Used as a powerful catalyst in organic synthesis, particularly in reactions involving the activation of carbon-carbon multiple bonds. It promotes electrophilic cyclization, hydration, and hydroamination of alkynes and alkenes. Commonly employed in the synthesis of heterocyclic compounds, including furans, pyrroles, and indoles, due to its strong Lewis acidity. Also utilized in Friedel-Crafts acylation and alkylation reactions where high reactivity and selectivity are required. Its triflate anion is non-nucleophilic, which enhances the cation's electrophilic character, making it effective under mild reaction conditions. Often preferred in transformations where other metal catalysts fail to provide desired yields or regioselectivity. Due to the toxicity of mercury-containing compounds, it should be handled with care and is typically avoided in large-scale industrial processes.