Synthesis of 3-Fluoroindoles via Photoredox Catalysis

A method for the synthesis of 3-fluoroindoles from N-arylamines substituted with the CF2I group is described. The reaction is mediated by a ruthenium photocatalyst in the presence of a substoichiometric amount of triphenylphosphine upon irradiation with blue light. The starting N-arylamines are readily obtained by nucleophilic iododifluoromethylation of iminium ions.