Iron-triethylamine complex

Poly(ethylene imine) (PEI) has also been employed for capping a preassembled octahedral iron(III) complex with H2LIO2O (Scheme 4-17) in DMSO in the presence of triethylamine [141]. The formation of amide Unkages has been proved by the presence of a band at 1641 cm" in the IR spectra. However, the formation of a bicapped cage structure remains imcertain. 

Olefin cyclopropanation with diazoacetates proceeds in the presence of p-oxo-bis[(salen)iron(III)] complexes (Scheme 4-298, Scheme 4-299). The air-stable complexes are prepared from the corresponding salen ligands with iron(III) chloride hexahydrate in the presence of triethylamine. The method also allows the transformation of trisubstituted and tetrasubstituted olefins. No exclusion of air is required for this procedure. ... 

First, 240 ml. of air-free water is placed in a 1-1. nitrogen-filled three-necked flask equipped with a stirrer and a reflux condenser. Then, 110 ml. (160 g. 0.82 mol) of iron pentacarbonyl and 83 ml. (60 g. 0.59 mol) of triethylamine are added, and the mixture is stirred and heated at 80° under nitrogen for 10 hours or overnight, whichever is more convenient. It is important that the proper temperature be maintained, because below 75° the reaction is incomplete and above 90° decomposition of the iron complex occurs. 

The first [M Dm3(ttnFe)2](C104)2 complexes of this type were obtained [79] by the interaction of iron(II) acetate and copper, zinc, nickel, cobalt, and manganese acetates with dimethylglyoxime and 1,4,7-trimethyl-1,4,7-triazacyclononane ttn) in methanol in the presence of triethylamine (Reaction 20). In this case, a triazamacrocycle served as the protecting group in the octahedral capping nFe "03 fragment. 

The heteronuclear mixed-valence complexes 16b,c were obtained from H2L 15, triethylamine, and iron(III) chloride in the presence of an excess of cobalt(II) chloride or copper(II) chloride. In neutral 16b,c iron is present only in the oxidation state 3 , as unambiguously confirmed by Mossbauer spectroscopy, which reveals only one quadruple doublet. Cyclic voltammetric investigation of the redox-active metal centers of neutral 16b shows a reversible three-potential one-electron transfer process. The half-wave potentials of -660 and -1310 mV correspond to the redox processes [(Fe )2Co"OLf ] [Fe Fe Co OLf ]" [(Fe")2Co"OLf ] , whereas... 

The demonstration of a new photobleaching pathway for /ac-[ReBr(bipy)-(00)3], involving the use of triethylamine in DMF, is of interest in relation to nucleophilic attack at iron(II)-diimine complexes (see Section 8.2.2 below), for the mechanism involves ethylation of coordinated 2,2 -bipyridyl. Finally, the [ReO(MeC=CMe)2(py)] cation undergoes associative ligand exchange, with retention of configuration. 

An alternative method to halolactonization of unsaturated acids consists of reaction with triethylamine followed by benzenesulphenyl chloride to give phenyl-thio-lactones (e.g. 42). Elimination of the sulphur group by standard methods gives saturated or unsaturated fused lactones. Essentially the same method, but using phenylselenenyl chloride, has also been reported. Vinyloxirans undergo carbonyl insertion when treated with iron pentacarbonyl oxidation of the resulting complexes (e.g. 43) with cerium(iv) gives (44) as the only lactone isolated. ... 

This can easily be explained by taking into account the weaker donor properties of thioether sulphur atoms as compared to thiol or thione sulphurs [62]. This mode of coordination of isothiosemicarbazones was later used for carrying out similar condensation reactions in the presence of other metal ions as templates. Thus by interaction of equimolar amounts of 2-hydroxybenzaldehyde 5-methyl-isothiosemicarbazone, anhydrous iron( III) chloride, and 2-hydroxybenzaldehyde in a mixture of absolute ethanol and DMF the template reaction became possible, giving rise to the formation of [Fe(L62)Cl] (Eq. 2.27) [63]. The synthesis of dimers [Fe(L62)]20 (R = CH3, C2H5, n-C3H7, n-C4H9) was performed by reaction of 2-hydroxybenzaldehyde 5-alkylisothiosemicarbazone and 2-hydroxybenzaldehyde with anhydrous FeCl3 in absolute ethanol or -butanol, followed by addition of triethylamine as base [64]. For these complexes the possibility was established of mutual transformations (Eq. 2.28). 

Further uses of tricarbonylcyclohexadienylium iron complexes have appeared throughout the year. Spirocyclization of the complex (5) by triethylamine at -78 C leads to the product arising from carbon-carbon coupling, whereas the complex (6) gave exclusive cyclization via the oxygen atom, in accord with Baldwin rules (Scheme 12). 

Scheme 4-110. Alkylation of (ri -diene)iron complexes. Formation of c/5-pentadienol ethers by addition of triethylamine.

A solution of 4-[(2 )-(2-acetoxypropyl)]-5-amino-l,2-dimethoxy-3-methylbenzene (1.96 g, 7.33 mmol) and tricarbonyl(ri -cyclohexadienylium)iron tetrafluoroborate (1.12 g, 3.66 mmol) in acetonitrile (30 mL) was stirred at room temperature for 9 days in air. A saturated aqueous solution of sodium hydrogen carbonate (20 mL) was added to the reaction mixture and the aqueous layer was extracted with ethyl acetate (3 x 20 mL). The combined organic layers were washed with water (2 x 20 mL) and dried with sodium sulfate. After removal of the solvent, the residue was subjected to flash chromatography (hexane/ethyl acetate/triethylamine, 8 2 1) on silica gel to afford the tricarbonyl(il -4a,9a-dihydrocarbazole)iron complex as a bright yellow viscous liquid [a]n = -13.0 (c = 0.5, CHCI3) 1.67g(94%). ... 

---