DABCO-catalyzed C–C bond formation reaction between electron-deficient alkynes and 1,3-dicarbonyl compounds
作者:Hua Cao、Haiping Zhong、Yuanguang Lin、Liuqing Yang
DOI:10.1016/j.tet.2012.03.047
日期:2012.5
excellent catalyst DABCO has been found to catalyze C–C bond formation reaction between activated methylenes and alkynes. The transformation has provided a facile route for the synthesis of 2H-pyran-2-ones or unsaturated alkenoicacidester derivatives and explored the new possibilities of N-catalysts for Michael addition of nucleophiles with alkynoates.
Triphenylphosphine Catalized Reaction Between 1,3-Dicarbonyl Compounds and Acetylenic Esters
作者:Issa Yavari、Farough Nasiri、Hoorih Djahaniani
DOI:10.1080/714040976
日期:2003.12.1
group and rotation about the partial double bond in (E) and (Z) geometricalisomers is slow on the NMR time scale at ambient temperature. Thus, these ylides exist as a mixture of geometricalisomers. From the reaction of dimedone with dimethyl acetylenedicarboxylate (DMAD) in the presence of triphenylphosphine, a chromene derivative is obtained. A Michael addition product was obtained from the reaction
One-Pot Synthesis of Functionalized 2H-Chromene (=2H-1-Benzopyran) Derivatives via a Three-Component Reaction between a CH-Acid, a Dialkyl Acetylenedicarboxylate, and Methyl Chloroglyoxylate or Benzyl Carbonochloridate Mediated by Triphenylphosphine
An effective route to functionalized 2H‐chromene (=2H‐1‐benzopyran) derivatives 4 is described (Scheme 1). This involves the reaction of a 1,1‐diactivated alkene, resulting from the reaction of dimedone (=5,5‐dimethylcyclohexane‐1,3‐dione; 1a) with methyl chloroglyoxylate (ClC(O)COOMe), benzyl carbonochloridate (ClC(O)OCH2Ph) or 3,5‐dinitrobenzoyl chloride (3,5‐(NO2)2C6H3C(O)Cl), and a dialkyl
描述了一种功能化的2 H-色烯(= 2 H -1-苯并吡喃)衍生物4的有效途径(方案1)。这涉及1,1-双活化烯烃的反应,这是由二甲酮(= 5,5-二甲基环己烷-1,3-二酮; 1a)与氯乙醛酸甲酯(ClC(= O)COOMe),苄基氯代氯酸( ClC(O)OCH 2 Ph)或3,5-二硝基苯甲酰氯(3,5-(NO 2)2 C 6 H 3 C(O)Cl)和乙炔基二羧酸二烷基酯(=二烷基丁-2-炔二酸酯) )在存在分子内Wittig反应以生成2的Ph 3 P存在下H-色烯衍生物(方案1)。
Copper oxide catalyzed domino process for the synthesis of substituted 2H-pyran-2-ones and polyhydroxy coumarin derivatives
Isoquinoline-catalyzed reaction between 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one and dialkyl acetylene dicarboxylates: synthesis of coumarin and pyranopyrane derivatives
In this work we report the reaction between dialkyl acetylenedicarboxylates and enolic systems such as 5,5-dimethyl-1,3-cyclohexanedione, 1,3-cyclohexanedione, 4-hydroxycoumarin or 4-hydroxy-6-methylpyran-1-one in the presence of isoquinoline, which leads to new coumarin and pyranopyran derivatives.