• Journal of Photoscience
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• 제2권2호
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• pp.99-101
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• 1995

A semiempirical methods(PM3-CI-UHF, MM2) for the evaluation of ground and excited state electronic structures of electron-donating substituents are applied to 4, 5', 8-trimethylpsoralen(TMP) with TMP dimer. Three types of product have been proposed; (1) pyrone< >pyrone, (2) pyrone< >furan, (3) hetero dimer resulting from the C$_4$-cycloaddition between the furan end of one TMP moiety and the pyrone end of the other, with cis-syn configuration.

• Bulletin of the Korean Chemical Society
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• 제25권1호
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• pp.133-135
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• 2004

• 공업화학
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• 제31권3호
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• pp.258-266
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• 2020

CO₂로부터 5원환 탄산염의 합성은 지구 온난화를 문제를 해결하고 정밀한 화학 물질을 생산하는 유망한 방법 중 하나이다. 본 총설에서는 CO₂와 에폭시 화합물로부터 5원환 탄산염 합성을 위한 다공성 결정 물질인 metal-organic framework (MOF)의 촉매로써 적용 가능성에 대해 검토하였다. CO₂와 에폭시 화합물의 부가 반응에 대하여 MOF의 구조적 기능과 그에 따른 불균일계 촉매로써의 활성을 조사하였다. 그 결과, 5원환 탄산염 합성에서 MOF 촉매의 산점(acidic site)과 친핵체(nucleophile)의 상승효과(synergistic effect)에 의하여 반응성이 높아지는 것을 확인하였다. 또한 CO₂의 부가반응에서 설계된 MOF의 구조에 대한 영향과 반응메커니즘을 조사하여 제시하였다.

• Bulletin of the Korean Chemical Society
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• 제28권5호
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• pp.763-766
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• 2007

Oxypalmatine and oxypseudopalmatine were synthesized in three steps from the benzonitrile 11 and toluamides 12a, b. The lithiated cycloaddition reaction yielded 3-arylisoquinolinone intermediates. A subsequent internal SN2 reaction produced the corresponding 8-oxoprotoberberines, oxypalmatine and oxypseudopalmatine.

• Bulletin of the Korean Chemical Society
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• 제18권5호
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• pp.534-540
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• 1997

4H,6H-Furo[3,4-c]isoxazoles (Ⅰ-Ⅳ), potential fungicides, have been designed and synthesized via intramolecular [2+3] cycloaddition of nitroalkyne 3 as a key step. The broad spectrum of fungicidal activities of furoisoxazoles (Ⅰ-Ⅳ) were observed on plant pathogens at 250 ppm. Furoisoxazoles Ⅱ, Ⅲ with chlorophenyl at 6-position and methyl or alkylated oxime group at 3-position gave effective control of plant diseases. The furoisoxazole Ⅳ with a chlorophenyl group at 4-position also resulted in high fungicidal activities.

• Bulletin of the Korean Chemical Society
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• 제4권5호
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• pp.197-200
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• 1983

The Diels-Alder cycloaddition reactions between dienes and allenic ketones were studied theoretically using CNDO/2 method. It was found that the reaction is a neutral electron demand type with matrix element control and the reactivity, the regio- and stereo-selectivities can be correctly predicted based on interaction energies calculated with the 4-center FMO formalism.

• Journal of Photoscience
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• 제2권2호
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• pp.95-98
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• 1995

The photodimers with cyclobutane rings and C$_2$ symmetry, derived from coumarin (syn, head to tail and anti, head to head) have been calculated by PM3-UHF-CI and Molecular Mechanics force field. The photocycloaddition to coumarin and 5,7-dimethoxycoumarin(DMC) dimers were deduced to be formed by their preferable frontier orbital interactions and via more stable cycloaddition by the C$_3$, C$_4$ bond. These results are consistent with the coumarin dimer model that the theoretical C$_4$-photocyclodimer of coumarin is predicted much more than the experimental C$_4$-photocyclodimer.

• Bulletin of the Korean Chemical Society
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• 제4권2호
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• pp.95-99
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• 1983

Photoreaction of 8-methoxypsoralen (8-MOP) with thymine (${\ge}$ 300 nm) was carried out in the dioxane-water frozen state. One major and two minor monoaddition products between 8-MOP and thymine were isolated by various chromatographic methods. Major monoadduct was characterized to be a C4 cycloaddition product formed between 5,6-double bond of thymine and 3,4-double bond of 8-MOP with cis-anti stereochemistry. Two minor adducts were proved to be stereoisomers of this major adduct.

• Bulletin of the Korean Chemical Society
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• 제16권11호
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• pp.1037-1042
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• 1995

The reaction of acetophenone 1-ureidoethylidenehydrazones 6 with a mixture of triphenylphosphine, carbon tetrachloride, and triethylamine in dichloromethane provides a general route to 1-(1-phenylethenyl)-5-(N-substituted amino)-1,2,4-triazoles 11 via the electrocyclization of the expected azino carbodiimide intermediates 9 to give the resonance stabilized azomethine imine 10a followed by a proton abstraction from the methyl group by amide anion. However, the same reaction of benzaldehyde 1-ureidoethylidenehydrazones 5 was unsuccessful. Under the same conditions, the reactions of benzaldehyde 1-N-acylureidoethylidenehydrazones 7 or acetophenone 1-N-acylureidoethylidenehydrazones 8 afforded 4H-1,2,4-triazolo[1,5-c][1,3,5]oxadiazines 16 or 17 via the zwitterionic species 15, or a [4+2] intramolecular cycloaddition from the carbodiimide intermediates 14, respectively.

• Bulletin of the Korean Chemical Society
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• 제13권2호
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• pp.173-176
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• 1992

The spectroscopic studies of the 5,7-dimethoxycoumarin(5,7-DMC) and 4,5',8-trimethylpsoralen(TMP) and the conformational stability of 5,7-DMC-thymidine, 4,5',8-TMP-thymine were carried out by the CNDO/S and molecular mechanics calculation. Theoretical transition energies and direction of polarizations calculated by the CNDO/S method have been used for the interpretation of the observed results. The calculated absorption spectra of 5,7-DMC are qualitatively similar to experimental ones with their characteristic visible bands. MM2 force field calculation on the possible $C_4-cyclophotoadducts$ formed between 5,7-DMC and thymidine through a cycloaddition. of $C_3$, $C_4$ bond of 5,6-DMC to $C_5$, $C_6$ bond of thymidine showed the most stable photocycloadduct to have the anti-head to tail configuration. The major photoadduct of 4,5',8-TMP-thymine has the cis-anti configuration.