Metal, iodine and oxidant-free electrosynthesis of substituted indoles from 1-(2-aminophenyl)alcohols

A green and straightforward electrosynthesis of substituted indoles has been developed through dehydration and intramolecular dehydrogenative C–N bond-forming radical cross-coupling from 1-(2-aminophenyl)alcohols under metal, iodine and oxidant-free conditions. This electrochemical indole synthesis strategy has an excellent functional group, water and air tolerance. And, a possible cyclization process was proposed based on the radical-trapping, intermediate verification, cyclic voltammetry, EPR and control experiments.