- Highly enantioselective construction of CF3-bearing all-carbon quaternary stereocenters: Hiral spiro-fused bisoxazoline ligands with 1,1′-binaphthyl sidearm for asymmetric Michael-type Friedel-Crafts reaction
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A novel class of chiral spiro-fused bisoxazoline ligands possessing a deep chiral pocket was prepared. The developed ligands have been employed in the nickel-catalyzed highly enantioselective Michael-type Friedel-Crafts reaction, affording the products bearing a trifluoromethylated all-carbon quaternary stereocenter with moderate to excellent yields (up to 99%) and good to excellent enantioselectivies (up to > 99.9% ee). Moreover, a proposed model of chiral pocket revealed that the attack of indole from the Re-face of β-CF3-β-disubstituted nitroalkene was favorable.
- Bao, Robert Li-Yuan,Fu, Kang,Shi, Lei
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supporting information
(2021/11/27)
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- Palladium-catalyzed regio- and stereoselective formate reduction of fluorine-containing allylic mesylates. A new entry for the construction of a tertiary carbon attached with a fluoroalkyl group
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The regioselective palladium-catalyzed formate reduction of γ-fluoroalkylated allylic esters is described. Reduction of the allylic esters under the influence of palladium with a monodentate phosphine ligand proceeded preferentially at the γ position, the corresponding reduction products with a fluoroalkyl group at the tertiary carbon being afforded in high yields. When the chiral allylic ester was employed, complete chirality transfer was observed, leading to the optically active materials in high yields.
- Konno, Tsutomu,Takehana, Tsuyoshi,Mishima, Makoto,Ishihara, Takashi
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p. 3545 - 3550
(2007/10/03)
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- Catalytic aerobic oxidative decarboxylation of α-trifluoromethyl-α-hydroxy acids to trifluoromethyl ketones
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The oxidative decarboxylation of α-trifluoromethyl-α-hydroxy acids to trifluoromethyl ketones is carried out under mild catalytic aerobic conditions using a cobalt(III) complex in the presence of pivalaldehyde.
- Blay, Gonzalo,Fernández, Isabel,Marco-Aleixandre, Alicia,Monje, Belén,Pedro, José R,Ruiz, Rafael
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p. 8565 - 8571
(2007/10/03)
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- New catalytic oxidation of trifluoromethyl carbinols by a ruthenium(II) complex
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The first catalytic oxidation of trifluoromethyl carbinols has been accomplished by a novel ruthenium(II) complex using sodium periodate as an oxidant. Trifluoromethyl ketones were obtained under mild conditions and in excellent yields. (C) 2000 Elsevier Science Ltd.
- Kesavan, Venkitasamy,Bonnet-Delpon, Danièle,Bégué, Jean-Pierre,Srikanth, Abirami,Chandrasekaran, Srinivasan
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p. 3327 - 3330
(2007/10/03)
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- A convenient preparative method for α-trifluoromethyl amines
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α-Trifluoromethyl amines (IV) were prepared in three steps: preparation of α-trifluoromethyl ketones (I), their conversion to benzyloximes (II), and reduction of the oximes (II) with lithium aluminium hydride and sodium methoxide. For example, α-trifluoromethyltridecylamine was obtained from the reduction of trifluoromethyl dodecyl ketone benzyl oxime. Elsevier Science S.A.
- Watanabe, Shoji,Fujita, Tsutomu,Sakamoto, Masami,Hamano, Hiroyuki,Kitazume, Tomoya,Yamazaki, Takashi
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- Chemoselective Trifluoromethylation of Methyl Esters Using an Et3GeNa/C6H5SCF3 Combination: Efficient Synthesis of Trifluoromethyl Ketones
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Various trifluoromethyl ketones were synthesized from the corresponding methyl esters by effective nucleophilic trifluoromethylation using an Et3GeNa/C6H5SCF3 combination. This trifluoromethylation proceeded che
- Yokoyama, Yasuo,Mochida, Kunio
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p. 907 - 908
(2007/10/03)
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- Studies on trifluoromethyl ketones. VII. Ene reaction of trifluoroacetaldehyde and its application for synthesis of trifluoromethyl compounds
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As an extension of our studies on the ene reaction of trifluoromethyl ketones, the ene reaction of trifluoroacetaldehyde was examined. The aldehyde reacted with various ene compounds as a good enophile in the presence of Lewis acids, among which methylaluminum dichloride worked best, though polymerization of the aldehyde caused by the Lewis acid often lowered the isolation yields of the ene reaction. The ene reaction products were successfully oxidized to trifluoromethyl β,γ-unsaturated ketones with Dess-Martin reagent. Reduction of the ene reaction products followed by oxidation with Jones reagent gave saturated trifluoromethyl ketones. The β,γ-unsaturated ketone rearranged on thermolysis to an α,β-unsaturated ketone. These ketones obtained were converted to other types of trifluoromethyl compounds. Thus, the ene reaction of trifluoroacetaldehyde provides a versatile method for synthesis of many types of trifluoromethyl compounds. During the derivatization, a trifluoromethyl group was found to behave as a much larger substituent than a decyl group.
- Ogawa,Nagai,Nonomura,Takagi,Koyama,Ando,Miki,Kumadaki
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p. 1707 - 1712
(2007/10/02)
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