Ytterbium(III) Trifluoromethanesulfonate Catalysed Friedel–Crafts Acylation of Substituted Thiophenes

Ytterbium(III) trifluoromethanesulfonate [Yb(OTf) 3 ] has been used to catalyse Friedel–Crafts acylation of substituted thiophenes in different solvents to produce several intermediates of pharmaceuticals and pesticides with good yields. The amount of catalysis was discussed and Yb(OTf) 3 could be reused without loss of activity.