• Title/Summary/Keyword: Hydroboration

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New Synthetic Method of Aminophosphonic Acid via Amination of Organoboranes (유기 붕소 화합물의 아민화 반응을 이용한 Aminophosphonic Acid의 새로운 합성방법)

  • Kim, Sang Beom;Jo, Gyeong Yeon;Hong, Seok In
    • Journal of the Korean Chemical Society
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    • v.38 no.9
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    • pp.682-686
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    • 1994
  • New synthetic method of aminophosphonic acids by the amination of organoboranes containing phosphorus was developed. Thus, the hydroboration of diethyl 2-propenylphosphonate, diethyl 2-methyl-2-propenyl-phosphonate, diethyl 3-butenylphosphonate with borane-THF, followed by amination of the resulting organoboranes with hydroxylamine-O-sulfonic acid gave diethyl 3-aminopropylphosphonate, diethyl 3-amino-2-methyl-2-propylphosphonate and diethyl 4-aminobutylphosphonate, respectively. 3-Aminopropylphosphonic acid and 4-aminobutylphosphonic, acid were obtained by the hydrolysis of the corresponding esters, respectively.

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Synthesis of Novel Cyclopropyl Nucleoside Derivatives as Potential Antiherpetic Agent (새로운 사이클로프로필 뉴크레오사이드 유도체의 합성과 생리활성)

  • Kang, Jin-Ah;Chun, Pu-Soon;Moon, Hyung-Ryong
    • YAKHAK HOEJI
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    • v.56 no.4
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    • pp.230-235
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    • 2012
  • Synthesis of novel cyclopropyl pyrimidine and purine nucleoside derivatives 2~8 with ${\alpha}$-configuration was successfully accomplished using an epoxide-ring opening reaction, lactonization, a hydroboration-oxidation reaction and a Mitsunobu reaction as the key steps. Antiviral activities against HSV-1 and -2, HIV-1 and -2, coxsackie B1and B3 viruses and poliovirus were assayed. Three compounds 4, 7 and 8 exhibit cytotoxicity-derived antiviral activity only in HIV-1 and -2.

Preparation of Mesoporous SiCBN Ceramic Templated by Mesoporous Carbon

  • Nghiem, Quoc Dat;Ryoo, Hyang-Im;Kim, Dong-Pyo
    • Journal of the Korean Ceramic Society
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    • v.44 no.7
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    • pp.358-361
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    • 2007
  • Well-ordered mesoporous SiCBN ceramics have been successfully synthesized by infiltrating a polymeric precursor, which was prepared from borazine and 2,4,6-trimethyl-2,4,6-trivinylcyclotrisilazane via a hydroboration reaction, into a mesoporous carbon (CMK-3) as a hard template. This was followed by pyrolysis at $1400^{\circ}C$ under nitrogen gas and subsequent oxidative removal of the carbon template without chemical etching. The prepared mesoporous SiCBN ceramic was characterized by a small-angle XRD, TEM, and BET surface area. The resulting mesoporous SiCBN ceramic revealed a BET surface area of $275 m^2g^{-1}$ and a pore volume of $0.8 cm^3 g$ with no crystallization.

Thermal and Solid State Assembly Behavior of Amphiphilic Aliphatic Polyether Dendrons with Octadecyl Peripheries

  • Chung, Yeon-Wook;Lee, Byung-Ill;Cho, Byoung-Ki
    • Macromolecular Research
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    • v.16 no.2
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    • pp.113-119
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    • 2008
  • A series of amphiphilic dendrons n-18 (n: generation number, 18: octadecyl chain) based on an aliphatic polyether denderitic core and octadecyl peripheries were synthesized using a convergent dendron synthesis consisting of a Williamson etherification and hydroboration/oxidation reactions. This study investigated their thermal and self-assembling behavior in the solid state using differential scanning calorimetry (DSC), Fourier transform infrared (FT-IR) absorption spectroscopy, and small angle X-ray scattering (SAXS). DSC indicated that the melting transition and the corresponding heat of the fusion of the octadecyl chain decreased with each generation. FT-IR showed that the hydroxyl focal groups were hydrogen-bonded with one another in the solid state. DSC and FT-IR indicated microphase-separation between the hydrophilic dendritic cores and hydrophobic octadecyl peripheries. SAXS data analysis in the solid state suggested that the lower-generation dendrons 1-18 and 2-18 self-assemble into lamellar structures based upon a bilayered packing of octadecyl peripheries. In contrast, the analyzed data of higher-generation dendron 3-18 is consistent with 2-D oblique columnar structures, which presumably consist of elliptical cross sections. The data obtained could be rationalized by microphase-separation between the hydrophilic dendritic core and hydrophobic octadecyl peripheries, and the degree of interfacial curvature associated with dendron generation.