Nickel Complexes of Allyl and Vinyldiphenylphosphine

Monodentate phosphine-ligated
nickel compounds, e.g., [Ni(PPh3)4] are relevant as active catalysts
across a broad range of reactions. This report expands upon the coordination
chemistry of this family, offering the reactivity of allyl- and vinyl-substituted
diphenylphosphine (PPh2R) with [Ni(COD)2] (COD
= 1,5-cyclooctadiene). These reactions provide three-coordinate dinickelacycles
that are intermolecularly tethered through adjacent {Ni}-olefin interactions.
The ring conformation of such cycles has been studied in the solid-state
and using theoretical calculations. Here, a difference in reaction
outcome is linked to the presence of an allyl vs vinyl group, where
the former is observed to undergo rearrangement, bringing about challenges
in clean product isolation.