Cu–Catalyzed Tandem Oxidation of N ‐Substituted Indolines to Isatins

Abstract The direct transformation of N ‐substituted indoline to isatin derivatives has been developed, this reaction employed cheap Cu catalyst and aqueous tert ‐butyl hydroperoxide as an oxidant. Primary mechanism studies suggested that the indolines was initially oxidized to indoles which further undergo Cu‐catalyzed oxidation to isatins.