Bridging Vinyliminium‐ and Enaminoalkylidenediiron Complexes as Organometallic Ligands

Abstract

AbstractThe SPh‐functionalized vinyliminium complexes [Fe2{μ‐η1:η3‐Cγ(R′)=Cβ(SPh)Cα=N(Me)(R)}(μ‐CO)(CO)(Cp)2][SO3CF3](R = Xyl, R′ = Me, 3a; R = R′ = Me, 3b; R = Xyl, R′ = CH2OH, 3c; R = Me, R′ = CH2OH, 3d; Xyl = 2,6‐Me2C6H3; Cp = η5C5H5) react with NaBH4, in thf solution, to afford the corresponding μ‐vinylalkylidene complexes [Fe2{μ‐η1:η3‐Cγ(R′)Cβ(SPh)=Cα(H)N(Me)(R)}(μ‐CO)(CO)(Cp)2] (5a–d). This reaction transforms the iminium into an amine group, thereby generating an N‐donor functionality. Consequently, the bridging organic framework in 5a–d, which contains S and N donor atoms, can act as an ambidentate ligand toward coordinatively unsaturated metal fragments. In particular, the complexes [Fe2{μ‐η1:η3‐Cγ(R′)Cβ(SPh)=Cα(H)NMe2}(μ‐CO)(CO)(Cp)2] (R′ = Me, 5b; R′ = CH2OH, 5d) react with [PdCl2(CH3CN)2] to give [PdCl2(N,S‐5b)] (6a) and [PdCl2(N,S‐5d)] (6b), respectively. The molecular structure of 6b has been determined by X‐ray diffractometry. In an analogous reaction, compound 5d acts as an “organometallic ligand” for the unsaturated rhodium fragment generated upon treatment of [Rh(NBD)Cl]2 (NBD = norbornadiene) with AgClO4. This reaction affords the trinuclear complex [Rh(NBD)(κ2‐N,S‐5d)][ClO4] (7). The bridging ligand in the zwitterionic complex [Fe2{μ‐η1:η3‐Cγ(CH2OH)=Cβ(S)Cα=N(Me)(Xyl)}(μ‐CO)(CO)(Cp)2] (2a) contains an OH group in addition to the N and S functionalities. This bridging framework acts as a O,S bidentate ligand and the reaction of 2a with [Ti(Cp)2(CH3CN)2](SO3CF3)2 leads to the formation of the adduct [Ti(Cp)2(κ2‐O,S‐2a)][SO3CF3]2 (8). (© Wiley‐VCH Verlag GmbH & Co. KGaA, 69451 Weinheim, Germany, 2009)