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Masaki Matsui - One of the best experts on this subject based on the ideXlab platform.
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reversal of diastereoselectivity in reactions of the trifluoroacetaldehyde ethyl Hemiacetal with enamines and imines metal free complementary anti and syn selective synthesis of 4 4 4 trifluoro 1 aryl 3 hydroxy 2 methyl 1 butanones
ChemInform, 2011Co-Authors: Kazumasa Funabiki, Kei Matsunaga, Hitoshi Yamamoto, Hiroshi Gonda, Takao Arima, Yasuhiro Kubota, Masaki MatsuiAbstract:Treatment of the Hemiacetal (II) with imines of type (I) is found to result in efficient formation of syn-adducts like (III).
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a versatile approach to 2 substituted 3 trifluoromethyl 1 3 diols based on the reaction of trifluoroacetaldehyde ethyl Hemiacetal with enamines derived from aldehydes
Chemistry Letters, 2010Co-Authors: Kazumasa Funabiki, Hiroshi Gonda, Yasuhiro Kubota, Yudai Furuno, Fumiaki Sato, Masaki MatsuiAbstract:Treatment of trifluoroacetaldehyde ethyl Hemiacetal with various enamines, derived from various aldehydes, at room temperature, followed by hydrolysis with 10% HCl aqueous solution and reduction wi...
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Catalytic in-situ generation of trifluoroacetaldehyde from its Hemiacetal and successive direct aldol reaction with ketones
2007Co-Authors: Kazumasa Funabiki, Masaki MatsuiAbstract:Trifluoroacetaldehyde ethyl Hemiacetal reacted with unmodified ketones in the presence of 30 to 50 each mol% of amines and acids at ambient temperature, affording the corresponding β-hydroxy-β-trifluoromethylated ketones in good yields with good to excellent diastereoselectivities. Furthermore, L-proline-catalyzed asymmetric direct aldol reaction of trifluoroacetaldehyde ethyl Hemiacetal with unmodified ketones also proceeded smoothly to produce the corresponding β-hydroxy-β-trifluoromethylated ketones with good to excellent diastereo- and enantio-selectivities.
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Hemiacetal and hemiaminal formation at fluoroacyl moiety
Tetrahedron, 2005Co-Authors: Masaki Matsui, Kaede Yamada, Kazumasa FunabikiAbstract:Abstract Hemiacetals and hemiaminals were produced not only at a trifluoroacetyl (CF3CO) moiety but also at difluoroacetyl (CHF2CO) and pentafluoroalkanoyl (C2F5CO) moieties. As larger was the electron-withdrawing nature and less bulky was the fluoroalkyl (Rf) group and smaller was the size of an alcohol, the ratio of Hemiacetal form increased. Not only a CF3CO moiety but also monofluoroacetyl (CH2FCO), CHF2CO, and C2F5CO moieties produced the hemiaminals. As larger was the electron-withdrawing nature of Rf group and smaller was an amine, the ratio of hemiaminal form increased.
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The Use of Trifluoroacetaldehyde Ethyl Hemiacetal or Hydrate in a Simple and Practical Regioselective Synthesis of β-Hydroxy-β-trifluoromethyl Ketones from Enamines and Imines
The Journal of Organic Chemistry, 2003Co-Authors: Kazumasa Funabiki, Kei Matsunaga, Miwa Nojiri, Wataru Hashimoto, Hitoshi Yamamoto, Katsuyoshi Shibata, Masaki MatsuiAbstract:The reaction of trifluoroacetaldehyde ethyl Hemiacetal or hydrate with an equimolar amount of enamines, derived from various methyl ketones, smoothly proceeded to give the corresponding β-hydroxy-β-trifluoromethyl ketones in high yields. An equimolar amount of imines derived from various methyl ketones with aliphatic, aromatic, and heteroaromatic substituents also readily reacted with trifluoroacetaldehyde ethyl Hemiacetal or hydrate to afford the corresponding β-hydroxy-β-trifluoromethyl ketones in good to excellent yields. Difluoroacetaldehyde ethyl Hemiacetal as well as pentafluoropropionaldehyde also participated in the reaction, affording good yields of the corresponding β-hydroxy-β-difluoromethyl or β-pentafluoropropyl ketones.
Kazumasa Funabiki - One of the best experts on this subject based on the ideXlab platform.
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reversal of diastereoselectivity in reactions of the trifluoroacetaldehyde ethyl Hemiacetal with enamines and imines metal free complementary anti and syn selective synthesis of 4 4 4 trifluoro 1 aryl 3 hydroxy 2 methyl 1 butanones
ChemInform, 2011Co-Authors: Kazumasa Funabiki, Kei Matsunaga, Hitoshi Yamamoto, Hiroshi Gonda, Takao Arima, Yasuhiro Kubota, Masaki MatsuiAbstract:Treatment of the Hemiacetal (II) with imines of type (I) is found to result in efficient formation of syn-adducts like (III).
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a versatile approach to 2 substituted 3 trifluoromethyl 1 3 diols based on the reaction of trifluoroacetaldehyde ethyl Hemiacetal with enamines derived from aldehydes
Chemistry Letters, 2010Co-Authors: Kazumasa Funabiki, Hiroshi Gonda, Yasuhiro Kubota, Yudai Furuno, Fumiaki Sato, Masaki MatsuiAbstract:Treatment of trifluoroacetaldehyde ethyl Hemiacetal with various enamines, derived from various aldehydes, at room temperature, followed by hydrolysis with 10% HCl aqueous solution and reduction wi...
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Catalytic in-situ generation of trifluoroacetaldehyde from its Hemiacetal and successive direct aldol reaction with ketones
2007Co-Authors: Kazumasa Funabiki, Masaki MatsuiAbstract:Trifluoroacetaldehyde ethyl Hemiacetal reacted with unmodified ketones in the presence of 30 to 50 each mol% of amines and acids at ambient temperature, affording the corresponding β-hydroxy-β-trifluoromethylated ketones in good yields with good to excellent diastereoselectivities. Furthermore, L-proline-catalyzed asymmetric direct aldol reaction of trifluoroacetaldehyde ethyl Hemiacetal with unmodified ketones also proceeded smoothly to produce the corresponding β-hydroxy-β-trifluoromethylated ketones with good to excellent diastereo- and enantio-selectivities.
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Hemiacetal and hemiaminal formation at fluoroacyl moiety
Tetrahedron, 2005Co-Authors: Masaki Matsui, Kaede Yamada, Kazumasa FunabikiAbstract:Abstract Hemiacetals and hemiaminals were produced not only at a trifluoroacetyl (CF3CO) moiety but also at difluoroacetyl (CHF2CO) and pentafluoroalkanoyl (C2F5CO) moieties. As larger was the electron-withdrawing nature and less bulky was the fluoroalkyl (Rf) group and smaller was the size of an alcohol, the ratio of Hemiacetal form increased. Not only a CF3CO moiety but also monofluoroacetyl (CH2FCO), CHF2CO, and C2F5CO moieties produced the hemiaminals. As larger was the electron-withdrawing nature of Rf group and smaller was an amine, the ratio of hemiaminal form increased.
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The Use of Trifluoroacetaldehyde Ethyl Hemiacetal or Hydrate in a Simple and Practical Regioselective Synthesis of β-Hydroxy-β-trifluoromethyl Ketones from Enamines and Imines
The Journal of Organic Chemistry, 2003Co-Authors: Kazumasa Funabiki, Kei Matsunaga, Miwa Nojiri, Wataru Hashimoto, Hitoshi Yamamoto, Katsuyoshi Shibata, Masaki MatsuiAbstract:The reaction of trifluoroacetaldehyde ethyl Hemiacetal or hydrate with an equimolar amount of enamines, derived from various methyl ketones, smoothly proceeded to give the corresponding β-hydroxy-β-trifluoromethyl ketones in high yields. An equimolar amount of imines derived from various methyl ketones with aliphatic, aromatic, and heteroaromatic substituents also readily reacted with trifluoroacetaldehyde ethyl Hemiacetal or hydrate to afford the corresponding β-hydroxy-β-trifluoromethyl ketones in good to excellent yields. Difluoroacetaldehyde ethyl Hemiacetal as well as pentafluoropropionaldehyde also participated in the reaction, affording good yields of the corresponding β-hydroxy-β-difluoromethyl or β-pentafluoropropyl ketones.
Katsuyoshi Shibata - One of the best experts on this subject based on the ideXlab platform.
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The Use of Trifluoroacetaldehyde Ethyl Hemiacetal or Hydrate in a Simple and Practical Regioselective Synthesis of β-Hydroxy-β-trifluoromethyl Ketones from Enamines and Imines
The Journal of Organic Chemistry, 2003Co-Authors: Kazumasa Funabiki, Kei Matsunaga, Miwa Nojiri, Wataru Hashimoto, Hitoshi Yamamoto, Katsuyoshi Shibata, Masaki MatsuiAbstract:The reaction of trifluoroacetaldehyde ethyl Hemiacetal or hydrate with an equimolar amount of enamines, derived from various methyl ketones, smoothly proceeded to give the corresponding β-hydroxy-β-trifluoromethyl ketones in high yields. An equimolar amount of imines derived from various methyl ketones with aliphatic, aromatic, and heteroaromatic substituents also readily reacted with trifluoroacetaldehyde ethyl Hemiacetal or hydrate to afford the corresponding β-hydroxy-β-trifluoromethyl ketones in good to excellent yields. Difluoroacetaldehyde ethyl Hemiacetal as well as pentafluoropropionaldehyde also participated in the reaction, affording good yields of the corresponding β-hydroxy-β-difluoromethyl or β-pentafluoropropyl ketones.
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enamine assisted facile generation of trifluoroacetaldehyde from trifluoroacetaldehyde ethyl Hemiacetal and its carbon carbon bond forming reaction leading to β hydroxy β trifluoromethyl ketones
Chemical Communications, 1998Co-Authors: Kazumasa Funabiki, Masaki Matsui, Miwa Nojiri, Katsuyoshi ShibataAbstract:Trifluoroacetaldehyde ethyl Hemiacetal 1 readily reacts with various enamines 2 in hexane at room temperature for 1 h to give the corresponding β-hydroxy-β-trifluoromethyl ketones in good yields.
Yong-jun Chen - One of the best experts on this subject based on the ideXlab platform.
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ticl4 catalyzed friedel crafts reaction of trifluoroacetaldehyde ethyl Hemiacetal tfae
ChemInform, 2012Co-Authors: Jing Zhang, Yong-jun Chen, Liang ZhangAbstract:A novel strictly hydroxyl-directed Friedel—Crafts reaction of various phenols with trifluoroacetaldehyde ethyl Hemiacetal (II) is reported.
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TiCl4-Catalyzed Friedel—Crafts Reaction of Trifluoroacetaldehyde Ethyl Hemiacetal (TFAE).
ChemInform, 2012Co-Authors: Jing Zhang, Yong-jun Chen, Liang ZhangAbstract:A novel strictly hydroxyl-directed Friedel—Crafts reaction of various phenols with trifluoroacetaldehyde ethyl Hemiacetal (II) is reported.
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Facile Synthesis of Spiropyrans from Chromene Hemiacetal Esters and Bifunctional Nucleophiles.
ChemInform, 2011Co-Authors: Li Liu, Nicolas Demoulin, Zhe Liu, Dong Wang, Yong-jun ChenAbstract:Treatment of Hemiacetal esters with diamines, β-hydroxyamines, and 1-naphthylamine results in formation of new spiropyrans.
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Hafnium triflate as an efficient catalyst for direct FriedelCrafts reactions of chromene Hemiacetals
Advanced Synthesis & Catalysis, 2011Co-Authors: Li Liu, Nicolas Demoulin, Zhe Liu, Dong Wang, Yong-jun ChenAbstract:The direct Friedel-Crafts reaction of chromene Hemiacetals with indoles, furans and ster- ically hindered anilines has been accomplished with high selectivity and excellent yields in the presence of a catalytic amount of hafnium triflate (HfA4, 0.1 mol%, 0-408C). The mild conditions tolerate various sensitive functional and protecting groups, and the products were confirmed unambiguously from their spectra and by single-crystal X-ray analy- sis. This direct Friedel-Crafts reaction of chromene Hemiacetals should inspire and encourage the con- sideration of hafnium triflate in the development of mild reaction conditions for the efficient derivatiza- tion of Hemiacetal-containing compounds.
Liang Zhang - One of the best experts on this subject based on the ideXlab platform.
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ticl4 catalyzed friedel crafts reaction of trifluoroacetaldehyde ethyl Hemiacetal tfae
ChemInform, 2012Co-Authors: Jing Zhang, Yong-jun Chen, Liang ZhangAbstract:A novel strictly hydroxyl-directed Friedel—Crafts reaction of various phenols with trifluoroacetaldehyde ethyl Hemiacetal (II) is reported.
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TiCl4-Catalyzed Friedel—Crafts Reaction of Trifluoroacetaldehyde Ethyl Hemiacetal (TFAE).
ChemInform, 2012Co-Authors: Jing Zhang, Yong-jun Chen, Liang ZhangAbstract:A novel strictly hydroxyl-directed Friedel—Crafts reaction of various phenols with trifluoroacetaldehyde ethyl Hemiacetal (II) is reported.