Reaction of hydroxide with

Finally, reaction of hydroxide with 29 furnishes 31 approximately 20 times faster than methoxide promoted rearrangement of 29 to 23 (R = Ph), suggesting ring closure is the rate-determining step. 

The reaction of hydroxide with dimethyl sulfate clearly should not be concerted the dissociative corner, 12, is far too high in energy, yet the reaction would not show... 

The nucleophilic reaction of hydroxide with carbonyl ligands of transition metal complexes,... 

An even more extreme case is the reaction of hydroxide with acetonitrile. In the ICR spectrometer, the bare hydroxide ion yields a simple proton transfer product, by way of reaction (9). In contrast, in aqueous solution the bulk-solvated hydroxide ion reacts to hydrolyze the nitrile group to give the carboxylate ion plus... 

Figure 8-20. The reaction of hydroxide with the free ligand 8.20 gives a stabilised anion.

The mechanisms used for reaction of hydroxide with monocarbonyl and dicarbonyl compounds differed because for the more reactive dicarbonyl compounds the desolvation cost of bringing hydroxide into direct contact with the acidic CH became large relative to the overall kinetic barrier instead the reaction involved a bridging water that lost a proton to hydroxide as it abstracted a proton from carbon, thus avoiding the unfavorable contact species. An analogous mechanism was needed for water reaction with dicarbonyl compounds with two waters being involved so that formation of a direct complex of hydronium ion with the enolate carbon could be avoided. Thus, the mechanisms for the monocarbonyl compounds were two-dimensional and for the dicarbonyl compounds were three-dimensional. These mechanisms are illustrated in Fig. 11. 

The nucleophilic substitution reaction of hydroxide with bromomethane. 

The general answer to these questions is yes. In 1989, DePuy and coworkers measured the gas-phase DPEs of a number of small alkanes using the reaction of hydroxide with alkyltrimethylsilanes in a flowing afterglow-selected ion flow tube. Their experimental DPEs for some simple alkanes are listed in Table 3.6. The DPE of cyclopropane, 411.5 kcal mol is much lower than that of a typical acyclic alkane (415-420 kcal mol ). Cyclobutane is less acidic than cyclopropane, reflecting the diminished s-character of its C-H bonds. Also listed in Table 3.6 are... 

Many of the basic concepts of micellar-polymer flooding apply to alkaline flooding. However, alkaline flooding is fundamentally different because a surfactant is created in the reservoir from the reaction of hydroxide with acidic components in crude oil. This reaction means that the amount of petroleum soap will vary locally as the water-to-oil ratio varies. The amount of petroleum soap has a large effect on phase behavior in crude-oil-alkali-surfactant systems. 

The sensitivity, or otherwise, of the ct-dicarbonyl substrate determines the reaction conditions. However, variations in conditions are not especially large. Although 1 equiv. of base may be used, more usually an excess is employed — sometimes 10 equiv. or more to accelerate the reaction. Studies on the reaction of hydroxides with benzil indicate that the rate depends to some extent on the cation, and it can be advantageous to use Ba(OH)2 rather than the more usual NaOH or KOH. With hydroxide ion, favored solvents are water and aqueous ethanol. Heterogeneous conditions, for example potassium hydroxide and diethyl ether or sodamide and toluene, have also been employed. The reactions are conducted at room temperature (sometimes requiring up to 4 d) or under reflux (10 min-24 h). With methoxide or -butoxide the corresponding anhydrous alcohol or benzene are employed as solvents. ... 

Calculation of the equilibrium constant for the proton transfer reaction is easy. Proton transfers go toward the formation of the weaker base. Let s use the reaction of hydroxide with hydrochloric acid as an example. The reaction goes from the stronger base, hydroxide, p/fabH 15 7, to the weaker base, chloride, pifabH 7. 

Hydroxide ion, being a much weaker nucleophile than amide, attacks pyridine only at very high temperatures to produce a low yield of 2-pyridone, which can be usefully contrasted with the much more efficient reaction of hydroxide with quinoline and isoquinoline (9.3.1.3) and with pyridinium salts (8.12.3). 

A trap for the unwary is not to investigate fully the cause of the U-shaped non-linear free energy relationship. Young and Jencks [105c] studied the reaction of hydroxide with acetophenone bisulphites (Eqn. 124)... 

Reaction of a-haloketone with a nucleophile can give carbonyl addition, direct substitution, and proton abstraction. DFT calculations suggest that the reaction of hydroxide with a-bromoacetophenone (PhCOCH2Br) is a borderline case, with an addition/substitution TS, where hydroxide interacts with/bridges the two carbons. Such a TS could serve for two mechanisms, with path bifurcation after the TS, leading to the respective hydrate anion [Ph-C(0H)(0 )CH2Br] and substitution products... 

Determine why the aromatic substitution reaction of hydroxide with 3-nitro-l-bromobenzene is much slower than the identical reaction with 4-nitro-l-bromobenzene. 

Electrostatic potential map showing the nucleophile (OH ) reacting at its negative (red) end with the electrophilic carbon (blue) in the reaction of hydroxide with chloromethane. 

The effect of solvation is not spiecifically included in the Marcus equation (Eq. 7.63). However, one expects a solvent effect on the reaction of hydroxide with methyl bromide (the example used in this chapter when Marcus theory was discussed). In what manner does solvation come into this equation, such that it works in a variety of solvents ... 

In the reaction of hydroxide with p-nitrobenzyl chloride, you might expect p-nitrobenzyl alcohol to be the major product via a simple Sn2 reaction. However, p-nitrobenzyl chloride is acidic enough to be deprotonated by hydroxide, leading to a carbon nucleophile that reacts with a second equivalent of p-nitrobenzyl chloride, subsequently... 

Quaternary alkylammonium salts, tertiary amines, and crown ethers have all been utilized as catalysts in the reaction of hydroxide with chloroform to yield dichlorocarbene. The most commonly utilized catalyst has been benzyltriethylammonium chloride (see Sect. 1.7) but other quaternary ammonium chloride catalysts have proved effective. Cetyltrimethylammonium chloride and tricaprylmethylammonium chloride (Aliquat 336) have both been used effectively in the cyclopropanation of simple alkenes. The use of Z e a-hydroxyethyltrialkylammonium hydroxides as phase transfer catalysts results in increased regioselectivity in the addition of dichlorocarbene to olefins [12]. Crown ethers such as dibenzo and dicyclohexyl-18-crown-6 have both been utilized in place of quaternary ammonium compounds. 18-Crown-6 has also been used as a catalyst in the phase transfer thermal decomposition of sodium trichloroacetate to yield dichlorocarbene [13]. 

Construct an explanation for why the reaction of hydroxide with cyclohexanol is approximately thermoneutral while the reaction of hydroxide with phenol is down hill (exothermic). 

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