Friedel-Crafts acetylation of indole, 5-methoxyindole and 5-chloroindole using copper triflate under microwave irradiation

Abstract

Friedel-Crafts acetylation is an important reaction in organic synthesis processes. Acetylation of indole derivatives with acetic anhydride as acylating reagent using Cu(OTf)2 as a catalyst has been investigated under microwave irradiation. Different from traditional Lewis acidic catalyst, Cu(OTf)2 was found to be an efficient catalyst for Friedel-Crafts acetylation of indoles under mild conditions. Moreover, Cu(OTf)2 was safe-to-handle, recovered and reused several times without significant loss of catalytic activity.