An External-Catalyst-Free Trifluoro­methylation/Cyclization Strategy To Access Trifluoromethylated-Dihydro­isoquinolinones/Indolines with Togni Reagent II

A novel and efficient CF₃ radical-involved external-catalyst-free trifluoromethylation/cyclization methodology to access a group of new trifluoromethylated dihydroisoquinolinones was developed, by reacting different N-allylbenzamides with Togni-II in one pot under mild reaction conditions. Meanwhile, this external-catalyst-free trifluoromethylation/cyclization protocol was also well suitable for being employed to synthesize many valuable trifluoromethylated N-acetylindolines, by reacting N-aryl-N-allylacetamides with Togni-II. In both reactions, the amide groups of reactants themselves acted as the catalysts to promote the generation of the CF₃ radical required for the following radical-cascade trifluoromethylation/cyclization reactions.