Environmentally Friendly Protocol for 2,3-Difunctionlization of Indole Derivatives.

Environmentally friendly and highly regioselective C-3 dichlorination and C-2 oxidation of N-substituted indoles have been established using NaCl as a chlorine source and HO as an oxygen source. A series of 3,3-dichloro-2-oxindoles were obtained in moderate to excellent yields. The gram-scale synthesis and derivatization reaction were explored. The possible mechanism for this reaction was elucidated.