Carbon saturated

The simplest case is the substitution of a halogen at a saturated carbon atom by an alkyl group. Organocopper reagents exhibit strong carbanionic capacity, and do attack ester groups only slowly (D.E. Bergbreiter, 1975). Ketones, however, should be protected. The relative re-... 

Some values of physical properties of CO2 appear in Table 1. An excellent pressure—enthalpy diagram (a large Mohier diagram) over 260 to 773 K and 70—20,000 kPa (10—2,900 psi) is available (1). The thermodynamic properties of saturated carbon dioxide vapor and Hquid from 178 to the critical point,... 

Carbon dioxide, the final oxidation product of carbon, is not very reactive at ordinary temperatures. However, in water solution it forms carbonic acid [463-79-6] H2CO2, which forms salts and esters through the typical reactions of a weak acid. The first ionization constant is 3.5 x 10 at 291 K the second is 4.4 x 10 at 298 K. The pH of saturated carbon dioxide solutions varies from 3.7 at 101 kPa (1 atm) to 3.2 at 2,370 kPa (23.4 atm). A soHd hydrate [27592-78-5] 8H20, separates from aqueous solutions of carbon dioxide that are chilled at elevated pressures. 

In general, substituents removed from the ring by two or more saturated carbon atoms undergo normal aliphatic reactions, and substituents attached directly to fused benzene rings or aryl groups undergo the same reactions as do those on normal benzenoid rings. 

According to Section 4.02.3.1.8 substituents removed from the pyrazole ring by two or more saturated carbon atoms and substituents on the benzene ring of indazoles are similar in reactivity to the corresponding aromatic derivatives. For instance, chloromethyl-pyrazoles are comparable to benzyl chlorides and 5-hydroxyindazoles to /3-naphthols in their reactivity. 

TABLE 2-244 Thermophysical Properties of Saturated Carbon Tetrachloride... 

The as-spun acrylic fibers must be thermally stabilized in order to preserve the molecular structure generated as the fibers are drawn. This is typically performed in air at temperatures between 200 and 400°C [8]. Control of the heating rate is essential, since the stabilization reactions are highly exothermic. Therefore, the time required to adequately stabilize PAN fibers can be several hours, but will depend on the size of the fibers, as well as on the composition of the oxidizing atmosphere. Their are numerous reactions that occur during this stabilization process, including oxidation, nitrile cyclization, and saturated carbon bond dehydration [7]. A summary of several fimctional groups which appear in stabilized PAN fiber can be seen in Fig. 3. 

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, ... 

C. A. Bunion, Nucleophilic Substitution at a Saturated Carbon Atom, Elsevier, New Vbrk, 1963. 

Stereochemical course of the reaction. This kind of information was critical in the elucidation of the SnI and Sn2 pathways for nucleophilic substitution at saturated carbon. 

To make this more specific. Table 5-3 gives examples of several reaction types that fit the RIP pattern. Consider nucleophilic substitution on saturated carbon. The concerted mechanism is the one-step bimolecular 5, 2 process ... 

The Sn2 direct displacement reaction at saturated carbon can be represented as Y + R3CX R3CY + X ... 

We consider first the Sn2 type of process. (In some important Sn2 reactions the solvent may function as the nucleophile. We will treat solvent nucleophilicity as a separate topic in Chapter 8.) Basicity toward the proton, that is, the pKa of the conjugate acid of the nucleophile, has been found to be less successful as a model property for reactions at saturated carbon than for nucleophilic acyl transfers, although basicity must have some relationship to nucleophilicity. Bordwell et al. have demonstrated very satisfactory Brjinsted-type plots for nucleophilic displacements at saturated carbon when the basicities and reactivities are measured in polar aprotic solvents like dimethylsulfoxide. The problem of establishing such simple correlations in hydroxylic solvents lies in the varying solvation stabilization within a reaction series in H-bond donor solvents. 

Most of the kinetic measures of solvent effects have been developed for the study of nucleophilic substitution (Sn) at saturated carbon, solvolytic reactions in particular. It may, therefore, be helpful to give a brief review of aliphatic nucleophilic substitution. Two mechanistic routes have been clearly identified. One of these is shown by... 

The reaction of ap- or o-nitrobenzene derivative with a nucleophilic reagent is generally first order with respect to each reactant and follows a bimolecular course according to Eq. (1). The reaction is then formally similar to the corresponding change at a saturated carbon ( Sj 2 ... 

The latter mechanism is characterized by a transition-state structure of type 64 and by its being (in part) analogous to the mechanism at a saturated carbon. The preference of a two-step mechanism to the apparently simpler one-step mechanism is suggested by the isolation of Meisenheimer complexes and by the kinetics of their formation. The experimental evidence on these... 

An electron-withdrawing substituent leads to a product where it is bound to a saturated carbon center. Benzoic acid 9 is reduced to the cyclohexa-2,5-diene carboxylic acid 10 ... 

Nucleophilic substitution reaction (Section 11.1) A reaction in which one nucleophile replaces another attached to a saturated carbon atom. 

In the more complex case of the saturated hydrocarbons, the anisotropic equations have not been solved. Rough estimates from approximate solutions indicated that the anisotropy of hydrogen and of saturated carbon atoms is small but an accurate check on this matter would be desirable. 

Volume 8 Volume 9 Volume 10 Volume 12 Volume 13 Proton Transfer Addition and Elimination Reactions of Aliphatic Compounds Ester Formation and Hydrolysis and Related Reactions Electrophilic Substitution at a Saturated Carbon Atom Reactions of Aromatic Compounds Section 5. POLYMERISATION REACTIONS (3 volumes)... 

The parameter 5 is a measure of the susceptibility of the substrate to nucleophilic attack, and n a measure of the nucleophilic reactivity as defined by a reference reaction. The rate constants for attack at saturated carbon are used to define the values of n.14 Table 10-4 lists the values of n for certain nucleophiles. This particular compilation lists the... 

Attempts to use n values for one class of reactions (e.g., attack at saturated carbon) for another (e.g., attack at carbonyl carbon) are not entirely successful. Edwards proposed a two-term equation,15... 

The most common backbone structure found in commercial polymers is the saturated carbon-carbon structure. Polymers with saturated carbon-carbon backbones, such as polyethylene, polypropylene, polystyrene, polyvinyl chloride, and polyacrylates, are produced using chain-growth polymerizations. The saturated carbon-carbon backbone of polyethylene with no side groups is a relatively flexible polymer chain. The glass transition temperature is low at -20°C for high-density polyethylene. Side groups on the carbon-carbon backbone influence thermal transitions, solubility, and other polymer properties. 

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