Rhodium(iii)-catalyzed synthesis of spirocyclic isoindole N-oxides and isobenzofuranones via C-H activation and spiroannulation.

Rhodium(iii)-catalyzed mild and oxidative [4+1] spiroannulation has been realized via C-H activation of oximes and benzoic acids with 1-diazonaphthelen-2(1H)-ones as coupling reagents. This transformation integrates C-H activation and dearomatization and provides a direct approach to spirocyclic isoindole N-oxides and isobenzofuranones with functional group tolerance.