Friedel–Crafts alkylation of indoles with nitroalkenes catalyzed by Cu(II)–imine complex

A series of new ligands L1–L7 were readily prepared in one step. Friedel–Crafts alkylation of indoles with nitroalkenes catalyzed by a novel Cu(II)–L complex has been developed. The remarkable advantages of this reaction are mild reaction conditions, simple workup procedure, high yields of products and the use of ethanol as a green solvent.