A Free-Radical Cascade Trifluoromethylation/Cyclization of N-Arylmethacrylamides and Enynes with Sodium Trifluoromethanesulfinate and Iodine Pentoxide

An I2O5-promoted free-radical cascade trifluoromethylation/cyclization of a broad range of N-arylmethacrylamides and enynes with sodium trifluoromethanesulfinate in aqueous medium has been achieved. This strategy allows highly selective access to a variety of CF3-containing oxindoles and pyrrolidines. Electron spin resonance (ESR) studies indicate that atom-transfer processes are involved in this system.