DMAP-catalyzed decarboxylative [3+2] cycloadditions: A strategy for diastereoselective synthesis of trifluoromethylated chromanone-fused pyrrolidinyl spirooxindoles. Issue 49 (4th December 2020)

• Record Type: Journal Article
• Authors: Liu, Xiong-Wei; Yue, Jing; Li, Zheng; Wu, Dan; Tian, Min-Yi; Wang, Qi-Lin; Zhou, Ying
• Is Part Of: Tetrahedron. Volume 76:Issue 49(2020)
• Publication Date: 2020-12-04
• Subjects: Diastereoselective [3+2] cycloaddition -- N-2, 2, 2-Trifluoroethylisatin ketimines -- Azomethine ylides -- Carboxylic acid-activation and decarboxylation strategy -- Four contiguous stereogenic centers; Chemistry, Organic -- Periodicals; 547.005
• DOI: 10.1016/j.tet.2020.131678
• Languages: English
• ISSNs: 0040-4020

Abstract

Abstract: Inspired by the chemistry and biology of fluorine-containing molecules, chromanones and pyrrolidinyl spirooxindoles, herein we report a highly diastereoselective [3 + 2] cycloaddition reaction of commercially available 3-carboxylic acid chromones and N-2, 2, 2-trifluoroethylisatin ketimines as azomethine ylide precursors in the presence of the catalyst DMAP, which enabled diversity-oriented synthesis of a series of potentially bioactive scaffolds containing CF3, chromanone and pyrrolidinyl spirooxindole with high efficiency (up to 87% yield and 15:1 diastereomeric ratio). The high efficiency of the cycloaddition relies on the use of a carboxylic acid-activation and then decarboxylation strategy for the less reactive chromones. In particular, this is the first construction of CF3-containing multiple rings-fused pyrrolidinyl spirooxindoles, bearing four contiguous stereogenic centers including one tetra substituted carbon, which might be valuable in medicinal chemistry. Graphical abstract: Image 1 Highlights: The first construction of CF3 -containing multiple rings-fused pyrrolidinyl spirooxindoles. The use of a carboxylic acid-activation and then decarboxylation strategy. Diversity-oriented synthesis of a series of potentially bioactive scaffolds, which might be valuable in medicinal chemistry