Iron catalysts synthetic routes

Weak Base Anion Exchangers. Both styrenic and acrylic copolymers can be converted to weak base anion-exchange resins, but different synthetic routes are necessary. Styrene—DVB copolymers are chloromethylated and aminated in a two-step process. Chloromethyl groups are attached to the aromatic rings (5) by reaction of chloromethyl methyl ether [107-30-2], CH3OCH2Cl, with the copolymer in the presence of a Friedel-Crafts catalyst such as aluminum chloride [7446-70-0], A1C13, iron(III) chloride [7705-08-0]9 FeCl3, or zinc chloride [7646-85-7], ZnC. ... 

A large number of intermediate pathways arc possible when catalytic reactions interfere with the polymerization-dehydrogenation steps. A common scenario is the catalytic dehydrogenation of hydrocarbons on nickel surfaces followed by dissolution of the activated carbon atoms and exsolution of graphene layers after exceeding the solubility limit of carbon in nickel. Such processes have been observed experimentally [40] and used to explain the shapes of carbon filaments. In the most recent synthetic routes to nanotubes [41] the catalytic action of in situ-prepared iron metal particles was applied to create a catalyst for the dehydrogenation of cither ethylene or benzene. 

The formation of cresols (and xylenols) by Friedel-Crafts type alkylation in the reaction of phenol with methanol at 300-450°C over a solid catalyst usually a modified metal oxide is an important and well established synthetic route (ref.22) and typically can result in predominantly o/p substitution (o-cresol,54%, p-cresol,30%, and m-cresol, 17%). Selectivity can be achieved with a magnesium oxide or metal oxide-iron oxide mixture to afford o-cresol and... 

Removal of the iron from ferrocene has been accomplished by brief treatment (5 min) with lithium in ethylamine to give reasonable yields ( 70 %) of cyclopentadiene (Trifan and Nicholas, 1957). More recently, a hydrogenation procedure for ferrocenes employing Pd/C as catalyst under mild conditions (1 atm hydrogen, room temperature) but in acid solution (aqueous perchloric acid in acetic acid) has been reported as a synthetic route to substituted cyclopentanes. No yields were given (Van Meurs et a ., 1975). 

The aziridination of olefins, which forms a three-membered nitrogen heterocycle, is one important nitrene transfer reaction. Aziridination shows an advantage over the more classic olefin hydroamination reaction in some syntheses because the three-membered ring that is formed can be further modified. More recently, intramolecular amidation and intermolecular amination of C-H bonds into new C-N bonds has been developed with various metal catalysts. When compared with conventional substitution or nucleophilic addition routes, the direct formation of C-N bonds from C-H bonds reduces the number of synthetic steps and improves overall efficiency.2 After early work on iron, manganese, and copper,6 Muller, Dauban, Dodd, Du Bois, and others developed different dirhodium carboxylate catalyst systems that catalyze C-N bond formation starting from nitrene precursors,7 while Che studied a ruthenium porphyrin catalyst system extensively.8 The rhodium and ruthenium systems are... 

Most of the industrial chlorinations of organic compounds are, at present, performed by free CI2 either in the absence of catalysts or in the presence of Lewis acid catalysts such as the halides of aluminium and iron. The major handicap of the Lewis acid catalysts like FeCb or AICI3, is the difficulty of their disposal, after use in the chlorination reaction, in an environmentally friendly manner. The use of zeolite catalysts in the chlorination processes will avoid corrosion and disposal problems. Work-up procedures to isolate and recover the desired product will also be easier leading to simpler and cleeiner process routes. In addition, if zeolites are used as solid catalysts, one may anticipate that desired changes in selectivity (enhanced para-selectivity in nuclear chlorination of aromatics, for example) may be achieved. Zeolite catalysts are well known to catalyze various synthetic transformations, however, relatively a few reports are available on the selective chlorination of aromatics using zeolite catalysts [1-4],... 

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