Metal-triflate-catalyzed intramolecular Friedel–Crafts acylation of 3-arylpropanoic and 4-arylbutanoic acids in triflate-anion ionic liquids under monomodal microwave irradiation is reported. The environmentally benign synthetic procedure allows the formation of cyclic ketones in good yields within a short reaction time. The catalytic metal triflate in triflate-anion ionic liquids can be easily recovered and reused several times without significant loss of the catalytic performance.
- metal triflate
- Ionic liquid