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Yamaguchi-shi, Japan

Ohtsuka Y.,Sagami Chemical Research Institute | Uraguchi D.,Sagami Chemical Research Institute | Uraguchi D.,Nagoya University | Yamamoto K.,Sagami Chemical Research Institute | And 2 more authors.
Tetrahedron | Year: 2012

Direct trifluoromethylation of 1,3-dicarbonyl compounds with CF 3I in the presence of a Fenton reagent in dimethylsulfoxide was investigated. 1,3-Diketones, 3-oxocarboxylates and 3-oxocarboxamides were readily trifluoromethylated at the methylene carbon between two oxo groups. Cycloaddition of hydrazine derivatives to the obtained 2-(trifluoromethyl)-1,3- dicarbonyl compounds provided fluorinated pyrazoles. 4-(Trifluoromethyl)pyrazole derivatives were formed from 2-(trifluoromethyl)-1,3-diketones, while 3-oxo-2-(trifluoromethyl)carboxylates or carboxamides gave 5-fluoropyrazole-4- carboxylates or carboxamides, respectively, via 3-hydrazono-2-(trifluoromethyl) carboxylates or carboxamides as an intermediate. © 2012 Elsevier Ltd. All rights reserved. Source

Kino T.,Sagami Chemical Research Center | Kino T.,Tokai University | Nagase Y.,Tokai University | Ohtsuka Y.,Sagami Chemical Research Center | And 4 more authors.
Journal of Fluorine Chemistry | Year: 2010

Trifluoromethylation of aromatic and hetero-aromatic compounds by CF3I in the presence of Fe(II) compound, H2O2 and dimethylsulfoxide was investigated. Various trifluoromethylated benzene derivatives, six-membered nitrogen-containing aromatic compounds and five-membered hetero-aromatic compounds were obtained under mild conditions. General orientation of electrophilic substitution of aromatic compounds was observed similarly as reported in other radical trifluoromethylation previously. © 2009 Elsevier B.V. All rights reserved. Source

Milcent T.,University Paris - Sud | Hao J.,University Paris - Sud | Kawada K.,Tosoh F Technology Inc. | Soloshonok V.A.,University of the Basque Country | And 2 more authors.
European Journal of Organic Chemistry | Year: 2014

1,4-Diazabicyclo[2.2.2]octane-catalyzed asymmetric aza-Baylis-Hillman (ABH) reaction of (R)-N-tert-butanesulfinyl-(3,3,3)-trifluoroacetaldimine with various Michael acceptors proceeds with exceptionally high rates and stereochemical outcome. This ABH approach provides convenient and practical access to previously unknown enantiomerically pure α-methylene β-CF3 β-amino esters/acids, forthright useable for peptide synthesis. Copyright © 2014 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheim. Source

Shevchuk M.V.,Ukrainian Academy of Sciences | Kukhar V.P.,Ukrainian Academy of Sciences | Roschenthaler G.-V.,Jacobs University Bremen | Bassil B.S.,Jacobs University Bremen | And 4 more authors.
RSC Advances | Year: 2013

Enantiomerically pure N,O-protected β-trifluoromethyl isoserine derivatives of (2S,3S)- and (2R,3S)-absolute configurations have been easily prepared by diastereoselective addition of the enolates, derived from O-protected α-hydroxyacetates, to (S)-N-tert-butanesulfinyl (3,3,3)-trifluoroacetaldimine with high combined yield and good syn/anti stereoselectivity. To explain the unusual stereochemical outcome in these reactions a mechanistic rationale involving the addition of Z-enolates to (S)-imines via open transition states was proposed on the basis of the experimental data. Elaboration of these products via chemoselective manipulation of the protecting groups has been demonstrated. © 2013 The Royal Society of Chemistry. Source

Shibata N.,Nagoya Institute of Technology | Nishimine T.,Nagoya Institute of Technology | Tokunaga E.,Nagoya Institute of Technology | Kawada K.,Tosoh F Technology Inc. | And 4 more authors.
Chemical Communications | Year: 2012

Organic base-catalyzed reaction of (S)-N-tert-butanesulfinyl (3,3,3)-trifluoroacetaldimine with dialkyl malonates was found to be effective for synthesis of both (S,S S) and (R,S S) β-aminomalonates in high yield with good to excellent diastereoselectivity (76-98% de). The products of this Mannich reaction provide direct access to β-trifluoromethyl-β-alanine of either (R) or (S) absolute configuration. © 2012 The Royal Society of Chemistry. Source

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