Nitrosoalkanes

Martynov, I.V., A.N. Ivanov, T.A. Epishina, and V.B. Sokolov. "Reaction of 1,1-Dichloro-l-nitrosoalkanes with Phosphorus (III) Chlorides." Seriya Khimicheskaya 9 (1988) 2128-2132 (In Russian). 

Reaction of Dichloromethylphosphine with 1,1-Dichloro-l-nitrosoalkanes." Zhurnal... 

Hindered di-t-alkylamines RNHBu1 (R = t-Bu, t-octyl or 1-adamantyl) have been synthesized from t-alkylamines as follows. Reaction with peracetic acid gave the nitrosoalkanes RNO, which were treated with t-butyl radicals, generated from t-butylhydrazine and lead(IV) oxide, to yield t-butyloxyhydroxylamines. Reduction with sodium naphthalide in THF gave the products (equation 12). The di-t-alkyl-amines are inert to methyl iodide and dimethyl sulphate but can be alkylated by methyl fluorosulphonate42. 

Since the primary photochemical process for nitrosoalkane involves the homolytic dissociation of the C—N bond to generate free radicals141, recent studies on the photochemistry of nitrosoalkanes pay more attention to radical reactions and to the methods of detection, such as spin trapping studies coupled with ESR techniques142. 

Unlike most tertiary nitrosoalkanes, 1-chloronitrosocyclohexane forms adducts with various 1,3-dienes. Although the reaction is sluggish and reversible, good yields of dihy-drooxazines can be obtained if ethanol is present (equation 100)95. 

Another approach toward Af-unsubstituted dihydro-1,2-oxazines involves cycloaddition of easily available a-chloro nitrosoalkanes 155 to 1,3-dienes (e.g. 156, equation 101). Subsequent alcoholysis results in the removal of the alkyl function and provides N-unsubstituted cyclic hydroxylamines of type 157 (equation 101) ... 

Carbazole oxidized by nickel peroxide in the absence of light and in the presence of 2-methyl-2-nitrosopropane gave the radical 71, an observation taken as additional evidence for the intermediacy of radical cations, trapped in this case by the nitrosoalkane, in oxidative dimerization of carbazoles (see Section II,A,2). 

Insertion of coordinated NO into one of the metal alkyls would yield a nitrosoalkane, which could dissociate and in turn react with the starting material via 0-atom transfer. The independent observation that PhNO reacted with Cp W(NO)(CH2SiMe3)2 to form Cp W(0)2(CH2SiMe3) in low yield supports the role of the nitrosoalkane as an alternative oxidant. 

Complexes involving oxime ligands display a variety of reactivity modes that lead to unusual types of chemical compounds. As far as the oxime chemistry of platinum is concerned, these complexes are involved in facile deprotonation of the OH group with formation of oximato complexes, reduction of Pt(IV) species, Pt(II)-assisted reactions with coordinated allene," alkylation by ketones, oxime-ligand-supported stabilization of Pt(III)—Pt(III) compounds, oxidative conversion into rare nitrosoalkane platinum(II) species, and coupling with organocyanamides. ... 

At low concentrations of chlorine, dimeric nitrosoalkanes free from chlorine are produced when alkanes are treated also with nitric oxide. Under these circumstances, molecular chlorine is first converted into atomic chlorine which attacks the alkane to form alkyl radicals and hydrogen chloride. The alkyl radicals, in turn, form nitrosoalkanes with nitric oxide. This reaction is most effectively carried out when the ultraviolet radiation is between 380 and 420 mp. [43, 56],... 

It is natural to presuppose that the reduction of nitro compounds should lead to the nitroso compounds, at least as an intermediate stage. Until quite recently, no reductive processes for the formation of nitrosoalkanes were known [3], More recently, some indirect evidence is said to show that, on electrolytic reduction of tertiary aliphatic nitro compounds, the final t-alkyl-hydroxylamines are produced by the intermediate formation of nitroso compounds which were not isolated [99]. 

Bis(nitrosoalkane), see Nitroso dimers p-Bromoazobenzene, 334 Bromomethylazobenzenes, 309 1 -Bromo-3-methyl-1,2-butadiene, 30... 

The bimolecular reduction of aliphatic nitroso compounds is complex and somewhat unreliable. With careful control of reaction conditions, a-nitroso ketones (in dimeric form) may be reduced with stannous chloride in an acidic medium at room temperature to the azoxy compounds, while dimeric a-nitroso acid derivatives may be reduced at about 50°C [10, 35, 36]. Nitrosoalkanes, on the other hand, are decomposed at room temperature to alcohols and nitrogen, and are reduced to amines at 50°-60°C. It has been postulated that only the dimeric nitroso compounds can be reduced to azoxy compounds and, in fact, that the dimer has a covalent nitrogen-nitrogen bond. Equations (31)—(34) summarize these data [10]. 

Certain olefins have been converted into l-chloro-2-nitrosoalkane dimers on treatment with nitrosyl chloride (Eq. 3). Terminal olefins appear to be active only if they are not allylic in nature. The addition of nitrosyl chloride to norbornene is of particular interest, and details are presented in the body of... 

The naming of monomeric nitroso compounds is generally quite straightforward. In this discussion a dimer is simply indicated as nitrosoalkane dimer or as nitrosoarene dimer if reasonable evidence for the isolation of the dimer is at hand. In the works of Muller and Metzger ([14], etc.) terms such as bis(nitrosoalkane) are used to indicate the dimers. 

Much of the pioneering research on nitrosoalkane dimers is based on reactions involving the formation of free radicals. Most of the reactions are of little value from the preparative standpoint, either because a highly specialized apparatus (e.g., photolysis equipment, high-vacuum trains, even a Van de Graaff generator) is used or because complex mixtures of products are produced. However, this work is of such importance in the historical development of aliphatic nitroso chemistry that it merits a brief review here rather than relegation to Section 5. 

---