Reaction of iron and ruthenium halogenide complexes with GaCp^* and AlCp^*: Insertion, Cp^* transfer reactions and orthometallation

The reactions of the Fe(II) and Ru(II) halogenide complexes [Fe(PPh₃)₂Br₂], [Fe(NCCH₃)₂Br₂], [Ru(PPh₃)₃Cl₂], and [Ru(dmso)₄Cl₂] with GaCp^* and AlCp^*, respectively, are investigated. The reactions of [FeBr₂L₂] with ECp^* exclusively proceed via Cp^* transfer, leading to [FeCp^*(GaCp^*)(GaBr₂)(PPh₃)] (1) (L = PPh₃, E = Ga), [FeCp^*(GaCp^*)₂ (GaBr₂)] (2) (L = NCCH₃, E = Ga) and [FeCp^*(μ³-H)(κ²-(C₆H₄)PPh₂)(AlCp^*)(AlBr₂)] (3) (L = PPh₃, E = Al), the latter of which is formed via orthometallation of one PPh₃ ligand. The reaction of [Ru(dmso)₄Cl₂] leads to the homoleptic complex [Ru(GaCp^*)₆Cl₂] (4) in high yields, while [Ru(PPh₃)₃Cl₂] gives 4 in rather low yields. The reason for this difference in reactivity is investigated and it is shown that Cp^* transfer and orthometallation are the limiting side reactions of the reaction of [Ru(PPh₃)₃Cl₂] with GaCp^*. All compounds were characterized by NMR spectroscopy, and single crystal X-ray diffraction studies were performed for 1, 3, and 4.