Carbon monoxide with alcohols

Reaction of Carbon Monoxide with Alcohols to Form Acids... 

The reaction of carbon monoxide with alcohols to form fatty acids, having one more carbon atom per molecule than the alcohol, has recently received attention. The experimental work with the reaction has been based largely on one of the proposed mechanisms for the formation of higher alcohols from mixtures of hydrogen and carbon monoxide.80 Thus, the mechanism first proposed occurred through the following steps ... 

Until the 1920s the major source of methanol was as a byproduct m the production of charcoal from wood—hence the name wood alcohol Now most of the more than 10 billion lb of methanol used annually m the United States is synthetic prepared by reduc tion of carbon monoxide with hydrogen... 

Attempts have been made to develop methods for the production of aromatic isocyanates without the use of phosgene. None of these processes is currently in commercial use. Processes based on the reaction of carbon monoxide with aromatic nitro compounds have been examined extensively (23,27,76). The reductive carbonylation of 2,4-dinitrotoluene [121 -14-2] to toluene 2,4-diaLkylcarbamates is reported to occur in high yield at reaction temperatures of 140—180°C under 6900 kPa (1000 psi) of carbon monoxide. The resultant carbamate product distribution is noted to be a strong function of the alcohol used. Mitsui-Toatsu and Arco have disclosed a two-step reductive carbonylation process based on a cost effective selenium catalyst (22,23). 

The Reppe process for manufacture of acrylic esters uses acetylene and carbon monoxide, with a nickel carbonyl catalyst having high acute and longterm toxicity, to react with an alcohol to make the corresponding acrylic ester ... 

The shift towards the monoaminocarbonylation, obtained under these conditions, as compared with the dialkoxycarbonylation observed in alcoholic solvents, is due to the basicity of the amine, which favors the formation of an alkynylpalladium complex (Scheme 37). This species then inserts carbon monoxide with formation of an alkynoylpalladium intermediate, which undergoes nucleophilic displacement by R2NH to give the final 2-ynamide. 

In the past, methanol was obtained by heating wood without allowing the wood to burn. The products were collected, and methanol (sometimes called wood alcohol ) was separated by distillation. Today methanol is manufactured by reacting carbon monoxide with hydrogen gas. 

Reaction of Carbon Atoms with Alcohols and Ethers. The electro-philicity of atomic carbon and the exothermicity of carbon monoxide formation in its reactions facilitates attack on, and removal of oxygen by C atoms. Deoxygenation of ethers, alcohols, and carbonyl compounds has been reported. This process is generally a highly exothermic reaction, which is likely to generate products with excess energy. 

Alkenes can be converted to succinic esters by reaction with carbon monoxide, an alcohol, and palladium chloride in the presence of mercuric chloride.1,12 The addition is mostly syn. In similar reaction, both terminal and internal alkynes can be converted to esters of maleic acid. 

Alcohols and jlkenes are also primary products and are not shown in the simplified Eq. 15.182. The overall reaction is complicated and, as a result, its mechanism has been the subject of considerable debate.188 The reaction may be viewed as the reductive polymerization of carbon monoxide, with molecular hydrogen as the reducing agent. A variety of heterogeneous catalysts, such as metallic iron and cobalt on alumina, have been used. It is believed that carbon monoxide dissociates on the catalytic surface to give carbides and that these are in turn hydrogenated to give surface carbenes 1 " n ... 

Platinum(II) halides react with cyanate salts to give cyanato complexes. Reacting the compounds Pt(NCO)4 with triphenylphosphine gives Pt(NCO)2(PPh3)2.1628 These platinum(II) complexes are N-bonded. Treatment with carbon monoxide and alcohol yields the complex (172 equation 476).1629... 

OXYL PROCESS. A method for directly producing higher alcohols by catalyhcaUy reducing carbon monoxide with hydrogen. 

REPPE PROCESS. Any of several processes involving reaction of acetylene (1) with formaldehyde to produce 2-butync-l,4-diol which can be converted to butadiene (2) with formaldehyde under different conditions to produce propargyl alcohol and, form this, allyl alcohol (3) with hydrogen cyanide to yield acrylonitrile (4) with alcohols to give vinyl ethers (5) with amines or phenols to give vinyl derivatives (6) with carbon monoxide and alcohols to give esters of acrylic acid (7) by polymerization to produce cyclooctatetraene and (8) with phenols to make resins. The use of catalysis, pressures up to 30 atm, and special techniques to avoid or contain explosions are important factors in these processes. 

Alcohols are among the most important and commonly encountered of all organic chemicals. Methanol (CH3OH), the simplest member of the family, was once known as wood alcohol because it was prepared by heating wood in the absence of air. Approximately 1.6 billion gallons of methanol are manufactured each year in the United States by catalytic reduction of carbon monoxide with hydrogen gas ... 

The carbanion is trapped with iodine to give 42. which makes a further functionali/aiion possible. Conversion of vinylic iodide 42 into a lactone is accomplished by palladium-cataly/ed carbonyla-tion under Stille conditions.13 This process ean be broken down into the following elementary reactions a) Oxidative addition of Pd° to vinylic iodide 42 with formation of 43 b) An insertion reaction of carbon monoxide with creation of the pallada-acyl species 44 c) Reaction of acid-chloride equivalent 44 with the alcohol to give lactone 13. 

Acrylic acid (CH2=CHC02H, melting point 13.5°C, boiling point 141°C, density 1.045, flash point 68°C) and acrylates were once prepared by reaction of acetylene and carbon monoxide with water or an alcohol, with nickel carbonyl as catalyst. 

Eq. 4.54 shows the reaction of n-heptanol (151) with Pb(OAc)4 under high-pressured carbon monoxide with an autoclave to generate the corresponding 8-lactone (152). This reaction proceeds through the formation of an oxygen-centered radical by the reaction of alcohol (151) with Pb(OAc)4,1,5-H shift, reaction with carbon monoxide to form an acyl radical, oxidation of the acyl radical with Pb(OAc)4, and finally, polar cyclization to provide 8-lactone [142-146]. This reaction can be used for primary and secondary alcohols, while (3-cleavage reaction of the formed alkoxyl radicals derived from tertiary alcohols occurs. 

The Fischer-Tropsch process Reaction of carbon monoxide with hydro- 9,16.28, 32,44, gen in the presence of a solid catalyst to produce a mixture of 58,64.65,66. hydrocarbons, alcohols, aldehydes, ketones, and acids depending upon 67, 68. 69,85, operating conditions and the nature of the caialyst 105... 

Acrylic Acid, Acrylates, and Acrylonitrile. Acrylic acid [79-10-7], C3H402, and acrylates were once prepared by reaction of acetylene and carbon monoxide with water or an alcohol, using nickel carbonyl as catalyst. I11 recent years tliis process has been completely superseded in the United States by newer processes involving oxidation of propylene (2). I11 western Europe, however, acetylene is still important in acrylate manufacture (see Acrylic acid and derivatives Acrylic ester polymers). 

The interaction of carbon monoxide with palladium salts produces under rela tively mild (but rigorously anhydrous) conditions such species as [Pd(CO)Cl2 ] 2, [Pdj CU(CO)j and probably, under higlier carbon monoxide pressure, species such as Pd(CO)2 CI3. Only under severe conditions are reduced species such as [Pd(CO)Xlrt X = Br. Cl formed, but since the catalytic reaction is carried out under a relatively mild carbon monoxide pressure, it is rather improbable that such reduced species are present in considerable amounts. For a general discus sion of the mechanism, however, the characteri .ation of the exact nature of the palladium(Il) carbonyl complexes formed m sint is irrelevant, ( nerally speaking, carbon monoxide coordination to a Pd(U) ion will produce a facile nucleophilic attack on CO by the alcohol. The question of whether such an attack is produced by free alcohol or by a palladium bonded alkoxy group, is worth examination. 

In Secs. 5-10 we present a series of selected examples of the use of the external reflectance technique to investigate some electrochemical systems of interest. Results from the electrochemical literature on the adsorption of hydrogen, carbon monoxide and alcohols are discussed and compared with the data from UHV measurements (Secs. 5-7). 

Volume 17 covers gas-phase combustion, which includes probably the most complex processes investigated by chemists. Chapter 1, about half the book, deals with the oxidation of hydrogen and carbon monoxide, with extensive consideration of all the individual reactions occurring. In Chapter 2, the combustion of hydrocarbons is discussed, with emphasis on the general mechanisms which have been suggested to account for the numerous products of partial oxidation. In Chapter 3, the oxidation of aldehydes, which are important intermediates in combustion of other compounds, is considered, and in Chapter 4, the oxidation of alcohols, ketones, oxirans, ethers, esters, peroxides, amines and halocarbons. 

Among the carbon electrophiles, carbonyl compounds [113,114] were first applied in the reaction with lithiated ferrocenylalkyl amines (Sect. 4.S.3.3 and Fig. 4-18). Analogously, carboxylic acids are obtained from CO2 [153]. The reactivity pattern of palladated ferrocenylalkyl amines with carbon electrophiles is somewhat different. Carbon monoxide in alcohols leads to the formation of esters of substituted ferrocenecarboxylic acids [124]. With prochiral alcohols, a moderate asymmetric induction is observed [154]. a, -Unsaturated ketones react with palladated ferrocenylalkyl amines not with addition to the carbonyl group, but with substitution of a hydrogen at the carbon—carbon double bond, allowing the introduction of longer side chains at the ferrocene ring (Fig. 4-27c) [124, 152]. 

Carbonylation of aryl bromides and iodides with carbon monoxide, an alcohol, a base, and a palladium catalyst, give carboxylic esters. Even very sterically hindered... 

Despite the presence of a formally divalent carbon atom, CO is not in fact a particularly reactive molecule and much of its chemistry depends on the use of either extreme conditions, energetic reagents or some form of catalysis. Perhaps the simplest examples of such catalysis are found in the reactions of carbon monoxide with protic reagents such as alcohols or secondary amines, affording esters or amides of formic acid. These reactions are catalyzed by alkoxide or amide anions, respectively, and, as shown in Scheme 1, the key step is nucleophilic attack on CO by the catalyst to give a strongly basic alkoxyacyl or aminoacyl anion which is immediately trapped by proton transfer from the alcohol or amine, so generating the catalytic species. 

Heck and Breslow found that alkyl halides, sulfates, and sulfonates undergo carboalkoxylation in the presence of carbon monoxide, an alcohol, a base, and a catalytic amount of sodium cobalt carbonylate, as illustrated for the reaction of 1-iodooctane in methanol with the strongly basic hindered amine dicyclohexylethyl-amine as base. Use of an unhindered amine leads to formation of the amide. 

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