Regioselective Halogenation of 2‐Oxindoles and β‐Keto Esters Using Oxone‐Halide with or without Aryl Iodine

Efficient and environmentally benign regioselective halogenation protocols have been achieved through the mediation of oxone‐halide, with or without the assistance of aryl iodine. The key to the success of the regioselectivity process is the controlled generation of the active [X] + or halogen‐substituted hypervalent iodine (III) by manipulating the components of the oxone‐halide‐aryl iodine system.