Tertiary trialkyl amines

Direct conversion of fatty alcohols to primary amines by reaction with ammonia is not commercially practised but new catalyst developments show improved yields with this technology [10]. However, production of dialkylamines from alcohols is practised particularly with C8-C10 alcohols due to the limited availability of the corresponding acids. Alcohols are commonly used in the manufacture of tertiary alkyldimethylamines either through reductive amination with dimethylamine or by conversion to the alkylhaUde followed by reaction with dimethylamine. Both primary and secondary amines can be reacted with alcohols to produce tertiary trialkyl amines [11]. The chain branching seen with some synthetic alcohols means that the derived amines are not identical to those from natural sources. 

Dialkylmethyl Trialkyl symmetrical) Tertiary fatty amines... 

The liquid anion exchangers at present available are based largely on primary, secondary and tertiary aliphatic amines, e.g. the exchangers Amberlite LA.l [A/-dodecenyl(trialkylmethyl)amine] and Amberlite LA.2 [A/-lauryl(trialkyl-methyl)amine], both secondary amines. These anion exchange liquids are best employed as solutions (ca 2.5 to 12.5% v/v) in an inert organic solvent such as benzene, toluene, kerosene, petroleum ether, cyclohexane, octane, etc. 

The use of a trialkyl amine, for example triethyl amine, as a scavenger is not recommended because 1-chloroalkyl chloroformates react very easily with tertiary alkyl amines to afford N,N-disubsituted carbamates (Ref. 68) as discussed in section 3-3. 

Formation of adduct 23 is usually less of a problem with tertiary oryZamines because of their lesser nucleophilicity and lower solubility as compared to trialkyl amines. Consequently, the competing hydrolysis of benzenesulfonyl chloride by hydroxide ion (Eq. 25.55) allows recovery of most of the amine. However, this class of amines is often subject to other side reactions that produce a complex mixture of... 

The gas-phase affinities of primary, secondary and tertiary alkyl amines towards MesSi were determined in a high-pressure mass spectrometer. The MesSi affinities were found to increase linearly with the proton affinities of the amines. In these measurements trialkyl amines were found to undergo only very slow associations with MesSi ions, which was explained by steric effects. The proton affinities of trimethylsilylamines which have been measured in these studies demonstrated again that the ability of an a-silicon to stabilize a positive charge on nitrogen is somewhat smaller than that at a carbon atom. 

In the absence of a tertiary amine, the initial reaction is again the formatfon of a trialkyl phosphite and hydrogen chloride. The latter now reacts rapidly with the trialkyl phosphite to give the alkyl chloride and the dialkyl hydrogen... 

Low surface energy substrates, such as polyethylene or polypropylene, are generally difficult to bond with adhesives. However, cyanoacrylate-based adhesives can be effectively utilized to bond polyolefins with the use of the proper primer/activa-tor on the surface. Primer materials include tertiary aliphatic and aromatic amines, trialkyl ammonium carboxylate salts, tetraalkyl ammonium salts, phosphines, and organometallic compounds, which are initiators for alkyl cyanoacrylate polymerization [33-36]. The primer is applied as a dilute solution to the polyolefin surface, solvent is allowed to evaporate, and the specimens are assembled with a small amount of the adhesive. With the use of primers, adhesive strength can be so strong that substrate failure occurs during the course of the shear tests, as shown in Fig. 11. 

The addition of Grignard reagents to aldehydes, ketones, and esters is the basis for the synthesis of a wide variety of alcohols, and several examples are given in Scheme 7.3. Primary alcohols can be made from formaldehyde (Entry 1) or, with addition of two carbons, from ethylene oxide (Entry 2). Secondary alcohols are obtained from aldehydes (Entries 3 to 6) or formate esters (Entry 7). Tertiary alcohols can be made from esters (Entries 8 and 9) or ketones (Entry 10). Lactones give diols (Entry 11). Aldehydes can be prepared from trialkyl orthoformate esters (Entries 12 and 13). Ketones can be made from nitriles (Entries 14 and 15), pyridine-2-thiol esters (Entry 16), N-methoxy-A-methyl carboxamides (Entries 17 and 18), or anhydrides (Entry 19). Carboxylic acids are available by reaction with C02 (Entries 20 to 22). Amines can be prepared from imines (Entry 23). Two-step procedures that involve formation and dehydration of alcohols provide routes to certain alkenes (Entries 24 and 25). 

Tertiary amines can often be formed by the reaction between a trialkyl phosphate on an amine3 at a high temperature ... 

Sterically unhindered tertiary amines add readily and reversibly to sulfenes (208) to give zwitterionic carbanions [91] that when protonated give trialkyl (alkylsulfonyl) ammonium salts [92] (King et al., 1972). Since salts of this type... 

Trimerization of imidates is a valuable route to 1,3,5-triazines. Imidates can be considered as activated nitriles and cyclotrimerize more readily. Most symmetrical 2,4,6-trialkyl-1,3,5-triazines are easily formed, although large alkyl substituents may give rise to steric hindrance (61JOC2778). Symmetrical isocyanurates (525) are readily available from isocyanates, RNCO catalysts include tertiary amines, phosphines and sodium methoxide. Aldehydes RCHO and ammonia give hexahydro-1,3,5-triazines (526), known as aldehyde ammonias (73JOC3288). 

Trialkyl- and triarylperoxyarsoranes have been obtained by the reaction of triorganyl dihaloarsoranes with either an alkylhydroperoxide in the presence of a tertiary amine or with the sodium salt of alkylhy-droperoxides. These can also be prepared by the reaction between amino halides R3As(NH2)X and an alkylhydroperoxide or by the following exchange reactions ... 

Methods of deoxygenation of nitrones (28), nitrile oxides (29), heteroaromatic N-oxides (30) and tertiary amine oxides (31) are described in this section. There are some reagents, such as trialkyl phosphites, which can deoxygenate compounds of all these types as well as those in the preceding section, whereas others are more limited in scope. Oae and coworkers have outlined three distinct mechanistic types of deoxygenation process, which are illustrated in Scheme 17. Clearly, a mechanism of type C will not apply to tertiary amine oxides (31) on the other hand, these compounds are more easily deoxygenated than heteroaromatic N-oxides, such as (30), by some reagents because the aromatic N-oxides are inherently more stable. 

Chloride initiation of chloral polymerization could be readily achieved with tetraalkyl ammonium chlorides, such as tetrabutyl ammonium chloride, or with trialkyl sulphonium chlorides as initiators. Chloral polymerization initiated with R4NCI behaved very similarly to that with tertiary amine initiation. It is likely that the actual initiator of chloral polymerization with tertiary amines was chloride ion, which was presumably formed by chloride abstraction from chloral by the amine. The ease of chloride exchange in chloral reactions was demonstrated by initiation studies with Cl as initiator. 

In addition, amine N-oxides (82) can be treated with trialkylsilyl triflates to generate, after methyl-lithium treatment, a-siloxyamines (83) which, when allowed to react with Grignaid reagents (or trialkyl-aluminum), generate tertiary amines (M) in modest yields (Scheme IS). ... 

Problem 8.23 Explain how the following substances act as inhibitors or retarders in cationic polymerization water, tertiary amines, trialkyl phosphines, and p-benzoquinone. 

Tertiary amines and trialkyl phosphines react with propagating chains to form stable cations that are unreactive to propagation ... 

From the up-to-date literature and patent review of catalysts used In anhydride and phenolic cured epoxy molding compounds, It Is evident that Imidazoles and their derivatives predominate (Table I). Metal complex, trialkyl or triaryl phosphines and their complexes, Lewis acids such as zinc or stannous octoate are used to a much lesser extent (Table II). There are a few examples of tertiary amines and urea derivatives used. 

The rate of self-polymerization of isocyanates to dimers (uretidine diones) depends upon the electronic or steric influences of ring substituents. Ortho substitution greatly retards dimerization of the NCO groups, with the ortho NCO slower to dimerize. This dimerization is catalyzed strongly by trialkyl phosphines (38, 39) and more mildly by tertiary amines, such as pyridine (40. 41). MDI dimerizes slowly on standing at room temperature even without catalysts but is stable at low or at slightly elevated temperatures (40-50 °C). 

Trialkyl and triaryl alanes give stable 1 1 adducts with neutral donor molecules (e.g., ethers, thioethers, tertiary amines, tertiary phosphines) ... 

Ketone, aromatic nitrate, tertiary amine, pyridine, sulfone, trialkyl phosphate or phosphine oxide + 0 + + 0 + +... 

Some isocyanates also react with themselves to form thermally reversible dimer structures, the so-called uretidinediones. Such self reaction is apparently confined to aromatic isocyanates, and is illustrated with phenyl isocyanate in Fig. 8.4. The dimerization reaction is catalyzed vigorously by trialkyl phosphines and less by tertiary amines such as pyridine. 

A tetrahedraUy coordinated benzazaborine is generated as a major product 51 in 40% yield by the reaction of three equivalents of an aryUithium with a trialkyl borate (Scheme 22) (20000M206). In a plausible mechanism, the treatment ofB(OiPr)3 with two equivalents of the aryUithium generates diarylborane 49 which upon treatment with a third equivalent of the aryl-Hthium does not generate a triarylborane, but instead gives the tetrahedraUy coordinated borane species 50. This is probably due to the increased acidity of the a-protons on the tertiary amine as a result of the coordinate covalent B- N bond. Subsequent loss of an alkoxide leads to the formation of 51, and its structure has been confirmed by X-ray crystaUography and NMR spectroscopy. 

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