Phosphonioalkynyl indenylruthenium(II) complexes [Ru{C CC(R)H(PR3)}(eta(5)-C9H7)(PPh3)(2)][PF6] (R = Ph, PR3 = PMe3; R = H, PR3 = PPh3): suitable precursors of highly unsaturated sigma-alkynyl and vinylidene derivatives

Deprotonation of the phosphonioalkynyl ruthenium(II) complexes [Ru{C=CC(R-1 )H(PR3)} (eta(5)-C9H7)(PPh3)(2)][PF6] (R-1 = Ph, PR3 = PMe3 1; R-1 = H, PR3 = PPh3 2) with LiBun in THF at - 20 degrees C gave the ylide alkynyl deriv atives [Ru{C=CC(R-1)=PR3} (eta(5)-C9H7)(PPh3)(2)] (R-1 = Ph, PR3 = PMe3, 3; R-1 = H, PR3 = PPh3 4), which react in situ with aldehydes or ketones via a Wittig process to afford the neutral sigma-enynyl complexes [Ru{C=CC(R-1) =(CRR3)-R-2}(eta(5)-C9H7)(PPh3)(2)] [(RR3)-R-2 = CH2(CH2)(3)CH2, R-1 = Ph 5 a or H 6a; R-2 = H, R-3 = Me, R-1 = Ph 5b or H 6b; R-2 = R-3 = R-1 = Ph 5c] . Compounds 5b and 6b have been obtained as mixtures of the corresponding E and Z stereoisomers. Protonation of 5 and 6 with HBF4 . Et2O in THF at -20 degrees C takes place selectively on the C-beta of the enynyl chain to yie ld the cationic vinylvinylidene derivatives [Ru{=C=C(H)C(R-1)=(CRR3)-R-2)(e ta(5)-C9H7(PPh3)(2)][BF4] [(RR3)-R-2 = CH2(CH2)(3)CH2, R-1 = Ph 7a or H 8a; R-2 = H, R-3 = Me, R-1 = Ph 7b or H 8b; R-2 = R-3 = R-1 = Ph 7c]. The sigm a-polyenynyl complexes [Ru{C=CC(R-1)=CH(CH=CH)(n)R-2}(eta(5)-C9H7)(PPh3)(2) ] (n = 1, R-2 = Ph, R-1 = Ph 9a or H 10a; R-2 = Pr-n, R-1 = Ph 9b or H 10b; n = 2, R-2 = Me, R-1 = Ph 11 or H 12) have been obtained in high yields, a s mixtures of the E and Z stereoisomers, by reaction of 3 and 4 with unsatu rated aldehydes. Protonation of these derivatives yielded the highly unsatu rated vinylidene complexes [Ru{=C=C(H)C(R-1)=CH(CH=CH)(n)R-2} (eta(5)-C9H7) (PPh3)(2)][BF4] (n = 1, R-2 = Ph, R-1 = Ph 13a or H 14a; R-2 = Pr-n, R-1 = Ph 13b or H 14b; n = 2, R-2 = Me, R-1 = Ph 15 or H 16). The sigma-ynenynyl and sigma-keteniminyl complexes [Ru {C=CC(Ph)=CH(C=CPh)} (eta(5)-C9H7)(PPh3 )(2)] and [Ru{C=CC(Ph)=C=NPh} (eta(5)-C9H7)(PPh3)(2)] have also been prepar ed by reaction of 3 with PhC=CCHO and phenyl isocyanate, respectively. The H-1, P-31-{H-1} and C-13-{H-1} NMR data for all the novel complexes are rep orted.