Iron complexes ethers

Condensation of the iron complex with cyclopentanone in perchloric acid-acetic anhydride-ether medium had been attempted. The non-crystalline residue, after methanol washing and drying in air for several weeks, exploded on being disturbed. This was attributed to possible presence of a derivative of ferrocenium perchlorate, a powerful explosive and detonator. However, methyl or ethyl perchlorates alternatively may have been involved. 

We found that LiHBEt3 cleanly reduces the ethylvinyl ether salt 18b in THF to a 6-ethoxyethyl iron complex in 80% yield In contrast, Pt PMe+BHi - in CH2C12 transforms 18b into 1 1 mix-... 

B. Iron Complex of a Crown Ether-Porphyrin Conjugate Suitable for... 

Reaction of the iron complex salt 602 with the arylamine 921 in the presence of air led directly to the tricarbonyl(ri -4b,8a-dihydro-9H-carbazole)iron complex (923) by a one-pot C-C and C-N bond formation. Demetalation of complex 923 and subsequent aromatization by catalytic dehydrogenation afforded 3,4-dimethoxy-l-heptyl-2-methylcarbazole (924), a protected carbazoquinocin C. Finally, ether cleavage of 924 with boron tribromide followed by oxidation in air provided carbazoquinocin C (274) (640) (Scheme 5.120). 

Cleavage of the iron complex and the ben/yl ether functions is accomplished with boron tribromide solution. 

High yields of the moisture-sensitive tris(chelates) Fe(ArNNNAr)3 have been obtained by shaking anhydrous iron(III) chloride with silver(I) triazen-ides in dry ether at room temperature (18). Silver triazenides also react with the iron complexes FeX(CsH5)L2 [L = PPhj, P(OMe)j, P(OPh>3, or CO] via unstable binuclear species (C5H5)LFe(ArNNNAr)AgX to give the chelate triazenide complexes Fe(ArNNNAr)(C5H5)L (13). The complexes... 

The regioselective nudeophUic attack of the arylamine at the 2-methoxy-substituted iron complex salt is controlled by the methoxy group, which directs the arylamine to the para-position. Moreover, electrophilic attack takes place at the sterically less-hindered orfho-amino position. Iron-mediated oxidative cyclization of the resulting iron complex to the carbazole followed by proton-catalyzed aimulation of the furan ring provides 8-methoxyfurostifoline. Oxidation with 2,3-dich]oro-5,6-dicyano-l,4-benzoquinone (DDQ) to O-methylfurodausine-A followed by deavage of the methyl ether provides furoclausine-A (five steps, 9 % overall yidd). 

The chemistry of iron vinylidene complexes is dominated by the electrophilicity of the carbon atom adjacent to the iron organometallic unit. While addition of water leads to an acyl complex (i.e., the reverse of the dehydration shown in equation 10), addition of an alcohol leads to a vinyl ether complex. Similarly, other iron vinyl complexes can be prepared by the addition of thiolate, hydride, or an organocuprate (Scheme 33). " The nucleophilic addition of imines gave enaminoiron intermediates that could be further elaborated into cyclic aminocarbenes. This methodology has been used to provide access to /3-lactams and ultimately penicillin analogs, and good diastereoselectivities were observed (6 1-15 1) (Scheme 34). 04 Iso, vinylidene complexes are intermediates in cyclizations of alkynyl irons with substituted ketenes, acid chlorides, and related electrophiles an example is shown (equation 11). These cyclizations led to the formation of a series of isolable and characterizable cyclic vinyl iron complexes. 

Le Caer S, Heninger M, Lemaire J, Boissel P, Maitre P, Mestdagh H. (2004) Structural characterization of selectively prepared cationic iron complexes bearing monodentate and bidentate ether ligands using infrared photodissociation spectroscopy. Chem Phys Lett 273-279. 

Diene)tricarbonyliron complexes have found use as synthons for the preparation of functionalized dienes. Substituted 4-vinylcyclohexene derivatives are isomerized by pen-tacarbonyliron into a mixture of conjugated cyclohexadiene tricarbonyl iron complexes . When the 4-vinyl cyclohexene 90 was refluxed with 1.2 equivalents of fclCOjs in di-n-butyl ether, a 3 1 mixture of cyclohexadiene isomers 91 and 92 was acquired in 75% overall yield (equation 48). 

A further example is the detection of iron in the combustion residue of a textile sample or directly on the fibre material. For example, after adding a few drops of 1 N hydrochloric acid p.a. and 1 N ammonium thiocyanate a red iron complex is formed which can be concentrated by extraction with ether so that the detection limits are very low (more detailed description in Section 8.5.1). 

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