Dual Gold/Silver Catalysis: 3-Alkynylpyrroles via a Tandem C(sp ² )–H Alkynylation/N-Alkynylation

A dual gold/silver-catalyzed cascade C(sp2)–H alkynylation/N-alkynylation of enamines with hypervalent iodine(III) reagents for the synthesis of 3-alkynylpyrroles is reported. This cooperative Au/Ag catalytic system enables the one-step construction of multisubstituted pyrrole frameworks under mild conditions. Mechanistic studies allowed the capture of the initially formed Au(I) species and support a pathway involving an alkynyl Au(III) intermediate together with a silver-assisted C–H activation process. The cascade sequence efficiently forges C–C and C–N bonds, providing 3-alkynylpyrroles in good yields with broad functional group tolerance. Gram-scale synthesis and further derivatization of the products highlight the practicality and synthetic utility of this transformation.