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

Abstract

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.