Bifunctional Amine‐Squaramide Catalyzed Friedel–Crafts Alkylation Based on ortho‐Quinone Methides in Oil‐Water Phases: Enantioselective Synthesis of Triarylmethanes

An efficient enantioselective Friedel–Crafts alkylation reaction of electron‐rich β‐naphthol with in situ generated ortho‐quinone methides catalyzed by chiral bifunctional amine‐squaramide catalysts has been developed. The chiral triarylmethane derivatives were obtained in good to high yields (up to 97% yield) with high enantioselectivities (up to 97% ee) for most substrates under mild conditions. This study also revealed that the oil‐water biphase could significantly improve the efficiency of this catalytic system.