Cyclometallation reactions. Part 16. Some reactions of η-cyclopentadienylruthenium phosphine complexes

Abstract

ortho-Metallation reactions of several η-cyclopentadleylruthenium complexes are described. The complex [RuMe(ηC₅H₅)(PPh₃)₂] affords [[graphic omitted]Ph₂)(ηC₅H₅)(PPh₃)], which with hexafluorobut-2-yne gives [[graphic omitted]Ph₂}(ηC₅H₅)]. The tripheyl phosphite complex [Ru(η-C₅H₅)Cl{P(OPh)₃}₂] on heating yields [[graphic omitted](OPh)₂}(η-C₅H₅){P(OPh)₃}].With azobenzenes, m-RC₆H₄N:Nph (R = H, Me, OMe, CO₂Et, or CF₃), the complex [RuMe(ηC₅H₅)(PPh₃)₂] yields a mixture of isomers [[graphic omitted]C₆H₄)Z-(η-C₅H₅)(PPh₃)](Y = H, Z = R : or Y = R, Z = H). Using m-RC₆H₄N:NC₆F₅(R = H, Me, or CF₃) the complexes [[graphic omitted]C₆F₅)(η-C₅H₅)(PPh₃)], [[graphic omitted]C₆H₄R(η-C₅H₅)(PPh₃)], and [[graphic omitted]C₆H₃R·C₆H₄PPh₂)(η-C₅H₅)] were formed, whilst from C₆F₅N:NC₆F₅ only [[graphic omitted]NC₆H₅)(η-C₅H₄C₆H₄PPh₂)] was isolated Speculation on the mechanism of the fluorine-elimination reaction is given some credence by the synthesis of [Ru(η-C₅H₅)F(PPh₃)₂].