• Title/Summary/Keyword: 1,3-Dipolar cycloaddition

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Total synthesis of Antofine by using Intramolecular 1.3-dipolar cycloaddition of Azidealkene

  • Lee, Jae-Kwang;Lee, Tae-Ho;Song , So-Young
    • Proceedings of the PSK Conference
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    • 2002.10a
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    • pp.362.2-362.2
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    • 2002
  • Antofine belongs to the Phenathroindolizidine group of alkaloids. This natural products exhibit interesting biological properties such as antitumour activity. and anti-inflammentory. Wittig reaction of phenathrenealdehyde with the phosponium salt provided the phenathreneazidealkene in good yield. Intramolecular 1.3-dipolar cycloaddition of the resulting azidealkent in refluxing benzene proceeded the imine. It was reduced with cyanoborohydride of Noyori's Asymmetric Hydrogenation. (omitted)

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Synthesis of Perfluorinated Heterocyclic Compounds Having a Long Alkyl Chain Functionality by 1,3-Dipolar Cycloaddition

  • Lee, Chan-Woo;Hwang, Ho-Yun;Park, Joo-Yuen;Chi, Ki-Whan
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1305-1308
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    • 2010
  • Regioselective perfluorinated isoxazolidine (5 and 7), isoxazoline (9) and 1,2-addition products (6 and 8) having a long alkyl chain functionality have been prepared by 1,3-dipolar cycloaddition between a 1,3-dipole (NH-nitrone or nitrile oxide) and dipolarophile (perfluoro-2-methyl-2-pentene or styrene), respectively. Interestingly, unusual extended conjugated form of isoxazoline adduct (10) was obtained by dehydrofluorinated reaction from the corresponding perfluorinated isoxazoline adduct (9) which was derived from cycloadition between the perfluorinated long alkyl nitrile oxide 1,3-diplole and styrene olefin. This synthetic methodology of heterocyclic compound having a long alkyl chain functionality is useful for the designing of synthetic strategy and potential self-assembled monolayers (SAM) application. These derivatives were characterized by IR, $^1H$ and $^{19}F$ NMR, and MASS analysis.

Immobilization of Homogeneous Catalyst on Functionalized Carbon Nanotube via 1,3-Dipolar Cycloaddition Reaction and its Ethylene Polymerization (1,3-Dipolar cycloaddition 반응을 통해 기능화된 carbon nanotube 표면 위에 균일계 촉매 담지 및 에틸렌 중합)

  • Lee, Jeong Suk;Lee, Se Young;Lee, Jin Woo;Ko, Young Soo
    • Korean Chemical Engineering Research
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    • v.54 no.4
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    • pp.574-581
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    • 2016
  • In this study, CNT functionalized with pyrrolidine ring via 1,3-dipolar cycloaddition reaction with various amino acid and aldehyde was synthesized. Metallocene was subsequently immobilized on the functionalized CNT and CNT/polyethylene composite was prepared via in-situ ethylene polymerization. The polymerization activities of metallocene supported on CNT functionalized with glycine and benzaldehyde (Gly+BA-CNT) were similar to those of metallocene supported on CNT functionalized with N-benzyloxycarbonylglycine and paraformaldehyde (Z-Gly+PFA-CNT) although its Zr content was lower than that of Z-Gly+PFA-CNT. In the case of metallocene supported on Z-Gly+PFA-CNT, the even distribution of active sites hindered the diffusion of ethylene monomer and cocatalyst MAO due to steric hindrance during ethylene polymerization. Compared to polyethylene produced from homogeneous metallocene catalysts, CNT/PE composites had a higher initial degradation temperature ($T_{onset}$) and maximum mass loss temperature ($T_{max}$). It suggests that pyrrolidine functionalized CNT is uniformly dispersed and strongly interacted with the PE matrix, enhancing the thermal stability of PE.

Synthesis of Novel 1,2-Diazepino[3,4-b] quinoxalines and pyridazino[3,4-b] quinoxalines (새로운 1,2-다이아제피노 [3,4-b]퀴녹살린류와 피리다지노 [3,4-b] 퀴녹살린류의 합성)

  • Kim, Ho-Sik;Lee, Seong-Uk;Jeong, Geuk;Lee, Man-Kil;Kurasawa, Yoshihisa
    • YAKHAK HOEJI
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    • v.44 no.4
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    • pp.325-333
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    • 2000
  • The 1,3-dipolar cycloaddition reaction of the quinoxaline 4-oxides 2 with 2-chloroacrylonitrile gave the 2,3-dihydro-1H-1,2-diazepino[3,4-b]quinoxalines 3, which were converted into the 2,3,4,6-tetrahydro-1H-1,2-diazepino[3,4-b]quinoxalines 5-7. The reaction of compounds 3 with selenium dioxide in acetic acid/water resulted in ring transformation to give the 1,4-dihydro-4-oxopyridazino[3,4-b]quinoxalines 8.

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Synthetic Studies on Carbapenam Skeletons

  • 구양모;서민효;이윤영
    • Bulletin of the Korean Chemical Society
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    • v.17 no.10
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    • pp.909-918
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    • 1996
  • Syntheses of carbapenam skeletons were achieved from 1,3-propanediol through 1,3-dipolar cycloaddition. 3-(Tetrahydropyran-2-yloxy)-(10) and 3-(t-butyldimethylsilyloxy) propanal (13) were obtained from 1,3-propanediol. 3-Hydroxypropanals (10, 13, 14) were reacted with N-hydroxyglycine esters to give C-(2-hydroxyethyl)-N-alkoxycarbonylmethylnitrones (15a-15d). 1,3-Dipolar cycloaddition of the nitrones with methyl acrylate or ethyl crotonate gave 3-(2-hydroxyethyl)isoxazolidines (16a-16b, 17a-17b, 18, 19a-19b). 3-(2-Hydroxyethyl)isoxazolidines (17a, 17c, 19a, 19b) were converted to 3-(2-iodoethyl)isoxazolidines (21a-21d) or 3-phenylthiocarbonylmethylisoxazolidines (25a-25d) which were cyclized to give 2-oxa-1-azabicyclo[3.3.0]octanedicarboxylates (22a-22d, 26a-26d). 2-Oxa-1-azabicyclo[3.3.0]octane-4,8-dicarboxylates (22c-22d, 26c-26d) were transformed to 6-(l-hydroxyethyl)carbapenam-3-carboxylates (30a-30b, 31a-31b).

Kinetics of the 1,3-dipolar Cycloaddition of p-substituted 3-phenylsydnones with DMAD

  • Youn, Byoung-Hee;Lyu, Hak-Soo;Han, Jee-Hyun;Hahn, Soon-Jong;Kim, Sun-Hwan
    • Bulletin of the Korean Chemical Society
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    • v.8 no.4
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    • pp.233-235
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    • 1987
  • The kinetics of the 1,3-dipolar cycloaddition of p-substituted 3-phenylsydnones 1a-d with DMAD have been investigated. The reaction rates over a temperature range $100-140^{\circ}C$ were measured by UV spectrometry. The reactions found to be second-order overall, insensitive to the dielectric constants of the solvents, and characterized by a large entropy of activation. These findings are consistent with the rate-determining step involving the formation of cyclic transition state 1 and the reaction proposed to be concerted.

Synthesis of Dendrimer Containing Dialkylated-fluorene Unit as a Core Chromophore via Click Chemistry

  • Han, Seung-Choul;Jin, Sung-Ho;Lee, Jae-Wook
    • Bulletin of the Korean Chemical Society
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    • v.33 no.1
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    • pp.137-142
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    • 2012
  • The convergent synthetic strategy for the emissive dendrimers having the chromophore at core via the coppercatalyzed 1,3-dipolar cycloaddition reaction between alkyne and azide was described. 2,7-Diazido-9,9-dioctyl-9H-fluorene, designed to serve as the core in dendrimer, was stitched with the alkyne-functionalized Frechettype and PAMAM dendrons by the click chemistry leading to the formation of the corresponding fluorescent dendrimers in high yields. The preliminary photoluminescence studies indicated that 2,7-diazido-9,9-dioctyl-9H-fluorene showed no fluorescence due to the quenching effect from the electron-rich ${\alpha}$-nitrogen of the azido group but the dendrimers fluoresced due to the elimination of the quenching through the formation of the triazole ring.