Recent chemistry of the η5-cyclopentadienyl dicarbonyl iron anion

The distinctive nucleophilicity of the η5-cyclopentadienyl dicarbonyl iron (Fp) is reviewed from 1994 to present. In addition to its nucleophilic reactivity, other distinguishing reactivity characteristics such as basicity and oxidizability are discussed. A section is included concerning various synthetic means used in generating the Fp anion. Substitution and addition reaction sections concerning both organic and inorganic electrophiles are covered. Fp anion reactions with organic electrophiles are explored according to sp3-, sp2-, and sp-hybridized electrophilic carbon bonds in forming new carbon–iron bonds. Besides intriguing mechanistic studies, applications of newly formed Fp complexes including, but not limited to, catalysis, asymmetric and regiospecific reactions, vapor pressure deposition, optical filtration, and polymerization are reviewed.