• Bulletin of the Korean Chemical Society
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• 제32권7호
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• pp.2446-2448
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• 2011

• Bulletin of the Korean Chemical Society
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• 제11권5호
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• pp.383-386
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• 1990

We have synthesized several bicyclic heteroaromatic compounds with bridgehead nitrogen from N-amine salts of heteroaromatic amines. 2-Amino and 2-unsubstituted thiazolo[3,2-b][l,2,4]triazole derivatives 2a-b were prepared by the cyclization reaction from N-amine salts of aminothiazole-5-yl(N-methoxyimino)acetate with cyanogen bromide and formamidine acetic acid salt, respectively. 2-Methylthiazolo[3,2-b][1,2,4]triazole 2c was obtained from N-acetylated N-amine salt of aminothiazole-5-yl(N-methoxyimino)acetate by the cyclization reaction in the presence of polyphosphoric acid (PPA). 2-Substituted and 2-unsubstituted thiazole[3,2-b][1,2,4]triazole derivatives 2a-c were coupled with 7-aminocephalosporanic acid (7-ACA). Coupled cephalosporin derivatives 1a-c did not have good antibacterial activities in vitro.

• Bulletin of the Korean Chemical Society
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• 제12권5호
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• pp.537-540
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• 1991

Electrophilic methylation reactions of five-membered heteroaromatic compounds, furan, pyrrole and thiophene, with the dimethylfluoronium ion, ${CH_3}{FCH_3}(+), have been investigated theoretically by the MNDO method. The site selectivity of ${\alpha}, {\beta}$ and heteroatom (X) is related to charge density of the site, indicating that the site selectivity is dictated by electrosatic interaction between two reaction centers. The reactivity order between the three heteroaromatics can not be determined decisively since the order differs depending on which site is compared, with relatively low activation enthalpies, ${\Delta}{H^\neq}$= 20-30 kcal/mol, in all cases. These site and substrate selectivity behaviors are consistent with the gas-phase experimental results.

• Bulletin of the Korean Chemical Society
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• 제10권3호
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• pp.279-282
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• 1989

Two rhodium(I) complexes of the types [Rh(BPPF)(NBD)]$ClO_4$ (10) and [Rh(BPPF)$Cl]_2$ (11) (BPPF = 1,1'-bis(diphenylphosphino)-ferrocene) have been prepared and investigated as catalysts for the regioselective hydrogenation of polynuclear heteroaromatic nitrogen and sulfur compounds such as quinoline (1), acridine (2), phenanthridine (3), 7,8-benzoquinoline (4), benzothiophene (5), isoquinoline (6), indole (7), pyridine (8), and thiophene (9). Both complexes 10 and 11, except for the cases of indole (7) and mononuclear heteroaromatics 8-9, are very efficient in the selective reduction under quite mild hydrogenation conditions to give the corresponding saturated nitrogen and sulfur heterocyclic analogues of 1-6 in fast conversion rates and in excellent yields. Relative rate studies revealed that the reduction depends significantly on the steric and electronic effects of the substrates. Of the two complexes 10-11, the dimeric species 11 gives faster reaction rates in all cases studied.

• Bulletin of the Korean Chemical Society
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• 제24권8호
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• pp.1051-1052
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• 2003

• 대한화학회지
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• 제34권3호
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• pp.248-254
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• 1990

5각-이종원자 방향족 고리화합물들인 푸란, 피롤 그리고 티오펜과 이소프로필 양이온간의 친전자성 친환반응에 관하여 MNDO 방법을 사용하여 이론적으로 연구하였다. ${\alpha},{\beta}$ 그리고 이종원자 방향족 고리화합물의 HOMO간의 전하전이 안정화(Charge transfer stabilization) 효과에 의하여 주로 결정됨을 알 수 있었다. 한편 $\alpha$ 와 $\beta$ 위치에 대한 반응성의 순서는 피롤>푸란>티오펜의 순서를 가지며 이러한 순서는 기체상 및 용액상 실험결과와 잘 일치하는 것이다.

• Bulletin of the Korean Chemical Society
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• 제28권12호
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• pp.2153-2161
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• 2007

The transition metal-induced in situ generation of carbene complexes from alkynes having a carbonyl or imino group as a nucleophilic functionality has been investigated. These reactive carbenoid species are generated with high atom efficiency through a 6-endo-dig cyclization mode based on the electrocyclization of vinylidene complexes or a 5-exo-dig cyclization mode in π-alkyne complexes, and have been found to serve as versatile intermediates in catalytic carbene transfer reactions. Highlighted and reviewed in this account are the generation and preparation of pyranylidene, furylcarbene, pyrrolylcarbene, and vinylcarbene complexes and their application to [3,3]sigmatropic rearrangement of acylcyclopropylvinylidenes, catalytic cyclopropanation reactions, [2,3]sigmatropic rearrangement or condensation reactions via ylides, ring-opening and substitution reactions with heteroaromatic compounds, and catalytic isomerization of oligoynes.

• Journal of Photoscience
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• 제8권2호
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• pp.79-82
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• 2001

2-(p-Diethylaminostyryl)pyrrole (I) and 2-[5-diethylaminothienyl]vinyl]pyrrole (II) derivatives with systematic variation of the acceptors have been synthesized and their first hyperpolarizabilities were measured. The $\beta$ values increased systematically as the aromatic resonance energy decreased. Moreover, the value of $\beta$ for the former increased gradually as the acceptor strength increased. The opposite trend observed in the latter series of compounds has been attributed to the distorted structure caused by the steric hindrance between the N-methyl group and the acceptor moiety.

• Quantitative Bio-Science
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• 제37권2호
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• pp.113-124
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• 2018

Pim kinases are important targets for cancer therapies because they are mainly responsible for cancer metastasis and overall therapeutic treatment responses. Because of their unusual structural feature in the hinge region of the ATP-binding site, new binding motifs have been discovered and used for the development of Pim kinases inhibitors. The results of a screening of 5-membered heteroaromatic compounds and the effects of structural modifications on the inhibition of Pim kinases' activities showed the potential scaffold for Pim inhibitors. 1,3,4-Oxadiazole-2(3H)-thione was found as a new scaffold for Pim kinase inhibitors.

• Bulletin of the Korean Chemical Society
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• 제32권spc8호
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• pp.3063-3073
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• 2011

The synthesis and biological evaluation of 1-heteroarylmethyl 1,4-diazepane derivatives as potential T-type calcium channel blockers is described. In this study, we have identified the compound 21i exhibiting the most potent T-type calcium channel blocking activity with $IC_{50}$ value of 0.20 ${\mu}M$, which is superior to that of mibefradil.