Arylation iron chloride

When thionyl chloride is used, diaryl sulfoxides are usually the main products. Unsymmetrical diaryl sulfides can be obtained by treatment of an aromatic compound with an aryl sulfenyl chloride (ArSCl) in the presence of a trace amount of iron powder.Aromatic amines and phenols can be alkylthiolated (giving mostly ortho product) by treatment with an alkyl disulfide and a Lewis acid catalyst. With certain substrates (primary amines with a chloro group, or a group not replaceable by chloro, in the para position), treatment with S2CI2 and NaOH gives thiophenolate salts ... 

Iron sulfate [82] and iron chloride [83] have also been reported as catalysts for the nucleophilic aromatic substitution of unactivated aryl halides. As solvents, liquid ammonia and DMSO at room temperature are used (Scheme 6.17). 

Metal catalysts such as bismuth triflate (Bi(OTf)3) and iron chloride hexa-hydrate (FeCl3 6H2O) have been shown to catalyse Ritter reaetions by Barrett and Cossy respeetively. Barrett used 20 mol% Bi(OTf)3 in the synthesis of A(-fe/t-butyl amides by coupling a range of alkyl and aryl nitriles with ferf-BuOH or tert-butyl aeetate (terf-BuOAc). Although Cossy used lower catalyst loadings of a cheaper metal, higher temperatures of 150 °C were... 

The equation for a net chemical reaction represents the overall transformation of reactants into products. Thus, thallium Ill) ions oxidize iron(II) ions according to Eq. (1-1), and a secondary amine reacts with an aryl chloride as in Eq. (1-2). 

Reaction of allyl nalides with the iron powders is rapid and exothermic and leads to near quantitative yields of the self-coupled product 1,5-hexadiene. Similarly, reaction of benzyl chloride with the iron powders at room temperature yields bibenzyl in 60-70% yields along with 20-25% of toluene. In contrast, reaction of aryl halides with the iron powders leads to reductive cleavage rather than self-coupling. Similarly, reaction of 1-bromoheptane with the iron powder in THF for three hours at room... 

Tricarbonyl(cyclohexadienyl)iron cations react with a variety of nucleophiles to give substituted tricarbonyl(cyclohexadienyl)iron complexes88 with arylamines, N- or C-alkylation can occur depending on the nature of aryl ring substituents. Deligation of C-alkylated arylamines can be achieved by either ferric chloride, which gives the free arylamine, or by iodine in the latter case, cyclization with concomitant oxidation occurs, and carbazoles are produced in moderate yield (Scheme 52).89... 

Attachment of dendritic wedges of either the carbosilane or benzylphenyl ether type to the para-hydroxy aryl site in [2,6-(ArN=CMe)2C5H3N (1 R = Me, Ar = 2-Me-4-OHC6H3), has been shown to proceed in good yield [162], Complexation with iron(II) chloride allows access to dendrimer-supported precatalyst 42 (Scheme 13). Using MAO as a co-catalyst, it was shown that 42 are active in the oligomerisation of ethylene the activity of these new catalysts is not, however, related to the type of dendritic wedge employed. 

Recent notable improvements by Knochel and co-workers include iron-catalyzed cross-coupling reactions of various acid chlorides 148 with dialkylzinc reagents (Equation (24))324 as well as the iron-catalyzed arylation of aroyl cyanides 149 with Grignard reagents (Equation (25)).3 5 In the first case Knochel s reaction conditions tolerate ester groups on the organozinc compounds, while in the latter case ester, aryl alkyl ether, cyano, and chloro functionalities on the aromatic moieties are compatibles with the reaction conditions. 

A viable iron carbonyl-mediated reduction process converts acid chlorides and bromoalkanes into aldehydes [3, 6]. Yields are high, with the exception of nitro-benzoyl chloride, and the procedure is generally applicable for the synthesis of alkyl, aryl and a,(i-unsaturated aldehydes from the acid chlorides. The reduction proceeds via the initial formation of the acyl iron complex, followed by hydride transfer and extrusion of the aldehyde (cf. Chapter 8). 

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... 

Crich and Rumthao reported a new synthesis of carbazomycin B using a benzeneselenol-catalyzed, stannane-mediated addition of an aryl radical to the functionalized iodocarbamate 835, followed by cyclization and dehydrogenative aromatization (622). The iodocarbamate 835 required for the key radical reaction was obtained from the nitrophenol 784 (609) (see Scheme 5.85). lodination of 784, followed by acetylation, afforded 3,4-dimethyl-6-iodo-2-methoxy-5-nitrophenyl acetate 834. Reduction of 834 with iron and ferric chloride in acetic acid, followed by reaction with methyl chloroformate, led to the iodocarbamate 835. Reaction of 835 and diphenyl diselenide in refluxing benzene with tributyltin hydride and azobisisobutyronitrile (AIBN) gave the adduct 836 in 40% yield, along with 8% of the recovered substrate and 12% of the deiodinated carbamate 837. Treatment of 836 with phenylselenenyl bromide in dichloromethane afforded the phenylselenenyltetrahydrocarbazole 838. Oxidative... 

However, arylmagnesium organometaUics can only be used in a few cases " like an iron-catalyzed homocoupling (equation 92) . Iron catalysis is further used for the dechlorination of electron-rich aryl chlorides by Grignard reagents . ... 

In 2002, Figad re and coworkers reported the mono-reduction of 2-aryl (or heteroaryl)-1,1-dibromo-l-alkenes (Scheme 23). The reaction is achieved with one equivalent of isopropylmagnesium chloride in the presence of iron(III) acetylacetonate. Pure ( )-alkenyl bromides are obtained. With two equivalents of alkyl Grignard reagent, the mono-substituted product is obtained in moderate yield. 

In 2005, Cahiez and coworkers and Nagano and Hayashi showed that a catalytic amount of iron(III) chloride is efficient when a suitable oxidant is added to the reaction mixture (Figure 3). Nagano and Hayashi used an excess of 1,2-dichloroethane (the stoichiometric amount is 0.5 equivalent) in refluxing diethyl ether to couple various aryl Grignard reagents in high yield (Scheme 46). 

Proton acids can be used as catalysts when the reagent is a carboxylic acid. The mixed carboxylic sulfonic anhydrides RCOOSO2CF3 are extremely reactive acylating agents and can smoothly acylate benzene without a catalyst.265 With active substrates (e.g., aryl ethers, fused-ring systems, thiophenes), Friedel-Crafts acylation can be carried out with very small amounts of catalyst, often just a trace, or even sometimes with no catalyst at all. Ferric chloride, iodine, zinc chloride, and iron are the most common catalysts when the reactions is carried out in this manner.266... 

Table 5.5 Scope of aryl chlorides and sulfonates in iron-catalyzed cross-coupling reaction with RMgBr.

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