Friedel–Crafts reaction of indoles with N-silyl-N,O-acetal catalyzed by Cu(OTf)2 in the presence of TMSCl leading to indolyl primary amines

A catalytic amount of copper(II) trifluoromethanesulfonate (Cu(OTf)2) in the presence of trimethylchlorosilane (TMSCl) effectively promoted the aminomethylation of indoles bearing a variety of functional groups with a N-silyl-N,O-acetal in good to excellent yields.