Highly regioselective Friedel-Crafts alkylation of indoles with α,β-unsaturated N-acylbenzotriazoles

The Friedel-Crafts alkylation rather than acylation of indoles was realized with α,β-unsaturated acylbenzotriazoles catalyzed by samarium(III) iodide under reflux in anhydrous THF. The reaction was highly regioselective, and a series of new 3-substituted indole derivatives were obtained in moderate to good yields with the potential to be further transformed into various indole derivatives due to the presence of active acylbenzotriazole moiety.

Graphical abstractThe Friedel-Crafts alkylation rather than acylation of indoles was realized with α,β-unsaturated N-acylbenzotriazoles catalyzed by samarium(III) iodide under reflux in dry THF. The reaction was highly regioselective, and a series of new 3-substituted indole derivatives were obtained and could be further transformed into various indole derivatives due to the presence of active acylbenzotriazole moiety.Download full-size image