Rh(II)-Catalyzed Chemoselective Synthesis of 3-Substituted Oxindoles by C(sp2)−H and C(sp2)−N Functionalization of β-Enaminoesters

A novel chemoselective synthesis of 3‐substituted oxindoles and 3‐substituted 3‐aminooxindoles starting from various 3‐diazoindolin‐2‐ones and β‐enaminoesters was developed through rhodium(II)‐catalyzed C(sp2)−H and C(sp2)−N functionalization. This protocol provides a rapid synthetic route to a diverse range of 3‐substituted oxindoles and 3‐substituted 3‐aminooxindoles with good yields. The chemoselectivity for the formation of the 3‐substituted oxindoles and 3‐substituted 3‐aminooxindoles was controlled by the substituents on the nitrogen atom of the β‐enaminoesters. Controlled chemoselectivity: Chemoselective synthesis of diverse 3‐substituted oxindoles has been developed through a Rh(II)‐catalyzed reaction of 3‐diazoindolin‐2‐ones by C(sp2)−H and C(sp2)−N functionalization of β‐enaminoesters. The chemoselectivity was controlled by the N‐substituents on the β‐enaminoesters as a result of their electronic and steric effects. The trans geometry of the β‐enaminoesters is retained in the C−N/H insertion products.