• 제목/요약/키워드: Aza-Wittig reaction

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Staudinger/Aza-Wittig 반응에 의한 삼발이 핵을 갖는 Fréchet-type 덴드리머의 합성 (Synthesis of Fréchet-type Dendrimers with Tripodal Core via Staudinger/Aza-Wittig Reactions)

  • 한승철;이재욱;진성호
    • 폴리머
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    • 제38권3호
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    • pp.386-390
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    • 2014
  • 덴드리머의 중심에 삼발이 핵을 갖는 덴드리머의 합성을 위한 효율적인 연결 방법이 개발되었다. 합성전략은 알데히드 덴드론과 아자이드기를 갖는 삼발이 핵 사이의 반응을 톨루엔 용매와 triphenylphosphine 존재하에서 진행하는 새로운 클릭화학(Staudinger/aza-Wittig 반응)을 이용하였다. 덴드리머의 삼발이 핵으로 작용할 수 있는 단위체인 1,3,5-tris-(3-azido-propoxy)-benzene을 합성하였고, 이 화합물의 아자이드기는 덴드리머의 형성에 이용되었다. 1,3,5-Tris-(3-azido-propoxy)-benzene을 이용하여 알데히드 덴드론과 Staudinger/aza-Wittig 반응을 통해 덴드리머를 합성하였으며, 모든 덴드리머는 높은 수득률로 얻어졌다.

Facile Synthesis of Aldehyde-focal Fréchet Type Dendrons and Dendrimers via Staudinger/Aza-Wittig Reactions

  • Han, Seung-Choul;Jin, Sung-Ho;Lee, Jae-Wook
    • Bulletin of the Korean Chemical Society
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    • 제32권10호
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    • pp.3624-3628
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    • 2011
  • Fr$\acute{e}$chet-type dendritic benzaldehydes were efficiently synthesized using 3,5-dihydroxybenzaldehyde as an aldehyde focal point functionalized unit by adding a generation to the existing dendron or direct oxidation of Fr$\acute{e}$chet-type dendritic benzyl alcohols. These dendritic benzaldehydes were applied for the construction of dendrimers containing secondary amines as connectors via Staudinger/aza-Wittig Reactions with ${\alpha}$,${\alpha}'$,-diazidop-xylene core.

Preparation of Fully Substituted 1,3,4-Oxadiazole Derivatives from N-Isocyaniminotriphenylphosphorane, (E)-Cinnamic Acids, Chloroacetone and Primary Amines

  • Ramazani, Ali;Nasrabadi, Fatemeh Zeinali;Karimi, Zahra;Rouhani, Morteza
    • Bulletin of the Korean Chemical Society
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    • 제32권8호
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    • pp.2700-2704
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    • 2011
  • The 1:1 imine intermediate generated by the addition of primary amine to chloroacetone is trapped by N-isocyaniminotriphenylphosphorane in the presence of (E)-cinnamic acids and the corresponding iminophosphorane intermediate was formed. Disubstituted 1,3,4-oxadiazole derivatives are formed via intramolecular aza-Wittig reaction of the iminophosphorane intermediate. The reactions were completed in neutral conditions at room temperature. The disubstituted 1,3,4-oxadiazole derivatives were produced in excellent yields.

One-pot, Three-component Synthesis of Fully Substituted 1,3,4-Oxadiazole Derivatives from (N-Isocyanoimino)triphenylphosphorane, Aromatic Carboxylic acids and (1R)-(-)-Campherchinon

  • Ramazani, Ali;Nasrabadi, Fatemeh Zeinali;Abdian, Behnaz;Rouhani, Morteza
    • Bulletin of the Korean Chemical Society
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    • 제33권2호
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    • pp.453-458
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    • 2012
  • Reactions of (N-isocyanimino)triphenylphosphorane with (1R)-(-)-campherchinon in the presence of aromatic carboxylic acids proceed smoothly at room temperature and in neutral conditions to afford sterically congested 1,3,4-oxadiazole derivatives in high yields. The reaction proceeds smoothly and cleanly under mild conditions and no side reactions were observed.

Efficient and Selective Construction of Pyrrolo[3,2-d]pyrimidine Derivatives

  • He, Ping;Wu, Jing;Hu, Yang-Gen;Li, Zai-Fang;Hou, Qiu-Fei;Wang, Yan-Ling;Zhao, Kun;Zhang, Erli
    • Bulletin of the Korean Chemical Society
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    • 제35권2호
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    • pp.617-621
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    • 2014
  • An efficient and selective method for the synthesis of ethyl 2-amino/aryloxy-3-aryl-4-oxo-5-phenyl-4,5-dihydro-3H-pyrrolo[3,2-d]pyrimidine-7-carboxylate derivatives has been developed. The main process involved the reaction of diethyl 1-phenyl-3-((triphenylphosphoranylidene)amino)-1H-pyrrole-2,4-dicarboxylate and aromatic isocyanates, followed by addition of amines/phenols in the presence of catalytic amount of sodium ethoxide or solid potassium carbonate.