Alkyl halides compounds

The Alkyl Halides. Ethyl bromide and iodide (see below) are typical alkyl halides. Compounds of this class are of very great importance in synthetic work, owing to the reactivity of the halogen atom. This is illustrated by the following reactions ... 

Aldehydes, formates, primary, and secondary alcohols, amines, ethers, alkyl halides, compounds of the type Z—CH2—Z, and a few other compounds add to double bonds in the presence of free-radical initiators/ This is formally the addition of RH to a double bond, but the R is not just any carbon but one connected to an oxygen or a nitrogen, a halogen, or to two Z groups (defined as on p. 548). The addition of aldehydes is illustrated above. Formates and formamides " add similarly ... 

We have already mentioned that the mixed alkyl halide compounds of aluminum dimerize, and the solubility parameters shown in Table 12.1 for these compounds are consistent with that assessment. The solubility parameters for triethylboron and diethylzinc are 15.4 and 18.2 in J cm 3/2, respectively. These values are indicative of liquids that are not strongly associated, which is known to be the case. 

In some cases, metallic tin reacts directly with an alkyl halide to produce mixed alkyl halide compounds. 

Mixed alkyl halide compounds result from the reaction of dialkylcadmium with cadmium halides. 

The ethereal solutions of these iodides do not fume in air, and removal of the solvent gives a liquid, which on further heating evolves dense white fumes, probably of beryllium oxide. Heating changes the alkyl beryllium halides to beryllium dialkyls. All the alkyl halide compounds are decomposed by water, with formation of the corresponding hydrocarbon. When carbon dioxide is passed through ethereal beryllium methyl iodide for three hours, the solution still gives a positive test and no acetic acid is found after hydrolysis. Acetanilide is formed from beryllium methyl iodide and phenyl isocyanate. 

In this and the next chapter, we ll be discussing the chemistry of alkyl halides—compounds that have a halogen atom bonded to a saturated, s/> -hybridized carbon atom. We ll begin in this chapter with a look at how to name and prepare alkyl halides, and we ll see several of their reactions. Then in the following chapter, we ll make a detailed study of the substitution and elimination reactions of alkyl halides—two of the most important and well-studied reaction types in organic chemistry. 

This chapter focuses on the substitution reactions of alkyl halides—compounds in which the leaving group is a halide ion (F , CF, Br , or F). The nomenclature of alkyl halides was discussed in Section 2.4. 

Duck et al. These systems are of particular interest in that they combine the use of a hydroxyl-containing support with a magnesium alkyl halide compound. Activities of some two orders of magnitude (on the basis of Ti) greater than that of a traditional TiCU catalyst were reported although no actual active centre determinations were carried out Also in this case much higher ratios of AI Ti were employed (typically 240 1) than for traditional catalysts although the actual alkyl aluminium concentration employed was about the same in both cases. 

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