Alcohols carboxylation

Typical nucleophiles known to react with coordinated alkenes are water, alcohols, carboxylic acids, ammonia, amines, enamines, and active methylene compounds 11.12]. The intramolecular version is particularly useful for syntheses of various heterocyclic compounds[l 3,14]. CO and aromatics also react with alkenes. The oxidation reactions of alkenes can be classified further based on these attacking species. Under certain conditions, especially in the presence of bases, the rr-alkene complex 4 is converted into the 7r-allylic complex 5. Various stoichiometric reactions of alkenes via 7r-allylic complex 5 are treated in Section 4. 

The reaction of alcohols with acyl chlorides is analogous to their reaction with p toluenesulfonyl chloride described earlier (Section 8 14 and Table 15 2) In those reactions a p toluene sulfonate ester was formed by displacement of chloride from the sulfonyl group by the oxygen of the alcohol Carboxylic esters arise by displacement of chlonde from a carbonyl group by the alcohol oxygen... 

In aqueous solution intermolecular association between carboxylic acid molecules IS replaced by hydrogen bonding to water The solubility properties of carboxylic acids are similar to those of alcohols Carboxylic acids of four carbon atoms or fewer are mis cible with water m all proportions... 

Esters can participate m hydrogen bonds with substances that contain hydroxyl groups (water alcohols carboxylic acids) This confers some measure of water solubil ity on low molecular weight esters methyl acetate for example dissolves m water to the extent of 33 g/100 mL Water solubility decreases as the carbon content of the ester increases Fats and oils the glycerol esters of long chain carboxylic acids are practically insoluble m water... 

Typical nonsieve, polar adsorbents are siUca gel and activated alumina. Kquilihrium data have been pubUshed on many systems (11—16,46,47). The order of affinity for various chemical species is saturated hydrocarbons < aromatic hydrocarbons = halogenated hydrocarbons < ethers = esters = ketones < amines = alcohols < carboxylic acids. In general, the selectivities are parallel to those obtained by the use of selective polar solvents in hydrocarbon systems, even the magnitudes are similar. Consequendy, the commercial use of these adsorbents must compete with solvent-extraction techniques. 

Some materials such as water, alcohols, carboxylic acids and primary and secondary amines may be able to act simultaneously as proton donors and acceptors. Cellulose and poly(vinyl alcohol) are two polymers which also function in this way. 

Another example of the effect of resonance is in the relative acidity of carboxylic acids as compared to alcohols. Carboxylic acids derived from saturated hydrocarbons have ipK values near 5, whereas saturated alcohols have pA values in the range 16-18. This implies that the carboxylate anion can accept negative charge more readily than an oxygen on a saturated carbon chain. This can be explained in terms of stabilization of the negative charge by resonance, ... 

Group of plastics composed of resins produced by reactions of epoxides or oxiranes with compounds such as amines, phenols, alcohols, carboxylic acids, acid anhydrides and unsaturated compounds. 

H-bond donor/acceptors water, alcohols, carboxylic acids, amines, amides. 

Recent mechanistic studies have shown that the many combinations of alcohols, carboxylic acids and solvents cannot be correctly described by a uniform mechanism. In certain cases the reaction appears to involve a pentavalent dialkoxyphos-phorane 10 as an intermediate, which is in equilibrium with oxyphosphonium salt 8 4 ... 

We commented earlier in this chapter that carboxylic acids are similar in some respects to both alcohols and ketones. Like alcohols, carboxylic acids can be depro-tonated to give anions, which are good nucleophiles in SN2 reactions. Like ketones,... 

Stoichiometric organocoppcr reactions become more y selective in the presence of boron trifluoride or trialkylboranes1Thus, RCu BF3 gives y substitution with allylic halides, alcohols, carboxylates and mesylates1119. 

The hydrocarbons are the basic framework for all organic compounds. Different classes of organic compounds have one or more of the hydrogen atoms replaced by other atoms or groups of atoms. All we need to be aware of at this stage are the three classes of compounds known as alcohols, carboxylic acids, and haloalkanes ... 

Carboxylic acids can be converted to esters with diazo compounds in a reaction essentially the same as 10-15. In contrast to alcohols, carboxylic acids undergo the reaction quite well at room temperature, since the reactivity of the reagent increases with acidity. The reaction is used where high yields are important or where the acid is sensitive to higher temperatures. Because of availability, the diazo compounds most often used are diazomethane (for methyl esters) ... 

While the above examples demonstrate that product control to a significant extent is possible in oxythallation by careful choice of substrate or reaction conditions, the synthetic utility of oxythallation has been illustrated most convincingly by the results obtained with highly ionic thallium(III) salts, especially the nitrate (hereafter abbreviated TTN). Unlike the sulfate, perchlorate, or fluoroborate salts (165), TTN can easily be obtained as the stable, crystalline trihydrate which is soluble in alcohols, carboxylic acids, ethers such as dimethoxyethane (glyme), and dilute mineral acids. Oxidations by TTN can therefore be carried out under a wide variety of experimental conditions. 

The transformations (1) lead to unstable alkyl nitrates, which can detonate very easily. The reactions (2) lead to more or less complete oxidations of the organic molecule. The formation of aldehydes is purely theoretical since they are more oxidisable than alcohols and therefore are not part of the oxidation process by nitric acid. On the other hand, a ketone can form with a secondary alcohol. With tertiary alcohols, carboxylic acid is the only possible outcome of the partial oxidation, which is caused by the breaking of C-C bonds. When the oxidation is out of control, it is likely to have a complete oxidation. Finally, with heavy metal... 

Hydrogen bonding 5, occurs when a proton-acceptor molecule (primary and secondary amines, and sulfoxides) interacts with a proton-donor molecule (alcohols, carboxylic acids, and phenols). 

The nucleophiles that are used for synthetic purposes include water, alcohols, carboxylate ions, hydroperoxides, amines, and nitriles. After the addition step is complete, the mercury is usually reductively removed by sodium borohydride, the net result being the addition of hydrogen and the nucleophile to the alkene. The regio-selectivity is excellent and is in the same sense as is observed for proton-initiated additions.17... 

Other Gas Reactions. Several other reactive gases or vapours were examined but found to be unsatisfactory. No ester formation ( 1745 cm"1) was found when oxidatized films were exposed to acetic acid or formic acid vapour. Alcohol/carboxylic acid reactions in the solid state have often been suggested as the source of ester products, but not substantiated (4,5). Gaseous ammonia reacted with carboxylic acid groups to give absorptions at 1550 cm"1 [-C(=0)-0 ] and 1300 cm"1 (NHi +). However, these absorptions were very broad and the method inferior to acid measurement by SF. Although N20 did not react with oxidized polyolefins, the reaction of N02 with oxi-... 

Carboxylesterase 3.1.1.1 esters, alcohols alcohols, carboxylic acids, alcohols >100... 

Lipases 3.1.1.3 esters, alcohols, amines alcohols, carboxylic acids, alcohols, amines >400... 

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