• Title/Summary/Keyword: Pyrrole

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Synthesis of 2,2'-Dipyrryl Ketones from Pyrrole-2-carboxylic Acids with Trifluoroacetic Anhydride

  • Kim, Se Hee;Lim, Jin Woo;Yu, Jin;Kim, Jae Nyoung
    • Bulletin of the Korean Chemical Society
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    • v.34 no.9
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    • pp.2604-2608
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    • 2013
  • An efficient synthesis of 2,2'-dipyrryl ketones has been carried out from pyrrole-2-carboxylic acids using trifluoroacetic anhydride (TFAA). Simultaneous generation of both mixed anhydride and 2-unsubstituted pyrrole, via facile decarboxylation with in-situ generated TFA, made their cross reaction (intermolecular Friedel-Crafts acylation) possible and efficient.

Studies on Conductive Polypyrrole Nanowires Fabricated with DNA templates (DNA를 형틀로 이용한 전도성 Polypyrrole Nanowire의 제작 연구)

  • Moon, Hock-Key;Roh, Yong-Han
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2006.11a
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    • pp.178-179
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    • 2006
  • 나노 크기를 가지는 DNA 분자를 template로 사용하여 전도성 고분자의 일종인 polypyrrole nanowire를 합성하였다. 본 논문에서 합성된 polypyrrole nanowire는 단량체인 pyrrole과 산화제와의 화학적인 반응에 의해 만들어졌다. 먼저 DNA 분자를 APTES(3-aminopropyltriethoxysilane) modified Si surface 위에 정렬한다. 그리고 이 기판을 농도를 달리한 pyrrole solution에서 incubationn한다. 마지막으로 APS (ammonium persulfate)와 반응시켜 conductive nanowire를 합성하였다. SEM을 이용하여 silicon 기판위에 1차원적으로 정렬된 나노 크기를 가지는 polypyrrole nanowire를 관찰할수 있었다. 그리고 pyrrole의 농도에 따라 nanowire의 uniformity를 조절할 수 있었다.

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The Mechanisms for Thermal and Photochemical Isomerizations of N-Substituted 2-Halopyrroles: Syntheses of N-Substituted 3-Halopyrroles

  • Park, Sung-Hyun;Ha, Hong-Joo;Lim, Chul-Taek;Lim, Dong-Kwon;Lee, Kwang-Hee;Park, Yong-Tae
    • Bulletin of the Korean Chemical Society
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    • v.26 no.8
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    • pp.1190-1196
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    • 2005
  • Halopyrroles, N-substituted 2-halopyrroles were prepared by halogenation of N-substituted pyrroles with NBS, NCS, or surfuryl chloride. N-Substituted 3-halopyrroles were synthesized by acid-catalyzed thermal and photochemical isomerization reactions of N-substituted 2-halopyrroles. Both the thermal and photochemical reactions were acid-catalyzed. For the acid-catalyzed isomerization, a mechanism of [1,3] bromine shift followed by deprotonation is operated. For the acid-catalyzed photoisomerization, an excited triplet state of 2-protonated N-benzyl-2-halopyrrole produces an intermediate N-substituted pyrrole complex with halonium ion which is equilibrated with N-substituted pyrrole plus halonium ion, and then the halonium ion newly adds to 3-position of N-substituted pyrrole followed by deprotonation to afford N-benzyl-3-halopyrrole.

Effect of pH on Synthesis of Polypyrrole Nanowires by Using DNA Molecule Templates (DNA 분자를 형틀로 이용한 Polypyrrole 나노와이어의 합성시 pH 효과)

  • Choi, Young-Hun;Kim, Kyoung-Soeb;Kim, Nam-Hoon;Roh, Yong-Han
    • Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
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    • 2007.11a
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    • pp.109-110
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    • 2007
  • Pyrrole and DNA can be used for synthesis of conducting nanowires. Protonated pyrrole and negatively charged DNA are absorbed by electrostatic interaction. The level of absorbance is related to pH of pyrrole. Therefore, DNA immobilized and aligned on the 3-aminopropyltrimethoxysi1ane (APTES) modified Si surface. Positive pyrrole monomers was deposited on aligned DNA for the synthesis of nanowire in various pH condition. And polypyrrole nanowires were synthesized by polimerization with ammonium persulfate (APS). These polypyrrole nanowires were measured by AFM, and then we found optimal pH level for the synthesis of nanowires.

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[$(3aR^*,6aS^*)$-6a-Hydroxy-Asymmetric Synthesis of cyclopenta[b]pyrrole-3a-carboxylate and Determination of Its Stereostructure via NMR Spectrum ($(3aR^*,6aS^*)$-6a-Hydroxy-cyclopenta[b]pyrrole-3a-carboxylate의 부제합성 및 NMR 스텍트럼을 통한 입체구조의 결정)

  • Kwon, Soon-Kyoung;Park, Myoung-Suk;Seo, Won-Jun
    • YAKHAK HOEJI
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    • v.38 no.5
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    • pp.544-554
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    • 1994
  • Pyrrolidine-2,3-dione derivative A was synthesized from oxalylation of chiral enamine Ba. The stereostructure of its major diastereomer $(A_{maj})$ was determined as octahydro-2,3-dioxo-6aS-hyd roxy-1-(1S-methoxycarbonyl-2-phenylethyl)-cyclopenta[b]pyrrole-3aR-carboxylic acid ethyl ester Aa by means of NMR spectrum. This result implied that the asymmetric carbon-carbon bond forming reaction occurred preferentially at the ${\beta}-face$ of Ba.

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Crystal Structures and Luminescence Properties of Pd(II) and Pt(II) Complexes with 2,5-Bis(thiophene)-1-nonyl-3,4-bis(methylthio)pyrrole

  • Kang, Jun-Gill;Oh, Sung-Il;Cho, Dong-Hee;Nah, Min-Kook;Park, Chang-Moon;Bae, Young-Ju;Woo, Tack-Han;Park, Young-Jin;Lee, Sang-Woo;Kim, In-Tae
    • Bulletin of the Korean Chemical Society
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    • v.30 no.5
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    • pp.1157-1163
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    • 2009
  • Complexes of Pd(btnbmtp)$Cl_2$ and Pt(btnbmptp)$Cl_2$ (btnbmtp = 2,5-bis(thiophen)-1-nonyl-3,4-bis(methylthio)- pyrrole) were prepared and their crystal structures were determined at room temperature. In the structures, the two thiophene moieties lie in cis form with an average dihedral angle of $55.26^{\circ}$ to the pyrrole frame. The luminescence properties of the free ligand and the complexes were investigated in solution and solid states. The luminescence of the compounds were not favored by substituting thiophene moieties to the pyrrole frame, compared to the unsubstituted nbmptp (nbmptp = 1-nonyl-3,4-bis(methylthio)pyrrole). In particular, thiophene substitution quenched the emission from the complexes dissolved in ,$CH_2Cl_2$ and reduced the charge transfer transitions from S atoms of the thio moieties to Pt in crystalline state, which was very characteristic of Pt(nbmptp)$Cl_2$.