• 한국진공학회:학술대회논문집
• /
• 한국진공학회 2007년도 제32회 학술대회 초록집
• /
• pp.72-72
• /
• 2007

• Bulletin of the Korean Chemical Society
• /
• 제26권4호
• /
• pp.658-660
• /
• 2005

• 대한화학회지
• /
• 제67권4호
• /
• pp.306-310
• /
• 2023

• 대한화학회지
• /
• 제13권1호
• /
• pp.89-95
• /
• 1969

The structural investigations on the adducts, formed from dichloroketene with cyclopentadiene, methyl and ethylcyclopentadiene, have been carried out by means of infrared and nuclear magnetic resonance spectroscopy and also by their chemical behaviors. It was confirmed by this study that the adducts were formed by 1, 2-cycloaddition reaction and had the fundamental structure of bicyclo [3. 2. 0]-7,7-dichloro-2-heptene-6-one. These results were well agreed with the hypothesis that a diradical intermediate was formed as the first step in 1, 2-cycloaddition. The reaction mechanism for the process in which tropolones were formed from these adducts was also discussed.

• Bulletin of the Korean Chemical Society
• /
• 제23권7호
• /
• pp.1021-1022
• /
• 2002

• Bulletin of the Korean Chemical Society
• /
• 제33권12호
• /
• pp.4079-4083
• /
• 2012

The mechanism of the cycloaddition reaction between singlet state dichlorosilylene germylidene ($Cl_2Si=Ge:$) and acetone has been investigated with B3LYP/6-$31G^*$ and B3LYP/6-$31G^{**}$ method, from the potential energy profile, we predict that the reaction has one dominant reaction pathway. The presented rule of the reaction is that the two reactants firstly form a Si-heterocyclic four-membered ring germylene through the [2+2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge atom in the Si-heterocyclic four-membered ring germylene and the ${\pi}$ orbital of acetone forming a ${\pi}{\rightarrow}p$ donor-acceptor bond, the Si-heterocyclic four-membered ring germylene further combines with acetone to form an intermediate. Because the Ge atom in the intermediate hybridizes to an $sp^3$ hybrid orbital after the transition state, then, the intermediate isomerizes to spiro-heterocyclic ring compound involving Si and Ge (P4) via a transition state.

• 대한화학회지
• /
• 제47권4호
• /
• pp.354-362
• /
• 2003

Xestoquinone의 퓨란-접합된 4환계화합물에 대한 합성전략을 모델연구를 통하여 조사하였다. 출발물질로서 3-butyn-1-ol을 이용하여, 5-iodo-1-methoxymethoxypentyne(5)이 5단계를 거쳐 제조되었다. Ethyl 2-phenylpropanoate와 5의 반응으로부터 ethyl 7-methoxymethoxy-2-methyl-2-phenyl-5-heptynoate(6)가 88%의 수득율로 얻어졌으며, 6으로부터 중요한 중간체인 methyl 9-oxo-4-methyl-4-phenyl-2,7-nonadiynoate(13)가 6단계를 거쳐 합성되었다. 13의 분자내 고리화반응은 5%의 수득율로 isobenzofuran 14을 생성하였으며, Lewis acid 존재 하에서 4환고리 구조로 전환되었다.

• Bulletin of the Korean Chemical Society
• /
• 제24권2호
• /
• pp.189-192
• /
• 2003

The reaction of 4-(2-methylaziridin-1-yl)-3-ureidobenzotrifluorides 4 with triphenylphosphine, carbon tetrachloride, and triethylamine (Appel's condition) led to the corresponding carbodiimides 5, which underwent intramolecular cycloaddition reaction with aziridine under the reaction condition to give the benzimidazolefused heterocycles, 2,3-dihydro-1H-imidazo[1,2-a]benzimidazoles 8 and 12,13-dihydro-5H-benzimidazo[2,3-b] [1,3]benzodiazepines 9.

• Bulletin of the Korean Chemical Society
• /
• 제35권6호
• /
• pp.1605-1612
• /
• 2014

Copper(I)-catalyzed Huisgen cycloaddition of terminal alkynes with unmasked azidoamines derived from amino acids is described. The reported strategy provides a new entry to highly hindered ${\beta}$-amino 1,2,3-triazole derivatives bearing a gem-diaryl group, which are potentially valuable entities as molecular catalysts for asymmetric transformations.

• 대한화학회지
• /
• 제16권3호
• /
• pp.178-188
• /
• 1972

Diethyl itaconate was found to react tetrafluoroethylene, trifluorochloroethylene, and 1,1-difluoro-2,2-dichloroethylene quite rendily at $180^{\circ}C$ to form 1-carboxy-2,2,3,3,-tetrahalo-cyclobutane ethanoic acid derivatives ${C{\underline{X_2-CF_2-CH_2-}}C-(COOEt)-CH_2COOEt$, where X is Cl or F). Diethylcitraconate failed to yeild any cycloaddition products. The Physical and Chemical properties of the above esters and their dericatives are characterized and compared with other similar ring compounds.