Hydrocarbons from carboxylic acids

The decarboxylation of carboxylic acid in the presence of a nucleophile is a classical reaction known as the Hunsdiecker reaction. Such reactions can be carried out sometimes in aqueous conditions. Man-ganese(II) acetate catalyzed the reaction of a, 3-unsaturated aromatic carboxylic acids with NBS (1 and 2 equiv) in MeCN/water to afford haloalkenes and a-(dibromomethyl)benzenemethanols, respectively (Eq. 9.15).32 Decarboxylation of free carboxylic acids catalyzed by Pd/C under hydrothermal water (250° C/4 MPa) gave the corresponding hydrocarbons (Eq. 9.16).33 Under the hydrothermal conditions of deuterium oxide, decarbonylative deuteration was observed to give fully deuterated hydrocarbons from carboxylic acids or aldehydes. 

Hydrocarbons from carboxylic acid chlorides COCl H... 

Ethylene derivatives from a / -ethyleneketones s. 12,115 limitations s. Soc. 1960, 1406 Hydrocarbons from carboxylic acids... 

Hydrocarbons from carboxylic acid esters COOR CH3... 

Participation of fluorocarbocations, derived from carboxylic acids and from halo acetones, in reactions of carbonyl compounds with sulfur tetrafluoride has been directly evidenced by trapping them with aromatic hydrocarbons [207, 20S],... 

Possible slight effects from carboxylic acids, anhydrides, aromatic and aliphatic hydrocarbons, alcohols, aldehydes, ketones, esters, chlorinated solvents... 

The plausible deoxygenation routes for production of diesel like hydrocarbons from fatty acids and their derivates are decarboxylation, decarbonylation, hydrogenation and decarbonylation/hydrogenation. The main focus in this study is put on liquid phase decarboxylation and decarbonylation reactions, as depicted in Figure 1. Decarboxylation is carried out via direct removal of the carboxyl group yielding carbon dioxide and a linear paraffinic hydrocarbon, while the decarbonylation reaction yields carbon monoxide, water and a linear olefinic hydrocarbon. 

Another way that has potential for the generation of perfluoroalkyl radicals from carboxylic acids is the use of Barton esters. However, unlike the situation for their hydrocarbon analogs, fluorinated thiohydroxamate esters have thus far only been able to be prepared in situ [65]. 

You probably can guess that many other carboxylic acids are formed from longer hydrocarbons. Many carboxylic acids occur in foods. 

Via intermediates Phenols from hydrocarbons via amines s. 1,192 a-Hydroxy ketones from ketones via a-isonitrosoketones s. 2,145 a-Hydroxycarboxylic acids from carboxylic acids via a-halogenocarboxylic acids s. 1,451 v.l. H —OH... 

Nitro from nitroso compounds with simultaneous oxidation of hydrocarbons to carboxylic acids... 

Carboxylic acids from hydrocarbons, simultaneously carboxylic acid chlorides from carboxylic acids... 

The use of carbon as a catalyst was reviewed. It was shown that interesting activity correlations could be obtained by studying the catalytic performance of a series of carbon materials prepared from the same precursor with similar tex-mral properties and different amounts of surface functional groups. The redox couple quinone-hydroquinone was found to be involved in the oxidative dehydrogenation of hydrocarbons, while carboxylic acid groups are the active sites for the dehydration of alcohols. In both cases, thermal treatments at different temperatures were used to identify the nature of the active sites, aud correlations... 

The application of GC-MS to PAH-analysis will allow considerable simplification of the work-up procedure. As far as solubility and dynamic range considerations will permit, the major PAH in airborne particulate matter samples can be accurately measured in the electron impact single or multiple ion monitoring mode, using the molecular ions of the respective PAH as specific ions, in the presence of much larger amounts of aliphatic hydrocarbons and carboxylic acids. Polar and ionic material is first removed from the combined benzene-methanol extract by liquid-liquid partition in water-diethylether. After drying, the addition of diazomethane results in derivatisation of the acidic components and the sample can be injected onto the column (Van Vaeck and Van Cauwenberghe (30)). 

Ketenes are most often prepared from carboxylic acid derivatives, and a novel reductive pathway has been described for the conversion of biomass derived fatty acid esters in microalgae oils into hydrocarbons through intermediate ketenes. The conversion into alkanes using Zr02-promoted Ni catalysis is explained as involving conversion of the esters into acids and dehydration to ketenes (observed by strong... 

Molecules derived from carboxylic acid are soluble in solvents (e.g., chlorinated alkanes and aromatic hydrocarbons). Moreover, similar to alcohols, carbonyl compounds with fewer than four carbons are soluble in water (Bruice, 2004). However, the solubility of esters in water decreases together with the increase of the chain length. As a result, none of the fats and oils (triesters of glycerol) are water soluble. 

Amines from carboxylic acid amides with simultaneous formation of hydrocarbons from tosylates... 

Carboxymic acids, esters, and amides from hydrocarbons via carboxylic acid chlorides... 

A selection of important anionic surfactants is displayed in table C2.3.1. Carboxylic acid salts or tire soaps are tire best known anionic surfactants. These materials were originally derived from animal fats by saponification. The ionized carboxyl group provides tire anionic charge. Examples witlr hydrocarbon chains of fewer tlran ten carbon atoms are too soluble and tliose witlr chains longer tlran 20 carbon atoms are too insoluble to be useful in aqueous applications. They may be prepared witlr cations otlrer tlran sodium. 

Nitroamlines. Acetyl derivatives (p. 388), Benzoyl derivatives (p. 388). Diamines. Diacet> l derivatives (p. 388), Dibenzoyl derivatives (p. 388). Halogeno-hydrocarbons, a-Naphthyl ethers (from reactive halogen compounds, p. 391, and their Picratcs, p. 394), Nitro-derivatives (p.39i). Carboxylic acid (if oxidisable side chain) (p. 393). 

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