-712
• /
• 2006

The synthesis of a new series of 1 $\beta$-methylcarbapenems having 5-(1,2-disubstituted ethyl)pyrrolidine moiety are described. Their in vitro antibacterial activities against both Gram-positive and Gram-negative bacteria were tested and the effect of substituents on the pyrrolidine ring was investigated. Among them, compound (IIIc) having 1-methoxyimino-2-hydroxyethyl moiety showed the most potent antibacterial activity.

• Bulletin of the Korean Chemical Society
• /
• v.24 no.6
• /
• pp.853-858
• /
• 2003

The reaction mechanism of the pyrolysis of sulphonyl oximes ($CH_3-C_6H_4-S(O)_2O-N=C(H)-C_6H_4Y$), in the gas phase is studied theoretically at HF/3-21G, ONIOM (B3LYP/6-31G**:HF/3-21G) and ONIOM (MP2/6- 31G**:HF/3-21G) levels. All the calculations show that the thermal decomposition of sulphonyl oximes is a concerted asynchronous process via a six-membered cyclic transition state. The activation energies (Ea) predicted by ONIOM (B3LYP/6-31G**: HF/3-21G) method are in good agreement with the experimental results for a series of tosyl arenecarboxaldoximes. Five para substituents, Y = $OCH_3$, $CH_3$, H, Cl, and $NO_2$, are employed to investigate the substituent effect on the elimination reaction. Linear Hammett correlations are obtained in all calculations in contrast to the experimental finding.

• Bulletin of the Korean Chemical Society
• /
• v.30 no.9
• /
• pp.2027-2031
• /
• 2009

The synthesis of a new series of diarylureas and amides having a 1-substituted-3-(3-chloro-5-methoxyphenyl)-4- pyridinylpyrazole scaffold is reported here. The in vitro antiproliferative activities of these diaryl derivatives against human melanoma cell line A375 were tested and the effect of substituents on the phenyl ring was investigated. Most of the newly synthesized compounds generally showed superior or similiar activity against A375 to Sorafenib. Among these compounds, IId, IIg and IIh showed excellent activity against A375 compared to Sorafenib.

• Bulletin of the Korean Chemical Society
• /
• v.25 no.2
• /
• pp.190-194
• /
• 2004

The structures and complexation energies of penta-O-tert-butyl ester 1 of p-tert-butylcalix[5]arene toward a series of alkyl ammonium guests have been optimized by ab initio HF/6-31G method. The calculated complexation efficiencies of 1 for alkyl ammonium guests have been found to be similar to the values of previously reported debutylated-calix[5]arene 2. Calculation results show that both of the calix[5]aryl derivatives have much better complexation ability toward ammonium cation without alkyl group over other alkyl ammonium guests. The structural characteristics of the calculated complexes are discussed as a function of the nature of the alkyl substituents of the ammonium guests.