描述了稀土金属和三氟甲磺酸ha催化的1,3-二酮,酮酸酯和酮酰胺的二次苄基化和烯丙基化。该程序在无水条件下进行。在CH 3 NO 2中使用0.5摩尔%的金属三氟甲磺酸酯,由取代的1-苯基乙醇生成各种1-苯基乙基阳离子。。阳离子与1,3-二酮和酮酸酯反应生成苄基化产物,收率很高。根据GC分析,可根据三氟甲磺酸的路易斯酸度和反应温度通过选择催化剂轻松优化反应条件。叔烷基化的二酮和相应的酮酸酯也被苄基化,以57-84%的收率得到具有季碳原子的产物。与二酮和酮酯反应中使用的那些相比,酮酰胺反应需要更强的路易斯酸。在Hf(OTf)4的存在下,研究了在芳环上具有各种取代基的苄醇与作为二酮的二苯甲酰甲烷(2b)的反应。富电子苄醇与2b反应以86-96%的产率收率,缺电子醇则以79-65%的收率得到所需的产物。尽管具有强的吸电子基团,但是1-(4-硝基苯基)乙醇的反应以61%的收率得到了相应的产物。也可以
The Lewis Acidic Ruthenium-Complex-Catalyzed Addition of β-Diketones to Alcohols and Styrenes Is in Fact Brønsted Acid Catalyzed
作者:Pei Nian Liu、Zhong Yuan Zhou、Chak Po Lau
DOI:10.1002/chem.200700705
日期:2007.10.15
toward 1-phenylethanol in the presence of HClO4; it also fails to catalyze the addition of acetylacetone to 1-phenylethanol. On the basis of these observations, it is proposed and confirmed by independent experiments that the catalytic addition of beta-diketones to the secondary alcohols is in fact catalyzed by the Bronsted acid HClO4, which is generated by the reaction of cis-[Ru(6,6'-Cl2bipy)2(H2O)2](ClO4)2
Monoallylation and monoalkylation of diketones and β-keto esters with allylic and benzylic alcohols catalysed by [Cp*Co(CH3CN)3][SbF6]2 (I) are reported. The method does not require any additive and affords regioselective products. The mechanistic investigations were done by in situ 1H NMR spectroscopy as well as control experiments. It has been shown that reactions proceed via η3-allyl complex formation or
报道了[Cp*Co(CH 3 CN) 3 ][SbF 6 ] 2 ( I )催化的二酮和β-酮酯与烯丙醇和苄醇的单烯丙基化和单烷基化。该方法不需要任何添加剂并提供区域选择性产物。通过原位1 H NMR 光谱以及对照实验进行了机理研究。已表明反应通过形成 η 3 -烯丙基络合物或烯丙基醚中间体进行。烷基化仅通过醚中间体发生。所得烯丙基化和烷基化产物已用于合成十一种新的三取代吡唑和一种吡唑啉酮。
Graphene oxide catalyzed ketone α-alkylation with alkenes: enhancement of graphene oxide activity by hydrogen bonding
Directα-alkylation of carbonylcompounds represents a fundamental bond forming transformation in organic synthesis. We report the first ketone-alkylation using olefins and alcohols as simple alkylating agents catalyzed by graphene oxide. Extensive studies of the graphene surface suggest a pathway involving dual activation of both coupling partners. Notably, we show that polar functional groups have
Perchloric Acid Catalyzed Homogeneous and Heterogeneous Addition of β-Dicarbonyl Compounds to Alcohols and Alkenes and Investigation of the Mechanism
作者:Pei Nian Liu、Li Dang、Qing Wei Wang、Shu Lei Zhao、Fei Xia、Yu Jie Ren、Xue Qing Gong、Jun Qin Chen
DOI:10.1021/jo100517k
日期:2010.8.6
The direct addition of various β-dicarbonylcompounds to a series of secondary alcohols and alkenes has been achieved using 1 mol % perchloric acid (HClO4) as the catalyst. The HClO4-catalyzed reactions could be conveniently conducted in commercial solvent and gave moderate to excellent yields. Moreover, the silica gel-supported HClO4 could also catalyze the heterogeneous addition for a series of substrates
AbstractSulfamic acid stabilized on the surface of silica by the n-propyl organic group linker which is named silica-bonded N-propylsulfamic acid was applied as an efficient heterogeneous catalyst with good recyclability and reusability for direct benzylation of 1,3-dicarbonyl compoundsusingsecondary aromatic alcohols or styrenes as alkylating agents in high yields and short reaction times. All the