• Title/Summary/Keyword: coupling reaction

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Concise Synthesis of Flurbiprofen via Palladium-Catalyzed Cross-Coupling Reactions (팔라듐 촉매하 결합반응을 이용한 플루비프로펜의 간결한 합성)

  • Han, Young Taek
    • YAKHAK HOEJI
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    • v.59 no.2
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    • pp.66-69
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    • 2015
  • A concise synthesis of flurbiprofen, a member of the non-steroidal anti-inflammatory 2-arylpropionic acids, has been accomplished. The key feature of this synthesis involves successive palladium-catalyzed cross coupling reactions. In particular, a 2-arylacylate intermediate, which easily converted to the key 2-arylpropionic acid scaffold, was afforded by a versatile palladium-catalyzed cross coupling reaction between diazopropanate and bisphenylboronic acid. This synthetic procedure would facilitate synthesis of the flurbiprofen and anti-inflammatory 2-arylpropionic acid derivatives.

Removal of TNT Reduction Products via Oxidative-Coupling Reaction Using Manganese Oxide (망간산화물을 이용한 TNT 환원부산물의 산화-결합반응에 의한 제거 연구)

  • Kang, Ki-Hoon;Lim, Dong-Min;Shin, Hyun-Sang
    • Journal of Korean Society of Environmental Engineers
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    • v.27 no.5
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    • pp.476-485
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    • 2005
  • In this study, abiotic transformation of TNT reduction products via oxidative-coupling reaction was investigated using Mn oxide. In batch experiments, all the reduction products tested were completely transformed by birnessite, one of natural Mn oxides present in soil. Oxidative-coupling was the major transformation pathway, as confirmed by mass spectrometric analysis. Using observed pseudo-first-order rate constants with respect to birnessite loadings, surface area-normalized specific rate constants, $k_{surf}$, were determined. As expected, $k_{surf}$ of diaminonitrotoluenes (DATs) ($1.49{\sim}1.91\;L/m^2{\cdot}day$) are greater about 2 orders than that of dinitroaminotoluenes (DNTs) ($1.15{\times}10^{-2}{\sim}2.09{\times}10^{-2}\;L/m^2{\cdot}day$) due to the increased number of amine group. In addition, by comparing the value of $k_{surf}$ between DNTs or DATs, amino group on ortho position is likely to be more preferred for the oxidation by birnessite. Although cross-coupling of TNT in the presence of various mediator compounds was found not to be feasible, transformation of TNT by reduction using $Fe^0$ followed by oxidative coupling using Mn oxide was efficient, as evaluated by UV-visible spectrometry.

Approach to the Total Synthesis of Acanthoside-D

  • Ngoc, Thyen-Truong;Park, Hae-Il
    • Proceedings of the PSK Conference
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    • 2003.10b
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    • pp.186.4-187
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    • 2003
  • Acanthoside-D, one of major components of Acanthopanacis Cortex, is known as a ginseng-like substance. it has been known to possess diverse biological effects. Acanthoside-D has a furofuran lignan structure and the synthesis of which poses interesting and often unsolved proplems of stereocontrol. Although a few interesting syntheses providing this natural product have been reported, an intermolecular McMurry coupling - intramolecular Mitsunobu cyclization route has not yet been explored. We report here a short and efficient synthetic pathway to the total synthesis of Acanthoside-D from aryl aldehydes and methyl acrylates via Baylis-Hillman reaction, intermolecular McMurry coupling and intramolecular Mitsunobu cyclization as key reaction.

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A Study on Development the Dynamic Model to Misaligned Gear Coupling (I) - The Focus on Development of Dynamic Model to n Gear Coupling (정렬불량을 가진 기어 커플링의 동역학적 모델 개발에 관한 연구 (I) - 기어 커플링의 동적모델 구축을 중심으로-)

  • Kim, Byung-Ok;Kim, Yong-Chul
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.27 no.6
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    • pp.857-863
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    • 2003
  • In rotating machinery, unbalance and misalignment are major concerns in vibration. Unbalance can be eliminated by balancing procedure to some degree. but little work has been done on the vibrations that occur in a misaligned rotor system. Currently, no generalized theoretical model based on a rotor system with flexible coupling is available to describe the vibrations caused by misalignment. As a part of systematic investigation on the misalignment, first of all, the study on flexible coupling with misalignment should be preceded. In this study, the geometry and reaction force and moment of a gear coupling with misalignment was investigated, also the theoretical model of a gear coupling with misalignment was presented by using the relationship between geometry and moment of gear coupling. It is expected that the proposed procedure can be applied to derive the theoretical model of other couplings.

망간산화물을 이용한 1-Naphthol의 산화-공유결합 반응 속도 연구

  • Im Dong-Min;Sin Hyeon-Sang;Jeon Byeong-U;Gang Gi-Hun
    • Proceedings of the Korean Society of Soil and Groundwater Environment Conference
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    • 2005.04a
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    • pp.49-52
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    • 2005
  • In this study, abiotic transformation of 1-naphthol via oxidative-coupling reaction was evaluated using Mn oxide which is ubiquitous in natural soils. The transformation of 1-naphthol catalyzed by synthetic birnessite $({\delta}-MnO_2)$ followed pseudo-lst order reaction, and the rate constants was in the range of $0.053{\sim}0.13\;min^{-1}$ with birnessite loadings of $12.5{\sim}50\;mg/20\;mL$. Since the oxidation of 1-naphthol was occurred on the reactive surface of the oxide particles, the rate constants with various birnessite loadings were correlated with birnessite surface area concentration. The correlation showed a strong linearity, which confirms the supposition of the surface reaction. From the correlation, therefore, the surface area normalized rate constant, $k_{surf}$, was determined to be 0.032 $L/m^2\;min$.

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Nickel-Catalyzed Coupling of Arenesulfonates with Primary Alkylmagnesium Halides

  • Cho, Chul-Hee;Sun, Myung-Chul;Park, Kwang-Yong
    • Bulletin of the Korean Chemical Society
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    • v.26 no.9
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    • pp.1410-1414
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    • 2005
  • Neopentyl arenesulfonates reacted with primary alkylmagnesium halides in the presence of $(PPh_3)_2NiCl_2$ to produce the corresponding alkylarenes. The efficiency of this coupling reaction considerably depends on the nature of catalyst and solvent. Highest yield was obtained by using three equivalents of Grignard reagent to a mixture of $(PPh_3)_2NiCl_2$ and arenesulfonate in refluxing $Et_2O$. This reaction represents a novel method allowing the efficient and creative substitution of sulfur-containing groups in aromatic compounds. It also shows that the alkyloxysulfonyl group might be a suitable alternative to halides and triflate in some circumstances.

Facile Synthesis of Natural Moracin Compounds using Pd(OAc)2/P(tBu)3-HBF4 as a Sonogashira Coupling Reagent

  • Lee, Jae Jun;Yun, So-Ra;Jun, Jong-Gab
    • Bulletin of the Korean Chemical Society
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    • v.35 no.12
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    • pp.3453-3458
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    • 2014
  • An efficient and practical synthesis of natural moracins, which have diverse range of biological properties including anticancer, antioxidant, and antibacterial activities, has been achieved using $Pd(OAc)_2/P(^tBu)_3-HBF_4$ as a Sonogashira coupling reagent which solved the unreactive problems in case of higher electron density of haloaryl compounds in the reaction. Lowering electron density of halophenol with acetylation and changing Sonogashira coupling reagent from $PdCl_2(PPh_3)_2$ to $Pd(OAc)_2/P(^tBu)_3-HBF_4$ smoothly produce the benzofuran structures in the syntheses of moracins M, N and S. The electron deficient halobenzaldehyde, however, easily forms the benzofuran using original Sonogashira conditions, and utilized for the first synthesis of moracin Y.

Palladium-Catalyzed Carbonylative Coupling of Aryl Iodide and Diethylmalonate (팔라듐 촉매를 이용한 요오드화 방향족 화합물과 Diethylmalonate 와의 CO 첨가 커플링반응)

  • Jin Il Kim;Kwang Hyek Lee;Tae Soon Yoon
    • Journal of the Korean Chemical Society
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    • v.33 no.5
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    • pp.530-537
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    • 1989
  • Diethylbenzoylmalonates with various substituents were synthesized in moderately good yields through palladium-catalyzed carbonylative coupling of aryl iodide and diethylmalonate with carbon monoxide. Palladium-catalyzed carbonylative coupling reaction usually proceeded well in polar aprotic solvents in the presence of three equivalents of inorganic bases and palladium(II) catalyst. When the reaction was carried out under 10 atm pressure of carbon monoxide, the yield of diethylbenzoylmalonate derivatives was much better than that of reaction under atomspheric pressure of carbon monoxide.

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XPS Investigation of A3 Coupling Reaction in Room Temperature Ionic Liquids

  • Kwon, Ji-Hye;Youn, So-Won;Kang, Yong-Cheol
    • Bulletin of the Korean Chemical Society
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    • v.27 no.11
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    • pp.1851-1853
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    • 2006
  • We herein report a new analytical application of XPS to the identification of organic molecules in room temperature ionic liquid for the first time. An organic compound, propargylamine (1), produced in 1-butyl-3-methylimidazolium hexafluorophosphate ([bmim][$PF_6$]), which is one of the room temperature ionic liquids (RTILs), via $A^3$ coupling reaction, is characterized by means of x-ray photoelectron spectroscopy (XPS) rather than using conventional organic compound analysis techniques. There are four non-equivalent carbons in RTILs and 1 each. The ratios of normalized integrated areas of the deconvoluted binding energy of core electron of carbon (C1s) peaks are well matched to the number of carbons in those compounds. The binding energies of C1s of the featured carbons in 1, C4 (sp carbons in acetylene group) and C5 ($sp^2$ carbons in benzene ring), are assigned 286.2 and 285.4 eV, respectively. These results will be able to provide an important tool and a new strategy for the analysis of organic molecules