Addition to Carbon Monoxide

Carbon forms a number of oxides in addition to carbon monoxide and dioxide but they are beyond the scope of this book. 

In addition to carbon monoxide (CO) and unbumed hydrocarbons (UHC), the most significant products of combustion are the oxides of nitrogen (NOx). At high temperatures, free oxygen not consumed during combustion reacts with nitrogen to form NO and NO2 (about 90% and lO /i of total NOx, respectively). 

In addition to carbon monoxide (CO) and carbon dioxide (C02), there is a third compound of carbon and oxygen called carbon suboxide. If a 2.500 g sample of carbon suboxide contains 1.32 g of C and 1.18 g of O, show that the law of multiple proportions is followed. 

Similarly, photolysis of the cyclobutane-1,3-diones 19—21 produces varying amounts of ethylenes, ketenes and polymers in addition to carbon monoxide and the cyclopropanone, as was shown in Scheme 4, Section 2.3. 10>81)... 

In addition to carbon monoxide, other unsaturated compounds, for example isonitriles and acetylenes, can also insert into C-H bonds to give aldimines and substituted alkenes, respectively [12, 13]. Similar to carbonylation, high terminal selectivity for n-alkanes were also observed in these reactions. 

A number of reactions of organomagnesium compounds, giving rise to new organomagnesium compounds, are covered in other chapters. They include addition to carbon-carbon multiple bonds (see Chapter 4), addition to isonitriles (see Section 5.4), addition to carbon monoxide (see Section 6.5), thiophilic addition to carbon-sulfur double bonds (see Chapter 7) and addition to carbenes (see Section 9.1). 

In addition to carbon monoxide, carbon dioxide and water, the products included methanol and a hydrocarbon assumed to be methane. Acids and peracids were detected, while at 298 °C hydrogen peroxide was present. 

Available data suggest that there are two pathways by which methylene chloride is metabolized. One utilizes the mixed function oxidase enzymes and produces carbon monoxide, while the other pathway involves glutathione transferase and produces carbon dioxide. The mixed function oxidase pathway seems to be the preferred pathway for methylene chloride metabolism following inhalation exposures. In addition to carbon monoxide and carbon dioxide, methylene chloride is also metabolized to a lesser extent to formaldehyde and formic acid. 

Ryu and Sonoda have extended this strategy to free radical carbonylation reactions [27], Under low pressures of carbon monoxide an alkyl halide, such as iodooctane (37) reacts with ally Itri butyl tin to form a y ,y-unsaturated ketone. The initially formed alkyl radical undergoes addition to carbon monoxide to form an acyl radical. This acyl radical then adds to allyltributyltin to form the final product (Scheme 7). It is interesting to note that the slow rate of addition of an alkyl radical to allyltributyltin allows this reaction to be carried out with much lower carbon monoxide pressures than are necessary with analogous reactions using tin hydrides as radical mediators. Ryu and Sonoda have also taken this reaction one step further, successfully intercepting the acyl radical with an electron-deficient alkene before addition to allyltributyltin [28]. In these reactions, three carbon-carbon bonds are formed and the products are y9-functionalized, (5, -unsaturated ketones. 

In addition to carbon monoxide, sodium cyanide or chlorodifluoromethane can serve as the one carbon fragment in conversion of trialkylboranes to trialkylcar-binols. In the former case, the borane is first treated with sodium cyanide, and the resulting adduct is then treated with trifluoroacetic anhydride. With chlorodifluoromethane, the other reagent required is a potassium t-alkoxide. An oxidation step (hydrogen peroxide) then yields the product. Formulate a mechanism for each system. 

In the first route, in addition to carbon monoxide, benzene, fluorine and the anilide of phthalic acid are produced, while in the second besides carbon dioxide, benzene, biphenyl and fluorene are found [19]. 

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