Using 1-thioaurones and 1-azaaurones as electron-deficient oxa-dienes, an organocatalyticasymmetric aromatizing inverse electron-demand [4+2] cycloaddition with γ-deconjugated butenolides and azlactones was developed. A wide range of opticallyactive benzothiophene-fused δ-lactones and indole-fused δ-lactones were obtained with desirable outcomes (up to 94% yield, >99 : 1 dr and 99% ee).
以1-硫代金酮和1-氮杂金酮作为缺电子氧杂二烯,开发了γ-去共轭丁烯内酯和吖内酯的有机催化不对称芳构化逆电子需求[4+2]环加成反应。以理想的结果获得了范围广泛的光学活性苯并噻吩稠合 δ-内酯和吲哚稠合 δ-内酯(高达 94% 的产率,>99:1 dr 和 99% ee)。
Stereo‐ and Regioselective Construction of Spirooxindoles Having Continuous Spiral Rings via Asymmetric [3+2] Cyclization of 3‐Isothiocyanato Oxindoles with Thioaurone Derivatives
作者:Hou‐Ze Gui、Zhe Meng、Zhan‐Shuai Xiao、Ze‐Ren Yang、Yin Wei、Min Shi
DOI:10.1002/ejoc.202001146
日期:2020.11.15
A highly efficient enantioselective [3+2] cyclization of 3‐isothiocyanato oxindoles with thioaurone derivatives was developed for the synthesis of spirooxindoles containing continuous spiral ring structures.
Dinuclear zinc-catalyzed enantioselective formal [3 + 2] cycloaddition of <i>N</i>-2,2,2-trifluoroethylisatin ketimines with low reactivity aurone derivatives
作者:Rui-Li Wang、Shi-Kun Jia、Ya-Jun Guo、Yang Yi、Yuan-Zhao Hua、Hui-Jie Lu、Min-Can Wang
DOI:10.1039/d1ob01599k
日期:——
Highly enantioselective formal [3 + 2] cycloaddition of N-2,2,2-trifluoroethylisatin ketimines with aurone derivatives of low reactivity using chiral dinuclear zinc catalysts has been developed via a Brønsted base and Lewis acid cooperative activation model. These transformations involving a domino Michael/Mannich reaction sequence led to efficient construction of a range of chiral spiro[benzofuran-pyrrolidine]