Synthesis, molecular structure, substitution and C-C coupling reactions of ruthenium complexes containing (g⁵-C₉H₇) Ru(PPh₃) as a molecular unit

The 2-methallyl complex [(η⁵-C₉H ₇)Ru(η³-2-MeC₃H₄)(PPh ₃)] (3), prepared from [(η⁵-C₉H ₇)Ru(PPh₃)₂Cl] (2) and 2-MeC₃H ₄MgCl, reacts with HX (X = Cl, CF₃CO₂) in the presence of ethene to give the chiral-at-metal compounds [(η⁵- C₉H₇)Ru(C₂H₄)(PPh₃)X] (4, 5) in nearly quantitative yields. Treatment of 2 with AgPF₆ and ethene affords [(η⁵-C₉H₇)Ru(C ₂H₄)(PPh₃)₂]PF₆ (6), which reacts with acetone to give the substitution product [(η⁵- C₉H₇)Ru(OCMe₂)(PPh₃) ₂]PF₆ (7). The molecular structure of 7 has been determined crystallographically. Whereas treatment of 4 with CH(CO ₂Et)N₂ yields the olefin complex [(η⁵- C₉H₇)Ru{η²-(Z)-C₂H ₂(CO₂Et)₂}(PPh₃)Cl] (8), the reactions of 4 and 5 with Ph₂CN₂, PhCHN₂ and (Me₃Si)CHN₂ lead to the formation of the carbeneruthenium(II) derivatives [(η⁵-C₉H ₇)Ru(CRR′)(PPh₃)Cl] (9-11) and [(η⁵- C₉H₇)Ru(CRR′)(PPh₃)(κ¹- O₂CCF₃)] (12-14), respectively. Treatment of 9 (R = R′ = Ph), 10 (R = H, R′ = Ph) and 11 (R = H, R′ = SiMe ₃) with MeLi produces the hydrido(olefin) complexes [(η⁵-C₉H₇)RuH(η²-CH ₂CPh₂)(PPh₃)] (15), [(η⁵-C ₉H₇)RuH(η²-CH₂CHPh)(PPh ₃)] (18a,b) and [(η⁵-C₉H ₇)RuH(η²-CH₂CHSiMe₃)(PPh ₃)] (19) via C-C coupling and β-hydride shift. The analogous reactions of 11 with PhLi gives the η³-benzyl compound [(η⁵-C₉H₇)Ru{η³-(Me ₃Si)CHC₆H₅}(PPh₃)] (20). The η³-allyl complex [(η⁵-C₉H ₇)Ru(η³-1-PhC₃H₄)(PPh ₃)] (17) was prepared from 10 and CH₂CHMgBr by nucleophilic attack.