Highly diastereoselective synthesis of spiro[cyclopropane-1,3′-indolin]-2′-ones via catalyst-free cyclopropanation using ethyl diazoacetate
摘要:
Substituted 3-methyleneindolin-2-ones were efficiently cyclopropanated with ethyl diazoacetate to yield spiro[cyclopropane-1,3'-indolin]-2'-ones in a catalyst-free and highly diastereoselective reaction in a mixture of ethanol acetonitrile (1:1 v/v) as solvent. (C) 2014 Elsevier Ltd. All rights reserved.
A highly regio- and stereoselective [3 + 2] cycloadditionreaction for constructing novel 3,3′-cyclopentenyldispirooxindoles incorporating two adjacent quaternary spirostereocenters is reported. Under the mild conditions, the asymmetric annulation of isatin-derived MBH carbonates with 3-methyleneoxindoles involving a chiral tertiary amine catalyst provides the corresponding dispirooxindole frameworks
Brønsted Base and Lewis Acid Cooperatively Catalyzed Asymmetric <i>exo</i>′-Selective [3 + 2] Cycloaddition of Trifluoromethylated Azomethine Ylides and Methyleneindolinones
作者:Yang Yi、Yuan-Zhao Hua、Hui-Jie Lu、Lan-Tao Liu、Min-Can Wang
DOI:10.1021/acs.orglett.0c00283
日期:2020.4.3
3-dipolar cycloaddition is reported through chiral dinuclear zinc catalysts. An asymmetric exo′-selective [3 + 2] cycloaddition of CF3-containing N-unprotected isatin-derived azomethineylides is realized. In the presence of 10 mol % of catalyst, azomethineylides react efficiently with methyleneindolinones, giving a series of trifluoromethyl-substituted 2,3-pyrrolidinyl dispirooxindoles with highly enantio-