Cyclopentadienyl dicarbonyl ferrate

Eisen (/j5-Cyclopentadienyl)-dicarbonyl-(ry2-ketenimin)-(Salze) XlII/9a, 505 Ferrat Acetyl-carbonyl-cyano-(r/5-cyclopentadienyl)- (K-Salz) XIII/9a, 409... 

Sodium dicarbonyl (cyclopentadienyl)ferrate Ferrate (1-), dicarbonyl-tt-... 

C7H704Rh, Rhodium(I), dicarbonyl(2,4-pentanedionato)-, 34 128 C7HgN4, Bis(l-pyrazolyl)methane, bpm, complex with nickel(ll), 34 139 CgH5FeKN20, Ferrate(ll), carbonyldicyano-(cyclopentadienyl)-, potassium, 34 172 CgH23Ns, Tetraethylenepentamine, tetren, complex with nickel(ll), 34 147, 148 CgH24B2N4, Diborane(4), tetrakis(dimethyl-amino)-, 34 1... 

Few cases of r -cyclopropenyl decomplexation have been reported. Conversion of various substituted cyclopropenylium cations with sodium dicarbonyl(cyclopentadienyl)ferrate gives (T-bound cyclopropenyliron complexes 1 which were converted to (x-cyclopropenylium complexes 2 or were decomplexed with self-coupling to form dicyclopropenylium systems 3. ... 

To a stirred suspension of 1,2-diphenylcyclopropenylium perchlorate (2.6 g, 8.95 mmol) in THF (10 mL), cooled at — 78 C, was slowly added a solution of sodium dicarbonyl(t -cyclopentadienyl)ferrate in THF (10 mL), which was prepared from dicarbonyl( -cyclopcntadienyl)iron dimer (1.7 g, 4.8 mmol) and 2% sodium amalgam (17 g). After warming the mixture to — 10 °C, the solvent was removed under vacuum, the residue was taken up in EtjO/dioxane (2 1, 15 mL), and the solution was cooled to — 10 C and rapidly filtered through a glass filter. The filtrate was evaporated at — 10 C under high vacuum, the... 

The reaction of 1,2,3-triphenylcyclopropenylium ion 28 with sodium dicarbonyl(// -cyclopen-tadienyl)ferrate afforded the tr-complex, dicarbonyl(f -cyclopentadienyl)(l,2,3-triphenylcy-cloprop-2-enyl)iron (29), whose structure was determined by X-ray crystallography." Complex 29 was transformed into the original cyclopropenylium ion or its dimer by various reagents."... 

Scheme 4-18. Formation of ri -allyliron complexes by alkylation of the dicarbonyl(cyclopentadienyl)ferrates.

A 4% sodium amalgam is prepared from the careful addition of sodium (3 g, 130 mmol), in small portions, to mercury (650 g, 3.25 mol), which is rapidly stirred. The amalgam is allowed to return to room temperature over 1 h, and then a tetrahydro-furan (100 mL) solution of tetracarbonyl(dicyclopentadienyl)diiron (10.62 g, 30 mmol) is added in one portion and is efficiently stirred for 2 h. The amber tetrahydrofuran solution of sodium dicarbonyl(cyclopentadienyl)ferrate is separated from the amalgam and transferred to a new flask via syringe. This solution is cooled to 0 °C and l-bromo-2,2-di-methoxypropane (llg, 60 mmol) in tetrahydrofuran (10 mL) is added dropwise over 30 min. The yellow-brown solution is stirred at 0 °C for a further 30 min and then at room temperature for 3 h. The solvent is removed, and the residue is extracted with pentane (ca. 

A solution of sodium dicarbonyl(cyclopentadienyl)ferrate prepared from the dicarbonyl(T] -cyclopentadienyl)iron dimer [Cp(CO)2pe]2 (4.11 g, 11.6 mmol) and sodium amalgam (2%, 35.3 g) in tetrahydrofuran (80 mL) is added slowly at -78 °C to a solution of 4-bromo-2//-chromene-3-carbaldehyde (5.5 g, 23 mmol) in tetrahydrohiran (70 mL). The mixture is stirred at -78 °C for 1 h and then allowed to warm to room temperature over a period of 1 h. The solvent is evaporated in vacuo, and the residue is dissolved in diethyl ether/acetone (1 1) and subsequently purified by column chromatography on silica gel. With petroleum ether/diethyl ether (2 1) tetracarbonyl(dicyclopentadienyl)diiron is separated, whereas with diethyl ether/acetone (1 1) the alkenyl-Fp complex is obtained. The solvent is evaporated and the yellow-brown solid is dissolved in dichloromethane (200 mL), dried (magnesium sulfate), and the solution concentrated in vacuo to yield the q -alkenyl-Fp complex as a yellow-brown, amorphous solid 6.9 g (89%). ... 

Alternatively, acyliron complexes can be obtained in a two-step sequence either from dicarbonyl(cyclopentadienyl)ferrates or from dicarbonyl(cyclopentadienyl)iron halides via alkyl-Fp complexes. The first method makes use of the nucleophilicity of [CpFe(CO)2] anions. Their reaction with alkyl halides provides alkyl-Fp complexes that, upon treatment with phosphanes or phosphites, undergo a migratory insertion of a carbonyl ligand into the metal-alkyl bond leading to an acyliron complex (Scheme 4-38). " ... 

Scheme 4—38. Acyliron complexes by sequential alkylation and migratory carbonyl insertion of dicarbonyl(t -cyclopentadienyl)ferrate.

---