[en] Aryl-(E)-2-(azidomethyl)alkenoate and aryl-(Z)-2-(azidomethyl)acrylonitrile from aryl aldehydes and activated alkenes (acrylate and acrylonitrile) were synthesized in one-pot consecutive way with excellent stereoselectivity in good to high yield. The method include a three-step one-pot processes: Baylis-Hillman reaction of aryl aldehydes and activated alkenes using DABCO followed by acetylation using acetic anhydride and a catalytic amount of DMAP and nucleophilic substitution using sodium azide in DMF at room temperature. Our one-pot synthetic protocol is efficient and simple. Organoazides are one of the most important synthetic intermediates for the preparation of nitrogen-containing organic compounds, for example, amines via reduction, imines via rearrangement, and other nitrogen-containing heterocycles via cycloaddition reactions. Because allyl azides among them are versatile building skeletons for the synthesis of biologically active nitrogen-containing heterocycles, the synthesis of allyl azides have become an attractive research area

[en] Complexes of cadmium azides and some other bivalent metal complexes with carbohydrazide (CH) are synthesized and investigated. It is shown that Cd azide forms a complex with one ligand molecule, which can be considered either as tetracoordinated compound with monodentate azide group or as hexacoodinated compound with bidentate azide group. The temperature of Cd(CH)(N₃)₂ decomposition is 240 deg C

[en] Cyclic voltammetric studies of triaminoguanidine nitrate (TAGN), 3,3'-hydrazino bis(bis[6,6'-(3,5-dimethylpyrazol-lyl])-1,2,4,5-tetrazine (HBPT), 4,6-dinitrobenzofuroxan (DNBF) and 3,3'-diamino-4,4'-azoxyfurazan (DAAF) were carried out at different pH conditions in 50% aqueous acetonitrile using glassy carbon electrode. Optimum pH was selected for individual compounds. Influence of scan rate and concentration on the voltammetric response were studied in optimum pH. The number of electron transferred was determined by controlled potential coulometry. All compounds undergo diffusion controlled electrochemical reaction. Based on cyclic voltammetric results, differential pulse and square wave voltammetric methods have been developed for the analytical determination. Instrumental parameters such as initial scan potential, amplitude, pulse increment, pulse period, pulse width and frequency were studied. Optimum experimental conditions for each compound were obtained. After fixing optimum conditions, the effect of concentration was studied and calibration plot was arrived. These plots can be used to determine the traces of the above said four energetic materials

[en] The chemical reactivity of enaminone 2 toward some nucleophilic and electrophilic reagents was investigated. Enaminone 2 was used as a key precursor for the synthesis of many important heterocyclic compounds. The synthesized compounds were characterized by IR, 1H-NMR, MS spectral and elemental analysis. (author)

[en] Second-order rate constants (k_N_3_−) for SNAr reactions of 1-(Y-substituted-phenoxy)-2,4-dinitrobenzenes (2a–2h) with math formula in 80 mol % H_2O/20 mol % DMSO at 25.0 ± 0.1 °C have been measured spectrophotometrically. The Brønsted-type plot is linear with β"l"g = −0.38. The Hammett plots correlated with math formula and math formula constants exhibit highly scattered points. In contrast, the Yukawa–Tsuno plot results in an excellent linear correlation with ρ_Y = 1.02 and r = 0.51, indicating that a negative charge develops partially on the O atom of the leaving Y-substituted-phenoxy moiety in the transition state. Accordingly, the reactions have been concluded to proceed through a stepwise mechanism, in which expulsion of the leaving group occurs in the rate-determining step. Comparison of k_N_3_− with the k_O_H_− values reported previously for the corresponding reactions with OH"− has revealed that math formula is only 6- to 26-fold less reactive than OH"− toward substrates 2a–2h, although the former is over 11 pK_a units less basic than the latter. Solvation and polarizability effects have been suggested to be responsible for the unusual reactivity shown by math formula and OH"−. Effects of changing nucleophile from OH"− to N_3"− on reaction mechanism and reactivity are discussed in detail

[en] High-nitrogen heterocyclic compounds have been recognized as one class of promising energetic materials. These energetic compounds with high nitrogen content have high heat of formation due to the large number of N-N and C-N bonds. A number of heterocycle-based energetic compounds were reported as potential materials for military and space applications. Of these, furazan ring served as an efficient build-block. The combination of furazan ring with energetic substituents, such as amino (-NH₂), nitro (-NO₂), azide (-N₃)¹³ and nitramine (-NHNO₂)¹⁴ have been investigated

[en] The direct lactamization of 1,3- and 1,4-azido amides has been achieved using triphenylphosphine and water, affording various γ- and δ-lactams in good to excellent yields. The direct lactamization of the azido amides was performed via the Staudinger-type reductive cyclization in which the amide group acts as the electrophile for lactam synthesis. This lactamization provides a mild, functional group tolerant and efficient route for the synthesis of various γ- and δ-lactams found in natural products and pharmaceuticals. Further studies will be conducted to develop new synthetic routes for the synthesis of various lactams. The lactam ring system is one of the most ubiquitous structural motifs found in natural products and pharmaceuticals. Owing to the prevalence of lactams, their synthesis has attracted considerable attention. Lactams are usually prepared by the coupling of activated carboxylic acid derivatives with amines. Alternative routes include the Beckmann rearrangement of oximes, the Schmidt reaction of cyclic ketones and hydrazoic acid, the Kinugasa reaction of nitrones and terminal acetylenes, the Diels-Alder reaction of cyclopentadiene and chlorosulfonyl isocyanate, transition metal catalyzed lactamization of amino alcohols, and iodolactamization of amides and alkenes. In particular, the intramolecular Staudinger ligation of azides and activated carboxy acids, including esters, is well known as an environmentally friendly and mild protocol for lactam synthesis

No abstract available

[en] Complex of Cd(2) nitrate with m-nitrobenzhydrazide (mNBH) of the composition: Cd(p-NBH)₄(NO₃)₂ has been synthesized. The complex prepared has been studied using infrare and X-ray spectroscopy. Conclusion on the structure of the complex is made. In the complex, its coordination number being 4, molecules of m NBH are coordinated in a monodentate way be atoms of CO group. The complex of Cd (2) is X-ray amorphous

[en] Investigations of complexes of 5f ions and 4f ions with nitrogen donor ligands show that trivalent actinide ions are more strongly complexed than trivalent lanthanide ions, and these properties can be exploited in actinide-lanthanide group separation by the choice of appropriate extraction systems. The higher affinity of nitrogen ligand for 5f trivalent ions is not attributable to the occurence of different type of complex for the two series (inner vs outer sphere), as shown by the use of several complexation techniques. This difference might be attributed to greater covalent bond contributions in the actinide complexes. Dialkyldithiophosphates can be better extractants than their dialkylphosphate equivalents, as shown by the synergistic extraction of U (VI) from concentrated phosphoric acid. This effect is probably due to the weaker hydrogen bonds of the P group which allow the formation of a greater variety of extracted species. In this particular case, we showed that the extracted species has the formula: UO₂ (H₂PO₄) (R₃PO)