Palladium-catalyzed coupling reactions between sp and sp4 carbon centers

Catalytic carbon-carbon bond formation is one of the most important reaction for constructing organic molecules. A two-component system containing palladium and copper effectively catalyzes a carbon-carbon coupling between sp2- and sp-carbons to give conjugated ene-vne compounds and aromatic acetylenes. This article reviews recent development of the palladium-catalyzed sp2-sp carbon carbon coupling and its application to the synthesis of functional materials such as bioactive compounds, π-conjungated compounds, and liquid crystals.