Ruthenium(II)‐Catalyzed Annulative CH Activation of α‐Carbonyl Phosphoniums with CF₃‐Imidoyl Sulfoxonium Ylides: Synthesis of 3‐Trifluoromethyl‐Isoquinolones

Herein, ruthenium(II)‐catalyzed CH activation/annulation of α‐carbonyl phosphoniums with CF 3 ‐imidoyl sulfoxonium ylides is carried out to generate a series of 3‐trifluoromethyl‐isoquinolones in 44–98% yields. A plausible mechanism involving a cascade CH activation of arenes, formation of ruthenium(II) carbenoid, migratory insertion of the Ru−aryl bond, and intramolecular aza‐cyclization is proposed. In addition, the reaction procedure features simple synthesis, wide substrate scope, and excellent functional group compatibility. Furthermore, the application potential of the developed protocol is demonstrated through successful scale‐up experiments and subsequent transformations.