Solvent-free, ruthenium-catalyzed, regioselective ring-opening of epoxides, an efficient route to various 3-alkylated indoles

Ruthenium-catalyzed regioselective ring-opening of aliphatic and aryl epoxides under solvent-free conditions is reported. It was found that RuCl3·nH2O catalyzes the Friedel–Crafts alkylation of indoles, providing 3-alkylated derivatives in good yields under mild reaction conditions.