The Experts below are selected from a list of 360 Experts worldwide ranked by ideXlab platform
Takashi Harayama - One of the best experts on this subject based on the ideXlab platform.
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Trifluoroacetylation induced houben hoesch type cyclization of cyanoacetanilides increased nucleophilicity of cn groups
ChemInform, 2010Co-Authors: Yusuke Kobayashi, Kosuke Katagiri, Isao Azumaya, Takashi HarayamaAbstract:Treatment of cyanoacetanilides with fluorinated carboxylic anhydrides is found to provide a mild and efficient approach to quinolinone derivatives.
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Trifluoroacetylation induced houben hoesch type cyclization of cyanoacetanilides increased nucleophilicity of cn groups
Journal of Organic Chemistry, 2010Co-Authors: Yusuke Kobayashi, Kosuke Katagiri, Isao Azumaya, Takashi HarayamaAbstract:Trifluoroacetic anhydride-mediated tandem Trifluoroacetylation/cyclization of cyanoacetanilides proceeded efficiently under mild conditions to give 4-hydroxy-3-trifluoroacetylquinolin-2(1H)-ones in good yields. Isolation and direct observation of the reaction intermediates revealed that α-Trifluoroacetylation resulted in the shortening of C≡N bonds and that the electron density of CN groups was high. A plausible reaction mechanism based on the results is also described.
Ernest Marechal - One of the best experts on this subject based on the ideXlab platform.
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characterization of functional aliphatic oligoamides using n Trifluoroacetylation ii size exclusion chromatography
European Polymer Journal, 1998Co-Authors: Valerie Girardon, Martine Tessier, Ernest MarechalAbstract:Abstract The molar mass distribution of several functional oligoamides was studied by size exclusion chromatography in methylene chloride (CH2Cl2) at room temperature. Sample solubilization in CH2Cl2 was performed by derivatization using trifluoroacetic anhydride. The internal calibration curves were easily obtained for the α,ω-diamino, α,ω-dicarboxy and α,ω-dihexyl oligoamides. The elution volume is influenced by the methylene group number of monomeric unit and by the nature of end groups. The molar masses determined by SEC were compared to the values obtained by chemical titration and by NMR analysis.
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characterization of functional aliphatic oligoamides using n Trifluoroacetylation i nmr analysis
European Polymer Journal, 1998Co-Authors: Valerie Girardon, Isabelle Correia, Martine Tessier, Ernest MarechalAbstract:The 1 H- and 13 C-NMR analysis of functional oligoamides was carried out after they had been modified by trifluoroacetic anhydride derivatization, leading to chloroform-soluble oligomers. The spectra of oligoamides-6, -11, -12, -6,6 and -6,10 were compared. The influence of the methylene group number on the CO amide chemical shift was studied by 13 C-NMR. The coupling constants J C-F and J C-C-F were also determined. Monomers, chain limiters and macromolecular structures were characterized and quantified from the 1 H- and 13 C-NMR spectral analysis. The number-average molar masses were also calculated from integration of the spectra and were compared with values obtained by end group chemical titration.
Pavel K Mykhailiuk - One of the best experts on this subject based on the ideXlab platform.
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direct noncatalytic electrophilic Trifluoroacetylation of electron rich pyrazoles
Synthesis, 2014Co-Authors: Dmytro V Yarmoliuk, V V Arkhipov, Maksym V Stambirskyi, Yurii V Dmytriv, Oleg V Shishkin, Andrei A Tolmachev, Pavel K MykhailiukAbstract:Electron-rich N-substituted pyrazoles smoothly reacted with trifluoroacetic anhydride in pyridine to form the corresponding trifluoromethyl ketones in good yields.
Yusuke Kobayashi - One of the best experts on this subject based on the ideXlab platform.
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Trifluoroacetylation induced houben hoesch type cyclization of cyanoacetanilides increased nucleophilicity of cn groups
ChemInform, 2010Co-Authors: Yusuke Kobayashi, Kosuke Katagiri, Isao Azumaya, Takashi HarayamaAbstract:Treatment of cyanoacetanilides with fluorinated carboxylic anhydrides is found to provide a mild and efficient approach to quinolinone derivatives.
-
Trifluoroacetylation induced houben hoesch type cyclization of cyanoacetanilides increased nucleophilicity of cn groups
Journal of Organic Chemistry, 2010Co-Authors: Yusuke Kobayashi, Kosuke Katagiri, Isao Azumaya, Takashi HarayamaAbstract:Trifluoroacetic anhydride-mediated tandem Trifluoroacetylation/cyclization of cyanoacetanilides proceeded efficiently under mild conditions to give 4-hydroxy-3-trifluoroacetylquinolin-2(1H)-ones in good yields. Isolation and direct observation of the reaction intermediates revealed that α-Trifluoroacetylation resulted in the shortening of C≡N bonds and that the electron density of CN groups was high. A plausible reaction mechanism based on the results is also described.
Valerie Girardon - One of the best experts on this subject based on the ideXlab platform.
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characterization of functional aliphatic oligoamides using n Trifluoroacetylation ii size exclusion chromatography
European Polymer Journal, 1998Co-Authors: Valerie Girardon, Martine Tessier, Ernest MarechalAbstract:Abstract The molar mass distribution of several functional oligoamides was studied by size exclusion chromatography in methylene chloride (CH2Cl2) at room temperature. Sample solubilization in CH2Cl2 was performed by derivatization using trifluoroacetic anhydride. The internal calibration curves were easily obtained for the α,ω-diamino, α,ω-dicarboxy and α,ω-dihexyl oligoamides. The elution volume is influenced by the methylene group number of monomeric unit and by the nature of end groups. The molar masses determined by SEC were compared to the values obtained by chemical titration and by NMR analysis.
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characterization of functional aliphatic oligoamides using n Trifluoroacetylation i nmr analysis
European Polymer Journal, 1998Co-Authors: Valerie Girardon, Isabelle Correia, Martine Tessier, Ernest MarechalAbstract:The 1 H- and 13 C-NMR analysis of functional oligoamides was carried out after they had been modified by trifluoroacetic anhydride derivatization, leading to chloroform-soluble oligomers. The spectra of oligoamides-6, -11, -12, -6,6 and -6,10 were compared. The influence of the methylene group number on the CO amide chemical shift was studied by 13 C-NMR. The coupling constants J C-F and J C-C-F were also determined. Monomers, chain limiters and macromolecular structures were characterized and quantified from the 1 H- and 13 C-NMR spectral analysis. The number-average molar masses were also calculated from integration of the spectra and were compared with values obtained by end group chemical titration.
