Enantioselective synthesis of 3-arylindole atropisomers via organocatalytic indolization of iminoquinones

Abstract

The direct enantioselective construction of axially chiral 3-arylindole frameworks via nucleophilic addition of 2-substituted indoles to iminoquinones has been achieved with high efficiencies under mild chiral phosphoric acid (CPA) catalytic conditions. The utility of this method was demonstrated in successful scale-up syntheses without compromising the product yields and enantioselectivities. The oxidation of products yields axially chiral heteroaryl-p-quinone monoimine, which could be subjected to structural diversification via addition of nucleophiles.