Recyclable Lewis acid catalysts by tuning supercritical vs liquid carbon dioxide phases: lanthanide catalysts with tris(perfluorooctanesulfonyl)methide and bis(perfluorooctanesulfonyl)amide

Lanthanide tris(perfluorooctanesulfonyl)methide and bis(perfluorooctanesulfonyl)amide catalysts are shown to be continuously employed in supercritical carbon dioxide by changing supercritical vs. liquid carbon dioxide phases. The lanthanide complexes are thus extremely efficient Lewis acid catalysts even in supercritical carbon dioxide phase by virtue of the highly electron-withdrawing and solubilizing effect of tris(perfluorooctanesulfonyl)methide and bis(perfluorooctanesulfonyl)amide without any hydrocarbon spacer. (C) 2002 Elsevier Science Ltd. All rights reserved.