Abstract A series of Pt(II) complexes of the type ([(L∼L)Pt(L′)(Ph)][BAr′<inf>4</inf>] (L∼L = 1,2-bis(dimethylphosphino)ethane, 1,2-bis(diphenylphosphino)ethane, (N-pyrrolyl)<inf>2</inf>P(CH<inf>2</inf>)<inf>2</inf>P(N-pyrrolyl)<inf>2</inf>, 1,3-bis(diphenylphosphino)propane, 1,1′-bis(diphenylphosphino)ferrocene, (bis-(diphenylphosphino)methyl)methylamine, 8-(diisopropylphosphino)quinoline, 1,1′-methylene-3,3′-di-tert-butylimidazol-2,2′-diylidine); L′ = THF or NCMe) has been synthesized and fully characterized. These complexes were screened as catalysts for ethylene hydrophenylation to yield ethylbenzene. All of the complexes exhibited selectivity for styrene production with low catalytic turnover. DFT calculations have been used to model reactivity of the [(dmpe)Pt(L')(Ph)][BAr′<inf>4</inf>] (dmpe = 1,2-bis(dimethylphosphino)ethane). It is shown that selective styrene formation is a result of a calculated ΔΔG<sup>‡</sup> of 5 kcal/mol for the benzene C-H activation step in the catalytic cycles for styrene versus ethylbenzene formation.
Brosnahan, A. M., Talbot, A., McKeown, B. A., Kalman, S. E., Gunnoe, T. B., Ess, D. H., & Sabat, M. (2015). Phosphine and N-heterocyclic carbene ligands on Pt(II) shift selectivity from ethylene hydrophenylation toward benzene vinylation. Journal of Organometallic Chemistry, 793, 248–255. https://doi.org/10.1016/j.jorganchem.2015.03.019