Phosphine and N-heterocyclic carbene ligands on Pt(II) shift selectivity from ethylene hydrophenylation toward benzene vinylation

Abstract

Dedicated in memory of Prof. A. E. Shilov and his many seminal contributions to the fields of organometallic chemistry and catalysis

Enhancing the catalytic properties of well-defined electrophilic platinum complexes

“…1. 25 Contrary to initial expectations, the reaction with the platinum complexes bearing di-phosphines gave rise to styrene as a major product with very low efficiency (less than 2 turnovers after 4 h at 100 1C), whereas systems incorporating mixed phosphine-pyridine units or bis-NHCs (4-6 in Fig. 1) were completely ineffective.…”

Facile Styrene Formation from Ethylene and a Phenylplatinum(II) Complex Leading to an Observable Platinum(II) Hydride

“…Given the demonstrated ability of Pt II complexes to activate C–H bonds, attempts to catalytically produce styrene from ethylene and benzene have also been made; however, the decomposition of Pt II –H species, presumably via disproportionation, has been suggested to limit turnover. − Thus, by using Rh I , for which the thermodynamics of disproportionation are unfavorable, an efficient catalytic cycle for styrene production has been realized . However, to the best of our knowledge, the purported hydride complexes have never been isolated in related catalytic transformations …”