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852616 
Journal Article 
Friedel-Crafts Reactions Catalyzed by Rare Earth Metal Teifluoromethanesulfonates 
Kawada, A; Mitamura, S; Matsuo, Ji; Tsuchiya, T; Kobayashi, S 
2000 
Yes 
Bulletin of the Chemical Society of Japan
ISSN: 0009-2673
EISSN: 1348-0634 
CHEMICAL SOC JAPAN 
TOKYO 
73 
10 
2325-2333 
English 
WOS:000165610400021 
Rare earth metal trifluoromethanesulfonates (rare earth metal triflates, RE(OTf)(3)) were found to be efficient catalysts for Friedel-Crafts acylation and alkylation. In the presence of a catalytic amount of RE(OTf)(3), acylation of aromatic compounds having electron-donating substituents such as anisole, thioanisole, and mesitylene with acid anhydrides proceeded smoothly to afford the corresponding aromatic ketones in high yields. Although RE(OTf)(3) alone is not effective for acylation of less reactive aromatics such as toluene, the combination of RE(OTf)(3) and lithium perchlorate (LiClO4) enhanced the catalytic activity dramatically. Friedel-Crafts acylation reactions using rare earth metal perfluoroalkanesulfonates were also successfully performed in supercritical carbon dioxide (scCO(2)). Moreover, in the presence of a catalytic amount of RE(OTf)(3), aromatic compounds reacted with benzyl chloride smoothly to afford the corresponding alkylation products in high yields. In these reactions, RE(OTf)(3) could be easily recovered after the reactions were completed and could be reused without loss of activity.