Carboxylation alkane

Laibinis P E, Flickman J J, Wrighton M S and Whitesides G M 1989 Orthogonal self-assembled monolayers— alkanethiols on gold and alkane carboxylic-acids on alumina Science 245 845-7... 

Alkanesulfonates are the petrochemically derived sulfur analogs of soaps, which are alkane carboxylates based on renewable resources. The main difference between alkanesulfonates and soaps is, however, that alkanesulfonates consist of a rather complex mixture of homologs with different carbon chain lengths and isomers with an almost statistical distribution of the functional group along the hydrophobic carbon chain (Fig. 1), whereas soap is a mixture of homologs of alkane 1-carboxylates with an even number of carbon atoms. 

E. L. Shock (1990) provides a different interpretation of these results he criticizes that the redox state of the reaction mixture was not checked in the Miller/Bada experiments. Shock also states that simple thermodynamic calculations show that the Miller/Bada theory does not stand up. To use terms like instability and decomposition is not correct when chemical compounds (here amino acids) are present in aqueous solution under extreme conditions and are aiming at a metastable equilibrium. Shock considers that oxidized and metastable carbon and nitrogen compounds are of greater importance in hydrothermal systems than are reduced compounds. In the interior of the Earth, CO2 and N2 are in stable redox equilibrium with substances such as amino acids and carboxylic acids, while reduced compounds such as CH4 and NH3 are not. The explanation lies in the oxidation state of the lithosphere. Shock considers the two mineral systems FMQ and PPM discussed above as particularly important for the system seawater/basalt rock. The FMQ system acts as a buffer in the oceanic crust. At depths of around 1.3 km, the PPM system probably becomes active, i.e., N2 and CO2 are the dominant species in stable equilibrium conditions at temperatures above 548 K. When the temperature of hydrothermal solutions falls (below about 548 K), they probably pass through a stability field in which CH4 and NII3 predominate. If kinetic factors block the achievement of equilibrium, metastable compounds such as alkanes, carboxylic acids, alkyl benzenes and amino acids are formed between 423 and 293 K. 

In 1980, in search for new collectors for cassiterite, a new collector [11] was synthesized at Freiberg Mining Academy. The investigations were carried out with alkane carboxylic acids with the general structure as shown in Figure 21.7, which was altered by controlled substitution with -COOH and other groups. 

Although these collectors were effective cassiterite collectors, their selectivity against topaz was not satisfactory. In order to overcome this problem, amino naphthol disulphonic acid was found to be a good topaz depressant in the presence of alkane carboxylic acid. This reagent scheme has not been tested in a commercial operation. 

Figure 21.7 General formula of alkane carboxylic acid used for cassiterite flotation studies.

The trend of discovering the analytical field of environmental analysis of surfactants by LC-MS is described in detail in Chapters 2.6-2.13 and also reflected by the method collection in Chapter 3.1 (Table 3.1.1), which gives an overview on analytical determinations of surfactants in aqueous matrices. Most methods have focused on high volume surfactants and their metabolites, such as the alkylphenol ethoxylates (APEO, Chapter 2.6), linear alkylbenzene sulfonates (LAS, Chapter 2.10) and alcohol ethoxylates (AE, Chapter 2.9). Surfactants with lower consumption rates such as the cationics (Chapter 2.12) and esterquats (Chapter 2.13) or the fluorinated surfactants perfluoro alkane sulfonates (PFAS) and perfluoro alkane carboxylates (PFAC) used in fire fighting foams (Chapter 2.11) are also covered in this book, but have received less attention. 

The value of = 1 X 10 s for the first-order rate constant for collapse of an ion pair between Me-4 and pentaflourobenzoate ion is larger than the second-order rate constant rcoo = 5x10 M s reported for the bimolecular addition of alkane carboxylates to Me-4. This second-order rate constant is limited by the rate constant for formation of an ion pair between Me-4 and a carboxylate ion. The larger barrier to encounter-limited reactions of carboxylate ions compared with the diffusion-limited reactions of anions such as azide ion, = 5 X 10 represents the barrier to desolvation of nucleophile that must precede formation of an ion pair between Me-4 and a carboxylate ion (Scheme 13). ... 

On irradiation of 86 (n = 2 and 3) in alcoholic solutions, methyl- (86%), ethyl- (74%), and isopropyl- (52%) esters of the corresponding j-(2-hydroxy-phenyl)-alkane carboxylic acids are formed.40,54 tert-Butanol, however, fails to yield any alcoholysis product whatsoever. A considerable influence of ring substituents on the quantum yield of ethanolysis of the lactones 86 and the... 

It may be desirable to define certain basic physical processes afresh, when we are dealing with systems essentially subject to two-dimensional conformations and hence two-dimensional constraints. This is the case for membranes, and also for a number of alkali salts of alkali -alkane carboxylates. These melt to give mesophases, in which the anions and cations are arranged in layerlike structures. At considerably higher temperatures the mesophases pass into isotropic ionic melts, but in the intervening temperature range they exhibit marked anisotropy of optical and physical properties. In these mesophases, which are ordered fluid... 

Aluminum—tetradentate ligand catalyst system, in epoxide homopolymerization, 11, 601 Aluminum(I) tetrahedra, synthesis, 9, 262 Aluminum(III)-tin exchange, process, 9, 265 Aluminum-transition metal bonds, characteristics, 9, 264 Amavadine, for alkane carboxylations, 10, 234—235 Ambruticin S, via ring-closing diene metathesis, 11, 218 Amide-allenes, cyclizations, 10, 718 Amide ether complexes, with Zr(IV) and Hf(IV), 4, 783 Amide hybrid ligands, in organometallic synthesis, 1, 64 Amides... 

A. Carboxylic acid and ester Carboxylic acid and alcohol Carboxylic acid and alkane Carboxylic acid and alkene... 

It has long been held that a separation of carboxylic acids by lEC requires the use of an acidic eluent to repress ionization of the analytes and thereby give sharp pcak.s. However, equilibrium constant calculations indicate that alkane carboxylic acids are... 

Schoot and Klassens (1956) extended the three-point theory to further aryl- and aryloxy-alkane carboxylic acids. In their opinion, the carboxyl group of the molecule attached to the active sites reacts to form high-energy phosphate, and subsequently Sr42 reaction proceeds at the a-carbon atom. 

Monohalo or dihalo alkanes, carboxylic acids, or ketones are obtained on treating diazoalkanes,1167 diazocarboxylic esters,1168 or diazo ketones with hydrogen halides or halogens. The reaction usually occurs at room temperature or below. However, preparative importance attaches only to the formation of the halo ketones from diazo ketones they are obtained free from isomers (cf. page 189). 

Why then, is intermediate A not a free alkyl radical In order to examine the reaction pathway of genuine free alkyl radicals under Gif-conditions, they were generated at room temperature by the photolysis of N-hydroxy-2(7//)-thiopyridone derivatives of alkane carboxylic acids and were allowed to react with dioxygen or added trapping reagents (Scheme 2) ... 

An alternative procedure for reductive decarboxylation without the use of trialkyltin hydrides as hydrogen atom donors has been developed Alkane carboxylic acid esters derived from AT-hydroxypyridine-2-thione decomposed to alkyl radical, which can readily accept a hydrogen atom from t-BuSH (equation 74) to give alkanes. This reaction can be conveniently performed as a one-pot experiment wherein the acid chloride of an alkane carboxylic acid, the sodium salt of thiohydroxamic acid, t-BuSH and 4-dimethyl-aminopyridine (DMAP) in benzene solution are heated to reflux. This procedure works well for COOH groups attached to primary and secondary carbon atoms. Instead of AT-hydroxypyridine-2-thione, one can use other thiohydroxamic acids, viz. iV-hydroxy-AT-methylthiobenzamide, 3-hydroxy-4-methylthiazole-2(3if)-thione (equation 75) and l-iV-hydroxy-3-AT-methylbenzoylenethiourea for decarboxylation reactions. 

One of the classical reactions in organic chemistry for the synthesis of alkanes through symmetrical coupling of alkane carboxylic acids is the Kolbe reaction . There are... 

Smaller organic anions Amino acids, alkane carboxylic acids (formate, acetate, propionate, butyrate), chloro carboxylic acids (chloroacetate, dichloroacetate), hydroxy acids (hydroxya-cetate, lactate, tartrate, citrate), glycolate, gluconate, pyruvate, dicarboxylic acids (oxalate, malonate, succinate, glutarate, fumarate, maleate), alkanesulfonic acids (methanesulfo-nate, ethanesulfonate). 

FLUORAD Fluorochemical Surfactant FC-126 Is an anionic fluorochemical surface active agent particularly useful as an emulsifier in the polymerization of fluorinated monomers where its surface activity and the highly fluorinated nature of micelles formed in aqueous media combine to give this unique utility. FC-126 is classified as an ammonium perfluoro-alkane carboxylate. It shows excellent surface activity in alkaline media. 

Scheme 2.9 Alkane carboxylation with CO and K2S20g, in TFA (a) General reaction [12, 15, 52-60] and (b) proposed mechanism for...

We have recently developed a new and cleaner method for the direct and highly efficient hydrocarboxylation of various C alkanes into the corresponding C , j carboxylic acids [18, 31], It consists in reacting an alkane with CO, H2O, and K2S20g, and in the presence of Cu-catalyst (Scheme 3.5). In contrast to prior alkane carboxylation methods [32, 33], this protocol does not require absolute trifluoroacetic acid as a solvent, and undergoes efficiently at mild temperatures (50-60 °C) and in aqueous acid-solvent-free medium (H20/MeCN mixed solvent), wherein water also plays a main role as a reagent, apart from being a component of the solvent system [18]. 

The alkane carboxylation reactions are typically undertaken in trifluoroacetic acid (TEA) at 80 °C with a V or Re complex catalyst and peroxydisulfate as the oxidant, under a CO atmosphere, and lead to the corresponding carboxylic acids with one more carbon (Scheme 22.4 for the cases of methane and ethane). 

When a carboxylic acid moiety is connected to a ring, the compound is named as an alkane carboxylic acid, for example ... 

Covers NIR spectra for prgqr cpmippuindsfmGluding alkanes, carboxylic acids, amines, dienes, dlkynes, heterocyclic compounds, amino acids, and aldehydes... 

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