Many applications have been considered, but few have been commercialized. ILs are used in the production of gasoline by catalyzing alkylation.
An IL based on tetraalkylphosphonium iodide is a solvent for tributyltin iodide, which functions as a catalyst to rearrange the monoepoxide of butadiene. This process was commercialized as a route to 2,5-dihydrofuran, but later discontinued.