A Strategy for Synthesizing Axially Chiral Naphthyl-Indoles: Catalytic Asymmetric Addition Reactions of Racemic Substrates

A new strategy for enantioselective synthesis of axially chiral naphthyl-indoles has been established through catalytic asymmetric addition reactions of racemic naphthyl-indoles with bulky electrophiles. Under chiral phosphoric acid catalysis, azodicarboxylates and o-hydroxybenzyl alcohols served as bulky but reactive electrophiles that were attacked by C2-unsubstituted naphthyl-indoles, which underwent a dynamic kinetic resolution to afford two series of axially chiral naphthyl-indoles in good yields (up to 98 %) and high enantioselectivities (up to 98:2 er).