Formation of a Ruthenium(II) Dicyclohexyl(η²-cyclohex-3-enyl)phosphine Hydride Complex from an Alkylidene Precursor

Treatment of Ru(CHPh)Cl2(PCy3)2 (Cy = cyclohexyl) with K[N(i-Pr2PS)2] afforded a mixture of Ru(CHPh)[N(i-Pr2PS)2](PCy3)Cl (1) and Ru(CHPh)[N(i-Pr2PS)2]2 (2). Reaction of 1 with TlOPh gave Ru(CHPh)[N(i-Pr2PS)2](PCy3)(OPh) (3), whereas that with NaOMe yielded the Ru(II) hydride compound Ru(H)[N(i-Pr2PS)2][PCy2(η2-C6H9)] (4), in which the dicyclohexyl(cyclohex-3-enyl)phosphine ligand binds to Ru via the phosphorus atom and the CC bond of the cyclohex-3-enyl ring. The structures of complexes 3 and 4 have been established by X-ray crystallography.