Intermolecular vinylsilylation of the alkynes 1b-c, having an alkoxy group
at the homopropargylic position, with the vinylsilane 2 proceeded in the pr
esence of AlBr3 to give the corresponding dienylsilanes 3b-c in moderate to
good yields. In contrast, no product was obtained in the reaction of 1-oct
yne. The AlBr3 mediated vinylsilylation of the phenylacetylene 9c, bearing
methoxy group at the ortho position, also proceeded in good yield.