Oxidative carbonylation of ethylene

The liquid phase reaction of ethylene with carbon monoxide and oxygen over a Pd VCu catalyst system produces acrylic acid. The yield based on ethylene is about 85%. Reaction conditions are approximately 140°C and 75 atmospheres  

The catalyst is similar to that of the Wacker reaction for ethylene oxidation to acetaldehyde, however, this reaction occurs in presence of carbon monoxide. 

Currently, the main route to acrylic acid is the oxidation of propene (Chapter 8). 

The direct addition of chlorine to ethylene produces ethylene dichloride (1,2-dichloroethane). Ethylene dichloride is the main precursor for vinyl chloride, which is an important monomer for polyvinyl chloride plastics and resins. 

Other uses of ethylene dichloride include its formulation with tetraethyl and tetramethyl lead solutions as a lead scavenger, as a degreasing agent, and as an intermediate in the synthesis of many ethylene derivatives. 

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Oxidative Carbonylation of Ethylene—Elimination of Alcohol from p-Alkoxypropionates. Spectacular progress in the 1970s led to the rapid development of organotransition-metal chemistry, particularly to catalyze olefin reactions (93,94). A number of patents have been issued (28,95—97) for the oxidative carbonylation of ethylene to provide acryUc acid and esters. The procedure is based on the palladium catalyzed carbonylation of ethylene in the Hquid phase at temperatures of 50—200°C. Esters are formed when alcohols are included. Anhydrous conditions are desirable to minimize the formation of by-products including acetaldehyde and carbon dioxide (see Acetaldehyde). 

The elimination of alcohol from P-alkoxypropionates can also be carried out by passing the alkyl P-alkoxypropionate at 200—400°C over metal phosphates, sihcates, metal oxide catalysts (99), or base-treated zeoHtes (98). In addition to the route via oxidative carbonylation of ethylene, alkyl P-alkoxypropionates can be prepared by reaction of dialkoxy methane and ketene (100). 

Acrylic acid can be prepared by the catalytic oxidative carbonylation of ethylene or by heating formaldehyde and acetic acid in the presence of KOH. 

The platinum complex is reported here as a model for the corresponding palladium complexes, which have not been isolated. Attack of coordinated or noncoordinated OR or OH groups on a metal carbonyl group was required as a way to form these complexes. The nature and reactivity of the M—C02Me bond was discussed. The isolation of a catalytic intermediate in oxidative carbonylation of ethylene and propylene was achieved... 

An interesting variant of oxidative carbonylation was recently achieved by ConsigUo and co-workers. In the presence of a cationic palladium complex it was possible to introduce three carbonyl groups in the oxidative carbonylation of ethylene or propylene, one of them under the form of ketone, using (Pd(H20)2[(5)-2,2 -dimethoxy-6,6 -bis(diphenylphosphino)biphenyl] (CF3S03)2 as catalyst precursor Scheme 15 also shows the proposed mechanism. 

A new process is the oxidative carbonylation of ethylene [459,460]. During the reaction the palladium catalyst is reoxidized by a cupric chloride cocatalyst system and oxygen. Selectivity is improved by the addition of a mercury or a tin salt [461]. 

Pd(PhCN)2Cl2-catalyzed oxidative carbonylation of ethylene or propylene with butyl nitrite under an atmosphere of CO (1.5 MPa) afforded dibutyl succinate or dibutyl methylsuccinate (eq 95).fii... 

M-NHC catalysts in this area. Metal catalysed carbonylation also provides an alternative synthetic ronte to the prodnction of materials that traditionally reqnire highly toxic precnrsors, like phosgene. This section discnsses carbonylation of aryl hahdes, oxidative carbonylation of phenolic and amino componnds, carbonylation of aryl diazoninm ions, alcohol carbonylation, carbonylative amidation, and copolymerisation of ethylene and CO. 

Meanwhile, Wacker Chemie developed the palladium-copper-catalyzed oxidative hydration of ethylene to acetaldehyde. In 1965 BASF described a high-pressure process for the carbonylation of methanol to acetic acid using an iodide-promoted cobalt catalyst (/, 2), and then in 1968, Paulik and Roth of Monsanto Company announced the discovery of a low-pressure carbonylation of methanol using an iodide-promoted rhodium or iridium catalyst (J). In 1970 Monsanto started up a large plant based on the rhodium catalyst. 

Propanediol is produced either from the reductive hydration of acrolein (Degussa-DuPont process), or through reductive carbonylation of ethylene oxide (Shell process), or through fermentation of glucose via glycerol (DuPont-Genencor process). 

P-Lactones can be obtained by oxidative carbonylation of alkenes in the presence of water. Ethylene, for example, is converted to p-propiolactone by carbonylation in aqueous acetonitrile at -20 C using a catalytic amount of PdCh and a stoichiometric quantity of copper(II) chloride (equation 37). Palladium-catalyzed carbonylation of halides can also be used to prepare p-lactones under mild conditions. The reaction takes place at room temperature and pressure in the presence of [PdCl2(PPh3)2] and has been applied to both bromides and chlorides (equations 38 and 39). 

Oxidative carbonylation of methanol to DMC, which takes place in the presence of suitable catalysts, has been developed industrially by EniChem (later Polimeri Europa). Carbonylation/transesterification of ethylene oxide to DMC via ethylene carbonate is also an attractive route. However, this route is burdened by the complexity of the two-step process, the co-production of ethylene glycol (even if it... 

Propionic acid is produced commercially by several different processes. It is a by-product of the liquid phase oxidation of hydrocarbons for the manufacture of acetic acid. It is also made from carbon monoxide and ethylene by the 0x0 process through a propionaldehyde intermediate or by the carbonylation of ethylene with a nickel-based catalyst. BASF uses the one-step Reppe carbonylation process with a nickel propionate catalyst to produce 40,000 metric tons per year of propionic acid in Ludwigshafen, Germany. The hydrocarboxylation chemistry is shown in Eq. (29) ... 

Palladium catalysts are widely used in liquid phase aerobic oxidations, and numerous examples have been employed for large-scale chemical production (Scheme 8.1). Several industrially important examples are the focus ofdedicated chapters in this book Wacker and Wacker-type oxidation of alkenes into aldehydes, ketones, and acetals (Scheme 8.1a Chapters 9 and 11), 1,4-diacetoxylation of 1,3-butadiene (Scheme 8.1b Chapter 10), and oxidative esterification of methacrolein to methyl methacrylate (Scheme 8.1c Chapter 13). In this introductory chapter, we survey a number of other Pd-catalyzed oxidation reactions that have industrial significance, including acetoxylation of ethylene to vinyl acetate (Scheme 8. Id), oxidative carbonylation of alcohols to dialkyl oxalates and carbonates (Scheme 8.1e), and oxidative coupling of dimethyl phthalate to 3,3, 4,4 -tetramethyl biphenylcarboxy-late (Scheme 8.1f). 

Oxidative carbonylation of alcohols in the presence of CO provides an economically viable route to dialkyl carbonates and/or oxalates (Eqs. (8.4) and (8.5)), both of which have important industrial applications. Dialkyl carbonates (e.g., dimethyl carbonate, propylene carbonate) are excellent solvents for a variety of organic substances [14]. Dialkyl oxalates have utility as solvents, C2 building blocks in fine chemicals synthesis, and intermediates in the manufacture of oxamide (as a fertilizer) [15]. Hydrogenation of dialkyl oxalates provides an alternative route to ethylene glycol that is independent of oil-derived resources [15,16]. 

Reactions that require phosgene are dangerous, and dimethyl carbonate (DMC) 33 is the most promising phosgene substitute. Current industrial processes for DMC synthesis are oxidative carbonylation of methanol and transesterification of ethylene carbonate with methanol. Hence, the direct reaction of CO2 and methanol (Scheme 58) is regarded as an attractive, next-generation process, but the limitation... 

Succinic acid Hydrogenation of maleic acid, oxidation of 1,4-butanediol and carbonylation of ethylene glycol Bacterial fermentation of glucose 1,4-Butanediol, tetrahydrofuran Solvents, polyesters, polyurethanes, nylon, food and beverage acidity control, fabrics, etc. 

Methacrylic acid produced from propionic acid in this process can be esterified with methanol to yield methyl methacrylate. Catalysts used in this route include alkali metal or alkaline-earth metal aluminosilicates, potassium hydroxide- or cesium hydroxide-treated pyrogenic silica, alumina, and lanthanum oxide. Both propionic acid and methyl propionate are commercially available through the Oxo process (i.e., by the carbonylation of ethylene or by the hydrofor-mylation of ethylene to propionaldehyde, followed by oxidation of the aldehyde to the corresponding acid). This alternative route has, however, shown only 50% conversion and >80% selectivity rates, and it appears that additional catalyst development is necessary in order to make this process more attractive. 

Acrylic acid and its esters formed by the reaction as shown in eq. (19.39) had been produced until the end of the 1960s. But now they are produced by the oxidation of propene. For the production of acetic acid by the carbonylation of methyl alcohol shown in eq. (19.41), nickel catalysts were at first used, but afterwards the rhodium catalysts as described previously in Chapter 18 have been used. However, even now nickel catalysts are used in the production of propionic acid by the carbonylation of ethylene shown in eq. (19.40) [72]. 

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