Recyclable hafnium(IV) bis(perfluorooctanesulfonyl)amide complex for catalytic Friedel-Crafts acylation and Prins reaction in fluorous biphase system

In fluorous biphase system, hafnium(IV) bis(perfluorooctanesulfonyl)amide complex (HfN(SO₂C₈F₁₇)₂]₄) was found to be a highly reactive and recyclable Lewis acid catalyst for Friedel-Crafts acylation and Prins reaction at significantly low catalyst loadings (≤1 mol%). In these reactions, HfN(SO₂C₈F₁₇)₂]₄ is selectively soluble in the lower fluorous phase and can be recovered simply by phase separation. Furthermore, the catalyst can be reused without decrease of activity.