Carbonylation, of acetylenes

Nickel carbonyl Carbonylation of acetylene and alcohols to produce acrylic and methacrylic acids Acute respiratory failure carcinogenic... 

Furane derivatives were also prepared by the carbonylation of acetylene derivatives. Phenylacetylene was converted to the furanone derivative shown in 3.35. under reductive conditions, while in the presence of oxygen 2-phenylmaleic anhydride was isolated as the main product.43... 

NiI(CO)3] catalyzed the carbonylation of acetylene in the presence of methanol to give methyl 3-vinylacrylate (equation 101 ).472 Unsaturated esters of higher molecular weight were also obtained. 

The carbonylation of acetylene to produce acrylic acid or ester (22) catalysed by Ni(CO)4 was a historical industrial process developed by Reppe. 

Carbonylation of the parent acetylene via stoichiometric or catalytic reactions involving transition-metal carbonyl complexes has been extensively studied. Various types of carbonylation reactions of acetylene were discovered. In 1968, Pino et al. [30] reported on the synthesis of hydroquinone via a Ru3(CO)12-cat-alyzed carbonylation of acetylene with H2 or H20. The product formally consisted of two molecules of acetylene and CO, and one molecule of H2 (Eq. 14). To achieve a good yield of hydroquinone, the H2 pressure must be kept under... 

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. 

A number of metal carbonyls and cyanides, particularly those of nickel and iron, form 7r-complexes with alkynes. These systems behave cat-alytically in the carbonylation of acetylene and in the formation of trimers (benzene) and tetramers (cyclooctatetraene). 

Acrylic acid is by far the most important product prepared by carbonylation of acetylene. The processes employed industrially since the mid-1950s for the homogeneously catalyzed carbonylation of acetylene (eq. (9)) have enabled the broad use of acrylic acid derivatives as mass products. This reaction was first discovered in 1939 by Reppe [19] and was investigated intensively in the subsequent period [20]. 

Whereas the carbonylation of acetylene lies firmly within the domain of homogeneous transition metal catalysis, in the case of vinylation the methods are as... 

Interestingly, carbonylation of acetylene to give A A (eq. (1)) was among the first large-scale industrial applications of homogeneous catalysis by organometal-lic complexes (cf. Section 2.3.2.1). 

Formation of heterocycles upon catalytic carbonylation of acetylenic compounds 03MI30. 

Syntheses of heterocycles by carbonylation of acetylenic compounds 04T5499. 

With alkynes hydrocarbonylative coupling leads to unsaturated ketones with exclusive cis addition of hydrogen and the acyl group. Thus, rhodium carbonyl catalyzed carbonylation of acetylenes and ethene with carbon monoxide and hydrogen stereospecifically leads to a./l-un-saturated ethyl ketones by cross hydrocarbonylation4- 5, e.g., diphenylacetylene with ethene in the presence of Rh4(CO)l3 gives ( )-1.2-diphenyl-l-penten-3-one in 91 % yield5. 

H 4.26%, O 45.03%. HOOCCH = CHCH=CH-COOH. Prepd by oxidation of phenol and peracetic acid Boeseken. Engelberts, C.A. 26t 2970 (1932) by treatment of ethyl 1,4-dtbromoadipate with alcoholic potassium hydroxide Guha, Sankaran, Org, Syn. 26, 57 (1946) by isomerization of 3-hydroxy-4-carbomethoxybut-1-ene-1-carboxylic acid lactone Elvidge et at, J, Chem, Soc, 1950, 2235 by carbonylation of acetylene Tsuji er al. J. Am. Chem, Soc. 86, 2095 (1964). Configuration and separation of isomers Boeseken, Kerkhoven, Rcc Trav. Chim. Si, 964 (1932) Elvidge et at, J. Chem Soc. 1953, 708. 

The carbonylation of acetylene with carbon monoxide and water to make acrylic acid is of historical interest, as it was the first carbonylation reaction carried out by Reppe. Until the mid-1980s, BASF operated an acrylic acid plant based on this technology to produce 110,000 metric tons per year at Ludwigshafen, Germany. The plant has been replaced with a propylene oxidation process. Today, the production of acrylic acid worldwide is exclusively by the propylene oxidation route. 

Carbonylation of acetylene to acrylic acid Ni salts or carbonyls Blumenberg (1984)... 

Scheme 8.16 Palladium-catalyzed oxidative carbonylation of acetylenes...

Carbonylation of acetylene carried out in the presence of catalytic amounts of PdBr2, LiBr, and H2O (H20/LiBr/PdBr2 molar ratio = 10 2 1) in CH3CN at 40 °C and 1 atm of total pressure [p(CO)/p(C2H2) = 2.5] afforded succinic anhydride in 70% yield. Working in the presence of oxygen, maleic anhydride was obtained as the main product. 

The reductive carbonylation of acetylenes proceeds via a different mechanism compared to the carbonylation of olefins, but through the addition of palladium hydride species to the triple bond. The most probable source of PdH is the WGS reaction, so water is required at two key steps of this catalytic cycle. Depending on conditions, the nature of the catalyst, and promoter additives, the carbonylation of acetylenes can lead to different products. An important role of cationic palladium complexes that readily form in the presence of water has been disclosed. "... 

Regiospecific reductive phopshine-free carbonylation of acetylenes in the presence of Pdl2 under modest pressure of CO gave furan-2(5//)-ones in good yield (Scheme 80). Similar results were obtained in a biphasic system.t ... 

A catalytic synthesis of a-methylenelactones by the pressure carbonylation of acetylenic alcohols, which gives a useful trans junction, has been described. The... 

As mentioned in the chapter on the reaction mechanism, the anion, especially of Ni-salts, is important in affecting the reaction course. The catalytic efficiency of the nickel halides strongly increases in the series fluoride, chloride, bromide, iodide [374—376]. The molar ratio of cobalt or nickel to iodine is also very important [414]. As in the hydroformylation reaction, metal carbonyls substituted by phosphine ligands are very reactive [377, 1009], and especially modified rhodium and palladium catalysts [1021, 1045] allow reactions under mild conditions. Thus, the nickel bromide triphenylphosphine allyl bromide complex shows an increased reactivity in the carbonylation of acetylenes. On the other hand, carbonyls substituted by phosphine ligands are also readily soluble in the reaction mixture [345, 377]. 

Oxidizing agents such as oxygen and nitrobenzene are catalyst poisons [365]. Surprisingly, CCI4 is also a catalyst poison in the carbonylation of acetylene with Ni(CO)4 [365]. 

The necessary temperatures and pressures of the carbonylation reactions are largely determined by the unsaturated starting material and the catalysts applied. In the pressureless stoichiometric carbonylation of acetylenes with Ni(CO)4, temperatures of 35 to 80 are sufficient. In the catalytic procedure with Ni(CO)4 temperatures of 120 to 220 °C and pressures around 30 atm are normally applied. In special cases lower temperatures may be used, e. g. in the acrylic acid and acrylic acid ester syntheses, which... 

The catalytic carbonylation of acetylenes or their derivatives with carbon monoxide and water yields unsaturated carboxylic acids or their derivatives. Thus, acetylene reacts with carbon monoxide and water to give... 

Contrary to the hydroformylation or carbonylation of olefins, in the carbonylation of acetylenes addition of the carboxyl group occurs, without exception, to one of the C-atoms of the triple bond. Generally, isomerization of the unsaturated bond via intermediate metalorganic complexes or isomerization of the carbon skeleton are not observed. 

As mentioned above, the carbonylation of acetylenes may also be effected without pressure with stoichiometric amounts of Ni(CO)4 as CO donor in the presence of aqueous acids. After reaction of the carbon monoxide which was complexed with nickel, the remaining nickel is found as the salt of the acid present. 

Carboxylic acid anhydrides are formed in the carbonylation of acetylenes if the alcohols are replaced by carboxylic acids (1). 

However, the reaction proceeded only under drastic conditions (pressure 700 upward to 900 atm) in the presence of mineral acids, BFg or metal halogenides. At that time metal carbonyls had been regarded as catalyst poisons. However, Reppe could prove that olefins react with carbon monoxide and water in the presence of metal carbonyls. The reaction products are saturated carboxylic acids. Whereas Ni(CO)4 is the preferred catalyst in the carbonylation of acetylenes, cobalt, rhodium and ruthenium catalysts are equivalent or superior in olefin carbonylation. Also palladium and hydrochloric acid containing catalyst systems are of special activity in hydrocarboxylation [469-471]. Iron has an accelerating effect [472]. Addition of boric acid to Ni or Co catalysts increases the catalyst life and suppresses the formation of insoluble polymer products [473]. 

Generally in the olefin carbonylation stronger reaction conditions have to be applied than in the carbonylation of acetylenes. In the stoichiometric procedure with Ni(CO)4 as catalyst, 150 °C and CO-pressures of about 50 atm are required and in the catalytic procedure conversion can be reali-2ed at 250 °C and a pressure of 200 atm. Palladium-containing catalysts are active already at 80-150 °C [469-471, 1021]. 

Butenolides.—Interest continues in the carbonylation reaction catalysed by transition metals as a route to butenolides. The catalyst RluCCO) is used in the carbonylation of acetylenes in the presence of olefins yields of 5-alkyl-2(5H)-furanones are good, but mixtures of products are obtained in unsymmetrical cases. The reaction between trichloroacetic acid and olefins is mediated by RuCl2(PPh3)3, and gives initially 2,2-dichloro-4-alkylbutanolides which undergo dehydrochlorination to 4-alkylidenebut-2-enolides. These compounds are also obtained by the cyclization of acetylenic acids (126) (127). ° A general synthesis of disubstituted butenolides (128) has been published, which is simple and effective (Scheme 12) ... 

Carbonylation of acetylenes using palladium catalyst can show another case of dramatic alteration of selectivity depending on the nature of the catalyst and other factors. Thus, the carbonylation of naphthylacetylenes can be run under very mild conditions, even under atmospheric pressure of CO, to give a-naphthylacrylic acids, thus opening a convenient approach to the nonsteroidal anti-inflammatory drug naproxen [123] ... 

Joh, T. Doyama, K. Onitsuka, K. Shiohara, T. Takahashi, S. (1991) Rhodium catalysed carbonylation of acetylenes under water gas shift conditions. Selective synthesis of furan-2(5//)-ones, Organometallics, 10,2493-8. 

---