Used as a catalyst in organic synthesis, particularly in alkylation and acylation reactions. Commonly employed in the production of dyes, pharmaceuticals, and fragrances. Facilitates polymerization of certain unsaturated compounds and is effective in promoting ring-opening reactions of epoxides and cyclic ethers. Also utilized in analytical chemistry for detecting and quantifying compounds containing active hydrogens. Its Lewis acid properties make it valuable in promoting various electrophilic reactions.