Nitrogen-containing compounds nitrones

Addition of Ketene Acetals and Enoles In recent years, much attention has been given to the synthesis of optically active nitrogen-containing compounds, with the key step being the highly stereoselective nucleophilic addition of ketene silyl acetals to nitrones (Scheme 2.174). Similar to nitrone cyanations, in ketene silyl acetal reactions one observes an accelerating effect with thiourea derivatives (633). 

Reactions of Vmylation and Ethynylation Vinylation and ethynyla-tion of nitrones using vinyl (137, 202, 563, 564) and ethynyl (199, 213, 219) organometalic reagents is a convenient method for synthesizing various nitrogen-containing compounds such as a-amino aldehydes, a-amino acids, amino... 

Nitrobenzene chloride, sulfonylperoxy radical reactions, 1035, 1036 2-Nitrobenzenesulfinylperoxy intermediate, superoxide reactions, 1034 Nitrogen-containing compound oxidation bis(trimethylsilyl) peroxide reactions, 802-3, 804 dioxiranes, 1151-5 primary aromatic amines, 1151 A-oxidation, 531-8, 539 Nitrohpids, hpid hydroperoxides, 952-4 Nitronate ions, dioxirane oxidation, 1152-3 Nitrosation, malondialdehyde, 667 Nitroso compounds, spin trapping, 664 Nitrotyrosine, peroxynitiite determination, 740-1... 

Reactions of Nitrogen-containing Compounds. - Irradiation of cyclic nitrocompounds in base (i.e. as the nitronate anion) leads to ring-expansion [e.g. 

Phosphine may react violently with many nitrogen-containing inorganic compounds. It may ignite or explode by spark when mixed with nitric oxide, nitrons oxide, nitrogen... 

Mannich bases derived from polynitroalkanes are usually unstable because of the facile reverse reaction leading to stabilized nitronate anions. The nitration of Mannich bases to nitramines enhances their stability by reducing the electron density on the amine nitrogen through delocalization with the nitro group. The nitration of Mannich bases has been exploited for the synthesis of numerous explosives, some containing both C-NO2 and N-NO2 functionality. Three such compounds, (163), (164) and (165), are illustrated below and others are discussed in Section 6.10. 

Thus, the interaction of a-haloalkylnitrones 64a,b with amines and hydrazine leads to products that contain no iV-oxide oxygen atom. This allows aldehyde and ketone derivatives of 3-imidazoline nitroxide to be synthesized the latter are of interest as spin labels for biological systems (Schlude, 1973). The interaction of the same compounds (64a,b) with nitrogenous nucleophiles, which contain a more electronegative nitrogen atom than that in amines or hydrazine, as well as the interaction with C-, S-, and O-nucleophiles, proceeds with the preservation of the nitrone group and leads to nucleophilic substitution products. Dehydrobromination of 4-bromoalkyl derivatives leads to reactive a,j8-unsaturated nitrones... 

---