Mechanistic Insight into the Regioselective Palladation of Indole Derivatives: Tetranuclear Indolyl Palladacycles with High C2–Pd or C3–Pd Bond Selectivity

This research provides a straightforward understanding of the regioselective palladation of indole derivatives by capturing both C2–Pd and C3–Pd intermediates of N -phenylindole and N -methylindole. Those tetranuclear indolyl palladacycles suggest that the regioselectivity of palladation depends on the N-substituted protective groups of indoles as well as the acidity of the reaction medium.