Atroposelective Synthesis of Axially Chiral Styrenes Connecting an Axially Chiral Naphthyl-indole Moiety Using Chiral Phosphoric Acid Catalysis.

The organocatalytic asymmetric reactions of C2-unsubstituted racemic naphthyl-indoles with orthoalkynylnaphthols were employed to synthesize axially chiral styrenes connected to an axially chiral naphthyl-indole unit. Utilizing chiral phosphoric acid as the catalyst, these axially chiral styrenes were prepared in good yields (up to 96%) and excellent stereoselectivity (up to >99.9% ee, >20:1 dr, and >99:1 E / Z ) in mild conditions. Moreover, further synthetic transformations were achieved with high yields and excellent stereocontrol.