Cu(OTf) 2 -catalyzed C3 aza-Friedel-Crafts alkylation of indoles with N , O -acetals.

An efficient approach to access functionalized indole derivatives has been developed through Cu(OTf) 2 -catalyzed C3 aza-Friedel-Crafts alkylation of substituted indoles 5a-5m, N -methyl-pyrrole with linear N , O -acetals 4a-4l. As a result, a series of C3 amide aza-alkylated indole derivatives 6a-6ag and 7 were synthesized in moderate to excellent yields.