- Base-free two-step synthesis of 1,3-diketones and β-ketoesters from α-diazocarbonyl compounds, trialkylboranes, and aromatic aldehydes
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We describe a convergent, base-free two-step synthesis of 1,3-diketones and β-ketoesters from α-diazocarbonyl compounds, trialkylboranes, and aromatic aldehydes in a three-component process. The synthetic potential of this protocol was underscored by the
- Sanchez-Carmona, Miguel A.,Contreras-Cruz, David A.,Miranda, Luis D.
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supporting information; experimental part
p. 6506 - 6508
(2011/11/05)
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- Dynamic kinetic resolution with enantioselective borohydride reduction catalyzed by optically active β-ketoiminato cobalt(II) complexes: Highly diastereo- and enantioselective preparation of optically active anti-aldol compounds
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Optically active anti-2-alkyl-3-hydroxy esters were stereo-selectively obtained from the corresponding 2-alkyl-3-keto esters using enantioselective borohydride reduction along with dynamic kinetic resolution in the presence of optically active β-ketoimina
- Ohtsuka, Yuhki,Miyazaki, Daichi,Ikeno, Taketo,Yamada, Tohru
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- Surface-mediated solid phase reaction. Part 9. A convenient procedure for aldol reaction of ketene silyl acetals with aldehydes on the solid surface of alumina
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The aldol reaction of ketene silyl acetals with aldehydes proceeds efficiently on the solid surface of alumina impregnated with anhydrous zinc chloride under sonication providing aldol products in high yields and with good stereoselectivity.
- Ranu, Brindaban C.,Saha, Manika,Bhar, Sanjay
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p. 3065 - 3077
(2007/10/03)
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- Chele- and Anti-cheleselectivity, V. - On the Structure and Chemoselectivity of Some Transition Metal Derivatives of Carboxylic Acid Esters
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On account of the IR spectra of Et2OCCH2FeCl (2a), EtO2CCH2CoCl (3a), and EtO2CCH(Et)CoCl (3b), prepared in situ by transmetalation of the corresponding Li enolates, and EtO2CCH(Et)CrCl2 (5b), obtained in situ by one-electron oxidative addition of EtO2CCH(Et)Br to CrCl2, it is assumed that these and similar complexes (2b, 2c, 3c) form 8-membered cyclic dimers of type 11 in THF in analogy to the Reformatzky reagents.Representatives of these complexes and of corresponding Ti complexes were treated (THF, mol ratio 1:1:1) with substrate pairs, consisting of a normal ketone and β-functionalized ketone (Table 2) or alternatively of a normal ketone and an α-functionalized ketone (Table 3).In the first case high anti-cheleselectivity was observed, but in the second case high cheleselectivity.The reasons for this different behaviour are discussed. - Key Words: Carboxylic esters / Ketones / Chemoselectivity
- Kauffmann, Thomas,Moeller, Thomas,Wilde, Heinz-Wilhelm
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p. 2277 - 2284
(2007/10/02)
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- Enolboration. 6. Dicyclohexyliodoborane, a Versatile Reagent for the Stereoselective Synthesis of Either Z or E Enolates from Representative Esters
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A smooth, rapid, quantitative, and highly stereoselective synthesis of either Z or E enolates from representative esters has been achieved with dicyclohexyliodoborane, Chx2BI, in the presence of a suitable tertiary amine, such as triethylamine or N,N-diis
- Ganesan, Kumaraperumal,Brown, Herbert C.
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p. 2336 - 2340
(2007/10/02)
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- A NEW METHOD FOR THE SYNTHESIS OF β-HYDROXYESTERS BY USING METALLIC TIN
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Metallic tin or activated metallic tin, prepared by reduction of stannous chloride with lithium aluminum hydride, smoothly reacts with α-haloesters to yield tin enolates, which in turn react with carbonyl compounds under mild conditions to give, after hydrolysis, β-hydroxyesters in high yields.
- Harada, Taira,Mukaiyama, Teruaki
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p. 161 - 164
(2007/10/02)
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