Rhodium complex catalysts phosphine complexes

Phosphine, amino-rhodium complexes catalysts, hydroformylation, 6,261 Phosphine, 3-aminopropyldimethyl-photographic fixer, 6,100 Phosphine, bis(2-carboxyethyl)methyl-photography... 

To make butyraldehyde, the precursor for NBA, the so-called Oxo process is used, reacting chemical grade propylene with hydrogen and. carbon monoxide at 250-300°F and 3500-4000 psi. See Figure 14-4.) Under those conditions, both feeds are liquids. The catalyst is an oil-soluble cobalt carbonyl complex dissolved in the propylene. If rhodium-based catalysts or complexes based on rhodium carbonyls and triphenyl phosphine... 

The activity of rhodium complexes with phosphine or phosphite ligands is about three to four orders of magnitude higher than that of cobalt catalysts.21-23 [RhH(CO)(PPh3)3] preformed or prepared in situ has proved to be the active species when triphenylphosphine is used as ligand. Despite the high cost of rhodium, the mild reaction conditions and high selectivities make rhodium complexes the catalyst of choice in hydroformylation. 

Support-bound transition metal complexes have mainly been prepared as insoluble catalysts. Table 4.1 lists representative examples of such polymer-bound complexes. Polystyrene-bound molybdenum carbonyl complexes have been prepared for the study of ligand substitution reactions and oxidative eliminations [51], Moreover, well-defined molybdenum, rhodium, and iridium phosphine complexes have been prepared on copolymers of PEG and silica [52]. Several reviews have covered the preparation and application of support-bound reagents, including transition metal complexes [53-59]. Examples of the preparation and uses of organomercury and organo-zinc compounds are discussed in Section 4.1. 

Fell, B., Schobben, C. and Papadogianakis, G. (1995) Hydroformylation of homologous C0-alkenecarboxylate esters with water soluble rhodium carbonyl/tertiary phosphine complex catalyst systems. J. Mol. Catal. A Chem., 101, 179. 

Rhodium complexes of phosphinated glucopyranosides, [Rh(Me-a-glupOH)(cod)]BF4 and [Rh(Ph- -glup-OH)(cod)]BF4, reduced prochiral dehydroamino acid derivatives in water in the presence of surfactants [38, 39] addition of dodecyl sulfate increased both the rate and enantioselectivity of the hydrogenation, enantiomeric excesses up to 83% being obtained. The same trends were observed using [Rh(BPPM)(cod)]BF4 as the catalyst [40]. 

Researchers have worked to alleviate the problems of separation and corrosion in processes such as the oxo process by designing catalysts that are confined in a separate phase from the reactants (see Section 14.2.4). A commercially successful approach for propene hydroformylation resulted from preparation of water-soluble rhodium complex catalysts by sulfonation of the phenyl rings of the triphenyl phosphine ligands. The catalyst is used in a reactor with two liquid phases the propene is concentrated in the organic phase and the catalyst in the aqueous phase near the interface. The CO -I- H2 is bubbled into a mixed reactor, and the two-phase liquid product flows to a settler the organic product flows to downstream separation devices, and the aqueous phase with the catalyst is recycled to the reactor. 

The present interest in asymmetric catalysis was demonstrated by awarding Nobel prizes to three winners W. S. Knowles (USA) for elaboration of rhodium complex catalysts effective in asymmetric synthesis of anti-Parkinson medicine, R. Noyori (Japan) for elaboration of a new catalytic system based on chiral ruthenium-phosphine complex catalysts that are very effective in hydrogenation reactions, and B. Sharpless (USA) for elaboration of epoxidation and other reactions under the action of chiral titanium complexes. 

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]. 

The first report of an asymmetric hydrogenation catalyst refers to a German Patent (Bursian and Pracejus, 1972) where a rhodium complex with phosphinated cellulose was used. In two recent reports, an elaborate synthesis of a rhodium complex of a polymer having a chiral phosphine... 

Sertchook H., Avnir D., Blum J., J06 F., Katho A., Schumann H., Weimann R., Wemik S. Sol-gel entrapped lipophilic and hydrophilic ruthenium-, rhodium- and iridrum-phosphine complexes as recyclable isomerization catalysts. J. Mol. Catal. A Chem. 1996 108 153-160 Shvo Y., Becker Y. Sol-gel glass with enantioselective catalytic activity. J. Chem. Soc., Chem. Commun. 1994 2719-2720... 

Koch and Leitner extended this work in a comprehensive study (227,228) comparing the hydroformylation of 1-octene using a rhodium complex catalyst without modifiers and with both phosphine and phosphite ligands. They report that SCCO2 is a generally applicable reaction medium for highly efficient... 

A new homogeneous process for hydroformylation of olefins using a water-soluble catalyst has been developed (40). The catalyst is based on a rhodium complex and utilizes a water-soluble phosphine such as tri(M-sulfophenyl)phosphine. The use of an aqueous phase simplifies the separation of the catalyst and products (see Oxo process). 

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