Amines additions

Corrosion Inhibitors. The corrosion inhibitors used in diesel fuel ate generally similar to those used in gasoline and, like the latter, produce an effect primarily by surface action. If amine additives ate used for detergency, these may provide some corrosion protection as well. 

Under alkaline conditions, an amine addition reaction can occur. For example, in the reaction of C3H3CH2CH2NH2 and aEyl alcohol in the presence of sodium alcoholate at 108°C for 80 h, 43.4% A/-(3-hydroxypropyl)phenylethylamine is formed (12). 

Amine Addition to Double Bond. Pioduction of D,L-aspaitic acid fiom maleic acid estei 01 fumaiic acid estei is a typical example. 

The chemistry of NH2CI involves chlorination, amination, addition, condensation, redox, acid—base, and decomposition reactions. Monochloramine... 

Catalytic hydrogenation of the nitrile function of cyanohydrins can give amines. As in the case of ordinary nitriles, catalytic reduction of cyanohydrins can yield a mixture of primary, secondary, and tertiary amines. Addition of acid or acetic anhydride to the reaction medium minimizes formation of secondary or tertiary amines through formation of the amine salt or acetamide derivative of the primary amine. 

The ahphatic alkyleneamines are strong bases exhibiting behavior typical of simple aUphatic amines. Additionally, dependent on the location of the primary or secondary amino groups iu the alkyleneamines, ring formation with various reactants can occur. This same feature allows for metal ion complexation or chelation (1). The alkyleneamines are somewhat weaker bases than ahphatic amines and much stronger bases than ammonia as the piC values iadicate (Table 2). 

Unlike 1,2-diaminoethane, 1,2-phenylenediamine does not add to 1-dialky-laminobut-l-en-3-ynes in the presence of sulfuric acid (84DIS). An attempt to carry out the reaction in an aqueous medium under the conditions of hydroxyl-amine addition resulted in the isolation of 4-dialkylaminobut-3-en-2-one (84DIS). 

Addition of p-tert-butylthiophenol 178 to the racemic furanone 168 in dry toluene, and in the presence of quinidine as a chiral catalyst, provided (/ )-168 together with the Michael adduct 179. The enantiomeric excess of the recovered furanone (R)-168 was determined via the addition of (/)-Q -methylbenzylamine This amine addition showed complete diastereofacial control to give the adduct 180 in quantitative yield (Scheme 50) (94T4775). 

The effects of a variety of acids and amines are summarized in Scheme 7.12. As long as amounts of these amine additives are limited to three equivalents to... 

In addition to looking for a characteristic H absorption, there is also a simple trick for telling whether a compound is an amine. Addition of a small amount of HC1 produces a broad and strong ammonium band in the 2200 to 3000 cm "1 range if the sample contains an amino group. Figure 24.8 gives an example. 

Chloro-3-phenylethynylquinoxaline gave 2,3-dipiperidinoquinoxaline (piperidine, reflux, 5h 90%), 2,3-dimorpholinoquinoxaline (morpholine, similarly 95%), or 2,3-bis(2-hydroxyethylamino)quinoxaline (ethanolamine, PhH-EtOH, reflux, 15 h 74%). For an example of amine addition to the triple bond, see Section 4.2.1. 

The enantioselective mechanism proposed in the literature stated that the structure I might be the most predominant structure and structure II might be a minor structure. Structure I resulted in (S)-amino alcohol when (S)-amine additive was used. On the other hand, structure II resulted in (R)-amino alcohol when (S)-amine additive was used. When the alkyl group of keto alcohol is methyl, conformation of reactant might he composed mainly of structure I, therefore resulting in highly optically active alaninol as indicated in Scheme 2. However, according to the experimental results, structure I can be a major conformation in this reaction. 

The strategy for the asymmetric reductive acylation of ketones was extended to ketoximes (Scheme 9). The asymmetric reactions of ketoximes were performed with CALB and Pd/C in the presence of hydrogen, diisopropylethylamine, and ethyl acetate in toluene at 60° C for 5 days (Table 20) In comparison to the direct DKR of amines, the yields of chiral amides increased significantly. Diisopropylethylamine was responsible for the increase in yields. However, the major factor would be the slow generation of amines, which maintains the amine concentration low enough to suppress side reactions including the reductive aminafion. Disappointingly, this process is limited to benzylic amines. Additionally, low turnover frequencies also need to be overcome. 

Laboratory tests with quaternary amine additives showed a very low surface colonization and lower corrosion rates [556]. On the other hand, the biocidal effect of quaternary amines in the test fluids appeared to be minimal. These results suggest that quaternary amines may prevent MIC by mechanisms other... 

Transformations through 1,2-addition to a formal PN double bond within the delocalized rc-electron system have been reported for the benzo-l,3,2-diazaphospholes 5 which are readily produced by thermally induced depolymerization of tetramers 6 [13] (Scheme 2). The monomers react further with mono- or difunctional acyl chlorides to give 2-chloro-l,3,2-diazaphospholenes with exocyclic amide functionalities at one nitrogen atom [34], Similar reactions of 6 with methyl triflate were found to proceed even at room temperature to give l-methyl-3-alkyl-benzo-l,3,2-diazaphospholenium triflates [35, 36], The reported butyl halide elimination from NHP precursor 13 to generate 1,3,2-diazaphosphole 14 upon heating to 250°C and the subsequent amine addition to furnish 15 (Scheme 5) illustrates another example of the reversibility of addition-elimination reactions [37],... 

By contrast, much of the work performed using ruthenium-based catalysts has employed well-defined complexes. These have mostly been studied in the ATRP of MMA, and include complexes (158)-(165).400-405 Recent studies with (158) have shown the importance of amine additives which afford faster, more controlled polymerization.406 A fast polymerization has also been reported with a dimethylaminoindenyl analog of (161).407 The Grubbs-type metathesis initiator (165) polymerizes MMA without the need for an organic initiator, and may therefore be used to prepare block copolymers of MMA and 1,5-cyclooctadiene.405 Hydrogenation of this product yields PE-b-PMMA. N-heterocyclic carbene analogs of (164) have also been used to catalyze the free radical polymerization of both MMA and styrene.408... 

Dialkylamino derivatives of elements located in the periodic table to the left or below those listed above cannot be prepared by the above method due to either the ionic character of some of the inorganic halides or the formation of stable metal halide-amine addition products. Therefore, other methods must be applied. Dialkylamino derivatives of tin7 and antimony8 are conveniently obtained by reaction of the corresponding halides with lithium dialkylamides. Others, such as the dialkylamino derivatives of aluminum,9 are made by the interaction of the hydride with dialkylamines. Dialkylamino derivatives of beryllium10 or lithium11 result from the reaction of the respective alkyl derivative with a dialkylamine. 

Intramolecular amine addition to benzene has been reported in the phenyl-alkylamines 368 to give the meta adducts 369 in low yield,306 whereas the [co-(anilino)alkoxy]nitrobenzenes 370 undergo photocyclization in acetonitrile to give heterocycles 371.307... 

The most typical situation can be depicted for amine additions to a carbonyl group (Eq. 9)... 

Initial theoretical studies focused on steps (1) and (2). Several model systems were examined with ab initio calculations.1191 For the reaction of methyl amine with methyl acetate, it was shown that the addition/elimi-nation (through a neutral tetrahedral intermediate) and the direct displacement (through a transition state similar to that shown in Figure 5a) mechanisms for aminolysis had comparable activation barriers. However, in the case of methyl amine addition to phenyl acetate, it was shown that the direct displacement pathway is favored by approximately 5 kcal/mol.1201 Noncovalent stabilization of the direct displacement transition state was therefore the focus of the subsequent catalyst design process. 

Substituted Phenyl 2,4,6-trinitrophenyl sulphides. By UV-VIS measurements of the reactions of 4 -substituted phenyl 2,4,6-trinitrophenyl sulphides with amines in DMSO, Crampton s group131 showed the presence of two well-separated processes which were interpreted by Scheme 7129. In each case a rapid reversible equilibrium was established leading to the 3-adduct (10). They also observed a second, much slower process resulting in formation of the N-substituted picramide derivatives, 13. The final spectra were identical to those of the independently prepared products, 13. Chamberlain and Crampton133 showed that the reaction products are in rapid equilibrium with anions derived from them by amine addition at the 3-position and/or loss of a side-chain proton, but they did not find evidence for the accumulation of spectroscopically observable concentrations of intermediates such as 12. 

The successful synthesis of 2-thienyl and substituted 2- and 3-thienyl-acetylenes in yields as high as 60-80% opened a wide variety of synthetic applications. Various addition reactions with carbonyl compounds or epoxides could be carried out with ease. Aliphatic as well as aromatic amine addition reactions, or condensation reactions with hydrazine or hydroxylamine could be easily performed. 

Figure 8.6 Effect of aliphatic amines addition as inhibitors on PCDD/F concentration (measured on fly ash). (From D. Lenoir et ah, Umweltchem. Okotox., 1989.)...

Figure 4.10 shows the effect of additive concentration on the separation of clen-buterol enantiomers on a polysaccharide-based chiral stationary phase [79]. The peak shapes were dramatically improved by adding an amine additive and the separation time was also reduced from 14 to 7 min when 1.0% amine was added to the mobile phase. Phinney and Sander [100] investigated the effect of amine additives using chiral stationary phases having either a macrocyclic glycopeptide or a... 

Amine Additive Temperature Reaction time Isolated Yield 4a-e [%] ee [%] TON TOP... 

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