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-methox-ybenzamides are reported. The outcome of reactions is dependent on the structure of ketenimines. The beta-alkyl-substituted ketenimines furnish 3-iminoisoquinolin-1(2H)-ones in a formal [4 + 2] annulation manner, while the beta-ester substituted ketenimines afford 3-aminoisoindolin-l-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 coupling sequence. by a one-pot Rh-catalyzed annulation/Cia-catalyzed C-N coupling sequence.