Water-soluble rhodium hydroformylation

Two-Phase (Water-Soluble) Rhodium Hydroformylation Catalysts... 

An example of a large scale application of the aqueous biphasic concept is the Ruhrchemie/Rhone-Poulenc process for the hydroformylation of propylene to n-butanal (Eqn. (15)), which employs a water-soluble rhodium(I) complex of trisulphonated triphenylphosphine (tppts) as the catalyst (Cornils and Wiebus, 1996). 

The third generation process concerns the Ruhrchemie/Rhone-Poulenc process utilizing a two-phase system containing water-soluble rhodium-tppts in one phase and the product butanal in the organic phase. The process has been in operation since 1984 by Ruhrchemie (or Celanese, nowadays). The system will be discussed in section 8.2.5. Since 1995 this process is also used for the hydroformylation of 1-butene. 

The prototype reaction was the hydroformylation of oleyl alcohol (water insoluble) with a water-soluble rhodium complex, HRh(C0)[P(m-C6H4S03Na)3]3 (Figure 6.5). Oleyl alcohol was converted to the aldehyde (yield = 97%) using 2 mol % Rh with respect to the substrate and cyclohexane as the solvent, at 50 atmospheres CO/H2, and 100°C. The SAPCs were shown to be stable upon recycling, and extensive work proved that Rh is not leached into the organic phase. Since neither oleyl alcohol nor its products are water soluble, the reaction must take place at the aqueous-organic interface where Rh must be immobilized. Also, if the metal catalyst was supported on various controlled pore glasses with... 

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],... 

The other three studies in the literature also deal with the asymmetric hydroformylation of styrene and all three applied water soluble rhodium -phosphine catalysts (Scheme 4.9). BINAS (44), sulfonated BIPHLOPHOS (43), tetrasulfonated (R,R)-cyclobutane-DIOP (37, m=0) and tetrasulfonated (S,S)-BDPP (36, m=0) were applied as ligands of the rhodium catalyst prepared in situ from [Rh(acac)(CO)2] or [ Rh( Li-OMe)(COD) 2] and the phosphines. The results are summarized in Table 4.4. 

Similar to the above case, hydroformylation of 1-hexene using a water-soluble rhodium catalyst [RhH(CO)(TPPMS)3] gave lower yields when a-cyclodextrin was added to the biphasic reaction system [14]. Again, the reason was suspected in the interaction between the cyclodextrin and the rhodium catalyst. 

Homologous w-alkenecarboxylic acid methyl esters were hydroformyl-ated with the water-soluble rhodium/tppts catalyst in an aqueous-organic two-phase system (75). By addition of surfactants a micellar system was created. Cationic surfactants are better than anionic or nonionic surfactants for this hydroformylation. 

Mercier, C. and Chabardes, P. (1995) Organometallic chemistry in industrial vitamin A and vitamin E synthesis. Chem. Ind. (Dekker) Catal. Org. React., 62, 213. Fremy, G., Castanet, Y., Grzybek, R., Monflier, E., Mortreux, A., Trzedak, A.M. and Ziolkowski, J.J. (1995) A new, highly selective, water-soluble rhodium catalyst for methyl acrylate hydroformylation. /. Organomet. Chem., 505, 11. 

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. 

Fell B, Leckel D, Schobben C (1995) Micellar two phase-hydroformylation of multiple unsaturated fatty substances with water soluble rhodium carbonyl/tertiary phosphane complex catalyst systems. Fett Wiss Technol 97 219-228... 

The idea of applying water-soluble rhodium complexes as catalysts for the hydroformylation reaction [212, 213] was taken up and commercialized by Ruhrchemie AG for the hydroformylation of propene [269]. After only two years of development on the laboratory scale the first plant was erected in 1984, followed by rapid further increases in capacity to more than 600000 tons/year today [214]. An additional unit for the production of n-pentanal from n-butene has been brought onstream in 1995 [271, 294]. 

Johnson-Matthey Co. has reported that oleic acid methyl ester or linoleic acid methyl ester can be hydroformylated in micellar media using a water-soluble rhodium complex of monocarboxylated triphenylphosphine 45 as catalyst. As a further example, polyunsaturated linolenic acid methyl ester can be hydroformylated to the triformyl derivative with a selectivity of 55% with a Rh/TPPTS catalytic system in the presence of CTAB (Scheme 1.23). ... 

A first attempt at hydroformylation in a micellar system using a water-soluble rhodium catalyst (Rh-TPPTS) was made by Tinicci and Platone from Eniricerche in 1994 [ 59 ]. They converted olefins with carbon numbers up to 12 using a mixture of an anionic surfactant (SDS) and butanol (as co-surfactant). It has been shown that microemulsions made with non-ionic surfactants of the alcohol ethoxylate type are advantageous compared to ionic... 

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 hydroformylation of propene to form butyralde-hyde invariably produces some isobutyraldehyde at the same time (reaction 1.21).216 One of the best processes uses a water-soluble rhodium phosphine complex to produce 94.5% of the former and 4.5% of the latter.217 The products form a separate layer that is separated from the water. Rhodium is expensive so it is important to lose as little as possible. In 10 years of operation by Rhone-Poulenc-Ruhrchemie 2 million metric tons of butyralde-hyde have been made with the loss of only 2 kg of rhodium. The process is 10% cheaper than the usual one. Higher olefins are not soluble enough in water to work well in the process. The process does work for omega-alkenecar-boxylic acids such as 10-undecenoic acid, where a 97 3... 

Without a doubt, the most successful demonstration of aqueous catalysis has been the hydroformylation of low molecular weight terminal alkenes. The use of an aqueous biphasic medium to separate catalysts from products for this process was first envisioned by Kuntz at Rhone-Poulenc this eventually led to the development of a water-soluble rhodium catalyst [46] (cf. Section 6.1.1). 

Interfacial kinetics of biphasic hydroformylation of 1-dodecene catalyzed by water-soluble rhodium complex have been studied by a combined numerical and experimental approach [54]. 

Hydroformylation or oxosynthesis is a well-known homogeneous, transition metal catalyzed reaction which has known considerable and continuous development since its discovery by Otto Roelen in the laboratories of Ruhrchemie AG in 1938 [1], This reaction, which can be considered as the addition of a formyl group and hydrogen to a double bond, has been successfully applied in the industrial context by using two basic processes the homogeneous process where the rhodium or cobalt catalyst and the substrate are in the same phase (Shell, UCC, BASF, RCH processes) [2] and the aqueous/organic biphasic process where the water-soluble rhodium catalyst and the organic compounds are in two different phases (Ruhr-chemie/Rhone-Poulenc process) [3]. 

The substrate selectivity observed during the hydrogenation of a 1 1 mixture of olefins and the increase in the linear to branched aldehyde ratio during the hydroformylation of 1-octene were attributed to the formation of transient adducts between the substrate and a water-soluble rhodium complexes bearing /3-CD-modified diphosphines (Figure 18). ... 

Hydroformylation is a very important industrial process. Olefins are converted to aldehydes, which can be further transformed into acids, alcohols or amines. The Ruhrchemie/Rhone-Poulenc hydroformylation process is an aqueous-organic biphasic process which uses an easily separable water-soluble rhodium... 

A further approach is to carry out the reaction in two liquid phases such that the catalyst is located in a solvent that is immiscible with the reactant alkene and product aldehyde. Rhone Poulenc have patented the use of water-soluble rhodium systems containing sulphonated triphenylphosphine derivatives (12-14) as hydroformylation catalysts. Under conditions of acidic or neutral pH and at 80°C and 4 MPa these systems hydroformylated propene, for example, with high selectivity (n i = 30), efficiency (93%), and low Rh losses to the organic phase. However, these systems were only shown to be active at high pressures. 

Apparently, no colloids are formed when polyethylene glycol is added to rhodium trichloride hydrate to obtain a water-soluble rhodium polyethylene glycolate highly active in the hydroformylation of heavy alkenes such as dodec-l-ene [75]. Such a system does not require the presence of other ligands and works efficiently at 70-120 bar. Besides a hypothesis in which it is envisioned a migration of the catalyst into the organic phase, a model where the reaction takes place in the interphase, due to the presence of polyethylene glycol, is favored. 

Cuprous chloride tends to form water-soluble complexes with lower olefins and acts as an IPTC catalyst, e.g., in the two-phase hydrolysis of alkyl chlorides to alcohols with sodium carboxylate solution [10,151] and in the Prins reactions between 1-alkenes and aqueous formaldehyde in the presence of HCl to form 1,3-glycols [10]. Similarly, water-soluble rhodium-based catalysts (4-diphenylphosphinobenzoic acid and tri-Cs-io-alkylmethylam-monium chlorides) were used as IPTC catalysts for the hydroformylation of hexene, dodecene, and hexadecene to produce aldehydes for the fine chemicals market [152]. Palladium diphenyl(potassium sulfonatobenzyl)phosphine and its oxide complexes catalyzed the IPTC dehalogenation reactions of allyl and benzyl halides [153]. Allylic substrates such as cinnamyl ethyl carbonate and nucleophiles such as ethyl acetoactate and acetyl acetone catalyzed by a water-soluble bis(dibenzylideneacetone)palladium or palladium complex of sulfonated triphenylphosphine gave regio- and stereo-specific alkylation products in quantitative yields [154]. Ito et al. used a self-assembled nanocage as an IPTC catalyst for the Wacker oxidation of styrene catalyzed by (en)Pd(N03) [155]. 

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