 Another important application of samarium and its compounds is as catalyst and chemical reagent . Samarium catalysts assist decomposition of plastics , dechlorination of pollutants such as polychlorinated biphenyls ( PCBs ) , as well as the dehydration and dehydrogenation of ethanol . Samarium ( III ) triflate ( Sm ( OTf ) 3 , that is Sm ( CF3SO3 ) 3 ) , is one of the most efficient Lewis acid catalysts for a halogen @-@ promoted Friedel – Crafts reaction with alkenes . Samarium ( II ) iodide is a very common reducing and coupling agent in organic synthesis , for example in the desulfonylation reactions ; annulation ; Danishefsky , Kuwajima , Mukaiyama and Holton Taxol total syntheses ; strychnine total synthesis ; Barbier reaction and other reductions with samarium ( II ) iodide . 
