The major product
of the reaction between Ru(IMe4)2(PPh3)2H2 (1; IMe4 = 1,3,4,5-tetramethylimidazol-2-ylidene)
and P(C6F5)3 (PCF) is the five-coordinate
complex
Ru(IMe4)2(PF2{C6F5})(C6F5)H (2), which is
formed via a complex series of C–F/P–C bond cleavage
and P–F bond formation steps. In contrast, hydrodefluorination
of all six ortho C–F bonds in PCF occurs with Ru(PPh3)4H2 to afford Ru(PPh3)3HF (3). NaBArF
4 abstracted the
fluoride ligand in 3 to give [Ru({η6-C6H5}PPh2)(PPh3)2H][BArF
4], while B2pin2 reacted with 3 in C6D6 to yield a mixture of [Ru({η6-C6D6)(PPh3)2H]+ and Ru(PPh3)4H2. The treatment of 3 with HBpin (5 equiv) and HSiR3 (R = Et, Ph; 2 equiv)
afforded Ru(PPh3)3(σ-HBpin)H2 and Ru(PPh3)3(SiR3)3H3, respectively. No stable substitution products were
generated when 3 was reacted with Me3SiX (X
= CF3, C6F5).