Construction of Axially Chiral Styrenes Linking an Indole Moiety by Chiral Phosphoric Acid

Herein we report a chiral phosphoric acid-catalyzed intermolecular C2 Friedel-Crafts alkylation reaction between ortho-alkynylnaphthols and various 3-substituted indoles, affording axially chiral alkenes with up to 93% yields (E/Z > 20:1) and up to 98% ee under mild reaction condition. Other substituted indole derivatives could be also tolerated in this system, giving the corresponding axially chiral alkenes with high yields and in excellent enantioselectivity.

Automated summary

In this paper, a chiral phosphoric acid-catalyzed intermolecular C2 Friedel-Crafts alkylation reaction has been reported, which can afford axially chiral alkenes with high yields and excellent enantioselectivity by reacting ortho-alkynylnaphthols with various 3-substituted indoles under mild conditions.