Ligand-Free RuCl3-Catalyzed Alkylation of Methylazaarenes with Alcohols

RuCl3 efficiently catalyzes the alkylation of methylquinolines, methylpyridines, 2-methyl-benzooxazoles, and 2-methyl-quinoxa-lines with alkyl- or aryl-alcohols as alkylating agents. This synthetically useful and atom economical transformationdoes not require additional ligands.The mechanistic study indicated the alkylation reaction underwent a stepwise transfer hydrogenation, aldol condensation, and hydrogenation reaction pathway.