Hydroformylation catalytic

Synthesis gas is also an important building block for aldehydes from olefins. The catalytic hydroformylation reaction (Oxo reaction) is used with many olefins to produce aldehydes and alcohols of commercial importance. 

The catalytic hydroformylation of olefins is discussed in Chapter 5. The reaction of propylene with CO and H2 produces n-butyraldehyde as the main product. Isobutyraldehyde is a by-product °... 

The catalytic hydroformylation of alkenes has been extensively studied. The selective formation of linear versus branched aldehydes is of capital relevance, and this selectivity is influenced by many factors such as the configuration of the ligands in the metallic catalysts, i.e., its bite angle, flexibility, and electronic properties [152,153]. A series of phosphinous amide ligands have been developed for influencing the direction of approach of the substrate to the active catalyst and, therefore, on the selectivity of the reaction. The use of Rh(I) catalysts bearing the ligands in Scheme 34, that is the phosphinous amides 37 (R ... 

S. H., and Stitt, E.H. (2007) intensification of the solvent-free catalytic hydroformylation of cydododecatriene comparison of a stirred batch reactor and a heat-exchange reactor. Catal. Today, 128, 18-25. 

The system (23)/SnCl2, an active intermediate in the catalytic hydroformylation of 1-hexene, has been investigated by 31P NMR spectroscopy and two species are observed at low temperature, in equilibrium with the starting Pt complex (23). One is complex (27), and the other is a species which does not show Sn-P coupling and which has been tentatively attributed to a complex having chloride ions bridging the Pt and Sn metal centers. Formation of the complex (27) does not occur when EtOH is added to the CD2C12 or acetone solutions.91... 

C02Me)CH2-C02Me was regioselectively prepared in >82% enantiomeric excess by homogeneous catalytic hydroformylation. For other vinylidene esters, the asymmetric induction was lower.318... 

Table 4 Catalytic activity of rhodium complexes of the bis-phosphonio-benzophospholide 23 in catalytic hydroformylation of hexane using a H2iCO (1 1) mixture (data from [44])...

Garland s studies showed that, in general, catalytic hydroformylation rate is proportional to the concentration of [Rh(C(0)R)(C0)4], and kinetic data for hydrogeno-lysis of this acyl to liberate acetaldehyde have been determined (see Section 3.3.2.4)... 

The OATS concept was tested on the catalytic hydroformylation of 1-octene, a hydrophobic substrate. This reaction was selected because it has previously been shown to be inactive for traditional aqueous biphasic systems (18). The catalyst used was a Rh/TPPTS complex, an industrial water soluble catalyst (22). The application of the OATS concept increased catalytic efficiency by a factor of 65 (TOP increased from 5 h for biphasic to 325 h for monophasic). 

The preceding stoichiometric reactions are clearly closely related to the catalytic hydroformylation of epoxides. Somewhat less clear is their relation... 

Reaction 2.6, are important steps in catalytic hydroformylation and carbonyl-ation reactions, respectively. 

The catalytic hydroformylation of long-chain and branched olefins remains a challenge as the activity of the water-soluble catalysts decreases rapidly with increasing chain length of the olefin. Extensive work has been undertaken to overcome these limitations (74). 

TABLE 8 Data Characterizing Catalytic Hydroformylation of Various Olefins with Rhodium Polyethylene Glycolate Complex.°... 

The use of chiral SPOs in the hydroformylation reaction failed to lead to enantiomeric excess in the hydroformylation of styrene (72), a result that was surprising because the complexes otherwise behave like classic diphosphine catalysts, among which are highly enantioselective catalysts. Most likely, racemization of the chiral SPO had occurred. The catalytic hydroformylation of ethylene leads to mixtures of propanal, the expected product, and 3-pentanone. 

An alternate bimetallic pathway was also suggested, but not favored, by Heck and Breslow (also shown in Scheme 1). The acyl intermediate could react with HCo(CO)4 to undergo intermolecular hydride transfer, followed by reductive elimination of aldehyde to produce the Co-Co bonded dimer Co2(CO)s. A common starting material for HCo(CO)4-catalyzed hydroformylation, Co2(CO)g is well-known to react with H2 under catalysis reaction conditions to form two equivalents of HCo(CO)4. The bimetallic hydride transfer mechanism is operational for stoichiometric hydroformylation with HCo(CO)4 and has been proposed to be a possibility for slower catalytic hydroformylation reactions with internal alkenes.The monometallic pathway involving reaction of the acyl intermediate with H2, however, has been... 

D. Tertiary Phosphine Complexes In Catalytic Hydroformylation and Hydrogenation Reactions... 

Bando KK, Asakura K, Arakawa H, Isobe K, Iwasawa Y (1996) Surface structures and catalytic hydroformylation activities of rh dimers attached on various inorganic oxide supports. J Phys Chem 100 13636... 

Reactive acyl derivatives have been intercepted in the course of experiments aimed at mimicking the experimental catalytic hydroformylation conditions. When a benzene solution of RhH(CO)(PPh3)3 was treated with CO and ethylene, the propionylrhodium derivative of reaction (n) was observed by H-NMR spectrometry ... 

Palo, D.R. Erkey, C. Homogeneous catalytic hydroformylation of 1-octene in supercritical carbon dioxide using a novel rhodium catalyst with fluorinated arylphosphine ligands. Ind. Eng. Chem. Res. 1998, 37 (10), 4203-4206. 

---