19398-37-9

The liquid phase alkylation of benzene with dec-1-ene was catalyzed by 12-tungstophosphoric acid (WP) supported on different solids (ZrO2, SiO2, activated carbon and boehmite-Al2O3). Catalysts prepared with 20 w

Mixing of [(PBP)PtCl] complex with 1-decene and H2O afforded isomerized alkenes. Deuterium-labeling experiment indicated the catalytically active hydride species for alkene isomerization formed from water and [(PBP)Pt] complex. Reaction of [(PBP)PtNTf2] with H2O gave a platinum hydride complex having PNNP ligand with a loss of boron atom, but the resulting complex showed low catalytic activity. Two types of cationic platinum hydride complexes were suggested as active species for alkene isomerization.

WO3–x (W-1) was used to achieve controllable photoisomerization of linear olefins without substituents under 625 nm light irradiation. Thermodynamic and kinetic isomers were obtained by regulating the carbon chain length of the olefins. Terminal olefins were converted into isomerized products, and the internal olefin mixtures present in petroleum derivatives were transformed into valuable pure olefin products. Oxygen vacancies (OVs) in W-1 altered the electronic structure of W-1 to improve its light-harvesting ability, which accounted for the high activity of olefin isomerization under light irradiation up to 625 nm. Additionally, OVs on the W-1 surface generated unsaturated W5+ sites that coordinated with olefins for the efficient adsorption and activation of olefins. Mechanistic studies reveal that the in situ formation of surface π-complexes and π-allylic W intermediates originating from the coordination of coordinated unsaturated W5+ sites and olefins ensure high photocatalytic activity and selectivity of W-1 for the photocatalytic isomerization of olefins via a radical mechanism.

A process for migrating C=C double bonds within an unsaturated organic compound is described. The process involves contacting an unsaturated organic compound starting material with a heteropoly acid catalyst in the presence of light having a wavelength of less than or equal to 700 nm. Also described is a process for the preparation of novel heteropoly acids having markedly increased surface area.

The impact of the presence and amount of [BMIM][NTf2] ionic liquid during the preparation of bulk NiMoS catalysts was investigated. It was clearly shown that these factors have a strong influence on both the morphology and specific surface area of the obtained NiMoS samples. Most interestingly the catalytic activity for the transformation of decanoic acid increased up to three times when IL was present during synthesis. In the same time, a greater selectivity towards hydrocarbons was observed. On the whole a clear relationship between catalytic activity, selectivity and NiMoS morphology was demonstrated. Consequently, it is possible to modify the morphology of the materials and impact the catalytic properties by changing the synthesis conditions.

Dimethyl carbonate (DMC) chemistry has been extended to include acid-catalysed reactions of different aliphatic alcohols and phenols. For the first time, p-toluenesulfonic acid (PTSA), H2SO4, AlCl3 and FeCl3 have been shown to aid carboxymethylation for primary aliphatic alcohols at catalytic loadings with quantitative conversion and selectivity. For carboxymethylation of secondary alcohols, stoichiometric PTSA and catalytic AlCl3 both gave quantitative conversion and selectivity. Stoichiometric FeCl3 and H2SO4 promoted dehydration of linear aliphatic alcohols. Additionally FeCl3 catalysed methylation of cyclohexanol, whilst AlCl3 resulted in methylation of phenolic compounds. This research expands the range of potential application for DMC in green chemistry.

At 35 °C, in the presence of supercritical carbon dioxide (80-150 bar) as a solvent, α-olefins (RCHCH2, R = C4-C6) undergo highly selective self-metathesis catalyzed by supported Re-oxide (7%). To the best of our knowledge, this is the first procedure for the metathesis of alkenes, in which heterogeneous catalysts are combined with the use of dense CO2. The intrinsic eco-compatibility and the unique physicochemical properties of this medium offer both environmental and synthetic advantages: not only conventional toxic solvents (e.g. n-heptane and toluene) can be replaced, but the reaction is faster. For instance, after 2 h, the average conversion of 1-octene is 67% and 40% in scCO2 and n-heptane, respectively. The product of self-methatesis, 7-tetradecene, can be isolated in yields up to 68%. At 90 bar, the reaction is rather sensitive to the mole fraction of the olefin (in scCO2); though, the enhancement of the pressure (and the density) of the supercritical medium does not induce significant effects on either the rate or the selectivity of the process. The nature of the catalytic support also greatly affects the reaction outcome: Re-oxide shows good activity if dispersed over γ-Al2O3, while silica-based systems are ineffective.