Tertiary alkyl groups

Secondary alkyl group Tertiary alkyl group... 

Silver halide precipitates at a rate that depends upon the structure of the alkyl group, tertiary > secondary > primary. Tertiary halides usually react immediately at room temperature, whereas primary halides require heating. That complexes actually are formed between organic halides and silver ion is indicated by an increase in water solubility in the presence of silver ion for those halides that are slow in forming carbocations. 

To a limited extent, lanthanoids are separated from each other by tertiary amine extractants and by quaternary ammonium salts with long (Cg and Cio) alkyl groups. Tertiary amines in an organic phase preferentially extract the trivalent actinoids better than the lanthanoids by salting out (dehydrating) the cations from the aqueous phase with high LiCl concentration, e.g., the TRAMEX (tertiary amine extraction) process for Cm isolation . Recent developments in trivalent f-element separations, such as chelating and bifunctional extractants have been reviewed . 

Alkyl Group. Tertiary alkyl halides may be used in solvolyses with confidence that the reactions are proceeding by the Sj jl mechanism. Two compounds that allow you to examine the possible effects of the structure of the alkyl group on reaction rates are 2-chloro-2-methylpropane (ferf-butyl chloride) and 2[Pg.484]

Other basic compounds are Armeen derivatives, with R=C8 to C22 alkyl groups (tertiary amines) (Fig. 3.9). 

If, however, a tertiary amine has two alkyl groups and also an aryl group having the para position unsubstituted, then the action of nitrous acid is to insert the nitroso group directly into this para position. Dimethylaniline, for example, when treated with nitrous acid readily gives p-nitrosodimethyl-... 

Alkyl groups attached to aromatic rings are oxidized more readily than the ring in alkaline media. Complete oxidation to benzoic acids usually occurs with nonspecific oxidants such as KMnO, but activated tertiary carbon atoms can be oxidized to the corresponding alcohols (R. Stewart, 1965 D. Arndt, 1975). With mercury(ll) acetate, allyiic and benzylic oxidations are aJso possible. It is most widely used in the mild dehydrogenation of tertiary amines to give, enamines or heteroarenes (M. Shamma, 1970 H. Arzoumanian. 1971 A. Friedrich, 1975). 

Carbon atoms are classified according to their degree of substitution by other car bons A primary carbon is directly attached to one other carbon Similarly a secondary carbon is directly attached to two other carbons a tertiary carbon to three and a qua ternary carbon to four Alkyl groups are designated as primary secondary or tertiary according to the degree of substitution of the carbon at the potential point of attachment... 

Those derived from isobutane are the 2 methylpropyl (isobutyl) group and the 1 1 dimethylethyl (tert butyl) group Isobutyl is a primary alkyl group because its poten tial point of attachment is to a primary carbon tert Butyl is a tertiary alkyl group because Its potential point of attachment is to a tertiary carbon... 

Give the structures and lUPAC names of all the C5H11 alkyl groups and identify them as primary secondary or tertiary alkyl groups as appropriate... 

Give the lUPAC name for each of the following alkyl groups and classify each one as pn mary secondary or tertiary... 

FIGURE 4 13 The order of carbocation stability is methyl < primary < second ary < tertiary Alkyl groups that are directly attached to the positively charged car bon stabilize carbocations... 

The most frequently used organocuprates are those m which the alkyl group is pri mary Steric hindrance makes secondary and tertiary dialkylcuprates less reactive and they tend to decompose before they react with the alkyl halide The reaction of cuprate reagents with alkyl halides follows the usual 8 2 order CH3 > primary > secondary > tertiary and I > Br > Cl > F p Toluenesulfonates are somewhat more reactive than halides Because the alkyl halide and dialkylcuprate reagent should both be primary m order to produce satisfactory yields of coupled products the reaction is limited to the formation of RCH2—CH2R and RCH2—CH3 bonds m alkanes... 

The small differences m basicity between ammonia and alkylammes and among the various classes of alkylammes (primary secondary tertiary) come from a mix of effects Replacing hydrogens of ammonia by alkyl groups affects both sides of the acid-base equilibrium m ways that largely cancel... 

Tertiary alkyl group (Section 2 13) Structural unit of the type R3C— in which the point of attachment is to a tertiary carbon... 

Primary alkyl groups are more reactive than secondary and tertiary. PivaUc acid accelerates the rate of protonolysis of trialkylboranes with water and alcohols (207,208). The reaction can be controlled to give excellent yields of dialkylbotinic acids and esters. 

Moderate yields of acids and ketones can be obtained by paHadium-cataly2ed carbonylation of boronic acids and by carbonylation cross-coupling reactions (272,320,321). In an alternative procedure for the carbonylation reaction, potassium trialkylborohydride ia the presence of a catalytic amount of the free borane is utilized (322). FiaaHy, various tertiary alcohols including hindered and polycycHc stmctures become readily available by oxidation of the organoborane iatermediate produced after migration of three alkyl groups (312,313,323). 

Under moderate conditions, primary alkoxy radicals tend to undergo reaction 12 whereas secondary and tertiary alkoxys tend to undergo -scission. In general, the alkyl group that can form the lowest energy radical tends to become the departing radical. The -scission of secondary alkoxy radicals yields aldehydes as the nonradical products tertiary alkoxy radicals yield ketones. 

There are two main subclasses ofhydroperoxid.es organic (alkyl) hydroperoxides, ie, ROOH, and organomineral hydroperoxides, ie, Q(OOH), where Q is sihcon (43), germanium, tin, or antimony. The alkyl group in ROOH can be primary, secondary, or tertiary. Except for ethylbenzene hydroperoxide, only alkyl hydroperoxides are commercially important. 

Ritter Reaction (Method 4). A small but important class of amines are manufactured by the Ritter reaction. These are the amines in which the nitrogen atom is adjacent to a tertiary alkyl group. In the Ritter reaction a substituted olefin such as isobutylene reacts with hydrogen cyanide under acidic conditions (12). The resulting formamide is then hydroly2ed to the parent primary amine. Typically sulfuric acid is used in this transformation of an olefin to an amine. Stoichiometric quantities of sulfate salts are produced along with the desired amine. 

---