Pentacarbonyliron nucleophiles

Addition of nucleophiles to a carbon monoxide ligand of pentacarbonyliron provides anionic acyliron intermediates which can be trapped by electrophiles (H+ or R—X) to furnish aldehydes or ketones [18]. However, carbonyl insertion into alkyl halides using iron carbonyl complexes is more efficiently achieved with disodium tetracarbonylferrate (Collman s reagent) and provides unsymmetrical ketones (Scheme 1.2) [19, 20]. Collman s reagent is extremely sensitive towards air and moisture, but offers a great synthetic potential as carbonyl transfer reagent. It can be prepared by an in situ procedure starting from Fe(CO)5 and Na-naphthalene [20]. 

These reactions probably occur by the nucleophilic addition of the aryl anion to one of the CO groups of pentacarbonyliron followed by the addition of electrophiles. Pentacarbonyliron also causes carbonylation of electrophilic aryldiazonium salts [20]. 

Most of the preparations of molecular coordination compounds of iron published in Inorganic Syntheses or elsewhere require the readily available pentacarbonyliron or derivatives thereof. However, pentacarbonyliron is a rather stable compound that needs either thermal or photochemical activation to react. We describe here the selective, high-yield, one-pot synthesis of the title complexes from potassium tetracarbonylhydridoferrate(l — ), easily generated from pentacarbonyliron, a method that can be referred to as a nucleophilic activation of pentacarbonyliron. ... 

The results of recent studies on nucleophilic substitution of fluorine in pentafluorobenzonitrile and tetrafluorophthalonitrile are summarized in Schemes 13a and 13b. The ferrous phthalocyanine (40 , which can be degraded with concentrated nitric acid to tetrafluorophthalimide, has been prepared by heating tetrafluorophthalonitrile with pentacarbonyliron in boiling 1-methylnaphthalene. ... 

Treating pentacarbonyliron with dicyclopentadiene affords the dicarbonyl (ri -cyclopentadienyl)iron dimer [Cp(CO)2pe]2. Reduction of the latter with sodium amalgam provides the nucleophilic dicarbonyl(r -cyclopentadienyl)iron anion [Cp(CO)2Fe]. Allylic halides or tosylates can be reacted with this Fe(0) complex to afford ri -allyl-Fp-iron complexes (Fp = Fe(CO)2Cp, Scheme... 

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