The application of microwave dielectric heating to the synthesis of arene-metal complexes. Synthesis of [(η-arene) (CO)3Mn]PF6 complexes and [(η-arene) (η-cyclopentadienyl)Fe][PF6] complexes with triphenylphosphine, tert-butylbenzenes and a sterically hindered phenol as arene ligands

Article abstract of DOI:10.1016/S0022-328X(97)00289-1

Microwave-mediated syntheses of [(η-arene)(CO)₃Mn](PF₆) complexes are reported. Reaction times are reduced from several hours by conventional methods to a few minutes using an unmodified domestic microwave oven. The synthesis of a bis complexed triphenylphosphine iron sandwich complex, [{(η-C₆H₅)(η-Cp)Fel₂ PC₆H₅][PF₆]₂ is reported from A1C1₃-catalysed ligand exchange reactions between ferrocene and M(CO)₄(PPh₃)₂ complexes (M = Cr, Mo, W). Sterically hindered [(η-arene)(η-Cp)Fe][PF₆] complexes with tert-butyl substituents have been prepared in moderate to excellent yields using the above microwave technique. Attempts to synthesise the methyl cyclopentadienyl analogues resulted in appreciable de-alkylation. No evidence for restricted rotation was found in the latter complexes. The direct synthesis of the 1,3,5-trimethylphenol iron sandwich complex is reported. This is the first example of a phenol complex prepared via ligand exchange reactions in iron sandwich chemistry.