Iron chloride catalyst

Halogenation Bromine reacts with benzene in the presence of iron(lll) bro mide as a catalyst to give bromobenzene Chlorine reacts similarly in the presence of iron(lll) chloride to give chlorobenzene... 

If bromine is used in equation 8, carbon tetrabromide [558-13-4] is formed. With a minor amount of iodine present, and in the absence of iron catalyst, carbon disulfide and chlorine react to form trichioromethanesulfenyl chloride (perchloromethyl mercaptan [594-42-3]), CCI3SCI, which can be reduced with staimous chloride or tin, and hydrochloric acid to form thiophosgene (thiocarbonyl chloride [463-71-8], CSCI2, an intermediate in the synthesis of many organic compounds (see Sulfurcompounds). 

Aromatic compounds may be chlorinated with chlorine in the presence of a catalyst such as iron, ferric chloride, or other Lewis acids. The halogenation reaction involves electrophilic displacement of the aromatic hydrogen by halogen. Introduction of a second chlorine atom into the monochloro aromatic stmcture leads to ortho and para substitution. The presence of a Lewis acid favors polarization of the chlorine molecule, thereby increasing its electrophilic character. Because the polarization does not lead to complete ionization, the reaction should be represented as shown in equation 26. 

A successful procedure for the formation of 2,5-di-t-butylfuran involves reaction of the parent heterocycle with f-butyl chloride in the presence of iron(III) chloride and iron(III) oxide. Iron(III) oxide acts as a hydrogen chloride scavenger and at the same time regenerates the catalyst. Concurrent polymerization normally deactivates the catalyst (82CI(L)603). 

The Friedel-Crafts acylation reaction has also been performed in iron(III) chloride ionic liquids, by Seddon and co-workers [96]. An example is the acetylation of benzene (Scheme 5.1-66). Ionic liquids of the type [EMIM]Cl/FeCl3 (0.50 < X(FeCl3) < 0.62) are good acylation catalysts, with the added benefit that the ketone product of the reaction can be separated from the ionic liquid by solvent extraction, provided that X(FeCl3) is in the range 0.51-0.55. 

The ability of iron(III) chloride genuinely to catalyze Friedel-Crafts acylation reactions has also been recognized by Holderich and co-workers [97]. By immobilizing the ionic liquid [BMIM]Cl/FeCl3 on a solid support, Holderich was able to acetylate mesitylene, anisole, and m-xylene with acetyl chloride in excellent yield. The performance of the iron-based ionic liquid was then compared with that of the corresponding chlorostannate(II) and chloroaluminate(III) ionic liquids. The results are given in Scheme 5.1-67 and Table 5.1-5. As can be seen, the iron catalyst gave superior results to the aluminium- or tin-based catalysts. The reactions were also carried out in the gas phase at between 200 and 300 °C. The acetylation reac-... 

It was shown that dibenzothiophene oxide 17 is inert to 1-benzyl-l,4-dihydro nicotinamide (BNAH) but that, in the presence of catalytic amounts of metalloporphyrin, 17 is reduced quantitatively by BNAH. From experimental results with different catalysts [meso-tetraphenylporphinato iron(III) chloride (TPPFeCl) being the best] and a series of substituted sulfoxides, Oae and coworkers80 suggest an initial SET from BNAH to Fe1 followed by a second SET from the catalyst to the sulfoxide. The results are also consistent with an initial coordination of the substrate to Fem, thus weakening the sulfur-oxygen bond in a way reminiscent of the reduction of sulfoxides with sodium borohydride in the presence of catalytic amounts of cobalt chloride81. 

One of the products of the reaction of sulfur with chlorine is disulfur dichloride, S2C12, a yellow liquid with a nauseating smell it is used for the vulcanization of rubber. When disulfur dichloride reacts with more chlorine in the presence of iron(III) chloride as a catalyst, the foul-smelling red liquid sulfur dichloride, SC12, is produced. Sulfur dichloride reacts with ethene to give mustard gas (16), which has been used in chemical warfare. Mustard gas causes blisters, discharges from the nose, and vomiting it also destroys the cornea of the eye. All in all, it is easy to see why ancient civilizations associated sulfur with the underworld. 

Iron (III) chloride is a common catalyst used in electrophilic aromatic substitutions. In addition to those applications outlined above for the construction of aromatic C-C bonds, such salts have also been used for the introduction of heteroatom-based functional groups at the aromatic ring [47]. 

Freeder, B. G. et al., J. Loss Prev. Process Ind., 1988, 1, 164-168 Accidental contamination of a 90 kg cylinder of ethylene oxide with a little sodium hydroxide solution led to explosive failure of the cylinder over 8 hours later [1], Based on later studies of the kinetics and heat release of the poly condensation reaction, it was estimated that after 8 hours and 1 min, some 12.7% of the oxide had condensed with an increase in temperature from 20 to 100°C. At this point the heat release rate was calculated to be 2.1 MJ/min, and 100 s later the temperature and heat release rate would be 160° and 1.67 MJ/s respectively, with 28% condensation. Complete reaction would have been attained some 16 s later at a temperature of 700°C [2], Precautions designed to prevent explosive polymerisation of ethylene oxide are discussed, including rigid exclusion of acids covalent halides, such as aluminium chloride, iron(III) chloride, tin(IV) chloride basic materials like alkali hydroxides, ammonia, amines, metallic potassium and catalytically active solids such as aluminium oxide, iron oxide, or rust [1] A comparative study of the runaway exothermic polymerisation of ethylene oxide and of propylene oxide by 10 wt% of solutions of sodium hydroxide of various concentrations has been done using ARC. Results below show onset temperatures/corrected adiabatic exotherm/maximum pressure attained and heat of polymerisation for the least (0.125 M) and most (1 M) concentrated alkali solutions used as catalysts. 

The effects of various metal oxides and salts which promote ignition of amine-red fuming nitric acid systems were examined. Among soluble catalysts, copperQ oxide, ammonium metavanadate, sodium metavanadate, iron(III) chloride (and potassium hexacyanoferrate(II) with o-toluidine) are most effective. Of the insoluble materials, copper(II) oxide, iron(III) oxide, vanadium(V) oxide, potassium chromate, potassium dichromate, potassium hexacyanoferrate(III) and sodium pentacyanonitrosylferrate(II) were effective. 

Turpentine and fuming nitric acid do not ignite on contact in absence of added catalysts (fuming sulfuric acid, iron(III) chloride, ammonium metavanadate or copper(II) chloride). 

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. 

The most important starting materials for process A are 4,4, 4"-triamino-triphenylmethane, pararosaniline (119), and parafuchsin (118). Aniline and formaldehyde are treated at 170°C to form, apart from some formaldehyde-aniline intermediates, 1,3,5-triphenylhexahydrotriazine as the main component. Subsequent treatment with an acidic catalyst, for instance with hydrochloric acid, in excess aniline as a solvent initially affords 4,4 -diaminodiphenylmethane, which is finally oxidized to yield parafuchsin (118). Iron(III)chloride and nitrobenzene, which in the past were used as oxidants, are no longer used. The reaction is now performed by air oxidation in the presence of vanadium pentoxide as a catalyst. 

Cycloalkenone-2-carboxylates tautomerize to conjugated dienols in the presence of either acids or bases. Iron(III) catalysts have also been found to promote enone-dienol equilibration, and, at room temperature, dimerization64. Thus, treating 87 with 1 mol% iron(III) chloride hexahydrate in methylene chloride at room temperature affords 88 in 81% yield (equation 46). The cyclohexadiene-cyclohexanone is in a rapid equilibrium with its triendiol tautomer, 89 (equation 47). 

As well as chlorination, benzene can undergo bromination when bromine is used as the reagent along with aluminium chloride or iron(lll) chloride as catalyst. The electrophiles, Ch and BrC are generated by the reaction between the halogen and the catalyst ... 

Aiyl chlorides and bromides can be easily prepared by electrophilic substitution of arenes with chlorine and bromine respectively in the presence of Lewis acid catalysts like iron or Iron(III) chloride. 

The main emphasis was laid, in this initial work, on Haber s catalysts, e.g., osmium and uranium compounds, as well as on a series of iron catalysts. Some other metals and their compounds which we tested are, as we know today, less accessibble to an activation by added substances than iron. Therefore, they showed no improvement or only small positive effects if used in the form of multicomponent catalysts. Finally, the substances which we added to the metal catalysts in this early stage of our work were mostly of the same type as those which had proved to favor the nitride formation, e.g., the flux promoting chlorides, sulfates, and fluorides of the alkali and alkaline earth metals. Again, we know today that just these compounds do not promote, but rather impair the activity of ammonia catalysts. 

Iron(III) chloride occurs naturally as the mineral molysite. The compound is widely used to prepare a number of iron(lII) salts. Also, it is apphed in sewage and industrial waste treatment processes. It also is used in the manufacture of dyes, pigments and inks as a chlorinating agent and as a catalyst in chlorination reactions of aromatics. 

Metal complexes of bis(oxazoline) ligands are excellent catalysts for the enantioselective Diels-Alder reaction of cyclopentadiene and 3-acryloyl-l,3-oxa-zolidin-2-one. This reaction was most commonly utilized for initial investigation of the catalytic system. The selectivity in this reaction can be twofold. Approach of the dienophile (in this case, 3-acryloyl-l,3-oxazolidin-2-one) can be from the endo or exo face and the orientation of the oxazolidinone ring can lead to formation of either enantiomer R or S) on each face. The ideal catalyst would offer control over both of these factors leading to reaction at exclusively one face (endo or exo) and yielding exclusively one enantiomer. Corey and co-workers first experimented with the use of bis(oxazoline)-metal complexes as catalysts in the Diels-Alder reaction between cyclopentadiene 68 and 3-acryloyl-l,3-oxazolidin-2-one 69 the results are summarized in Table 9.7 (Fig. 9.20). For this reaction, 10 mol% of various iron(III)-phe-box 6 complexes were utilized at a reaction temperature of —50 °C for 2-15 h. The yields of cycloadducts were 85%. The best selectivities were observed when iron(III) chloride was used as the metal source and the reaction was stirred at —50 °C for 15 h. Under these conditions the facial selectivity was determined to be 99 1 (endo/exo) with an endo ee of 84%. 

Twenty-five years later, a dramatic improvement was reported by Fiandanese, Marchese and coworkers ° . They discovered that excellent yields of ketone were obtained when diethyl ether is replaced by THF. Moreover, iron acetylacetonate is used as a catalyst instead of iron(III) chloride because it is not hygroscopic and easier to handle. The scope of the procedure is very large and the reaction occurs highly chemoselectively under mild conditions (0 °C). It should be noted that excellent yields are obtained from stoichiometric amounts of Grignard reagents (Table 3). 

The second procedure uses 1.5% [(FeCl3)2(tmeda)3] as a catalyst (Scheme 43). The complex, which is not hygroscopic, is very easily obtained by adding 1.5 equivalents of TMEDA to a solution of iron(III) chloride in THF (Scheme 44). It is quantitatively isolated by filtration. 

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