Dehydrogenations catalytic

Dehalogenating reduction Salt elimination Disproportionation Electrochemical formation Dehydrogenative catalytic coupling... 

Although the mechanism of the platinum catalysis is by no means completely understood, chemists do know a lot about how it works. It is an example of a dual catalyst platinum metal on an alumina support. Platinum, a transition metal, is one of many metals known for its hydrogenation and dehydrogenation catalytic effects. Recently bimetallic platinum/rhenium catalysts are now the industry standard because they are more stable and have higher activity than platinum alone. Alumina is a good Lewis acid and as such easily isomerizes one carbocation to another through methyl shifts. 

Synthesis from Citronellol. Citronellol is hydrated to 3,7-dimethyloctan-l,7-diol, for example, by reaction with 60% sulfuric acid. The diol is dehydrogenated catalytically in the vapor phase at low pressure to highly pure hydroxydihydrocitronellal in excellent yield. The process is carried out in the presence of, for example, a copper-zinc catalyst [68] at atmospheric pressure noble metal catalysts can also be used [69]. 

Properties. Phenethyl alcohol is a colorless liquid with a mild rose odor. It can be dehydrogenated catalytically to phenylacetaldehyde and oxidized to phenylacetic acid (e.g., with chromic acid). Its lower molecular mass fatty acid esters as well as some alkyl ethers, are valuable fragrance and flavor substances. 

In general, a catalytic reaction may be named by adding the adjective catalytic to the standard chemical term for the reaction, for example, catalytic hydrogenation (or, if clarity demands, heterogeneous catalytic hydrogenation), catalytic hydrodesulphurisation, catalytic oxidative dehydrogenation, catalytic stereospecific polymerisation. 

This is probably the single most important material used by the fragrance industry. Several million pounds are used annually, mainly in soaps and detergents. The principal method of manufacture shown in Figure 10 is by hydration of citronellal via the bisulfite addition product (2). The aldehyde moiety must be protected before hydration. A second manufacturing process starts with citronellol which is hydrated under acid conditions. The primary alcohol end of the molecule is then dehydrogenated catalytically or by oxidation to the aldehyde. 

In the case of phenanthridine itself, this has been achieved by reduction with lithium aluminum hydride211 presumably stoichiometric quantities were employed since the hydride can reduce phenanthridine to its 5,6-dihydro derivative.212 In a procedure which has been adopted more widely, an excess of lithium aluminum hydride is employed and the resultant 5,6-dihydrophenanthridine is dehydrogenated catalytically or,213 better, with an excess of chlor-anil.102, 200 Oxidation with aqueous potassium permanganate has been employed for the second stage,139 but the method does not appear to be general.22... 

Patermarakis, G. (2003) The parallel dehydrative and dehydrogenative catalytic action of y-A1203 pure and doped by MgO kinetics, selectivity, time dependence of catalytic behaviour, mechanisms and interpretations. Appl. Catal. A-General, 252, 231-241. 

For 2-butanol dehydrogenation, catalytic reactions were carried out at atmospheric pressure in a fixed bed flow-microreactor. The feed was 4.2 Nl/h of helium with a partial pressure of 8.5 kPa of 2-butanol. Reaction temperatures were from 373 K to 573 K. Concentrations of reactants and products were measured at the reactor outlet by on-line gas chromatography. 

The catalytic reactions of interest in organic synthesis can conveniently be divided into five categories solid-acid catalysis, solid-base catalysis, catalytic hydrogenation and dehydrogenation, catalytic oxidation, and catalytic C-C bond formation. 

The use of successive cycling pulses, both sinusoidal and otherwise, in a chromatographic reactor has been treated and analyzed by Gore (35). An experimental treatment in which pulsed frequencies were used to optimize the cyclohexane dehydrogenation (catalytic) reaction has also been presented (36). 

Ethylbenzene [100-41-4] (phenylethane) has a water-clear appearance and characteristic odor. It is miscible with practically all organic solvents, but is insoluble in water. Ethylbenzene is of limited importance as a paints solvent. Its main use is as an industrial starting material for the production of styrene by catalytic dehydrogenation. Catalytic oxidation of ethylbenzene with air in the presence of heavy-metal oxides yields acetophenone and phenylmethylcarbinol. It also improves the antiknock properties of fuels for Otto engines. 

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