A free-radical cascade trifluoromethylation/cyclization of N-arylmethacrylamides and enynes with sodium trifluoromethanesulfinate and iodine pentoxide.

An I(2)O(5)-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 CF(3)-containing oxindoles and pyrrolidines. Electron spin resonance (ESR) studies indicate that atom-transfer processes are involved in this system.