Acceleration of the Baylis–Hillman Reaction in the Presence of Ionic Liquids

Abstract
The Baylis–Hillman reaction is accelerated in the presence of ionic liquids. Of various 1‐butyl‐3‐methylimidazolium (bmim)‐based ionic liquids tested, [bmim][PF6] has been found to result in the highest rate increase. In the company of Lewis acid and H‐bond‐donor additives, the reaction rates further improve, albeit only modestly. A preparatively useful Baylis–Hillman procedure prescribes the use of [bmim][PF6] with La(OTf)3 and 2,2′2″‐nitrilotris[ethanol], in which the net effect of the ionic liquid is to bring about a more than twofold rate increase over the otherwise same reaction in MeCN.