Silver Catalysis

Because it is less expensive than other expensive transition metals (TM), has great selectivity and stability, and is ecologically friendly, silver is a key catalyst in organic synthesis. These metal-catalyzed cycloaddition processes, which are essential tools in synthetic chemistry, include a subset of silver-catalyzed reactions. Azomethine ylides are nitrogen-based 1,3-dipoles that are shown as the most prevalent resonance form with an iminium ion and a carbon-centered anion adjacent to it. Huisgen's 1,3-dipolar cycloaddition of terminal alkynes with azides often needs high temperatures of up to 100 °C and yields a mixture of 1,4- and 1,5-disubstituted triazole isomers. Metal ions are cross-linked by dicyanamide in a spiral chain to form silver dicyanamide, a polymeric structure. Azolomethine imine was also used to illustrate the silver-catalyzed cycloaddition.