Copper-catalyzed atroposelective hydroarylation of 1-alkynylindoles

Catalytic enantioselective hydroarylation of alkynes is a concise protocol towards axial, helical, and planar chirality. By using an enantioselective π-acid catalysis strategy, these enantioenriched hydroarylation products could be obtained in a green pathway; however, noble-metal catalysts are unavoidable. Here we report a copper-catalyzed intramolecular atroposelective hydroarylation of 1-alkynylindoles with (hetero)arenes, providing a modular platform for the construction of C─N axially chiral carbazolyl and phenanthryl indoles in excellent yields with good to excellent ee values. Moreover, the constructed C─N axially chiral indoles could be easily diversified to various functional group-containing chiral frameworks, and further applied as a chiral ligand in asymmetric catalysis. Importantly, this reaction represents a rare non-noble metal-catalyzed enantioselective hydroarylation of alkynes by π-acid catalysis.