Carbon monoxide ketones

Carbon monoxide Ketone synthesis using cyanide ion Reactions with a-halo-carbonyl compounds Polyene Cyclisations Looking Forwards... 

Additionally, symmetric ketones have also been produced by the carbonylative homo-coupling of organometallic reagents [94-99]. Under the assistant of palladium catalysts and under the pressure of carbon monoxide, ketones were produced from alkenyl- and arylborates and boronic acids, diaryliodonium salts, organolead compounds and arylmercuric salts. [Rh(CO)2Cl]2 was also applied as a catalyst for the carbonylative homo-coupling of vinyl- and arylmercurials. 

The reaction of trivalent carbocations with carbon monoxide giving acyl cations is the key step in the well-known and industrially used Koch-Haaf reaction of preparing branched carboxylic acids from al-kenes or alcohols. For example, in this way, isobutylene or tert-hutyi alcohol is converted into pivalic acid. In contrast, based on the superacidic activation of electrophiles leading the superelectrophiles (see Chapter 12), we found it possible to formylate isoalkanes to aldehydes, which subsequently rearrange to their corresponding branched ketones. 

It has been known since the early 1950s that butadiene reacts with CO to form aldehydes and ketones that could be treated further to give adipic acid (131). Processes for producing adipic acid from butadiene and carbon monoxide [630-08-0] have been explored since around 1970 by a number of companies, especially ARCO, Asahi, BASF, British Petroleum, Du Pont, Monsanto, and Shell. BASF has developed a process sufficiendy advanced to consider commercialization (132). There are two main variations, one a carboalkoxylation and the other a hydrocarboxylation. These differ in whether an alcohol, such as methanol [67-56-1is used to produce intermediate pentenoates (133), or water is used for the production of intermediate pentenoic acids (134). The former is a two-step process which uses high pressure, >31 MPa (306 atm), and moderate temperatures (100—150°C) (132—135). Butadiene,... 

In the early 1920s Badische Arulin- und Soda-Fabrik aimounced the specific catalytic conversion of carbon monoxide and hydrogen at 20—30 MPa (200—300 atm) and 300—400°C to methanol (12,13), a process subsequendy widely industrialized. At the same time Fischer and Tropsch aimounced the Synth in e process (14,15), in which an iron catalyst effects the reaction of carbon monoxide and hydrogen to produce a mixture of alcohols, aldehydes (qv), ketones (qv), and fatty acids at atmospheric pressure. 

Decomposition products from primary and secondary dialkyl peroxides include aldehydes, ketones, alcohols, hydrogen, hydrocarbons, carbon monoxide, and carbon dioxide (44). 

Because di-/ fZ-alkyl peroxides are less susceptible to radical-induced decompositions, they are safer and more efficient radical generators than primary or secondary dialkyl peroxides. They are the preferred dialkyl peroxides for generating free radicals for commercial appHcations. Without reactive substrates present, di-/ fZ-alkyl peroxides decompose to generate alcohols, ketones, hydrocarbons, and minor amounts of ethers, epoxides, and carbon monoxide. Photolysis of di-/ fZ-butyl peroxide generates / fZ-butoxy radicals at low temperatures (75), whereas thermolysis at high temperatures generates methyl radicals by P-scission (44). 

Polyimides have been synthesized by Diels-Alder cycloaddition of bismaleimides and substituted biscydopentadienones (81,82). The iatermediate tricychc ketone stmcture spontaneously expeU carbon monoxide to form dihydrophthalimide rings, which are readily oxidized to imides ia the presence of nitrobenzene. 

The synthesis of copolymers of olefins with carbon monoxide (eq. 3) or ketones (eq. 4) leads to backbone or side-chain carbonyl functionaUty,... 

Other patents include copolymers of vinyl ketones with acrylates, methacrylates, and styrene (53) an ethylene—carbon monoxide (1—7 wt %) blend... 

Pyrrohdinone (2-pyrrohdone, butyrolactam or 2-Pyrol) (27) was first reported in 1889 as a product of the dehydration of 4-aminobutanoic acid (49). The synthesis used for commercial manufacture, ie, condensation of butyrolactone with ammonia at high temperatures, was first described in 1936 (50). Other synthetic routes include carbon monoxide insertion into allylamine (51,52), hydrolytic hydrogenation of succinonitnle (53,54), and hydrogenation of ammoniacal solutions of maleic or succinic acids (55—57). Properties of 2-pyrrohdinone are Hsted in Table 2. 2-Pyrrohdinone is completely miscible with water, lower alcohols, lower ketones, ether, ethyl acetate, chloroform, and benzene. It is soluble to ca 1 wt % in aUphatic hydrocarbons. 

With Unsaturated Compounds. The reaction of unsaturated organic compounds with carbon monoxide and molecules containing an active hydrogen atom leads to a variety of interesting organic products. The hydroformylation reaction is the most important member of this class of reactions. When the hydroformylation reaction of ethylene takes place in an aqueous medium, diethyl ketone [96-22-0] is obtained as the principal product instead of propionaldehyde [123-38-6] (59). Ethylene, carbon monoxide, and water also yield propionic acid [79-09-4] under mild conditions (448—468 K and 3—7 MPa or 30—70 atm) using cobalt or rhodium catalysts containing bromide or iodide (60,61). 

The problems with the combustion reaction occur because the process also produces many other products, most of which are termed air pollutants. These can be carbon monoxide, carbon dioxide, oxides of sulfur, oxides of nitrogen, smoke, fly ash, metals, metal oxides, metal salts, aldehydes, ketones, acids, polynuclear hydrocarbons, and many others. Only in the past few decades have combustion engineers become concerned about... 

Photodegradation may involve use of inherently photo-unstable polymers or the use of photodegradant additives. An example of the former are ethylene-carbon monoxide polymers in which absorption of light by the ketone group leads to chain scission. The polymer becomes brittle and forms a powder. Such materials are marketed by Dow and by Du Pont. Other examples are the copolymers of divinyl ketone with ethylene, propylene or styrene marketed by Eco Atlantic. 

If nitrogen or sulphur is present in the fuel then the mixture of eombustion produets may inelude oxides of these elements. In the absenee of exeess oxygen ineomplete oxidation oeeurs to produee partially oxidized earbon eompounds sueh as aldehydes, ketones, phenols, and earbon monoxide. Carbon monoxide is extremely toxie and some of the other eompounds are respiratory indtants. 

The reaction is sensitive to the presence of water, which inhibits the migration of the third alkyl group and leads to dialkyl ketones (see Chapter 12, Section II). The convenience of the hydroboration reaction combined with the use of carbon monoxide at atmospheric pressure provides the most accessible route to many trialkylcarbinols. 

As mentioned in the preceding section, the presence of water during the reaction of trialkylboranes with carbon monoxide inhibits the migration of the third alkyl group and leads to production of dialkyl ketones (i). This fact can be employed to advantage for the preparation of dialkyl ketones as shown in the scheme. 

The following dialkyl ketones may be prepared by an analogous procedure with the time required for the absorption of carbon monoxide as shown (Table 12.2). 

Polluted air often contains carbon monoxide and volatile organic carbon (VOC) gases, including ketones and aldehydes, as well as oxides of sulfur and... 

Although analogous to the direct coupling reaction, the catalytic cycle for the carbonylative coupling reaction is distinguished by an insertion of carbon monoxide into the C-Pd bond of complex A (see A—>B, Scheme 31). The transmetalation step-then gives trans complex C which isomerizes to the cis complex D. The ketone product E is revealed after reductive elimination. 

In the Fischer-Tropsch process, carbon monoxide reacts with hydrogen in the presence of a solid catalyst, with the formation of a mixture of hydrocarbons. The composition of the product varies considerably with the catalyst and the operating conditions. The mixture may include (in addition to hydrocarbons) alcohols, aldehydes, ketones, and acids. 

If the reaction between trialkylboranes and carbon monoxide (18-23) is carried out in the presence of water followed by addition of NaOH, the product is a secondary alcohol. If H2O2 is added along with the NaOH, the corresponding ketone is obtained instead. Various functional groups (e.g., OAc, COOR, CN) may be present in R without being affected,though if they are in the a or p position relative to the boron atom, difficulties may be encountered. The use of an equimolar... 

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