Electrochemical Dual Trifluoromethylation/Cyclization of 2-Aryl-N-Acryloyl Indoles Enabling Assembly ofIndole[2,1-a]isoquinolines

An electrochemical cascade radical cyclization of 2-aryl-N-acryloyl indoles with sodium trifluoromethanesulfinate as a coupling partner has been explored, which afforded the unexpected bis-trifluoromethylated indole[2,1-a]isoquinolines as products. Experimental results and DFT calculations disclose that this reaction involves trifluoromethylation-triggered cyclization and the second trifluoromethylation as the key steps. This strategy does not need any transition-metal catalysts or oxidants with a readily available trifluoromethylating reagent enabling facile synthesis of bis-trifluoromethylated indole-fused tricycles.