Halides fluoride

The lUPAC rules permit alkyl halides to be named m two different ways called func twnal class nomenclature and substitutive nomenclature In functional class nomencla ture the alkyl group and the halide (fluoride chloride bromide or iodide) are desig nated as separate words The alkyl group is named on the basis of its longest continuous chain beginning at the carbon to which the halogen is attached... 

Hydroxyl groups can also be replaced by halide. Fluorided catalysts show improved activity at low calcining temperatures. The electronic environment is probably altered considerably because termination rates are always depressed. The MWD is sometimes narrowed, suggesting a more uniform... 

Organohalide An organic compound that contains a halide (fluoride, chloride, bromide, or iodide). Organotriflate An organic compound that contains a trifluoromethanesulfonate (CF3SO3-) group. 

Due to the presence of silicon which stabilizes the a-carbanion, strong bases such as butyllithium and sodium amide are able to give an ylid from silylmethylammonium halides. Fluoride ion-assisted desilylation of these salts represents another means to create an ylid. These ylids are prone to rearrange and the results differ upon the nature of... 

Alkyl halides (fluorides R-F, chlorides R-Cl, bromides R-Br, or iodides R-I) contain the fluoro, chloro, bromo, or iodo groups... 

Metallothermic reduction of compounds. Metallothermic reduction of halides (fluorides), a method used for lanthanide metal preparation, was among the first methods to be successfully applied to actinides ... 

The tendency of halides to form metal halide complex is very important in understanding the stabilization of corrosion pit by prevention of the repassivation of a defect site within the passive layer. Among the halides, fluoride forms strong complexes with metals. The resistance of chromium to localized corrosion is because of slow dissolution kinetics of Cr(III) salts. Higher-valence oxides are the best passivators (films) because of their slow rates of dissolution. 

Numerous interhalogen compounds, as well as cations and anions, are known. Several engage in halide/fluoride ion transfer reactions. 

C-Glycosides 9, 881 suppl. 26 N-Giycosylation, directed, of N-heterocyclics 19, 539 suppl. 28 Glycosyl halides fluorides from chlorides 26,551... 

Mercury (I) cyanide, Hg2(CN)2 Silver cyanide, AgCN Halides Fluorides... 

Fluoroalkylation with Alkyl Halides. Fluoride-mediated nucleophilic fluoroalkylation of PhSCF2SiMe3with alkyl iodides and bromides was reported by Li and Hu. The reaction proceeded well with primary alkyl iodides and bromides in DME solvent when CsF and 15-crown-5 were used as the fluoride source and additive, respectively (eq 16). 

The solubility of ionic substances in relatively nonpolar aprotic solvents can be greatly enhanced by using catalytic quantities of macrocyclic polyethers, such as 18-crown-6, the structure of which is shown in Fig. 5.5. These macrocyclic ethers selectively solvate the cation, both enhancing solubility and also leaving the anion in a very weakly solvated state. The anions behave under these conditions as highly reactive species, sometimes termed naked anions. A study of the relative rates of nucleophilic substitution on benzyl tosylate by potassium salts in acetonitrile in the presence of 18-crown-6 revealed a pronounced leveling effect. " All the potassium halides (fluoride, chloride, bromide, and iodide) were approximately equal in their reactivity. Potassium acetate was observed to be almost ten times more reactive than potassium iodide under these conditions—a reversal of the normal reactivity of acetate ion versus iodide ion in nucleophilic substitution reactions. As measured by cHji values in Table 5.5, iodide is 3 log units, i.e., 10 times, more reactive than acetate ion in the protic solvent methanol. 

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