Palladium-iron catalyst

An acidic solvent is recommended for use with palladium. Other catalysts that have been used for this reduction include copper chromite and any of the three Raney catalysts, cobalt, iron, or nickel. 

The hydration of propylene with sulfuric acid catalyst in high-temperature water was investigated using a flow reaction system.31 The major product is isopropanol. A biopolymer-metal complex, wool-supported palladium-iron complex (wool-Pd-Fe), has been found to be a highly active catalyst for the hydration of some alkenes to the corresponding alcohols. The yield is greatly affected by the Pd/Fe molar ratio in the wool-Pd-Fe complex catalyst and the catalyst can be reused several times without remarkable change in the catalytic activity.32... 

The type of intermediate shown in structure (B) has also been supported by Muller and Gault (119) who showed that in the reaction of 1,1-dimethylcyclopropane with deuterium over a series of thick evaporated metal film catalysts, it was only on platinum that 1,1,3-da-neopen-tane (and 1,1,3,3-d4-neopentane) were dominant products. On palladium, iron, rhodium, nickel, and cobalt the major product was 1,3-d2-neopentane. 

A major limitation of such Group IVB metallocene catalysts is that they are air- and moisture-sensitive and not tolerant to heteroatom-containing monomers. In the case of heteroatom-containing monomers the unbonded electron pairs on the heteroatom, such as oxygen, preferentially coordinate to the Lewis acid metal center in place of the carbon-carbon double bond. Some so-called middle and late transition metal organometallics are more tolerant to the presence of such heteroatoms and can be used as effective cocatalysts. These include some palladium, iron, cobalt, and nickel initiators. 

The metal-catalysed hydrogenation of cyclopropane has been extensively studied. Although the reaction was first reported in 1907 [242], it was not until some 50 years later that the first kinetic studies were reported by Bond et al. [26,243—245] who used pumice-supported nickel, rhodium, palladium, iridium and platinum, by Hayes and Taylor [246] who used K20-promoted iron catalysts, and by Benson and Kwan [247] who used nickel on silica—alumina. From these studies, it was concluded that the behaviour of cyclopropane was intermediate between that of alkenes and alkanes. With iron and nickel catalysts, the initial rate law is... 

Berry, F.J., Smart, L.E., Prasad, P.S.S., Lingaiah, N. and Rao, P.K., Microwave heating during catalyst preparation influence on the hydrodechlorination activity of alumina-supported palladium-iron bimetallic catalysts,... 

Another isomerization mechanism, observed in some palladium, nickel and iron catalysts, is the allyl-hydride mechanism. This involves coordination of the olefin to a metal centre, which then abstracts an allylic H to form an allyl-metal hydride intermediate. The H can then re-add either to the same carbon or to the carbon on the opposite side (Equation 8). 

In some cases, vinyl halides can be coupled. An aryl Grignard reagent was coupled to a vinyl iodide in the presence of an iron catalyst.Butylmag-nesium chloride was coupled to vinyl triflates with Fe(acac)3. ° The palladium-catalyzed coupling of arylmagnesium halides and vinyl bromides has also been reported. ... 

Alkynes and allenes also react with amides. Phenylthiomethyl alkynes were converted to A-Boc-A-phenylthio allenes with Boc azide and an iron catalyst. The palladium-catalyzed reaction of an allene amide, with iodobenzene, leads to A-sulfonyl aziridines having an allyhc group at Other allene A-tosylamines... 

For illustration, we may consider the preparation of a palladium/zirconia catalyst highly active for the oxidation of CO [4.47,71], the preparation of a copper/zirconia catalyst for the hydrogenation of C02 [4.23], and the preparation of iron/zirconia for ammonia synthesis [4.44]. 

Ethylene for polymerization to the most widely used polymer can be made by the dehydration of ethanol from fermentation (12.1).6 The ethanol used need not be anhydrous. Dehydration of 20% aqueous ethanol over HZSM-5 zeolite gave 76-83% ethylene, 2% ethane, 6.6% propylene, 2% propane, 4% butenes, and 3% /3-butane.7 Presumably, the paraffins could be dehydrogenated catalyti-cally after separation from the olefins.8 Ethylene can be dimerized to 1-butene with a nickel catalyst.9 It can be trimerized to 1-hexene with a chromium catalyst with 95% selectivity at 70% conversion.10 Ethylene is often copolymerized with 1-hexene to produce linear low-density polyethylene. Brookhart and co-workers have developed iron, cobalt, nickel, and palladium dimine catalysts that produce similar branched polyethylene from ethylene alone.11 Mixed higher olefins can be made by reaction of ethylene with triethylaluminum or by the Shell higher olefins process, which employs a nickel phosphine catalyst. 

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