• Title/Summary/Keyword: Cyclopentadiene

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Diels-Alder Cycloaddition of Cyclopentadiene with Ethylacrylate Catalyzed by Mesoporous Al-MCM-48 and Al-MCM-41 Catalysts

  • Shon, Jeong-Kuk;Sim, Jae-Yi;Thakur, Santosh Singh;Ko, Eun-Mi;Kong, Soo-Sung;Choi, Ji-Yun;Kang, Min;Senapati, Bidyut Kumar;Choi, Doo-Seoung;Ryu, Do-Hyun;Kim, Ji-Man
    • Bulletin of the Korean Chemical Society
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    • v.29 no.10
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    • pp.1993-1997
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    • 2008
  • In the present work, Diels-Alder reaction of cyclopentadiene with ethylacrylate has been carried out by using two types of mesoporous solid acid catalysts (Al-MCM-41, Al-MCM-48) with different pore structures. The specific topology of Al-MCM-48 (cubic Ia3d structure composed of two independent 3-D channel systems) exhibit higher activity and stereo-control than those of Al-MCM-41 (hexagonal packing of 1-D channels). The physical properties of Al-MCM-48 catalyst, such as high accessibility of reactants to the acid sites, spatial confinement in the nanoscopic reactors, and 3-D channel network structure that are effective adsorption and diffusion of reactants, play a crucial role in the present study.

Theoretical Studies on the Diels-Alder Reactions between Cyclopentadiene and Conformationally Flexible Dienophiles (시클로 펜타디엔과 구조적으로 회전이 쉬운 Dienophile간의 Diels-Alder 반응에 대한 이론적 연구)

  • Kim, Chan Kyung;Lee, In Young;Lee, Bon Su;Lee, Ik Choon;Kim, Kwan Soo;Joo, Young Hyup
    • Journal of the Korean Chemical Society
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    • v.40 no.7
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    • pp.483-491
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    • 1996
  • Dieis-Alder reaction between cyclopentadiene and 5-membered ring compounds which have exo-cyclic double bond has been studied using the PM3 method. Transition states do not show large geometrical change with the variation of dienophiles. Two isomers are possible due to the rotation of the exo-cyclic double bond of a dienophile. The reactivity for the formation of different products are explained using the FMO energy gap. The exo and endo selectivity of the reaction has been also studied from the correlation between the deformation energy and the activation barrier. Minimum energy reaction path is discussed using the Curtin-Hammett principle.

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Determination of Reactivities by Molecular Orbital Theory (VII). SCF-IMO Studies on the Diels-Alder Reactions between Cyclopentadiene and 2-Substituted Acrylonitriles (화학반응성의 분자궤도론적 연구 (제7보). 시클로펜타디엔과 아크릴로니트릴 치환체간의 Diels-Alder 반응에 대한 SCF-IMO 연구)

  • Lee Ikchoon;Choi Eun Wha
    • Journal of the Korean Chemical Society
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    • v.19 no.4
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    • pp.218-224
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    • 1975
  • The ground state SCF IMO theory was applied to the Diels-Alder reactions of cyclopentadiene with 2-substituted acrylonitriles. The CNDO/2 MO of the separate systems, including both $\sigma$ and $\pi$ electrons, was used as starting point. The qualitative prediction of the relative reactivity was made with the calculated primary interaction energies. Here the calculated activation energies appeared to be realistic. The stereoselectivity determined by the calculated secondary interaction energies represented the endo-selectivity for all the substituents. The reason for the slightly unsymmetrical ring closure at the transition state was discussed in terms of valence inactive electron densities of the reacting atoms.

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Facial Synthesis of Versatile Chiral Norbornenes as Leukotriene D4 Antagonists from D-glucose

  • Lim, Yoong-Ho;Koh, Dong-Soo
    • Journal of Applied Biological Chemistry
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    • v.48 no.2
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    • pp.97-100
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    • 2005
  • Chiral dienophile 5 was synthesized from D-glucose by consecutive diisopropylidenation, partial deprotection, diol cleavage, and Wittig reactions. Under thermal conditions, asymmetric Diels-Alder reaction between chiral dienophile and cyclopentadiene gave four possible chiral norbornenes stereoisomers whose absolute configurations were determined through CADD and NMR.

Synthesis of 5-methylbicyclo[2.2.1]hept-2-ene-5-carboxylates (5-Methylbicyclo[2.2.1]hept-2-ene-5-carboxylates의 합성)

  • Lee, Yoon-Bae;Jun, Joon-Ho;Sung, Un-Gyung;Ma, Dong-Hwan
    • Proceedings of the KAIS Fall Conference
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    • 2008.11a
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    • pp.339-342
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    • 2008
  • Methacrylate와 Cyclopentadiene을 반응하여 5-methylbicyclo[2.2.1]hept-2-ene-5-carboxylate (MBHC)를 합성하고 만들어진 MBHC를 Column Chromatography를 이용하여 Endo와 Exo를 분리하였고, MBHC에 붙는 작용기에 따른 수율 및 Endo, Exo의 비율을 확인하였다.

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Synthesis of Cyclohexyl 5-methylbicyclo[2,2,1]hept-2-ene-5-carboxylate (Cyclohexyl 5-methylbicyclo[2,2,1]hept-2-ene-5-carboxylate의 합성)

  • Lee, Yoon-Bae;Ko, You-Jin;Park, Hee-Kyoung
    • Proceedings of the KAIS Fall Conference
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    • 2011.05a
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    • pp.493-495
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    • 2011
  • cyclohexyl methacrylate와 cyclopentadiene을 반응하여 cyclohexyl 5-methylbicyclo[2,2,1]hept-2-ene-5-carboxylate를 합성하고 합성된 Norbornene계 화합물을 GC를 이용하여 그 비율을 측정하였고 Column Chromatography를 이용하여 endo와 exo를 분리해 $^1H-NMR$을 이용하여 endo와 exo 화합물의 구조를 확인하였다.

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MO Theoretical Studies on Stereoelectronic Control in the Addition Reaction of 1, 4-Benzoquinone-4-(O-methyloxime)$^*$

  • Ik-Choon Lee;Eun-Sook Han
    • Bulletin of the Korean Chemical Society
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    • v.4 no.1
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    • pp.41-44
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    • 1983
  • The chlorine addition and Diels-Alder cycloaddition of cyclopentadiene to 1, 4-benzoquinone-4-(O-methyloxime) have been studied MO theoretically. It has been shown that the reactions occur predominantly to the quinone ring double bond which is oriented anti to the nitrogen lone pair due to an n-${\sigma}^*$ interaction between the nitrogen lone pair, n, and the app. vicinal bond, causing the ${\pi}$ bond to be weakened and destabilized due to the less conjugation from reduced delocalization.