Hydroformylation using

There are currentiy no commercial producers of C-19 dicarboxyhc acids. During the 1970s BASF and Union Camp Corporation offered developmental products, but they were never commercialized (78). The Northern Regional Research Laboratory (NRRL) carried out extensive studies on preparing C-19 dicarboxyhc acids via hydroformylation using both cobalt catalyst and rhodium complexes as catalysts (78). In addition, the NRRL developed a simplified method to prepare 9-(10)-carboxystearic acid in high yields using a palladium catalyst (79). 

The synthesis of aldehydes from alkenes known as hydroformylation using CO and hydrogen and a homogeneous catalyst is a very important industrial process [204]. Today, over seven million tons of oxoproducts are formed each year using this procedure, with the majority of butanal and butanol from propene. To further increase the efficiency of this process it can be combined with other transformations in a domino fashion. Eilbracht and coworkers [205] used a Mukaiyama aldol reaction as a second step, as shown for the substrate 6/2-63 which, after 3 days led to 6/2-65 in 91% yield via the primarily formed adduct 6/2-64 (Scheme 6/2.13). However, employing a reaction time of 20 h gave 6/2-64 as the main product. 

Until recently, the hydroformylation using palladium had been scarcely explored as the activity of palladium stayed behind that of more active platinum complexes. The initiating reagents are often very similar to those of platinum, i.e., divalent palladium salts, which under the reaction conditions presumably form monohydrido complexes of palladium(II). A common precursor is (39). The mechanism for palladium catalysts is, therefore, thought to be the same as that for platinum. New cationic complexes of palladium that are highly active as hydroformylation catalysts were discovered by Drent and co-workers at Shell and commercial applications may be expected, involving replacement of cobalt catalysts. 

The first reports on asymmetric hydroformylation using diphosphite ligands revealed no asymmetric induction. In 1992, Takaya et al. published the results of the asymmetric hydroformylation of vinyl acetate (ee = 50%) with chiral diphosphites.358... 

A phosphite degradation reaction that occurs during hydroformylation using an aryl-phosphite-modified rhodium catalyst involves replacement of one of the aryl groups with an alkyl group corresponding to the alkyl group of the hydroformylation prod-uct[.[27] This is illustrated in Equation 2.7... 

Liquid-liquid Biphasic, Rh-catalysed Hydroformylation Using Ionic Liquids... 

The group of Olivier-Bourbigou has shown, for example, that phosphite ligands can be used in the Rh-catalysed hydroformylation in ionic liquids as well as the well-known phosphine systems [51], Since phosphite ligands are usually unstable in aqueous media this adds, apart from the much better solubility of higher olefins in ionic liquids, another important advantage to biphasic hydroformylation using ionic liquids in comparison to the established biphasic reactions in water. 

TABLE 7.4. Biphasic hydroformylation using halogen-free octylsulfate and tosylate ionic liquids compared with the same reaction in [BMIM][PF6]... 

Rhodium Catalysed Hydroformylation Using Supported Ionic Liquid Phase SILP) Catalysis... 

Figure 7.11. Set-up for the continuous, Rh-catalysed propene hydroformylation using an impregnated SILP-catalyst...

To estimate costs for the liquid-liquid biphasic hydroformylation using ionic liquids, a process was designed for the production of 100,000 tons per year of nonanal. The use of ionic liquids in hydroformylation catalysis is a fairly new technology and exact kinetic data are scarce, thus the TOFs reported for the Rh-sulfoxantphos system [80] have been used to determine catalyst inventory and reactor dimensions. In a similar way the plant design for the SILP process for a production capacity of 100,000 tons per year of butanal has been derived based on preliminary literature results [68]. The process flow sheets for both process variations are shown in Figures 7.12 and 7.13. 

King and coworkers—hydroformylation using Fe carbonyl catalyst. In... 

Takaya and co-workers in 1993 were the first to report on asymmetric hydroformylation using phosphite-phosphine ligands [59]. In an attempt to combine the effectiveness of the BINOL chemistry for asymmetric catalysis and the effectiveness of the phosphite moiety for asymmetric hydroformylation, they developed the (.R,S)-BINAPHOS ligand 3, which turned out to be very efficient (Fig. 6). 

Table 8.3. Electronic effects in hydroformylation using thixantphos derivatives...

Table 8.6. Hydroformylation using rhodium bulky diphosphite catalysts3...

The first reports on asymmetric hydroformylation using diphosphite ligands revealed no asymmetric induction [71], In 1992, Takaya et al. published the results of the asymmetric hydroformylation of vinyl acetate (e.e.=50%) with chiral diphosphites [72], In 1992, an important breakthrough appeared in the patent literature when Babin and Whiteker at Union Carbide reported the asymmetric hydroformylation of various alkenes with e.e. s up to 90%, using bulky diphosphites derived from homochiral (2R,4R)-pentane-2, 4-diol (see Figure 8.20). Van Leeuwen et al. studied the influence of the bridge length, bulky substituents and cooperativity of chiral centres on the performance of the catalyst [73,74],... 

For instance, catalysis in liquid/liquid two phases is generally referred to as biphasic catalysis and has widened the practical scope of homogeneous catalysis the catalyst is present in one liquid phase, while reactants and products are present in the other liquid phase. Thus, the catalyst can be separated by simple phase separation. Celanese is operating a 300 000 t/a plant for propylene hydroformylation using a water-soluble rhodium phosphine complex in a biphasic mode of operation at the Ruhrchemie site in Oberhausen [142],... 

Table 6.2 Hydroformylation using rhodium bulky monophosphite catalysts. ...

The potential of QUINAPHOS ligands for asymmetric catalysis was assessed in rhodium-catalyzed enantioselective hydroformylation using styrene as a benchmark substrate (Table 2.1.5.2). The catalysts were prepared in situ from [(acac)Rh(CO)2] and 4 equiv of the diastereomeric mixture or the single diaste-... 

Relatively few hydroformylations using supported cobalt complexes have been reported. Moffat (78, 79) showed that poly-2-vinylpyridine reversibly reacted with both Co2(CO) and HCo(CO)4, the cobalt carbonyl being displaced by excess carbon monoxide. This enabled the polymer to pick up the cobalt carbonyl at the end of the reaction and, thus, allowed it to be separated from the products by filtration. The polymer acted as a catalyst reservoir by rapidly releasing the cobalt carbonyl into solution in the presence of further carbon monoxide, so that the actual catalysis was a homogeneous process. More recently, cobalt carbonyl has been irreversibly bound to a polystyrene resin... 

A lthough the hydroformylation of olefins has been known since 1938, the first successful attempts to synthesize optically active aldehydes by hydroformylation using optically active catalysts have been published only recently (I, 2, 3, 4). All the three possibilities to prepare optically active aldehydes (Scheme 1) have been successfully explored (5) using Co(R -Sal)2 or [Co(CO)4]2 and R -SalH (R -SalH = (S)-N-a-methylbenzylsalicylaldimine) as catalyst precursor, but the optical yields obtained were very poor. Much better results have been obtained... 

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