Oxime hydroxylamine

Oximes, Hydroxylamines, and Olher Nilrogen Deri raljves... 

Nitro compounds are versatile precursors for diverse functionalities. Their conversion into carbonyl compounds by the Nef reaction and into amines by reduction are the most widely used processes in organic synthesis using nitro compounds. In addition, dehydration of primary nitro compounds leads to nitrile oxides, a class of reactive 1,3-dipolar reagents. Nitro compounds are also good precursors for various nitrogen derivatives such as nitriles, oximes, hydroxylamines, and imines. These transformations of nitro compounds are well established and are used routinely in organic synthesis. 

If the addition of hydrogen takes place in a 1,2-mode the products are oximes, hydroxylamines, amines, and carbonyl compounds resulting from the hydrolysis of the oximes [567], Oximes and carbonyl compounds also result from reductions of a,/3-unsaturated compounds with iron [569, 570] and an oxime was prepared by catalytic hydrogenation of a )S-nitrostyrene derivative over palladium in pyridine (yield 89%) [571]. 

Oxime. Hydroxylamine reacts with aldehydes and ketones to form oximes. 

Primary Amines Primary amines result from condensation of hydroxylamine (zero alkyl groups) with a ketone or an aldehyde, followed by reduction of the oxime. Hydroxylamine is used in place of ammonia because most oximes are stable, easily isolated compounds. The oxime is reduced using catalytic reduction, lithium aluminum hydride, or zinc and HC1. 

On the other hand, conjugated nitroalkenes are very useful electron-poor alkenes, prone to act as nucleophilic acceptor, mainly in the Michael reaction (Berestovitaskaya et al., 1994) or in the Diels-Alder cycloaddition (Denmark and Thorarensen, 1996). Moreover, the nitro group can be easily turned into a respectable array of functional groups such as its reduction to a primary amine, replacement with hydrogen (Ballini et al., 1983 Ono, 2001), conversion into a carbonyl (Nef reaction) (Ballini and Petrini, 2004), and transformation into other important functionalities such as nitrile, nitrile oxide, oximes, hydroxylamines, and thiols (Colvin et al., 1979). 

H-Bonding, Strongly Associative (HBSA) Water Primary amides Secondary amides Polyacids Dicarboxylic acids Monohydroxy acids Polyphenols Oximes Hydroxylamines Amino alcohols Polyols... 

Endprodukt der Reduktion von Stickstoff-Verbindungen mit Jodwasserstoff sind die Amine, wobei je nach Reaktionsbedingungen das Nitroso-(Oxime), Hydroxylamin- bzw. Hydrazin-Derivat abgefangen werden kann. 

The 1952 example of this rare heterocyclic system, produced by the action of hydroxylamine on the isoxazolidone (223 Ar = 4-MeC6H4) remains unsubstantiated <52JCS3428>. No evidence for the 5-methyl-2-/ -tolyl-3,4-dihydro-2/f-l,2,6-oxadiazine structure (225) is presented other than an elemental analysis, and a comparison with a similar, but equally unsubstantiated, reaction involving the action of hydroxylamine on the lactone (226), which is deemed to give the 3,4-dihydro-2/7-l, 2,6-oxadiazine (228) <01M813>. If these structures are correct, then they represent the earliest examples of the 1,2,6-oxadiazine system and their production must involve formation of an N—O bond presumably by cyclization of oxime-hydroxylamine intermediates of the type (224) and (227) as indicated in Schemes 28 and 29. 

A. 4-AaetyXpyridine oxime. Hydroxylamine hydrochloride (25.0 g, 0.36 mol) (Note 1) is dissolved in 50 mL of water, and the solution Is added to 70 mL of 20% aqueous sodium hydroxide in a 500-mL Erlenmeyer flask. To this magnetically stirred solution is added at one time 4-acety1pyridine (36.3 g, 0.30 mol) (Note 2) a precipitate forms rapidly. The reaction mixture is stirred at 0-5°C for 2 hr then the precipitate is collected by suction filtration and washed with 500 mL of cold water. 

CH-CH-CHsOH, carboxylic acids, HsOz, MeaC-OOH, hydroxy-acids, oximes, hydroxylamine ... 

Metal alkoxides react readily with a wide variety of hydroxylic reagents such as water, " alcohol, " alkanolamines," carboxylic acids,j6-diketones and yd-ketoesters, Schiff bases, oximes, hydroxylamines, " and glycols, " to afford homo- and heteroleptic derivatives involving metals in novel coordination states and geometries. The reactions of metal alkoxides with monofunctional reagents (LOH) can be illustrated by Eq. (2.182) ... 

Population of oxime-hydroxylamine tautomers B and C can be high, since unlike the initial dioximes A, they are conjugated systems and the energy gain of their formation should be considerable. Besides, highly basic medium is favorable for prototropic migration of the double bonds and enolization. The essential contribution of tautomers B and C in overall reaction is supported by the formation of isoxazoles, the predictable intramolecular cyclization of the tautomer in their Z-configurations. It is obvious that tautomers B and C as very reactive species (combination of the oxime and hydroxylamine functions with azadiene system), in the system KOH/ DMSO/acetylene, can tolerate various reactions, namely, vinylation, cyclization, elimination, polymerization, and polycondensation. 

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