An Efficient Construction of CF
<sub>3</sub>
‐Substituted Spirooxindole‐Fused Benzo[a]quinolizidines by a Three‐Component Cyclization
作者:Yijie Hu、Liufeiyang Ye、Jie Chen、Hui Zhang、Hongmei Deng、Jin‐Hong Lin、Weiguo Cao
DOI:10.1002/ejoc.202100809
日期:2021.8.13
Since benzo[a]quinolizidine is a key subunit in numerous natural products and pharmaceuticals, its synthesis has received attention. Described herein is a convenient three-component cyclization for the efficient construction of CF 3 -substituted spirooxindole-fused benzo[a]quinolizidines by using CF3 -propiolate as a building block. This attractive protocol may find great synthetic utility as CF 3
Double Thiol-Chiral Brønsted Base Catalysis: Asymmetric Cross Rauhut–Currier Reaction and Sequential [4 + 2] Annulation for Assembly of Different Activated Olefins
the intermolecular cross Rauhut-Currierreaction of 2-cyclopentenone and isatin-based alkylidene malononitriles. The resulting chiral adducts were sequentially assembled with diverse electron-deficient olefins to furnish highly enantioenriched cyclohexane derivatives (up to 96:4 er, >19:1 dr). A similar catalytic system of 2-mercaptobenzoic acid and quinine was further developed for the reaction of
A phosphine-catalyzed [3 + 2] annulation of MBH phosphonates with isatylidene malononitriles is developed. The described method, which is different from most traditional phosphorus ylide intermediate reaction modes of MBH carbonates with isatylidene malononitriles, represents a novel approach to highly regioselective and diastereoselective synthesis of spirocyclopenteneoxindole phosphonates.
Multicomponent Synthesis of Spiro-dihydropyridine Oxindoles <i>via</i> Cascade Spiro-cyclization of Knoevenagel/Aza-Michael Adducts
作者:Basavaraja D、Athira C S、Siddalingeshwar V. D、Ashitha K. T、Sasidhar B. Somappa
DOI:10.1021/acs.joc.2c01063
日期:2022.11.4
An efficient, straightforward, and one-pot synthesis of biologically relevant spiro-dihydropyridine oxindoles was described via readily available isatin, malononitrile, allenoate, and amines. The metal/organocatalyst-free, Et3N-mediated reaction proceeds via cascade spiro-cyclization of in situ generated Knoevenagel/aza-Michael adducts. The reaction has great flexibility over electron-rich and electron-poor
通过容易获得的靛红、丙二腈、联烯酸和胺,描述了一种高效、直接和一锅法合成生物学相关的螺-二氢吡啶羟吲哚。无金属/有机催化剂、Et 3 N 介导的反应通过原位生成的 Knoevenagel/aza-Michael 加合物的级联螺旋环化进行。该反应对富电子和缺电子取代基具有很大的灵活性,能够以良好到极好的收率提供所需的产物。我们还展示了选定的螺二氢吡啶,用于后期多样化,成为具有制药相关性的新型螺二氢吡啶杂化物。
Isocyanide-Based Multicomponent [2+2+1]-Cycloaddition Strategy to Construct Functionalized Spirocyclic Oxindoles
作者:Jian Li、Xueshun Jia、Haohua Jie、Chunju Li
DOI:10.1055/s-0032-1317030
日期:——
Isocyanide-based three-component [2+2+1]-cycloaddition reactions from isocyanides, activated alkynes, and isatylidene malononitriles were investigated to provide a new access to spirocyclic oxindole with five-membered carbon rings. The displacement of isatylidene malononitrile with oxindolylideneacetate essentially results in opposite regioselectivity, which adds to its attractiveness.