• Title/Summary/Keyword: Tandem synthesis

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Selective Tandem Synthesis of Oximes from Benzylic Alcohols Catalyzed with 2, 3-Dichloro-5, 6-dicyanobenzoquinone

  • Aghapour, Ghasem;Mohamadian, Samaneh
    • Bulletin of the Korean Chemical Society
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    • v.33 no.4
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    • pp.1209-1212
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    • 2012
  • In spite of many reports in the literature concerning with oxidation of benzylic alcohols to carbonyl compounds with 2,3-dichloro-5,6-dicyanobenzoquinone (DDQ) in stoichiometric amounts or even more, we surprisingly found that benzylic alcohols are directly oxidized to oximes using a catalytic amount of DDQ in the presence of hydroxylamine hydrochloride under solvent-free conditions. The present tandem catalytic method can be efficiently used for preparation of oximes in the presence of some other functional groups with excellent chemoselectivity.

Efficient Synthesis of Benzoprostacyclins Using Free-Radical and Palladium-Catalyzed Tandem Alkene Insertion Strategies

  • Lee, Nam Ho;Richard C. Larock
    • Bulletin of the Korean Chemical Society
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    • v.22 no.8
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    • pp.857-866
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    • 2001
  • Efficient syntheses of PGI2 analogue 2a and its epimer 3 have been accomplished. Using aryl iodide 6 as the common intermediate, either radical or palladium-assisted tandem alkene insertion strategies have been employed for construction of the benzoprostacyclin framework.

Synthesis of Cyclohexene Derivatives from 1,5-Enynes via Gold-Catalysis and Iodocyclization: A Comparative Study and Applications in the Synthesis of 7/5- or 8/5-Fused Rings and Biaryls

  • Lee, Young-Un;Lim, Choong-Min;Kim, Sung-Hwan;Shin, Seung-Hoon
    • Bulletin of the Korean Chemical Society
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    • v.31 no.3
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    • pp.670-677
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    • 2010
  • A comparative study on the Au(I)-catalyzed and IBr-promoted tandem cyclization of 1,5-enyne was reported. This study provides a meaningful mechanistic insight to the concerted nature of this tandem reaction and also provides interesting applications in the synthesis of 7/5- or 8/5-fused bicycles and biaryls.

Total Synthesis of (±)-Aspidospermidine Starting from 3-Ethyl-5-bromo-2-pyrone

  • Cho, Hyun-Kyu;Tam, Nguyen Thanh;Cho, Cheon-Gyu
    • Bulletin of the Korean Chemical Society
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    • v.31 no.11
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    • pp.3382-3384
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    • 2010
  • A new synthetic route to ($\pm$)-aspidospermidine was devised, starting from the cycloadduct of 3-ethyl-5-bromo-2-pyrone with vinyl sulfide through a tandem conjugate addition-alkylation sequence. The requisite 3-ethyl-5-bromo-2-pyrone was prepared via the C3-selective Pd-catalyzed coupling reaction with $Et_3Al$-dimethylaminoethanol complex.

A Facile and Efficient Synthesis of Dronedarone Hydrochloride

  • Li, Feng;Jin, Chunhua;Zou, Jianwei;Wu, Jun
    • Bulletin of the Korean Chemical Society
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    • v.35 no.7
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    • pp.1970-1972
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    • 2014
  • A facile and efficient synthesis of dronedarone hydrochloride starting from commercially available 4-nitrophenol is described. This approach features a tandem-type synthesis of 3-carbonylated benzofuran involving cyclization of 2-ethynylphenol followed by $CO_2$ fixation at the 3-position of the benzofuran ring mediated by potassium carbonate without the addition of any transition metal catalyst.

Optimum Design of a Viscous-driven Micropump with Tandem Rotating Cylinders (한 쌍의 실린더를 가진 점성구동 마이크로 펌프의 최적설계)

  • Choi, Hyung-Il;Kim, Ki-Dong;Cho, Il-Dae;Choi, Dong-Hoon;Maeng, Joo-Sung
    • Transactions of the Korean Society of Mechanical Engineers A
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    • v.28 no.4
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    • pp.378-385
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    • 2004
  • Viscous-driven pumping is a very promising type in microscale applications. However, there exist a few disadvantages such as low efficiency and small volume flow rate. In the present study, a pump with tandem rotating cylinders and its optimum synthesis are proposed fur enhancing pumping performance. First, using an unstructured grid CFD method, we investigate the effects of geometrical parameters and then the performance of the pump with tandem cylinders is evaluated. Next, an optimum design synthesis tool is constructed by combining the aforementioned CFD analysis model with the mathematical optimization model, namely, Modified Method of Feasible Directions (MMFD). This technique is used to optimize the geometrical parameters of the pump, fur maximizing pumping efficiency. From the optimization results, it is believed that the present optimum synthesis is robust and has a potential fur other microfluidic device design.