Oxidative transformations of the aldehydes, ketones, and their azomethine derivatives such as hydrazones, Schiff bases, azines, and oximes are presented and discussed. The oxidants used have been hydrogen peroxide in the presence of selenium compounds as catalysts, peroxycarboxylic acids, and eerie ammonium nitrate. Some of reported reactions have practical value in the synthesis of phenols, es...

in an environmentally benign solventless system, aldehydes and ketones were readily converted to their corresponding azines with hydrazine sulfate, sodium hydroxide and alumina in high yield.

In an environmentally benign solventless system, aldehydes and ketones were readily converted to their corresponding azines with hydrazine sulfate, sodium hydroxide and alumina in high yield.

Multicomponent reactions involving azines (4-methylpyridine, isoquinoline and N-methyl imidazole) and acetylenic ester were undertaken in the presence of CH compound such as 2-furoyl trifluoroacetone(4,4,4-trifluoro-1-thiophen-2-yl-butan-1,3-dione) to generate enaminoesters as stable 1,4-diionic compounds in high yields.

The first examples of transannular ring transformations in azirino-fused eight-membered O,N- or S,N-heterocycles involving selective aziridine ring opening and medium-sized ring contraction are described, which provide an access to functionalized 1,4-benzox(thi)azines or 1,3-benzox(thi)azoles.

Determining the accurate chemical structures of synthesized compounds is essential for biomedical studies and computer-assisted drug design. The unequivocal determination of N-adamantylation or N-arylation site(s) in nitrogen-rich heterocycles, characterized by a low density of hydrogen atoms, using NMR methods at natural isotopic abundance is difficult. In these compounds, the heterocyclic moi...

We show that the positive electrostatic potentials and molecular quadrupole moments characteristic of π-acidic azines, which underlie the ability of these rings to bind anions above their centres, arise from the position of nuclear charges, not changes in the π-electron density distribution.

The reactions of 2-, 3- and 4-aminopyridines with 4,5-dichloro-1,2,3-dithiazolium chloride (Appel salt) 4 to give N-(4-chloro-5H-1,2,3-dithiazol-5-ylidene)pyridin-X-amines 1a (X = 2), 1g (X = 3) and 1k (X = 4) were optimized with respect to base, temperature and reaction time. Based on these conditions a total of thirteen [(dithiazolylidene)amino]azines 1a-m were prepared and fully characterized.

The most refined nucleus-independent chemical shift index (NICS(0)(πzz)) and the extra cyclic resonance energies (ECREs), based on the block localized wave function (BLW) method, show that the aromaticity of all azines is like that of benzene. The same is true for aza-naphthalenes relative to naphthalene. The lower relative energies of isomers with vicinal N's are due to the weakness of NN bond...