Structure of the Complex Ni(C8H12)(L) and Its Reactivity toward Organometallic Reagents

Oxidative dimerization of 1,3-dienes on Ni(0) is one of the most fundamental elemental processes; however, the molecular structure of the key intermediate, Ni­(C8H12)­(L), arising from 1,3-butadiene had not yet been defined. We first identified the detailed structure of Ni­(C8H12)­(L) (L = PCy3) by X-ray crystallography and revealed that the C8 moiety was bound to Ni in an η1:η3 fashion with a cis-C–C double bond of the σ-allyl group located in the same face with the central carbon of the π-allyl group. In addition, the formation of the corresponding anionic complexes upon treatment with organometallic reagents was confirmed by NMR.