Erbium(III) Triflate as an Extremely Active Acylation Catalyst

Erbium(III) triflate is a powerful catalyst for the acylation of alcohols and phenols. The reaction works well for a large variety of simple and functionalized substrates by using different kinds of acidic anhydrides {Ac 2 O, (EtCO) 2 O, [(CH 3 ) 3 CO] 2 O, Bz 2 O, and (CF 3 CO) 2 O} without isomerisation of chiral centres. Moreover, the catalyst can be easily recycled and reused without significant loss of activity.