- Phase-Transfer Catalyzed Asymmetric [4 + 1] Annulations for the Synthesis of Chiral 2,2-Disubstituted Tetrahydrothiophenes
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An efficient catalytic asymmetric [4 + 1] reaction, which features the use of simple β-keto esters as one-carbon nucleophiles and 5-succinimidothio-pent-2-enoates as four-atom bielectrophiles, has been developed in the presence of a bifunctional chiral ph
- Yin, Qi,Wen, Xiaolu,Chen, Yiwei,Gong, Xiangnan,Hu, Lin
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supporting information
p. 7529 - 7534
(2021/10/02)
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- With anti-bacterial activity of the piperidine link 1, 2, 3 - triazole class compound and its preparation method and application
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The present invention discloses a piperidine link 1,2,3-triazole compound with antibacterial activity and a preparation method therefor and application thereof, and belongs to the technical field of synthesis of compounds with antibacterial activity. The
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Paragraph 0110-0113
(2017/11/16)
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- A donor-acceptor cyclopropene as a dipole source for a silver(i) catalyzed asymmetric catalytic [3+3]-cycloaddition with nitrones
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Silver(i)-catalyzed asymmetric formal [3+3]-cycloaddition of nitrones with a donor-acceptor cyclopropene, formed in situ from dirhodium acetate-catalyzed dinitrogen extrusion/intramolecular cyclization of enoldiazoacetates, effectively generates 3,6-dihydro-1,2-oxazine derivatives in high yield and with exceptional stereocontrol.
- Xu, Xinfang,Zavalij, Peter J.,Doyle, Michael P.
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supporting information
p. 10287 - 10289
(2013/10/22)
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- Organocatalyzed asymmetric synthesis of morphans
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A general effective organocatalyzed synthesis of enantioenriched morphans with up to 92% ee was developed. The morphan scaffold was constructed in a one-pot tandem asymmetric organocatalyzed Michael addition followed by a domino Robinson annulation/aza-Michael intramolecular reaction sequence from easily available starting materials.
- Bradshaw, Ben,Parra, Claudio,Bonjoch, Josep
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p. 2458 - 2461
(2013/06/27)
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- β-Keto esters derived from 2-(trimethylsilyl)ethanol: An orthogonal protective group for β-keto esters
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β-Keto esters derived from 2-(trimethylsilyl)ethanol undergo cleavage and decarboxylation when treated with 0.75 equivalents of tetrabutylammonium fluoride trihydrate in tetrahydrofuran at 50°C, while β-keto esters derived from methanol, tert-butyl alcohol, allyl alcohol, or benzyl alcohol stay intact. Conversely, methyl-, tert-butyl-, allyl-, or benzyl β-keto esters can be cleaved and decarboxylated without the 2-(trimethylsilyl)ethyl β-keto esters being affected. Similarly, mixed bis(β-keto esters) derived from 2-(trimethylsilyl)ethanol and methanol, tert-butyl alcohol, allyl alcohol, or benzyl alcohol can be defunctionalized chemoselectively under the same reaction conditions. Georg Thieme Verlag Stuttgart.
- Knobloch, Eva,Brueckner, Reinhard
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experimental part
p. 2229 - 2246
(2009/04/08)
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- PYRROLOPYRIDAZINE DERIVATIVES
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The invention relates to compound of the formula (I) or its salt, in which R1, R2, R3 and R4 are as defined in the description, their use of as medicament, the process for their preparation and use for the treatment of PDE-IV or TNF-α mediated diseases.
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- Process for producing 3-oxocarboxylic acid esters
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A novel process for producing 3-oxocarboxylic acid esters, which are useful as intermediates in the synthesis of ceramides to be used as a humectant, biodegradable polymers, drugs, etc., at a high purity and a high yield without requiring any troublesome procedure, is disclosed. The process comprises reacting an acetoacetic ester with a calcium compound, a barium compound or a strontium compound in the presence of an organic solvent at a temperature of 10 to 120° C., further reacting the obtained product with a carboxylic acid chloride to thereby acylate it, and then adding thereto an alcohol in an amount 1 to 5 times by mol as much as the calcium compound, barium compound or strontium compound to thereby deacetylate the same.
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- A short, efficient synthesis of monofluoro ketomethylene peptide isostere core units
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Monofluoro ketomethylene peptide isosteres can be prepared by a four step sequence from carboxylic acids in satisfactory overall yields (30-60%). Fluorine is introduced by electrophilic fluorination of a β-ketoester enolate with SelectFluor(TM).
- Hoffman, Robert V.,Saenz, James E.
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p. 8469 - 8472
(2007/10/03)
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- A convenient synthesis of unsymmetrical, substituted γ-pyrones from Meldrum's acid
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A unique approach to the synthesis of mono and disubstituted γ-pyrones from acylated Meldrum's acid and vinyl ethers has been developed. The convenient one pot synthesis of these versatile polyketide equivalents is accomplished without strong base or low temperature.
- Zawacki, Frank J.,Crimmins, Michael T.
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p. 6499 - 6502
(2007/10/03)
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- Enones with Strained Double Bonds. 7. Precursors for Substituted Bicyclononane Systems
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Compounds 11c, 12, and 13 have been synthesized as potential precursors for the 2-substituted bicyclonon-1(2)-en-3-ones 5 (R = Ph and t-Bu).The lactone 34 and its derivatives 32 have also been synthesized as potential precursors for the parent bicyclo enone 1.
- House, Herbert O.,Outcalt, Russell J.,Cliffton, Michael D.
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p. 2413 - 2419
(2007/10/02)
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