Used as a Lewis acid catalyst in organic synthesis, particularly in esterification, glycosylation, and Friedel-Crafts reactions. It is effective in promoting carbon-carbon and carbon-heteroatom bond formations under mild conditions. Due to its moisture tolerance and stability, it is suitable for reactions in aqueous or mixed solvent systems. Also employed in the activation of carbonyl compounds and in the synthesis of pharmaceuticals and fine chemicals where strong acidity without nucleophilic interference is required.