Unexpected Formation of the Vinyl−Phosphonio Complex [CpRu(PPh<INF>3</INF>)(C<INF>6</INF>H<INF>4</INF>PPh<INF>2</INF>CH&dbd;CH<INF>2</INF>)][PF<INF>6</INF>] from a Vinylidene Complex via Nucleophilic Addition and Ortho Metalation of Triphenylphosphine

The reaction of Ru−vinylidene complexes with triphenylphosphine led to the formation of vinyl−phosphonio complexes in good yields. The results obtained by using a deuterium-labeled complex and a methyldiphenylphosphine analogue indicated that the present reaction proceeded via nucleophilic addition to the α-carbon of the vinylidene group, followed by ortho metalation of the phenyl ring on the cationic phosphorus atom.