Neat benzoin condensation in recyclable room-temperature ionic liquids under ultrasonic activation

A new method for the benzoin condensation is proposed in imidazolium-based ionic liquids as solvents/catalysts. The use of a 30 kHz ultrasonic irradiation as activation method provides a quantitative yield of benzoin in 1-octyl-3-methyl-imidazolium bromide without degrading the ionic medium which can be-reused at least three times with no loss of activity.