Dysprosium, symbol Dy and atomic number 66, is primarily utilized in the refining industry as a component of catalytic compounds. Notably, dysprosium compounds like DyCl3 and Dy(OTf)3 maintain their catalytic effectiveness in the presence of Lewis basic nitrogen groups, enabling them to catalyze reactions involving substances with N or O functional groups. Furthermore, these compounds are effective catalysts in protic or ionic liquids. DyCl3 and Dy(OTf)3 are also well-suited for green chemistry due to their relatively easy recyclability.