Chiral Broensted Acid Catalyzed Enantioselective Friedel—Crafts Reaction of 4,7‐Dihydroindoles with Trifluoromethyl Ketones.

In the presence of a chiral phosphoric acid, reaction of substrates (I) with aromatic trifluoromethyl ketones (II) and ethyl 4,4,4-trifluoroacetoacetate (V) gives 2-substituted 4,7-dihydroindoles with a trifluoromethylated tertiary alcohol moiety.