Ligand-Free Iron-Catalyzed Carbon(sp2)-Carbon(sp2) Cross-Coupling of Alkenyllithium with Vinyl Halides.

An efficient ligand-free iron-catalyzed cross-coupling reaction involving alkenyllithium and vinyl iodides was developed to form diene species in moderate to good yields. This new iron-catalyzed cross-coupling reaction provides a mild, inexpensive, and environmentally friendly avenue toward synthesis of diversified diene derivatives.