Reppe carbonylation

Kiss G (2001) Palladium-catalyzed Reppe carbonylation. Chem Rev 101(ll) 3435-3456. doi 10.1021/ct010328q... 

A much shorter route is the Reppe carbonylation [83] of propyne. Propyne is, together with propadiene (allene), part of the C3 stream of the cracking process. The order of metal substrate binding strength is allenes>alkynes>alkenes. Thus the desired reaction can only proceed if the propadiene has been removed from the feed, since it is an inhibitor of the Pd catalyst. Equally important, the alkyne complex reacts much faster than the alkene complex. Thus the product is neither a substrate nor an inhibitor for the catalyst (Scheme 5.46). 

The reaction of an aUcene (or aUcyne), CO, and H2O to directly produce a carboxylic acid is called Reppe carbony-lation chemistry or, more recently, hydrocarboxylation (see Reppe Reaction). An excellent review of palladium-catalyzed Reppe carbonylation systems has been published recently by Kiss, and coverage of this important material will not be repeated here. This catalytic reaction has been known for quite some time, although the stoichiometric Ni(CO)4-based carbonylation of acetylene was the first commercial carbonylation process implemented (equation 13). The extreme toxicity of Ni(CO)4, however, has limited practical applications (see Nickel Organometallic Chemistry). Co, Rh, and Pd catalysts have certainly replaced Ni(CO)4 in smaller-scale laboratory reactions, though for historical reasons a number of the fim-damental mechanisms discussed in this section are based on Ni(CO)4. 

Carbonylations which are accompanied hy oxidation reactions, are frequently called oxidative carbonylations . Reactions of this type are usually carried out in the presence of a catalyst and an oxidant, for example air. In principle, similar starting materials to those in classical Reppe carbonylations may be used, but as a result of the additional oxidation step different reaction products are obtained. To some extent, this method represents an extension of the Reppe carbonylation. For... 

Palladium-Catalysed Reppe Carbonylation," Kiss. G. Chem. Rev., 2001, 101, 3435. 

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) ... 

The Reppe carbonylation route to aldehydes and alcohols has been known for some time, where alkenes react with a metal carbonyl, CO, and water in the presence of base. In the original work [Fe(CO)s] was used as catalyst precursor, but recently precious metal cluster catalysts have been described by Pettit and Laine." The proposed mechanism is given in Scheme 2. Pettit screened a number of carbonyl clusters of Ru, Rh, Os, Ir, and Pt for the Reppe carbonylation of propene at 2.4 MPa CO and 1 MPa propene with... 

For the Reppe carbonylation, it is proposed that the reaction involves the initial oxidative addition of a nucleophile to the transition metal complex, followed by the complexation of an unsaturated hydrocarbon to the metal and insertion into a metal-H bond. Subsequently, migration of hydrocarbon species to CO followed by a reductive elimination afford the corresponding product." Scheme 1 illustrates the formation of ester from acetylene, CO, and methanol in the presence of a catalytic amount of Pd[CO]4. In addition, a mechanism analogous to that of Hydroformylation is proposed and displayed in Scheme 2 for the Reppe formylation. 

SCHEME 1. Preparation of ester from acetylene, CO, and alcohol by the Reppe carbonylation. 

Other references related to the Reppe carbonylation are cited in the literature. ... 

A quite different process, called Reppe carbonylation, has been used to convert acetylene to acrylic acid esters. The catalysts are carbonyls of iron, cobalt or nickel and the hydrogen source is a hydrogen halide, HX. The process is thought to involve oxidative addition of HX to the metal carbonyl, followed by coordination and insertion of alkyne into the M—H bond and insertion of CO into the M—C bond. The resulting acyl complex is cleaved by alcohol to produce the ester and the metal hydride catalyst. De Angelis et al. have reported a theoretical analysis of the Ni(CO)4 system. 

Actual operating capacities of Reppe carbonylation processes are difficult to estimate since only a few data are available in the literature. However, it is known that some of the syntheses are carried out on an industrial scale, e. g. the synthesis of acrylates from acetylene, carbon monoxide and alcohols (BASF) [1004, 1005], the acetic acid synthesis from methanol and carbon monoxide and the synthesis of higher molecular weight saturated carboxylic acids from olefins, carbon monoxide and water. Propionic acid (30,000 tons/year) and to a smaller extent heptadecanoic dicarboxylic acid are manufactured via the carbonylation route at BASF. Butanol is made from propylene in Japan [1003, 1004]. 

Hydroformylation, ring closure reactions and the Koch acid syntheses may be carried out in autoclaves made from stainless steel. If the formation of iron pentacarbonyl has to be completely avoided, silver or copper lined autoclaves may be used. If hydrogen halides or hydrogen halide generating compounds are used, which e.g., is the case in the Reppe carbonylation reactions, stainless steel autoclaves cannot be used due to corrosion. HasteUoy B or Hastelloy C should be used instead. 

At the moment, isobutanol is mostly produced through petrochemical processes, from crude oil as the starting feedstock through Reppe carbonylation and hydrofor-mylation (Hahn et al. 2000). It has been detected that certain microorganisms... 

The Reppe carbonylation of acetylene with Ni(CO)4 has been studied with DF and MD calculations. Insertion of HCCH into the Ni-H bond of a... 

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