Hydrogenation of 1-octene

Figure 12. Catalytic activities of the Ni and Ni-Zn nanoclusters with and without Xi02 for the hydrogenation of 1-octene.

Similar low activities were found in the hydrogenation of 1-octene [47]. The use of [Ni(PPh3)2I2] in the hydrogenation of norbomadiene resulted in considerable amounts of nortricyclene, via transannular ring closure, whereas 1,5-cyclo-octadiene yielded bis-cyclo-[3.3.0]oct-2-ene. According to these authors, the re-... 

Fig. 5.4 Dihydrogen pressure drop of the hydrogenation of 1-octene using an /n-s/tM-formed catalyst containing Ni(OAc)2 and the ligand o-MeO-dppe. After 30 and 150 min, fresh 1-octene is added to the reaction mixture and the H2 pressure is reset to 50 bar. (Reproduced from [57])...

Scheme 5.4 Three processes in which nickel diphosphane complexes can be involved under catalytic hydrogenation conditions. (A) ligand exchange (B) oxidation and (C) hydrogenation of 1-octene. For simplicity, the reac-...

Solvent-free hydrogenations of 1-octene, 2-pentene, cyclohexene, and styrene were carried out with catalyst loadings as low as 0.05 mol.% of the dimer, in some cases with TOF values as high as 6000 IT1 [71]. Total turnover numbers of almost 2000 were obtained in most of these cases. Solvent-free hydrogenation of ketones such as Et2C=0, cyclohexanone, and diisopropyl ketone were also reported at the same temperature and H2 pressure, but with somewhat lower TOFs for the hydrogenation of C=0 compared to C=C hydrogenations. 

Figure 8.8 The increase in turnover frequency for the hydrogenation of 1-octene using a fluorous derivative of Wilkinson s catalyst as the catalyst (or catalyst precursor)...

A simple system, NiBr2 in alkaline 2-propanol, has been reported to exhibit high activity in the transfer hydrogenation of 1-octene.435... 

Os(H)4(PEtPh3)3] catalyzes the hydrogenation of 1-octene at normal pressure and raised temperature, but considerable isomerization occurs. The complex can be recovered unchanged after the reaction. The cis complex [Os(H)2(PEtPh2)4] catalyzes isomerization more rapidly than hydrogenation.208... 

The complex RhCl(ttp), where ttp = PhP(CH2CH2CH2-PPh2)2, in the presence of either triethylaluminum or diethylaluminum chloride, is an effective homogeneous catalyst for hydrogenation of 1-olefins and 1-octyne. The rates of hydrogenation of substituted olefins are considerably slower than for terminal olefins. H-l and P-31 NMR spectra were used to identify several different chemical species [including RhH(ttp)] in these catalyti-cally active solutions. The observed rate of hydrogenation of 1-octene to n-octane at 20 0.3°C and under a constant H2 pressure of 750 torr is 6.4 x min 9... 

Figure 3. A plot of hydrogen consumption vs. time for the hydrogenation of 1-octene at constant pressure...

Figure 4. A plot ofLn P(H2) vs. time for hydrogenation of 1-octene at...

Brown and Brown prepared an active platinum catalyst by in situ reducing chloroplatinic acid (1 ml of 0.2M solution) in 40 ml ethanol by injecting 5.0 ml of 1M sodium borohydride in ethanol the excess borohydride is destroyed by injecting 4.0 ml of 6M hydrochloric acid. The platinum catalyst thus prepared was nearly twice as active as a commercial Adams catalyst in the hydrogenation of 1-octene at 25°C and atmospheric hydrogen pressure.146... 

Pd-hexadecylammonium montmorillonite (Pd-HDAM) catalysts have been prepared by a novel synthetic route. Sample characterization including XRD and TEM measurements confirmed the existence of interlayer Pd nanocrystallites which occupy clay particle defect sites. The catalytic activities of Pd-HDAM samples were tested by hydrogenation of 1-octene and styrene in the liquid phase. The reaction of styrene was found to be less dependent on the dispersion of Pd than that of 1-octene. The highest activities were observed for samples of low and medium Pd content. The application of various solvents made it pos le to establish a correlation between the activities and the basal spacings dL of Pd-HDAM samples. When the value of dL exceeded 3 ran, interlamellar active sites became more accessible for reactants. 

The catalytic hydrogenations of 1-octene and styrene were effected in a conventional hydrogenation apparatus with a molar ratio of Pd substrate = 1 500 at 298 K and atmospheric pressure. In each case, 5 x 10 g sample was pretreated in H2 at 298 K for 1 h and subsequently in 1 cm of solvent, under stirring, for another 45 min. After introduction of the reactant, a vigorous stirring was applied (1240 rpm), and the reaction was conducted until the theoretical volume of H2 has been consumed. After removing the catalyst by filtration, the products were identified and analyzed by GC. 

The hydrogenation of 1-octene was studied in toluene. According to XRD measurements, toluene provides a considerable expansion of the clay lamellae (dL = 4.07 nm), which opens access for reactant molecules to interlayer active sites. As a result, the reaction of 1-octene may take place in the interlamellar space of Pd-HDAM samples. 

The decrease of the dispersion values indicated by Table 1 is attributed to the effect of Pd aggregation. However, the amount of exposed metal atoms displayed no particular change. In contrast to supported Pd catalysts, usually considered as structure insensitive in alkene hydrogenations [13], the initial rates and the turnover frequencies obtained for Pd-HDAM samples considerably vary with the dispersion values. This suggests that in the hydrogenation of 1-octene, Pd-ffl)AM catalysts act in a different way. The difference observed may be... 

The effect of pressure in the hydrogenation of 1-octene was studied at 70°C, and between 172 - 207 bar in the 100 mL reactor. The catalyst employed for this study was RhCl(TANi5DPPA)3 with rhodium/polymer ratio of 3. The initial mole fractions of 1-octene and hydrogen were 0.001 and 0.033, respectively. These mole fractions were kept constant in all the experiments. The substrate to catalyst mole ratio was 400. Figure 9 shows the experimental results. Experiments were run twice to determine reproducibility, the points represent the average, and the error bars the standard deviation. Derivations from the transition-state theory [15] show that the thermodynamic effect of pressure on reactivity and selectivity for reactions at supercritical conditions are related to the following equations, respectively ... 

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