An Oxidant-Free Strategy for Indole Synthesis via Intramolecular C–C Bond Construction under Visible Light Irradiation: Cross-Coupling Hydrogen Evolution Reaction
We describe here an oxidant-free strategy to synthesize indoles, i.e., under visible-light irradiation (λ = 450 nm), catalytic amounts of an iridium(III) photosensitizer and cobaloxime catalyst transform various N-arylenamines exclusively into indoles. Our methodology affords indoles in good to excellent yields under mild reaction conditions and produces H2 as the only byproduct. Spectroscopic and