On the Mechanism of the Metal Mediated Vinylic Cross Coupling Reactions. 1. Oxidative Addition: The Reaction of Vinyl Triflates with Zerovalent Platinum. Kinetics, Stereochemistry, and Molecular Structure

Article abstract of DOI:10.1021/ja00191a036

The oxidative addition reaction of alkylvinyl triflates with (Ph3P)4Pt and (Ph3P)2Pt(C2H4) was investigated as a prototypical example of the first step of the Ni triad metal mediated vinylic cross coupling reactions.Kinetic, stereochemical, and variable temperature NMR experiments were carried out to establish the involvement of ?-alkene complexes in these reactions.The proposed mechanism involves rate-determining formation of a ?-alkene Pt complex, followed by rapid rearrangement to a ?-vinyl triflato-Pt(II) complex, and then addition of PPh3 to yield a ?-vinylcationic Pt(II) complex.Both ?-vinyl complexes were isolated and fully characterized, as stable crystalline species.A single crystal molecular structure determination is reported for the ?-(trans-2-butenyl)tris(triphenylphosphine)platinum(II) triflate complex.