Lanthanide trifluoromethanesulfonates as reusable catalysts: catalytic Friedel-Crafts acylation

The Friedel-Crafts acylation of substituted benzenes proceeds smoothly by using a catalytic amount of a lanthanide trifluoromethanesulfonate [Ln(OTf)3], which is easily recovered from the reaction mixture and reused without a decrease in catalytic activity.