Rh-Catalyzed Annulations of N‑Methoxy­benzamides and Ketenimines: Sterically and Electronically Controlled Synthesis of Isoquinolinones and Isoindolinones

Rhodium-catalyzed C–H activation/annulation reactions of ketenimines with N-methoxy­benzamides are reported. The outcome of reactions is dependent on the structure of ketenimines. The β-alkyl-substituted ketenimines furnish 3-iminoisoquinolin-1­(2H)-ones in a formal [4 + 2] annulation manner, while the β-ester substituted ketenimines afford 3-aminoisoindolin-1-ones in a formal [4 + 1] annulation manner. The synthesized [4 + 2] products undergo an intramolecular Cu-catalyzed C–N coupling to be converted to benzo­[4,5]­imidazo­[1,2-b]­isoquinolin-11-ones, which can be directly prepared from ketenimines and N-methoxy­benzamides by a one-pot Rh-catalyzed annulation/Cu-catalyzed C–N coupling sequence.