New discovery in the traditional Baylis-Hillman reaction of arylaldehydes with methyl vinyl ketone

In the Baylis-Hillman reaction of arylaldehydes with methyl vinyl ketone, w e found that, besides the normal Baylis-Hillman reaction product 1, the dia dduct 2 can also be formed at the same time and the yield of 2 can reach 55 % by increasing the amount of methyl vinyl ketone; but for acrylonitrile an d methyl acrylate, only the normal Baylis-Hillman adduct was obtained; the substituent's effects were also examined and a plausible reaction mechanism was proposed for the formation of 2.