88335-91-5Relevant academic research and scientific papers
Development of Bifunctional Thiourea Organocatalysts Derived from a Chloramphenicol Base Scaffold and their Use in the Enantioselective Alcoholysis of meso Cyclic Anhydrides
Yan, Lin-Jie,Wang, Hai-Feng,Chen, Wen-Xue,Tao, Yuan,Jin, Kai-Jun,Chen, Fen-Er
, p. 2249 - 2253 (2016)
The synthesis of new chloramphenicol-base-derived thiourea organocatalysts, (1S,2R)-12 a–f and (1R,2R)-15 a–c, and their use in the enantioselective alcoholysis of meso-anhydrides are described. In particular, hemiesters afforded excellent enantioselectivities if low loadings of (1S,2R)-12 a–f were used. Almost no enantioselectivities were achieved with the use of (1R,2R)-15 a–c. This technique was used to synthesize (R)-(?)-baclofen.
Asymmetric Methanolysis of Cyclic meso-Anhydrides with Tripodal 2,6-trans-1,2,6-Trisubstituted Piperidine as Chiral Amine Catalyst
Okamatsu, Tohru,Irie, Ryo,Katsuki, Tsutomu
, p. 1569 - 1572 (2007)
An optically active tripodal amine, (2S,6S)-2,6-bis(o-hydroxyphenyl)-1-(2- pyridylmethyl)piperidine, was proven to be a potent chiral catalyst (1-5 mol%) for methanolytic asymmetric desymmetrization of cyclic meso-anhydrides to hemiesters. A good level of
Enantioselective Esterification of Cyclic Dicarboxylic Anhydrides Using Chiral Amino Alcohols as Auxiliaries
Shimizu, Makoto,Matsukawa, Kohzoh,Fujisawa, Tamotsu
, p. 2128 - 2130 (1993)
Cyclic dicarboxylic anhydrides were enantioselectively esterified with the complex formed from cinchonidine, diethylzinc, and methanol, and the half-esters obtained were readily transformed into lactones via reduction and dehydration.
Photocatalyzed, β-Selective Hydrocarboxylation of α,β-Unsaturated Esters with CO2under Flow for β-Lactone Synthesis
Kang, Guowei,Romo, Daniel
, p. 1309 - 1315 (2021/02/01)
A photocatalyzed, β-selective hydrocarboxylation of α,β-unsaturated esters employing CO2 radical anion generated under flow conditions was developed. A range of substrates bearing a variety of functional groups were tolerated, demonstrating chemoselectivity. A series of quaternary carboxylic acids were obtained from sterically demanding β,β-disubstituted alkenes including those derived from natural products. Mechanistic studies support a Giese-type CO2 radical anion conjugate addition followed by hydrogen atom transfer from (TMS)3SiH as the principal reaction pathway. Finally, a telescoped process involving the described β-carboxylation followed by a α-bromination/β-lactonization sequence provides a strategy for β-lactone synthesis.
Synthesis method of trans 1 and 2 - cyclohexane dicarboxylic acid monomethylester
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Paragraph 0044-0048; 0049-0053, (2021/08/25)
The invention provides a synthesis method of trans 1 and 2 - cyclohexane dicarboxylic acid monomethylester, and belongs to the field of organic synthesis. The trans 1-2 -cyclohexane dicarboxylic acid monomethylester synthesis method comprises the following steps: trans-cyclohexane -1 and 2 -dicarboxylic acid anhydride. The methanol and solvent is added to the reaction vessel, stirred and purified to obtain the target product trans 1, 2 - cyclohexanedicarboxylate, wherein the solvent is any one or more of tetrahydrofuran, 2 - methyltetrahydrofuran, benzene, toluene, methylene chloride, chloroform, ethyl acetate, methyl acetate or diethyl ether. Since a specific solvent is selected for the reaction solvent, racemization does not occur in the process of synthesizing trans 1 and 2 - cyclohexane dicarboxylic acid monomethyl ester, and the trans ee and 1 cyclohexane dicarboxylic acid monomethyl ester with higher 2 - value can be finally obtained.
Ionic Liquid Gels: Supramolecular Reaction Media for the Alcoholysis of Anhydrides
Rizzo, Carla,Mandoli, Alessandro,Marullo, Salvatore,D'Anna, Francesca
, p. 6356 - 6365 (2019/05/24)
The search of new enantioselective catalysts, able to promote synthetically useful organic reactions with high levels of asymmetric induction, should be associated with the attention to the suitable reaction medium able to achieve the best efficiency in c
Synthesis of trans-fused octahydroisoindole-1-carboxylic acids
Laborda, Pedro,Sayago, Francisco J.,Cativiela, Carlos,Gotor, Vicente
, p. 404 - 411 (2018/05/22)
trans-Fused octahydroisoindole-1-carboxylic acids are bicyclic proline analogues of potential interest in the search for new drugs. Within this work, the trans-fused octahydroisoindole system has been constructed using methyl trans-2-(hydroxymethyl)cycloh
Synthesis of cinchona alkaloid sulfonamide polymers as sustainable catalysts for the enantioselective desymmetrization of cyclic anhydrides
Takata, Shohei,Endo, Yuta,Shahid Ullah, Mohammad,Itsuno, Shinichi
, p. 72300 - 72305 (2016/08/09)
The Mizoroki-Heck polymerization of cinchona-based sulfonamide dimers and aromatic diiodides was investigated in the presence of a palladium catalyst, to obtain chiral polymers in high yields. An iodobenzenesulfonamide derivative of a cinchona alkaloid was also polymerized via self-polycondensation under the same reaction conditions. The catalytic activities of these chiral polymers were examined by using them as catalysts in the enantioselective desymmetrization of cyclic anhydrides.
Monomeric and Dimeric 9-O Anthraquinone and Phenanthryl Derivatives of Cinchona Alkaloids as Chiral Solvating Agents for the NMR Enantiodiscrimination of Chiral Hemiesters
Uccello Barretta, Gloria,Mandoli, Alessandro,Balzano, Federica,Aiello, Federica,De Nicola, Beatrice,Del Grande, Alessandro
, p. 693 - 699 (2015/10/12)
Mono- and bis-alkaloid chiral auxiliaries with anthraquinone or phenanthryl cores were probed as chiral solvating agents (CSAs) for the enantiodiscrimination of chiral cyclic hemiesters. The dimeric anthraquinone derivative and the monomeric phenanthryl o
Asymmetric synthesis of 3,4-disubstituted proline derivatives: Application in synthesis of hepatitis C virus protease inhibitor telaprevir
Zhang, Fan,Wen, Xiaoan,Xu, Qing-Long,Sun, Hongbin
, p. 8101 - 8109 (2015/02/02)
A practical asymmetric synthesis of 3,4-disubstituted proline derivatives has been realized with high stereoselectivity and moderate yield. The key steps involved are desymmetric ring-opening reaction of commercially available anhydrides, intramolecular Strecker reaction and thermodynamically controlled cyanide hydrolysis. Based on this methodology, the synthesis of HCV protease inhibitor Telaprevir was achieved.
