Rh(II)‐Catalyzed Single‐Carbon‐Atom Skeletal Editing of Pyrazolidinones with Diazoindolinones for the Synthesis of 3‐Spirooxindoles

Abstract The 3‐spirooxindole scaffolds play important roles in medical and biological research of many marketed drugs and natural products. In this study, we report the single‐carbon‐atom skeletal editing of pyrazolidinones by employing a Rh(II)‐catalyzed one‐carbon insertion and [5 + 1] ring expansion strategy with diazoindolinones as the carbene precursors, providing a series of 5“,6”‐dihydro spiro[indoline‐3,2“‐pyrimidine]‐2,4”‐diones. This protocol exhibits a broad functional group tolerance, mild reaction conditions, simple operation, and excellent atom economy. Moreover, diazoindolinones are demonstrated to be able to edit N─N bond and provide N ‐heterocycle 3‐spirooxindole derivatives, which have a dinitrogen substituted quaternary carbon center, broadening their synthetic application prospects.