Fluorous Biphase Catalytic Friedel-Crafts Acylation: Ytterbium Tris(Perfluoroalkanesulfonyl)methide Catalysts - Barrett, Anthony G M; Braddock, D Christopher; Catterick, David; Chadwick, David; Henschke, Julian P; McKinnell, R Murray (Synlett, 2000)