Asymmetric IntramolecularHydroamination to ConstructDiverse N–N/C–N Indole Atropisomers via CooperativePd(0) and Chiral Phosphoric Acid Catalysis

Here we present an enantioselective intramolecular hydroamination reaction of <i>o</i>-aminophenyl-1,3-enynes via cooperative catalysis of Pd(0) and chiral phosphoric acid. This approach enables the efficient construction of N–N/C–N axially stereogenic indoles with broad skeletal diversity and high levels of enantioselectivity in a completely atom-economic manner. Mechanistic studies indicate that a protonation of the alkyne moiety via Pd(0) π-Lewis base activation is favored, and the chiral phosphate counteranion plays a crucial role in controlling the atroposelectivity in the ring-closure step.