Chiral Bronsted Acid-Catalyzed Asymmetric Friedel−Crafts Alkylation of Pyrroles with Nitroolefins

A highly efficient Friedel-Crafts reaction of pyrroles with nitroolefins by a chiral phosphoric acid was realized. With 5 mol % of catalyst, reactions conducted at rt afforded the 2-substituted or 2,5-disubstituted pyrroles in up to 94% ee for a wide range of substrates.