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-