Baylis–Hillman reaction promoted by a recyclable protic-ionic-liquid solvent–catalyst system: DABCO–AcOH–H2O

A recyclable protic-ionic-liquid solvent–catalyst system, DABCO–AcOH–H2O, has been developed and used in the Baylis–Hillman reaction of aromatic aldehydes, aliphatic aldehydes, and cinnamaldehydes with acrylates and acrylonitrile, showing comparable performance to free DABCO in traditional solvents. The DABCO–AcOH–H2O solvent–catalyst system could be reused for at least five times without significant loss of activity.