Titanium(IV) Chloride and the Amine-Promoted Baylis−Hillman Reaction

In the Baylis-Hillman reaction, we found that, when the reactions of arylaldehydes with methyl vinyl ketone were carried out at-20 degrees C using a catalytic amount of amine as a Lewis base in the presence of titanium(IV) chloride, the chlorinated compounds 1 could be obtained as the major product in very high yields for various arylaldehydes. In addition, acrylonitrile could undergo the same reaction to give the corresponding chlorinated product in moderate yield.