Catalytic asymmetric C-7 Friedel–Crafts reaction of 4-aminoindoles: construction of N-substituted quaternary carbon atoms

Abstract

A novel and enantioselective C-7 Friedel–Crafts alkylation reaction of 4-amino indoles with α-aryl enamides catalyzed by chiral H₈-BINOL-derived phosphoric acid has been developed. The established method gives access to a wide variety of chiral amine derivatives bearing a quaternary carbon stereocenter (23 examples) in good-to-high yields and enantioselectivities (up to 96% yield, >99% ee) under mild reaction conditions.