Multisubstituted Indoles by a Dual Gold/Silver-Catalyzed Aminoalkynylation of 2-Alkynylanilines

A straightforward and efficient method for the synthesis of multisubstituted indoles has been developed through a dual gold/silver-catalyzed aminoalkynylation of 2-alkynylanilines using hypervalent iodine(III) reagents under open-air conditions. This approach features the <i>in situ</i> generation of alkynyl Au(III) species, which facilitates the aminoalkynylation of 2-alkynylanilines with excellent functional group tolerance and high yields. Mechanistic studies reveal that the alkynyl gold(III) intermediate plays a crucial role in the reaction pathway. Moreover, the protocol is scalable to gram quantities and offers the potential for further transformation into diverse functionalized compounds.