ACHIRAL AND CHIRAL LANTHANIDE(III) SALTS OF SUPERACIDS AS NOVEL LEWIS-ACID CATALYSTS IN ORGANIC-SYNTHESIS

Lanthanide(lll) salts of superacids, such as trifluoromethanesulfonic acid, perfluorooctanesulfonic acid and perchloric acid, can be readily prepared as stable solids (except perchlorate). Some of these work as novel water-tolerant Lewis acids to catalyze various types of organic reactions. The combined use of a lanthanide(lll) salt of superacid wi th an optically active ligand provides a special environment for an as ymmetric Diels-Alder reaction. New chiral nonracemic lanthanide(lll) s alts of (R)-(-)-1,1'-binaphthyl-2,2'-diylphosphoric acid were synthesi zed and used for a hetero-Diels-Alder reaction.