Amine aliphatic, oxidation

Rearrangement, Aliphatic amine oxides without an ahphatic hydrogen atom P to the nitrogen undergo Meisenheimer s rearrangement when heated to give trisubstituted hydroxylamines. 

Acylation. Aliphatic amine oxides react with acylating agents such as acetic anhydride and acetyl chloride to form either A[,A/-diaLkylamides and aldehyde (34), the Polonovski reaction, or an ester, depending upon the polarity of the solvent used (35,36). Along with a polar mechanism (37), a metal-complex-induced mechanism involving a free-radical intermediate has been proposed. 

Both amine oxides related to pyridines and aliphatic amine oxides (/25) are easily reduced, the former the more so. Pyridine N-oxide has been reduced over palladium, platinum, rhodium, and ruthenium. The most active was rhodium, but it was nonselective, reducing the ring as well. Palladium is usually the preferred catalyst for this type of reduction and is used by most workers 16,23,84 158) platinum is also effective 100,166,169). Katritzky and Monrol - ) examined carefully the selectivity of reduction over palladium of a... 

Ben2yl azide 1855 and N-benzyloxycarbonylbenzylamine 1859 are both transformed by the cheap polymethylhydrosiloxane (PMHS) 1856, in the presence of (B0C)20 and Pd/C, into 92-94% N-BOC-benzylamine 1857 and the polymer 1858 [81]. (Scheme 12.22). Aromatic and aliphatic amine oxides are readily reduced by 1856/Pd/C into their corresponding amines. Thus, e.g., pyridine-N-oxide 860 and quinohne-N-oxide 877 give pyridine and quinohne in 90 and 92% yield, respectively. Analogously, benzyldimethylamine-N-oxide is converted in 88% yield into free benzyldimethylamine [82]. 

Complexes of monodentate aliphatic amine oxides with the lanthanides have not been extensively investigated. The only series of complexes with a ligand of this type, Et3NO, has been reported by Pavlenko et al. (181). The complexes have the formula [Ln(Et3N0)6][Cr(NCS)6]-2H20. 

Other simple aliphatic amine oxides can be used as the oxidant in this reaction, but N-methylmorpholine N-oxide (1) is preferred because it generally gives a faster reaction rate and is easily prepared. The reaction can also be used to convert aliphatic amine oxides into amines... 

The purpose of preparing aliphatic amine oxides is usually their thermal decomposition to cis alkenes and N,N-dialkylhydroxylamines (Cope rearrangement) [156, 161, 1187]. Thus A, A -dimethylcyclohexylmethylamine is oxidized with 30% hydrogen peroxide in methanol to its oxide, whose decomposition at 90-100 °C at 10 mm of Hg and at 160 °C for 2 h furnishes 79-88% of methylenecyclohexane and 78-90% of A, A -dimethylhydroxyl-amine [161], Another example is the preparation of cw-cyclooctene from dimethylcyclooctylamine (equation 502) [1187]. 

Homer and Hoffmann" reported use of triphenylphosphine for the deoxygcnution of azoxy compounds to uzo compounds, of peroxides to ethers, of nitrones to Schiff bases, and of aliphatic amine oxides to amines. The lalier reiicliun was done in nfliKina iieatic anld and under these contillloni the N-oxides of pyridine and quinoline... 

A striking example of this theory is the large a effect (ca. 103) of pyridine N-oxides in contrast to the normal behavior of trimethylamine N-oxide and phenoxide (47). According to my explanation, P -P repulsion in the phe-noxide and the inductive (Coulombic) effect in the aliphatic amine oxide alone do not produce an a effect. However, the combined action of the inductive effect and P -P repulsion in the aromatic N-oxide produces the observed a effect. 

ACETOFENONA (Spanish) (98-86-2) Combustible liquid (flash point 170°F/77°C). Incompatible with strong acids, aldehydes, aliphatic amines, oxidizers, perchloric acid, hydrogen peroxide. Attacks some plastics, coatings, and rubber. 

Cope and his co-workers56 later showed that allyl and benzyl groups migrate also within aliphatic amine oxides e.g., JV,JV-dimethylbenzylamine oxide at 160° isomerizes to afford 0-benzyl-A, JV-dimethylhydroxylamine in 51% yield.57... 

The higher aliphatic amine oxides are commercially important because of their surfactant properties and are used extensively in detergents. Amine oxides that have surface-acting properties can be further categorized as nonionic surfactants however, because under acidic conditions they become protonated and show cationic properties, they have also been called cationic surfactants. Typical commercial amine oxides include the types shown in Table 1. 

Aromatic amine oxides, produced on a much smaller scale and having some pharmaceutical importance, do not demonstrate the surface-acting properties that the aliphatic amine oxides do. 

The N—O bond distances, found to be 0.133 to 0.139 nm for trimethyl amine oxide (1), are somewhat shorter than the single N—C bond distance of 0.147 nm in methyl amine. The N—C bond distance of 0.154 nm in trimethyl amine oxide approaches that of the C—C bond. This is in agreement with the respective absorptions in the infrared region valence vibrations of N—O bonds of aliphatic amine oxides are found between 970 920 cm (2). 

Decomposition. Most amine oxides undergo thermal decomposition between 90 and 200 °C. Aromatic amine oxides generally decompose at higher temperatures than aliphatic amine oxides and yield the patent amine... 

Reduction. Just as aromatic amine oxides are resistant to the foregoing decomposition reactions, they are more resistant than aliphatic amine oxides to reduction. Aliphatic amine oxides are readily reduced to tertiary amines by sulfurous acid at room temperature in contrast, few aromatic amine oxides can be reduced under these conditions. The aliphatic amine oxides can also be reduced by catalytic hydrogenation (27), with zinc in acid, or with stannous chloride (28). For the aromatic amine oxides, catalytic hydrogenation with Raney nickel is a fairly general means of deoxygenation (29). Iron in acetic acid (30), phosphoms trichloride (31), and titanium trichloride (32) are also widely used systems for deoxygenation of aromatic amine oxides. 

All lation. Alkylating agents such as dialkyl sulfates and alkyl hahdes react with aliphatic amine oxides to form trialkjialkoxyammonium quaternaries. For example (33), methyl iodide reacts with trimethjiamine oxide to form trimethjlmethoxyammonium iodide... 

Linear alpha-olefins are the source of the largest volume of aliphatic amine oxides. The olefin reacts with hydrogen bromide in the presence of peroxide catalyst, to yield primary alkyl bromide, which then reacts with dimethylamine to yield the corresponding alkyl dimethyl amine. Fatty alcohols and fatty acids are also used to produce amine oxides (Fig. 1). 

Empirical C22H43NO2 C18H36O2 Uses Surfactant in cosmetics Isostearamidopropylamine oxide Synonyms Amides, isostearic, N-[3-(dimethylamino) propyl], N-oxide N-[3-(Dimethylamino) propyl] isooctadecanamide, N-oxide Isooctadecanamide, N-[3-(dimethylamino) propyl]-, N-oxide Classification Aliphatic amine oxide Empirical C23H48N2O2 Uses Surfactant, hydrotrope, foam booster/stabilizer, thickener, lubricant, conditioner, vise, builder in cosmetics, household prods., janitorial prods. wetting agent for cone, electrolyte sol ns. 

Uses Antistat, surfactant in cosmetics Manuf./Distrib. Amyl http //www.amyi.com Myristyl/cetyl amine oxide Synonyms Amines, N-(C14-C16-alky I )-N,N-dimethyl-, N-oxides N,N-Dimethyl-1-my risty I am i ne/cety I am i ne-N -oxi de Classification Aliphatic amine oxide Formula R(CH3)2N O, R rep. mixt. of myristyl and cetyl alkyl groups... 

Schercomid OMI [Scher http //www.scherchem.com, Chesham Chems. Ltd http //www. cheshamchemicals. co. uk] Oleamidopropylamine oxide CAS 25159-40-4 EINECS/ELINCS 246-684-6 Synonyms N-[3-(Dimethylamino) propyl]-9-octadecenamide-N-oxide 9-Octadecenamide, N-[3-(dimethylamino)propyl]-, N-oxide Oleamidopropyl dimethylamine oxide Classification Aliphatic amine oxide Empirical C23H46N2O2 Properties Nonionic... 

Cyclic Voltammetric Data for 0.1 mM Aliphatic Amine Oxidation at Diamond... 

As with aliphatic amines, oxidation by peroxidic reagents proceeds through the hydroxylamine intermediate (see below), but this rapidly reacts further to a nitroso compound and cannot be isolated. Under slightly more vigorous conditions, the nitroso group is oxidised to nitro (equation 77) . 

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