Synthesis of 3-Aryl Oxindoles having Trifluoromethylated Quaternary Stereocenters via Catalyst Free Arylation

Herein we report the synthesis of 3-aryl oxindoles having trifluoromethylated quaternary stereocenters through the catalyst free arylation of 3-trifluoromethyl,3-tosyloxy oxindoles with anisoles. The transformation proceeds via electrophilic 3-(trifluoromethyl)-2H-indolium intermediate (Michael acceptor), which is generated by the heterolytic cleavage of C-OTs bond under metal-free conditions in PEG-400. The developed strategy offers broad substrate scope, extending to N,N-dimethyl-anilines, and thio-anisole to afford the range of 3-trifluoromethyl,3-aryl oxindoles in 62-91% yields.