Dicarbonyl iron

The commercially available (tj5-cyclopentadienyl)iron dicarbonyl dimer 1 is the source of the carbonyl(//5-cyclopentadienyl)iron(L) moiety. Reductive or oxidative cleavage of 1 provides reactive monomeric species that may be converted into iron-acyl complexes as described in the following sections (see also Houben-Weyl, Vol. 13/9a, p208). 

A small number of template mediated reactions which afford thioether macrocycles are also known, e.g. the small trithia [9]aneS3 is also obtained in good yield using Mo(CO)3 as a template.73,74 The crown trithioether is readily demetallated by addition of a further equivalent of [NMe4]2[S(CH2)2S(CH2)2S]. Also, dibenzo-[18]aneS6 and dibenzo-[15]aneS5 have been prepared via an iron dicarbonyl template.75,76 Metal-induced cyclo-oligomerization reactions of... 

Reactions of cyclopentadienyl- and (pentmethylcyclopentadienyl)iron dicarbonyl 2-alkynyl complexes as well as cyclopentadienylmolybdenum tricarbonyl 2-alkynyl complexes with 4,5-diphenyl-3,6-dihydro-l,2-dithiin 1-oxide 111 were shown to yield transition metal-substituted five-membered ring thiosulfinate esters 112 in moderate to excellent yields (Scheme 27) <19910M2936, 1989JA8268>. These reactions are formal [3-1-2] cycloadditions. When... 

Several cyclopentadienyl(alkyl)metal carbonyl derivatives have reacted with acetylenes. In some examples, insertion reactions may also be involved, although the mechanisms have not been investigated. Cyclopentadienyl(methyl)iron dicarbonyl with diphenylacetylene gave a 10% yield of cyclopen tadienyltetra-phenylcyclopentadienyliron 71). 

Any interconversion in a sample may give rise to temperature-dependent NMR spectra. For example, the 13C NMR spectrum of dimeric cyclopentadienyl iron dicarbonyl is temperature dependent [114]. This was attributed to intermolecular exchanges of carbonyls and interconversion between cis and trans complexes. 

Iron Dicarbonyl-pentafluoro-phenyl-(i)5-pentamethyl-cyclo-pentadienyl)- Xlll/9a. 364 [FjCo-Li + Br(CO),Fc-R]... 

An experimental illustration of the GA is shown in Fig. 21. The molecule cyclopentadieny 1-iron-dicarbonyl-chloride was irradiated with pulses of 800 nm radiation that were initially 80 ns long before entering the pulse shaper. The phases of the laser pulses were modified with... 

In > , >y -bis(cyclopentadienyl)iron dicarbonyl the <7-bonded ligand is easily attacked by HFA with conservation of the a bond. Photochemical treatment of 147 affords 146d, in which both cyclopentadienyl rings become n bonded (76). 

Carbodiimides also add to metal carbon bonds in metalorganic compounds. For example, cyclopentadienyl iron dicarbonyl 286 affords [2-f2] cycloadducts 287 with diphenyl- and... 

To make the reactive fulleride compound KeCeo in the Fe-Ceo synthesis, fullerenes and a slight excess of potassium were sealed in a glass tube under vacuum and heated for approximately four days at 250 °C. Both solid-state NMR and Raman spectroscopy were employed to determine that the KeCeo compound was in fact synthesized. The KeCeo product was then reacted in an inert atmosphere with cyclopentadienyl-iron-dicarbonyl-iodide (CpFe(CO)2l) in tetrahydrofuran (THF) to form the complex. The recovered product was dried in an inert atmosphere. Manipulations of air-sensitive materials were carried out in a glove box or using standard Schlenk techniques. THF was distilled just prior to use from sodium benzophenone ketyl. Ceo was obtained from Aldrich, and CpFeCCOjol was obtained from Strew. 

Thus the iron atom in (Tr-cyclopentadienvl)iron dicarbonyl bromide forms additional bonds with the halide ligands on palladium. Carbonyl substitution on the generated intermediate (XV) then occurs. In this case the cyclopentadienyl group acts as a bridge. In general, such a mechanism corresponds to an A-type substitution, where the halogens in (7T-tetraphenyl-cyclobutadiene)palladium dichloride function as nucleophiles. 

A slight variation of the [3-I-2] cycloaddition approach <1977ICA(25)165> has also been employed for the diastereoselective synthesis of the corresponding anti- and ry -iron-substituted 1,2-dithiolane 1-oxides 243 from 237, as a source of electrophilic disulfur monoxide, and 7] -allyl iron complex 242 (Scheme 39). The method was also tested with cyclopentadienyl iron dicarbonyl crotonyl complex 244 when four diastereomers 245-248 were generated in modest yields (35%) <19980M5534>. 

For the preparation of unsymmetrical ferrocenes, two ways by which only mono-substituted derivatives are produced have been suggested. One route starts from iron tetracarbonyl and a substituted cyclopenta-diene the other from monocyclopentadienyl iron dicarbonyl bromide, which on treatment with a substituted cyclopentadienyl lithium is finally converted into the corresponding mono-substituted ferrocene. Experience shows the first method to be more suitable for the preparation of aryl, and the latter method for the preparation of alkyl, derivatives (57). Corresponding work already carried out on substitution in Ru(C5H6)2 and Os CsH5)2 has also been fruitful. It is found that in the Friedel-Crafts reaction with acetyl or benzoyl chloride there is a distinct predominance of mono- over disubstitution as the atomic weight of the central atom increases (47, 72). 

Fe02CHj, Iron, methoxyoxo-, 22 87 Fe02C iH 2, Iron, dicarbonyl(ii -cyclopenta-dienyl)(2-methyI-l-propenyI-kC)-, 24 164... 

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