Hydroformylations of 1-decene

The use of catechol-based phosphites with PEG moieties in the thermoregulated phase-transfer hydroformylation of 1-decene was also investi-... 

The 3/Rh catalyst formed in situ (P/Rh = 4 1, substrate/Rh = 1000 1) has been applied to the aqueous-organic biphasic hydroformylation of 1-decene. The conversion of olefin and yield of aldehyde were 99.5 and 99.0%, respectively, after 5 h at 120 °C and 5.0 MPa of synthesis gas. Recycling tests showed that the aldehyde yield was still higher than 94.0% even after the catalyst had been recycled 20 times. 

Liu et al. [18] investigated the possibility of catalyst recycling in the nonaqueous hydroformylation of 1-decene by using the thermomorphic polyether phosphite 2a described earlier under phase-transfer conditions. Catalyst recovery with the procedure of phase-separable catalysis was possible with 0.92% rhodium loss in the seventh cycle. Complete olefin conversion and aldehyde yields of 98% were reached, but linear and branched aldehydes were formed in almost equal amounts. 

CH3(CH2)vCH(CH3)CHO, C11H22O, Mr 170.29, i pgg.skPa 119-120 °C, df 0.8948, 1.4205, is not reported to have been found in nature. It is a colorless liquid with an aldehydic, citrus-peel-like, waxy-green odor. 2-Methyldecanal is obtained as a by-product in the manufacture of 2-methylundecanal by hydroformylation of 1-decene (see 2-methylundecanal). It is used in perfumery to refresh green and citrus nuances. 

The fluorous biphasic catalysis concept was successfully demonstrated first by hydroformylation of 1-decene carried out in perfluoromethylcyclohexane and toluene, which forms a homogeneous liquid phase at 100°C in the presence of catalyst 2 prepared in situ according to Eq. (14.1) 125,133... 

Horvath and Rabai demonstrated the efficiency of their fluorous-soluble RhP[CH2CH2(CF2)5CF3]3 catalyst in the hydroformylation of 1-decene at 100 °C, usingaSOiSOvol toluene/CgFnCFsSolventmixtureandllbarofl 1 CO/H2[148]. 

The catalytic performance of the fluoropolymer ligands 1 and 2 was first tested in the fluorous biphase hydroformylation of 1-alkenes, styrene and n-butyl acrylate. The reaction was conducted in a batch reactor in a 40/20/40 vol% hexane/toluene/perfluoromethylcyclohexane solvent mixture (10 mL). The catalyst was formed in situ by adding [Rh(CO)2(acac)] (5 rmol, P/Rh = 6) to the polymer-containing solvent mixture followed by introduction of syngas (30 bar, CO/H2 = 1/1). Table 2 summarises the results obtained. The salient features of the results are Firstly, the activity of the fluorous soluble polymer catalysts are significantly higher than that reported for solid polymer- and aqueous soluble polymer-supported rhodium catalysts.18-22 For example, the average turnover frequency (TOF) for the fluorous biphase hydroformylation of 1-decene is 136 mole aldehyde h-1 per mol of rhodium catalyst with an aldehyde selectivity of 99%. In comparison, a rhodium catalyst supported on the... 

Recently, the activation energy for hydroformylation of 1-decene with HRh(CO)(TPP)3 was determined to be 48 kJ/mol, which is significantly lower [111]. A rate model was developed (eq. (11)) that was similar to Bourne s two-parameter eq. (8). The rates predicted by the model were found to agree within 6-8 % error with the experimental data. This time the oxidative addition of hydrogen was recognized as the rate-determining step. However, the model is not generally applicable as the phosphine concentration was not considered and the reaction temperatures were fairly low T = 50-70 °C). 

Rhodium complexes modified with polyether phosphine oxides according to the Structure 30 were used as catalysts for the hydroformylation of 1-decene and oleyl alcohol in micellar aqueous-biphase systems [56, 57]. 

Table 11.13 Hydroformylation of 1-decene by Rh(0) nanoparticles with different sizesl. Adapted from Ref [76].

The recycling effect of the catalyst was also examined. Aqueous phase containing the Rh/PEO-DPPPA catalyst after phase separation was re-used 20 times in the hydroformylation of 1-decene [21]. It should be pointed out that leaching of Rh into the organic phase might be diminished with difficulty to less than the ppm level by means of a single-phase separation. 

A rhodium complex with phosphine 61 in hydroformylation of 1-decene and 1-hexadecene gave linear-to-branched 1-alkene ratios from 4.8 1 to 5.9 1 at a turnover frequency of 136 h . For 1-hexene, this quantity under similar conditions was 1456 h .and the catalyst remained active up to the substrate-to-rhodium ratio of 200,000 1 [174]. 

Table 5. Effect of the phosphine concentration on the selectivity and activity of the hydroformylation of 1 -decene ...

The effect of the addition of unmodified cyclodextrins to a reaction mixture on the aqueous hydroformylation of 1-decene is rather small. The conversion was enhanced hy a factor 2 upon the addition of P-cyclodextrin. The modified P-cyclodextrins improved the activity to a greater extent in the optimized situation the activity increased with a factor of 14. These modified cyclodextrins are more efficient since they are soluble in both the organic phase and the aqueous phase thereby improving the efficiency of the substrate transfer process. Similar to the systems described above, the isomerization was suppressed under these optimized conditions. However, internal alkenes could not be hydroformylated using this system. Another striking difference is the selectivity of the reaction. The addition of the modified cyclodextrins resulted in a decrease of the l b ratio (2.7 to 1.9), whereas Reetz reported an increase for his supramolecular system So far no sohd explanation has been found for this difference. 

Scheme 3.5 Hydroformylation of 1-decene with formalin or paraformaldehyde.

Hydroformylation of 1-decene for the production of 1-undecanal is an important process in perfume manufacturing (Scheme 4.9). The first process developed... 

Scheme 5.55 Rh-catalyzed reductive hydroformylation of 1-decene with Me-BISBI as a...

Scheme 7.8 Hydroformylation of 1-decene in water in the presence of methylated cyclodex-trines.

Polyether phosphites with over 19 ethylene glycol units were used as ligands in the rhodium-catalyzed nonaqueous hydroformylation of 1-decene. The catalysts were recovered by precipitation from the reaction mixture after reaction on cooling to room temperature or lower. The precipitated catalysts could be reused up to six times without any decrease in activity. In situ formed polyetherphosphite/Ru3(CO)i2 catalyst was found to be active in hydroformylation of 1 -decene in n-heptane solution atl30°Cand50bar[20]. 

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