Synthesis, molecular structure, substitution and C–C coupling reactions of ruthenium complexes containing (η5-C9H7)Ru(PPh3) as a molecular unit

The 2-methallyl complex [(η5-C9H7)Ru(η3-2-MeC3H4)(PPh3)] (3), prepared from [(η5-C9H7)Ru(PPh3)2Cl] (2) and 2-MeC3H4MgCl, 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(C2H4)(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(CO2Et)N2 yields the olefin complex [(η5-C9H7)Ru{η2-(Z)-C2H2(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-C9H7)Ru(double bond; length as m-dashCRR′)(PPh3)Cl] (9–11) and [(η5-C9H7)Ru(double bond; length as m-dashCRR′)(PPh3)(κ1-O2CCF3)] (12–14), respectively. Treatment of 9 (R = R′ = Ph), 10 (R = H, R′ = Ph) and 11 (R = H, R′ = SiMe3) with MeLi produces the hydrido(olefin) complexes [(η5–C9H7)RuH(η2-CH2double bond; length as m-dashCPh2)(PPh3)] (15), [(η5-C9H7)RuH(η2-CH2double bond; length as m-dashCHPh)(PPh3)] (18a,b) and [(η5-C9H7)RuH(η2-CH2double bond; length as m-dashCHSiMe3)(PPh3)] (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-(Me3Si)CHC6H5}(PPh3)] (20). The η3-allyl complex [(η5-C9H7)Ru(η3-1-PhC3H4)(PPh3)] (17) was prepared from 10 and CH2double bond; length as m-dashCHMgBr by nucleophilic attack.