• 제목/요약/키워드: Cycloaddition

검색결과 208건 처리시간 0.024초

Cycloadditiona reaction of 5-(2-thienyl)methylene derivatives of thiazolidinone-4-thiones and their antimicrobial activities

  • Ead, Hamed A.;Metwalli, Nadia H.;Morsi, Nagwa M.
    • Archives of Pharmacal Research
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    • 제13권1호
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    • pp.5-8
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    • 1990

  • The cycloaddition of the newely synthesized 5-(2-thienyl)methylene derivatives of thiazolidinone-4-thiones, 2a-c to acrylonitrile (3a), ethylacrylate (3b), N-phenylmaleimide (6) and dimethyl fumarate (8) has been evaluated. Under thermal reaction conditions [4 +2] cycloaddition proceeds with complete site and regioselectivity to yield the cycloadduct, 4, 5, 7 and 9, respectively. The antimicrobial activities of some of the new products were tested.

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Regioselective 1,3-Dipolar Cycloaddition and 1,2-Addition between Benzaldoxime NH-nitrone and Perfluoro-2-methyl-2-pentene

  • Lee, Chan-Woo;Park, Joo-Yuen;Kim, Hyun-Uk;Chi, Ki-Whan
    • Bulletin of the Korean Chemical Society
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    • 제31권5호
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    • pp.1172-1176
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    • 2010

  • Regioselective perfluorinated [3+2] cycloadducts and 1,2-adducts have been prepared by 1,3-dipolar cycloaddition between benzaldoxime NH-nitrone and perfluorinated alkene, perfluoro-2-methyl-2-pentene. Although the cycloaddition reaction is carried out at room temperature, the corresponding perfluorinated compounds are effectively produced in a high yield. In particular, the methoxy-substituted adducts (4 and 7a) show the self-assembled structure by intermolecular interactions. These derivatives were characterized by IR, $^1H$ and $^{19}F$ NMR, and the absolute structure of perfluorinated adducts was confirmed by X-ray crystallography.

  • https://doi.org/10.5012/bkcs.2010.31.5.1172 인용 PDF KSCI

Ab Initio Study of Mechanism of Forming Spiro-Ge-Heterocyclic Ring Compound From C2Ge=Ge: and Formaldehyde

  • Lu, Xiuhui;Li, Yongqing;Ming, Jingjing
    • Bulletin of the Korean Chemical Society
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    • 제34권12호
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    • pp.3690-3694
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    • 2013

  • The $H_2Ge=Ge:$ and its derivatives ($X_2Ge=Ge:$, X = H, Me, F, Cl, Br, Ph, Ar${\ldots}{\ldots}$) is a new species. Its cycloaddition reactions is a new area for the study of germylene chemistry. The mechanism of the cycloaddition reaction between singlet state Cl2Ge=Ge: and formaldehyde has been investigated with CCSD(T)//MP2/$6-31G^*$ method. From the potential energy profile, it could be predicted that the reaction has only one dominant reaction pathway. The reaction rule presented is that the two reactants first form a fourmembered Ge-heterocyclic ring germylene through the [2+2] cycloaddition reaction. Because of the 4p unoccupied orbital of Ge: atom in the four-membered Ge-heterocyclic ring germylene and the ${\pi}$ orbital of formaldehyde forming a ${\pi}{\rightarrow}p$ donor-acceptor bond, the four-membered Ge-heterocyclic ring germylene further combines with formaldehyde to form an intermediate. Because the Ge: atom in intermediate hybridizes to an $sp^3$ hybrid orbital after transition state, then, intermediate isomerizes to a spiro-Ge-heterocyclic ring compound via a transition state. The research result indicates the laws of cycloaddition reaction between $H_2Ge=Ge:$ and formaldehyde, and laid the theory foundation of the cycloaddition reaction between $H_2Ge=Ge:$ and its derivatives ($X_2Ge=Ge:$, X = H, Me, F, Cl, Br, Ph, Ar${\ldots}{\ldots}$) and asymmetric ${\pi}$-bonded compounds, which is significant for the synthesis of small-ring and spiro-Ge-heterocyclic compounds. The study extends research area and enriches the research content of germylene chemistry.

  • https://doi.org/10.5012/bkcs.2013.34.12.3690 인용 PDF KSCI KPUBS HTML