Discovery of a Robust and Efficient Homogeneous Silver(I) Catalyst for the Cycloaddition of Azides onto Terminal Alkynes

A highly efficient, chemically stable, and well-defined homogeneous silver(I) catalyst is reported for the cycloaddition of azides onto terminal alkynes (Ag-AAC reaction). The Ag-AAC reaction occurs at room temperature or with heating to deliver exclusively the corresponding 1,4-triazole. A pronounced ligand effect was discovered through systematic modification to the ligand structure resulting in the discovery of a chemically stable active catalyst for this reaction.