Trapping of Transient Zwitterionic Intermediates by <i>N</i>-Acylpyridinium Salts: A Palladium-Catalyzed Diastereoselective Three-Component Reaction
作者:Dan Zhang、Zhenghui Kang、Wenhao Hu
DOI:10.1021/acs.joc.7b00560
日期:2017.6.2
We developed a palladium-catalyzed diastereoselective three-component reaction of N-aryl diazoamides, pyridine, and chloroformate, which proceeded through trapping of transient zwitterionic intermediates by in situ formed N-acylpyridinium salts in a regioselective 1,4-addition fashion. This reaction can rapidly provide a library of biologically relevant 4-(2-oxoindolin-3-yl)-1,4-dihydropyridine derivatives
我们开发了N-芳基重氮酰胺,吡啶和氯甲酸酯的钯催化非对映选择性三组分反应,该反应通过以区域选择性1,4-加成方式原位形成的N-酰基吡啶鎓盐捕获瞬态两性离子中间体而进行。该反应可快速提供具有生物学相关性的4-(2-氧代吲哚-3-基)-1,4-二氢吡啶衍生物库,产率高(高达98%),且具有中等至优异的非对映选择性(高达> 95:5 dr )在温和的反应条件下。
Pd(II)/β-ICD-Cocatalyzed Asymmetric Route to Oxindole Scaffold via Cascade Reaction of Diazoacetamides and MBH-Carbonates
作者:Yang Yang、Chaoqun Ma、Nilesh J. Thumar、Wenhao Hu
DOI:10.1021/acs.joc.6b01703
日期:2016.9.16
report an efficient method for asymmetricsynthesis of chiral oxindoles. Allyl palladium(II) chloride dimer (APC)-catalyzed, in combination with β-isocupreidine (β-ICD)-cocatalyzed, reaction of diazoacetamide with Morita–Baylis–Hillman (MBH) carbonates proves to be a facile protocol to access multifunctional oxindoles bearing a C-3 quaternary stereo center. This tandem reaction tolerates a wide variety of
Construction of 4-hydroxycoumarin derivatives with adjacent quaternary and tertiary stereocenters <i>via</i> ternary catalysis
作者:Mengchu Zhang、Tianyuan Zhang、Sifan Yu、Huang Qiu、Abdulla Yusuf、Xinfang Xu、Yu Qian、Wenhao Hu
DOI:10.1039/d3sc03452f
日期:——
4-Hydroxycoumarinderivatives represent one of the most important scaffolds in biologically active substances, pharmaceuticals and functional materials. Herein, we describe an efficient Pd/amine/Brønsted acid ternary-catalytic multicomponent reaction for the rapid construction of substituted 4-hydroxycoumarinderivatives with adjacent quaternary and tertiary stereocenters via convergent assembly of