Protonation of Cp*Fe(η5-C6H7) as a convenient procedure for the preparation of the valuable synthon [Cp*Fe(MeCN)3]+

The (cyclohexadienyl)iron complex Cp*Fe(η⁵-C₆H₇) obtained by a reaction of the cation [Cp*Fe(η⁶-C₆H₆)]⁺ with LiAlH₄ reacts with HBF₄·Et₂O or TfOH in MeCN to afford the acetonitrile cation [Cp*Fe(MeCN)₃]⁺ in a high yield. The structure of complex Cp*Fe(η⁵-C₆H₇) was determined by X-ray diffraction analysis.