SO2ClF‐Promoted Chlorooxidation of Tryptamine Derivatives: Synthesis of 3,3‐Disubstituted Oxindoles

Abstract A series of tryptamine derivatives were transformed into their corresponding 3‐chloro‐2‐oxidation products under simple and mild conditions. This protocol is an operationally simple system that utilizes a single reagent SO 2 ClF plays a dual role as both oxidant and chloride source and enables the construction of various 3,3‐disubstituted oxindoles with good functional group tolerance. The transformations of the product highlight its potential synthetic applications.