- Enantioselective Synthesis of 3,4-Dihydropyran-2-ones via Phase-Transfer-Catalyzed Addition-Cyclization of Acetylacetone to Cinnamic Thioesters
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Herein, we present the first example of synthesis of 3,4-dihydropyran-2-ones from cinnamic thioesters via a stereoselective phase-transfer-catalyzed domino Michael-cyclization reaction with acetylacetone. The reaction proceeded under the catalysis of Cinchona-derived quaternary ammonium phenoxide that, in combination with inorganic bases, provided 3,4-dihydropyran-2-ones in yields of up to 93% and enantioselectivities of up to 88% enantiomeric excess.
- Destro, Dario,Bottinelli, Carlo,Ferrari, Ludovica,Albanese, Domenico C. M.,Bencivenni, Grazia,Gillick-Healy, Malachi W.,Kelly, Brian G.,Adamo, Mauro F. A.
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supporting information
p. 5183 - 5192
(2020/04/10)
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- Anti-analogs and its preparation and use
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The invention relates to an antitoxin analogue as well as a preparation method and an application thereof and particularly discloses a novel antitoxin analogue. A structural formula of the novel antitoxin analogue is as shown in a formula I or formula II
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Paragraph 0203; 0208-0210
(2019/07/06)
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- Nickel-catalyzed, ligand-free, diastereoselective synthesis of 3-methyleneindan-1-ols
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Nickel-catalyzed, highly diastereoselective annulations between activated allenes and 2-acetylarylboronic acid or 2-formylarylboronic acids are reported. No ligand for nickel is required, and the reactions proceed efficiently at room temperature to give a broad range of substituted 3-methyleneindan-1-ols. Preliminary results of an enantioselective variant are also described.
- Panchal, Heena,Clarke, Christopher,Bell, Charles,Karad, Somnath Narayan,Lewis, William,Lam, Hon Wai
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supporting information
p. 12389 - 12392
(2018/11/20)
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- Multiplexing of combinatorial chemistry in antimycin biosynthesis: Expansion of molecular diversity and utility
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Diversity-oriented biosynthesis of a library of antimycin-like compounds (380 altogether) was accomplished by using multiplex combinatorial biosynthesis. The core strategy depends on the use of combinatorial chemistry at different biosynthetic stages. This approach is applicable for the diversification of polyketides, nonribosomal peptides, and the hybrids that share a similar biosynthetic logic. Copyright
- Yan, Yan,Chen, Jing,Zhang, Lihan,Zheng, Qingfei,Han, Ying,Zhang, Hua,Zhang, Daozhong,Awakawa, Takayoshi,Abe, Ikuro,Liu, Wen
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p. 12308 - 12312
(2013/12/04)
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- Synthesis of (2RS,E)-3-Ethylidene-azetidine-2-carboxylic acid (rac. polyoximic acid)
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Treatment of α-diazo β-ketoester 4 with a catalytic amount of rhodium (II) acetate followed by Wittig reaction with phosphorane 5 gave the isomeric phenylthioester derivative 6a and 6b. Reduction of 6a led to the corresponding allylic alcohol 7, which was further converted into the bromide 8. Dehalogenation of 8 with NaBH4/ DMF resulted in compound 9, which was deprotected with trifluoroacetic acid, giving racemic polyoximic acid (1).
- Emmer, Gerhard
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p. 7165 - 7172
(2007/10/02)
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- Cumulated Ylides, VII. A Method for the Synthesis of α,β-Unsaturated Carboxylic Compounds
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Phosphacumulene ylides 1 add alcohols, thiols, and NH-acidic compounds to form phosphoranes 3, which react with aldehydes to give esters, thiol esters, imidates, thioimidates, amidines, azolides, and sulfonamides of α,β-unsaturated carboxylic acids.
- Bestmann, Hans Juergen,Schmid, Guenter,Sandmeier, Dieter
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p. 912 - 918
(2007/10/02)
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