Ligand-Shell-Enabled Silver Catalysis on Gold Nanoclusters for the Straightforward Synthesis of β-Naphthol Ethers from Alkynes

Abstract The use of gold chlorides alongside cationic silver is widely regarded as a standard approach for generating cationic gold in π-acid-mediated organic reactions; however, in many cases, presynthesized cationic gold alone is insufficient to catalyze such transformations. Herein, we present a rare example of employing chloride-containing gold nanoclusters to form Au–Cl–Ag reactive intermediates within protective ligand shells, enabling the isomerization/cyclization of alkynes to directly construct naphthalene rings. Notably, this tandem reaction occurs at the silver active site and is initiated by an unusual alkyne-to-allene isomerization. Beyond providing an efficient synthetic route to multisubstituted β-naphthol derivatives, these findings shed new light on the fundamental mechanisms underlying homogeneous gold/silver dual catalysis and open fresh avenues for designing catalytic applications with metal nanoclusters.