Highly Enantioselective Sequential Hydrogenation of Ethyl 2-Oxo-4-arylbut-3-enoate to Ethyl 2-Hydroxy-4-arylbutyrate
摘要:
The hydrogenation of (E)-ethyl 2-oxo-4-arylbut-3-enoate with [NH2Me2](+)[{RuCl [(S)-SunPhos]}2(mu-Cl-3] gave ethyl 2-hydroxy-4-arylbutyrate with 94-96% ee. Further investigation has proved that the hydrogenation proceeded via a sequential hydrogenation of C = O and C = C bonds, which is sensitive to the reaction temperature. Hydrolysis of ethyl 2-hydroxy-4-phenylbutyrate (ee 93%) provided the 2-hydroxy-4-phenylbutyric acid with 81 % yield at 99% ee after a single recrystallization from 1, 2-dichloroethylene.
A Mild Method for Indium(III)-Catalyzed 1,4-Hydrosilylation of α,β-Enone Esters with Triethylsilane and Trifluoroacetic Acid
摘要:
A chemo- and stereoselective 1,4-hydrosilylation of alpha,beta-enone esters was developed using triethylsilane and trifluoroacetic acid under indium chloride catalysis.
Facile synthesis of pyrido[3,2-b]indole via multicomponent reaction strategy under aerobic conditions
作者:Rongrong Jiang、Youming Wang、Zhenghong Zhou
DOI:10.1016/j.tet.2016.08.050
日期:2016.10
developed an organocatalyzed three-component reaction of 1-acetylindolin-3-ones, β,γ-unsaturatedα-ketoesters and amines, which provide an efficient approach to access polysubstituted 1H-pyrido[3,2-b]indoles. Under the catalysis of 4-methylbenzenesulfonic acid monohydrate, the reactions of a wide range of 1-acetylindolin-3-ones, β,γ-unsaturatedα-ketoesters and amines took place smoothly to generate
我们已经开发了有机物催化的1-乙酰吲哚-3-酮,β,γ-不饱和α-酮酸酯和胺的三组分反应,这为获得多取代的1 H-吡啶并[3,2- b ]吲哚提供了一种有效的方法。在4-甲基苯磺酸一水合物的催化下,各种1-乙酰吲哚-3-酮,β,γ-不饱和α-酮酸酯和胺类的反应顺利进行,生成相应的稠密取代的1 H-吡啶基[3]。在温和的反应条件下,2-2- b ]吲哚衍生物的收率可以接受。另外,以良好的产率实现了代表性产物向生物学上重要的δ-碳卤化物的进一步转化。
Direct Synthesis of β,γ-Unsaturated α-Keto Esters from Aldehydes and Pyruvates
作者:John Mansaray、Jiarui Sun、Shisheng Huang、Weijun Yao
DOI:10.1055/s-0037-1612255
日期:2019.4
methods to synthesize β,γ-unsaturated α-keto esters directly from aldehydes and pyruvates promoted by BF3•Et2O in the presence of Ac2O or by Ti(OEt)4 under mild conditions. A variety of aromatic aldehydes was tolerated to afford the desired products in moderate to excellent yield. Moreover, aliphatic aldehydes and Isatin were also employed to give the γ-alkyl β,γ-unsaturated α-keto esters in moderate yield