Highly Enantioselective Friedel–Crafts Reactions of Indoles with Isatins Catalyzed by Chiral Imidodiphosphoric Acids

A highly enantioselective Friedel-Crafts arylation of indoles with isatins catalyzed by H8-BINOL imidodiphosphoric acids is reported here. This reaction could undergo smoothly under mild conditions and afford a range of 3-hydroxy-3-indolyloxindoles with high yields (up to 92%) and excellent enantioselectivities (up to 99% ee). It should be mentioned that this highly enantioselective arylation of indoles with isatins has been firstly catalyzed by the Bronsted acid to this day.