Unexpected formation of the vinyl-phosphonio complex (CpRu(PPh3)(C6H4PPh2CH=CH2)][PF6] from 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 a-carbon of the vinylidene group, followed by ortho metalation of the phenyl ring on the cationic phosphorus atom.