Cyclopentadienyl-ruthenium and -osmium chemistry. XXV. Conversion of alkoxycarbene complexes to vinyl ether derivatives: X-ray structure of Ru{;C(OPrⁱ)CHPh}(CO)(PPh₃)(η-C₅H₅)

Several cationic alkoxy(alkyl)carbene complexes containing the Ru(L)(PPh₃)(η-C₅H₅) (L = CO or PPh₃) moiety have been deprotonated with NaOMe to the corresponding vinyl ether derivatives. The reaction is reversed by addition of HPF₆. Many of the vinyl ether complexes were obtained as mixtures of E and Z isomers; the X-ray structure of Ru{;C(OPr¹)CHPh}(CO)(PPh₃)(η-C₅H₅) shows that it is obtained only as the E isomer, and that the unit cell contains equal numbers of the two enantiomers. Ru{;C(OPr¹)CHPh};(CO)(PPh₃)(η-C₅H₅) is monoclinic, space group P2₁/c, with a 10.337(5), b 15.161(4), c 18.714(5) Å, β 90.83(3)°, and Z = 4; 2240 reflections [I > 2.5σ(I)] were refined to R = 0.0388, R_w = 0.0436. Important distances: RuC(vinyl) 2.103(6), RuCO 1.832(7), RuP 2.298(2), CC(vinyl) 1.335(8), COMe 1.381(7) Å. Addition of NaOMe to the product of the reaction between RuCl(PPh₃)₂(η-C₅H₅) and HCCC(O)Me in MeOH afforded a mixture of Ru{;CCC(O)Me};(PPh₃)(η-C₅H₅) and Ru{;C(OMe)CHC(O)Me};(PPh₃)₂(η-C₅H₅). The latter loses PPh₃ on standing in solution at ambient temperatures, forming the chelate complex Ru{;C(OMe)CHC(O)Me};(PPh₃)(η-C₅H₅). The similar conversion of Ru{;C(OMe)CHC(O)OMe};(PPh₃)₂(η-C₅H₅) to the corresponding chelate complex required heating at 65°C for 75 minutes.