Conjugated enyne compounds have received much attention because of their wide applications in organic synthesis. For example, they can be reduced to saturated hydrocarbons, oxidized to ketones, cyclized and so on. Conjugated borylenynes have a boronate group in addition, so they are more useful, because the C－B bond can be transformed to a variety of functional groups such as C－O, C－N and C－C bonds.
In our current work, we investigated copper-catalyzed monoborylation of diyne compounds, which generated conjugated borylenyne compounds with high regio- and stereoselectivities. The catalytic efficiency is enhanced using monodentate phosphine ligands, and a range of diynes were borylated in good yield.