Synthesis of azaheterocycles from oxime derivatives

Abstract

Electrophilic amination of Grignard reagents has been accomplished by using O-sulfonyloximes as amination reagents. Benzophenone O-sulfonyloxime derivatives react with Grignard reagents on sp 2 nitrogen, yielding primary amines by successive hydrolysis of the resulting N-alkylimines.Various cyclic imines are synthesized by Pd-catalyzed reaction from olefinic oxime derivatives. That is, treatment of O-pentafluorobenzoyloximes of olefinic ketones with a catalytic amount of Pd(PPh 3 ) 4 and triethylamine affords nitrogen-containing heterocycles, such as pyrroles, pyridines, isoquinolines, spiro-imines, and aza-azulenes. This reaction proceeds via the initial formation of alkylideneaminopalladium(II) species generated by oxidative addition of the oximes to the Pd(0) complex, and the following intramolecular amination on the olefinic moiety.Cyclic imines are prepared from γ,δ-unsaturated O-acetyloximes by treatment with acetic acid and 1,4-cyclohexadiene in the presence of a catalytic amount of 1,5-naphthalenediol. γ,δ-Unsaturated ketone O-methoxycarbonyloximes are transformed to 2-bromomethyl-3,4-dihydro-2H-pyrroles by the action of a catalytic amount of Cu(I) bromide dimethyl sulfide complex and lithium bromide.

Highly efficient and stable peracid for rapid and selective oxidation of aliphatic amines to oximes

“…It was also observed that, oxime selectivity increases with temperature. As we increased temperature from room temperature (30 °C) to 50 °C oxime selectivity was also increased from 53% to 90% (Table 2 entries [10][11][12]. Further rise in the temperature does not show any influence on the oxime selectivity ( Table 2, entry 13).…”

“…It can be easily transferred into various important derivatives such as amide, [1][2][3] nitrile, [4][5][6] nitro compounds, 7,8 nitrone 9 and also used for the synthesis of azoheterocycles. 10,11 Various oxidizing systems have been employed for oxidation of aliphatic amines which utilizes oxidants such as dimethyldioxirane, [12][13][14] sodium perborate 15 and sulfonic peracid, 16 oxidant-metal systems such as H 2 O 2 -nano TiO 2 , 17 H 2 O 2 -titanium superoxide, 18 H 2 O 2 -oxidoperoxidotungsten(VI) complexes, 19 H 2 O 2 -SeO 2 , 20 H 2 O 2 -with various Mo catalysts, [21][22][23] H 2 O 2 -titanium silicate (TS-1), 24,25 and TBHP-chromium silicate. 26 Though in many cases the protocol offered good oxime selectivity, the reaction requires an excess amount of oxidant with longer time for completion and often the reaction results in poor conversion.…”

Synthesis of New Phosphonoamide and Phosphonocaprolactam Derivatives via the Diethyl Chlorophosphate‐Promoted Beckmann Rearrangement of γ‐Phosphonyloximes

“…Certain oxime derivatives have also found applications in coordination chemistry especially as uranium extractants . On the other hand, oximes and their derivatives are recognized as key intermediates for the synthesis of amines , amides , nitriles , nitro compounds , and azaheterocycles .…”

A rapid, convenient, solventless green approach for the synthesis of oximes using grindstone chemistry

“…Oximes are highly crystalline compounds that find applications not only for protection, but also for purification and characterization of carbonyl compounds [1,2]. Conversions into nitriles [3], nitro compounds [4,5], nitrones [6], amines [7], and synthesis of azaheterocycles [8] are some of the synthetic applications of oximes. They are also useful for selective α -activation [9] and are extensively used as intermediates for the preparation of amides by the Beckmann rearrangement [10,11] and fungicides and herbicides [12].…”