Synthesis of (<i>E</i>)-1,2-Divinyl-1,2-diethynylethene (DVDEE) via the Palladium-Catalyzed Reaction of Conjugated Diynes. A New Building Block for Molecular Scaffolding

Conjugated diynes undergo dimerization in the presence of acetic acid and catalytic amounts of Pd(PPh<sub>3</sub>)<sub>4</sub>. The unprecedented reaction gives a novel chromophore containing the (<i>E</i>)-1,2-divinyl-1.2-diethynylethene (DVDEE) module, which is a potentially viable building block for acetylenic scaffolding.