• Title/Summary/Keyword: Michael Addition

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Asymmetric Michael Addition of Ketones to Nitroolefins Catalyzed by a New Chiral Catalyst

  • Wang, Lian-Jun;Hu, Feng-Feng
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1280-1282
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    • 2010
  • A new chiral catalyst was synthesized and found that it could catalyzed the asymmetric Michael reaction of ketones with nitroolefins smoothly at room temperature, giving the desired adducts in 71 - 92% yields with excellent diastereoselectivities and high enantioselectivities (up to 95% ee).

Synthesis and Preliminary Antimicrobial Screening of New Benzimidazole Heterocycle

  • Fahmy, H.H.;El-masry, A.;Ali Abdelsahed, S.H.
    • Archives of Pharmacal Research
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    • v.24 no.1
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    • pp.27-34
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    • 2001
  • A series of 2-methylbenzimidazole incorporated to different heterocycles through ethyl or carbamoylethyl groups at position 1 of benzimidazole were synthesized. Also 3-(2-methylbenzimidazol-1-yl)propanoic acid hydrazide incorporated with semicarbazides and thiosemicarbazides were prepared. Moreover, the triazole 5e underwent Michael addition and alkylation reaction. Some of the newly synthesized compounds showed considerable antimicrobial activity against gram positive, negative bacteria and yeast.

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Solvent-Free Michael Addition Between EMME and Secondary Amine under Focused Microwave Irradiation

  • Kim, Ki-Won;Lee, Hee-Jung;Jo, Jeong-Im;Kwon, Tae-Woo
    • Bulletin of the Korean Chemical Society
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    • v.31 no.5
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    • pp.1155-1158
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    • 2010
  • Microwave-assisted Michael reaction between EMME and various amines such as diphenylamine, 4-methyl-N-phenylbenzenamine, N-phenylnaphthalen-1-amine, dihexylamine, diisopropylamine, and 4-nitrobenzenamine were described. Solvent-free conditions on alumina as solid support in the presence of $K_2CO_3$ catalysts gave moderate to good yields (55 - 93%) of diethylmalonate analogues having enamine moieties under focused microwave irradiation.

Quantitative Analysis of Grafted Methacrylate Groups by Michael Addition Reaction between Primary and Secondary Amino Groups on the Silica Nanoparticle Surface with 3-(Acryloyloxy)-2-Hydroxypropyl Methacrylate (실리카 나노 입자 표면에 결합된 1차 및 2차 아미노기와 3-(Acryloyloxy)-2-hydroxypropyl Methacrylate의 마이클 부가 반응에 의해 도입되는 메타크릴레이트기의 정량적 분석)

  • Lee, Sangmi;Ha, KiRyong
    • Polymer(Korea)
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    • v.39 no.2
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    • pp.300-310
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    • 2015
  • In this study, we modified silica nanoparticles with N-[3-(trimethoxysilyl)propyl]ethylenediamine (TPED) silane coupling agent, which has one primary and one secondary amino groups in a molecule, to introduce amino groups on the silica surface. After modification of silica, we used 3-(acryloyloxy)-2-hydroxypropyl methacrylate (AHM) to introduce methacrylate groups by Michael addition reaction. We found about 30% of N-H groups on the TPED modified silica surface reacted with acrylate groups of AHM compared to about 85% of reaction between N-H groups of pure TPED with acrylate groups of pure AHM. This lower degree of Michael addition reaction for heterogeneous reaction between N-H groups on the solid TPED modified silica and liquid AHM compared to homogeneous reaction between pure liquid TPED and pure liquid AHM may be caused by lower mobility of grafted amino groups of TPED moiety and higher steric hindrance caused by solid silica particles.

Studies on the Michael Addition Reaction between Secondary Amino Groups on the Silica Surface with Poly(ethylene glycol) Diacrylates (실리카 나노입자 표면에 결합된 2차 아미노기와 Poly(ethylene glycol) Diacrylate의 마이클 부가반응에 대한 연구)

  • Jeon, Ha Na;Ha, KiRyong
    • Polymer(Korea)
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    • v.36 no.6
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    • pp.822-830
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    • 2012
  • We used dipodal type bis[3-(trimethoxysilyl)propyl]amine (BTMA) silane coupling agent to modify silica nanoparticles to introduce secondary amino groups on the silica surface. These N-H groups were reacted with three different molecular weights (M.W. = 258, 575, and 700) of poly(ethylene glycol) diacrylates to introduce different attached layer thicknesses on the silica surface by Michael addition reaction. After Michael addition reaction, we used several analytical techniques such as fourier transform infrared spectroscopy (FTIR), elemental analysis (EA) and solid state $^{13}C$ cross-polarization magic angle spinning (CP/MAS) nuclear magnetic resonance spectroscopy to characterize introduced structures. We found almost complete Michael addition reaction of both two acrylate groups of PDGDA with N-H groups of BTMA modified silica to form ${\beta}$-amino acid esters. Between equimolar ratio of pure BTMA and pure PEGDA reaction, only one acrylate group of two acrylate groups of PEGDA reacted with N-H groups of pure BTMA to form ${\beta}$-amino acid ester and the other remaining acrylate group can be used to form a polymer later.

Synthesis and Pharmacological Studies of Some Pyrone and Benzodifuran Derivatives

  • Hishmat, Orchidee H.;El-Diwani, Hoda I.;Bakr, Sherifa M.A.;Mahmoud, Sawsan S.;Nada, Somaya A.
    • Archives of Pharmacal Research
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    • v.16 no.2
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    • pp.168-174
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    • 1993
  • The michael adducts 2a, b were obtained from the reaction of the phenylacelyl derivative 1 with benzadehyde and p-anisaldehyde and p-anisaldehyde respectively. 2a and 2b were subjected to react with cyanoethanoic acid hydrazide, malononitrile, cyanothioacetamide, cyanoacetamide and 1, 1, 3-tricyano-2-amino propene to yield 4a-h and 5a, b respecitively. Hydrogen peroxide oxidation of 2a, b gave the aurone derivative 6a, b. The pyone derivatives 8a, b were obtained from 2a, b by addition of chioroacetyl chioride followed by dehydrochlorination.

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Plastic Surgeons as Medical Directors: A Natural Transition into Medical Leadership

  • Jalalabadi, Faryan;Ferry, Andrew M.;Chang, Andrew;Reece, Edward M.;Izaddoost, Shayan A.;Hassid, Victor J.;Tahiri, Youssef;Buchanan, Edward P.;Winocour, Sebastian J.
    • Archives of Plastic Surgery
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    • v.49 no.2
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    • pp.221-226
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    • 2022
  • With the growing complexity of the U.S. health care system, highly motivated medical directors with strong leadership skills are vital to the success of health care facilities. Presently, there are no articles assessing a plastic surgeon's qualifications for the role of medical director. In addition, there is a paucity of literature comparing the responsibilities of medical directors across various types of health care institutions. Herein, we outline why plastic surgeons have the unique skillset to succeed in this role and highlight the differences between medical director positions across the vast landscape of health care. While the intricacies of this position vary greatly across different landscapes of the health care industry, successful medical directors lead by following a set of universal principles predisposing them for success. Plastic surgeons innately exhibit a subset of particular traits deeming them suitable candidates for the medical director position. While transitioning from the role of a surgeon to that of a medical director does require some show of adaptation, plastic surgeons are ultimately highly likely to find intrinsic benefit from serving as a medical director.

Indium(III) Chloride Mediated Michael Addition of Indoles to Ketene S,S-Acetals: Synthesis of Bis- and Tris-indolylketones

  • Singh, Thokchom Prasanta;Khan, Ruhima;Noh, Young Ri;Lee, Sang-Gyeong;Singh, Okram Mukherjee
    • Bulletin of the Korean Chemical Society
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    • v.35 no.10
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    • pp.2950-2954
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    • 2014
  • A series of bis and tris-indolylketones and meridianin alkaloids are prepared by one pot Michael reaction of indole and ketene S,S-acetals under solvent-free condition using mild Lewis acid $InCl_3$.

Single-walled Carbon Nanotube-triethylammonium Ionic Liquid as a New Catalytic System for Michael Reaction

  • Attri, Pankaj;Choi, Eun Ha;Kwon, Gi-Chung;Bhatia, Rohit;Gaur, Jitender;Arora, Bharti;Kim, In Tae
    • Bulletin of the Korean Chemical Society
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    • v.35 no.10
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    • pp.3035-3040
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    • 2014
  • A new efficient catalytic method for aza/thia-Michael addition reactions of amines/thiols with higher product yields has been developed. Combining single-walled carbon nanotubes (SWCNT) with triethylammonium hydrogen phosphate (TEAP) ionic liquid (IL) can work as a catalyst. We utilized Raman spectroscopy to gain insight into the interactions between IL and SWCNT. The interactions between SWCNT with TEAP were confirmed by the increasing intensity ratios and spectral shift in wavelength of the Raman D and G bands of SWCNT. Further, the morphology of the resulting composite materials of TEAP and SWCNT was determined by using scanning electron microscopy (SEM). Higher product yield in reduced reaction time is the key advantage of using bucky gel as a catalyst for Michael reaction.