Porphyrin iron chloride

Another approach to improved chemoselectivity utilizes sterically hindered alkenes, as reported by Konoike et al. (Scheme 3.25) [115]. Ursolic add 12, a steroid with a highly congested trisubstituted double bond, undergoes allylic hydroxylation at the C-ll position with MCPBA and tetrakis(pentafluorophenyl)porphyrin iron chloride [Fe(PFPP)Cl] as a catalyst to give a single diastereomer 13 in 91% yield. With sterically less encumbered systems only epoxidation was observed. 

Corroles are porphyrins which lack the 20-methine group. (7,13-dimethyl-2,3,8,12,17,18-hexa-ethylcorrolato)iron chloride reacts with cyanide to form a low-spin dicyano complex, which is subsequently reduced by excess of cyanide to give (152). The iron in the dicyano complex is still in the 3+ oxidation state, with the reduced correlate as a dinegative radical ligand. ... 

Vacuum sublimation of a Zn(III) complex solution produced a pink-colored solid, which was Zn(III) perfhiorotetraphenylporphyrin. NMR analysis of this product showed the absence of pyrrole hydrogen atoms, which is the evidence for complete replacement. Then bivalent iron chloride (FeCl2) was prepared according to the common technique [17]. This compound was then used for Zn(III) ion replacement in a porphyrin ring. For this purpose, the Zn(III) complex was dissolved in dimethylformamide (DMF) and then, with the addition of an FeCl2 solution, also in DMF. The reaction mixture was heated in a steam bath at water boiling point for 5 h. Finally, a dark-brown sediment was deposited, and the solution was colored blue, which is typical of iron(III) perfhiorotetraphenylporphyrin (perFTPhPFe(III)) dissolved in DMF. In this case, the active weight of the catalyst iron(III) perfhiorotetraphenylporphyrin equaled 47.05 mg. 

Recently Liu and coworkers used (porphyrin)iron(III) chloride complex 96 to promote 1,5-hydrogen transfer/SHi reactions of aryl azides 95, which provided indolines or tetrahydroquinolines 97 in 72-82% yield (Fig. 24) [148]. The reaction starts probably with the formation of iron nitrenoids 95A from 95. These diradicaloids undergo a 1,5- or 1,6-hydrogen transfer from the benzylic position of the ortho-side chain. The resulting benzylic radicals 95B react subsequently with the iron(IV) amide unit in an Sni reaction, which liberates the products 97 and regenerates the catalyst. /V,/V-Dialkyl-w// o-azidobenzamides reacted similarly in 63-83% yield. For hydroxy- or methoxy-substituted indolines 97 (R2=OH or OMe) elimination of water or methanol occurred from the initial products 97 under the reaction conditions giving indoles 98 in 74—78% yield. 

L. Manduchi (1998). Kinetie deuterium isotope effeet profiles and substituent effects in the oxidative N-demethylation of N,N-dimethylanilines catalyzed by tetrakis(pentafluorophenyl)porphyrin iron(Ill) chloride. J. Am. Chem. Soc. 120, 5783-5787. 

Wong A, Del Pilar Taboada Sotomayor M. Biomimetic sensa- based on 5,10,15,20-tetrakis(pentafluorophenyl)-21H,23H-porphyrin iron (HI) chloride and MWCNT for selective detection of 2,4-D. Sens Actuat B 2013 181 332-9. 

Many metals occur in crude oils. Some of the more abundant are sodium, calcium, magnesium, aluminium, iron, vanadium, and nickel. They are present either as inorganic salts, such as sodium and magnesium chlorides, or in the form of organometallic compounds, such as those of nickel and vanadium (as in porphyrins). Calcium and magnesium can form salts or soaps with carboxylic acids. These compounds act as emulsifiers, and their presence is undesirable. 

The reduction electrochemistry of ECP porphyrin films furthermore responds to added axial ligands in the expected ways. We have tested this (2,6) for the ECP form of the iron complex of tetra(o-amino)phenyl)porphyrin by adding chloride and various nitrogeneous bases to the contacting solutions, observing the Fe(III/II) wave shift to expected potentials based on the monomer behavior in solution. This is additional evidence that the essential porphyrin structure is preserved during the oxidation of the monomer and its incorporation into a polymeric film. 

Castro (1964) reported that iron(II) porphyrins in dilute aqueous solution was rapidly oxidized by DDT to form the corresponding iron(III) chloride complex (hematin) and DDE, respectively. Incubation of /5,//-DDT with hematin and ammonia gave p./Z-DDD, p./Z-DDE, bis(/5-chloro-phenyl)acetonitrile, l-chloro-2,2-bis(jD-chlorophenyl)ethylene, 4,4 -dichlorobenzophenone, and the methyl ester of bis (jo-chlorophenyl) acetic acid (Quirke et al., 1979). 

Reduction of p-oxo-bis[tetraphenylporphin iron(iii)] with sodium amalgam gives several products sequentially. The first reduction product is the radical-anion [(tpp)Fe ] , which has a spin state of - at 77 K and at 300 K. This is the first reported study of an Fe -porphyrin.Mossbauer data on a range of tetra-aryl-substituted iron-porphines and their p-oxo-bridged derivatives have been reported. A crystallographic study on bis(imidazole) otPy -tetraphenylporphinatoiron(iii) chloride-methanol solvate shows the [FeN ] core to be quasitetragonal. An n.m.r. study has been made of the related... 

SAMFETs have also been used in chemical sensing. The a-substituted quincpiethiophene SAMFETs were covered with a 10-nm pinhole-riddled iron tetraphenylporphyrin chloride layer, that acts as a receptor to nitric oxide (NO), an important biomarker [74]. The threshold voltage, measured by the FET transfer characteristics with the porphyrin receptor shifts upon increased exposure to NO. Annealing the monolayer FET in vacuum restores the initial FET behavior. Also, in the single monolayer HBC assembled FETs between metallic SWCNT source and drain electrodes increased current levels were measured in /d-Fds and Aj-Fg characteristics (Fig. 9) upon exposure to solutions of the electron acceptor TCNQ [68]. While the mechanism of response is not known, TCNQ has an affinity for coronene, and likely gives rise to charge transfer between electron-deficient TCNQ... 

Complexes of acetylacetone (acacH), benzoylacetone (bzacH) and dipivaloylmethane (dpmH) have been reported. The acetylacetonate [Cr(acac)2] has been prepared from chromium(II) acetate and acetylacetone.142,143 It can also be obtained by the addition of aqueous sodium acetylacetonate to an aqueous solution of chromium(II) chloride, but in any preparation the yellow solid must be filtered off and dried as rapidly as possible, otherwise the chromium(III) compound is obtained. Its magnetic moment is 4.99 BM at room temperature consistent with a high-spin d4 configuration. 142The powerful reducing ability of [Cr(acac)2] has been used to prepare iron(II) and chromium(II) complexes80 of porphyrins and related ligands. 

Acetylation and formylation are classical reactions in porphyrin chemistry. H. Fischer s synthesis of hemin, for which he was awarded the 1930 Nobel prize, required treatment of deuterohemin (49) with acetic anhydride (or acetyl chloride) in the presence of tin(IV) chloride as a Friedel-Crafts catalyst the product, 3,8-diacetyldeuterohemin-IX (50), was obtained in high yield. Fischer also accomplished formylation of iron porphyrins using dichloromethyl methyl ether and a Friedel-Crafts catalyst (B-37MI30700). Both of Fischer s examples resulted in peripheral substitution of unsubstituted iron porphyrins. However,... 

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