Domino allylation and cyclization of ortho-alkynylbenzaldehydes with allyltrimethylsilane catalyzed by Pd(II)–Cu(II) bimetallic systems

The reaction of ortho-alkynylated benzaldehydes with allyltrimethylsilane under the Pd(OAc)2–CuCl2 catalyst system gave the isochromene derivatives together with the chlorinated products . When the reaction was conducted in the presence of half equiv of H2O, the formation of was suppressed and was obtained in good to high yields. When the reaction of was carried out with trimethylsilylcyanide instead of allylsilane, the cyano group-substituted isochromene was obtained in 94% yield.