Atroposelective Construction of Arylindoles by Chiral Phosphoric Acid-Catalyzed Cross-Coupling of Indoles and Quinones

Structurally novel atropisomeric arylindole frameworks have been successfully constructed through chiral phosphoric acid-catalyzed asymmetric cross-coupling of indoles and quinone derivatives in a precise regioselective manner. This approach features high convergence and functional group tolerance to efficiently deliver diverse heteroaryl atropisomers with excellent enantiocontrol. The dominant formation of axial chirality but not central chirality, as the major unmet challenge for this type of reactions, was conquered by the rational and accurate modulation of the electronic and steric effects on both coupling partners. Preliminary investigation demonstrated the practicality of such axially chiral arylindoles as chiral ligands in asymmetric catalysis.