Design,Synthesis, and Anti-Proliferative Activity of Some New Quinoxaline-1,3,4-oxadiazole Sulfonamide Hybrids

Russian Journal of General Chemistry - In the current study, some new quinoxaline linked 1,3,4-oxadiazole sulfonamide hybrids have been designed, synthesized and characterized by IR, 1H and 13C...     

Aryne‐Induced Novel Tandem 1,2‐Addition/(3+2) Cycloaddition to Generate Imidazolidines and Pyrrolidines

A new “single‐flask” method was developed for the synthesis of imidazolidines and pyrrolidines with high stereoselectivity. First, a Schiff base was arylated with an aryne. Second, an intramolecular proton transfer took place from the methylene position to the anionic aryne ring. Third, the resultant ylide reacted with a second equivalent of the same Schiff base in situ or an electron‐deficient alkene through a (3+2) cycloaddition. These sequential tandem 1,2‐addition/(3+2) cycloaddition reactions led to the desired heterocycles in 63–88 % yields.     

Formation of Periodic γ‐Turns in α/β‐Hybrid Peptides: DFT and NMR Experimental Evidence

Hybrid peptidic oligomers comprising natural and unnatural amino acid residues that can exhibit biomolecular folding and hydrogen‐bonding mimicry have attracted considerable interest in recent years. While a variety of hybrid peptidic helices have been reported in the literature, other secondary structural patterns such as γ‐turns and ribbons have not been well explored so far. The present work reports the design of novel periodic γ‐turns in the oligomers of 1:1 natural‐α/unnatural trans‐β‐norborenene (TNAA) amino acid residues. Through DFT, NMR, and MD studies, it is convincingly shown that, in the mixed conformational pool, the heterogeneous backbone of the hybrid peptides preferentially adopt periodic 8‐membered (pseudo γ‐turn)/7‐membered (inverse γ‐turn) hydrogen bonds in both polar and non‐polar solvent media. It is observed that the stereochemistry and local conformational preference of the β‐amino acid building blocks have a profound influence on accessing the specific secondary fold. These findings may be of significant relevance for the development of molecular scaffolds that facilitate desired positioning of functional side‐chains.     

Facile Synthesis of Spiro Oxindoles,Azaoxindoles, and Dihydroisoquinolone

Formation of 1-aryl-4-oxo-cyclohexa(e)nonecarboxylates from the Diels–Alder cycloaddition of 2-trimethylsilyloxy-1,3-butadiene and Danishefsky diene with aryl- and pyridylacrylates and further conversion thereof to spirocycles is described. This provides an efficient method for spiro oxindoles, azaoxindoles, and dihydroisoquinolones.

Reaction of Anthranilamide with Phosphorus Pentasulfide: Formation of 2-Mercapto-(1H)-1,3,2λ5-benzodiazaphosphorine-2,4-dithione

The reaction of anthranilamide with phosphorus pentasulfide in boiling pyridine leads to the benzodiazaphosphorine-pyridine salt 2 . The structure is established by elemental analysis, ¹H- ¹³C- ¹⁵N- ³¹P-NMR, and mass spectral data.     

Synthesis,Characterization, Molecular Docking,and Antimicrobial Activity of New Arylidene-Substituted Imidazoles

Russian Journal of General Chemistry - The title compounds are synthesized by condensation of 2-[4-(arylidene)-5-oxo-4, 5-dihydrooxazol-2-yl]phenylacetate with aromatic amines in presence of the...     

Growth and characterization of a promising nonlinear optical organic crystal

The growth of single crystals of acetoacetanilide using slow evaporation technique is reported. Good-quality crystals up to a size of 20×10×1 mm³ are obtained. The grown crystals are characterized by employing UV-VIS spectrum, IR spectrum, and hardness measurements. Acetoacetanilide shows very good second-harmonic generation (SHG) efficiency.     

Ternary Cu(II) complexes: synthesis,structural elucidation,and biological studies (DNA binding,cleavage, antibacterial,cytotoxicity)

Research on Chemical Intermediates - The present work focused on the assembly of 2-((2-(4-chlorophenylamino)phenylimino)methyl)-6-methoxyphenol as primary ligand (VBL) and bidentate nitrogen...     

Oxomolybdenum(V) complexes of 2-benzothiazolyl hydrazones

Summary Oxomolybdenum(V) complexes of general formulae [Mo₂O₃L₂Cl₂]H₂O and [Mo₂O₃L₂(OH)₂(H₂O)₂] (LH = hydrazones derived from 2-hydrazinobenzothiazole with salicyladehyde, 5-methyl-, 5-chloro-, 5-bromo-, 3-methoxysalicyldehyde and 2-hydroxy-1-naphthaldehyde) have been prepared and characterized by elemental analysis, conductivities, magnetic moments, thermal studies, and i.r., u.v.-vis. and e.p.r. spectra. The data suggest that the complexes are non-electrolytes, paramagnetic and have distorted octahedral structures with possible metal-metal interactions via oxo bridging.     

A highly efficient synthesis of imidazo-fused polyheterocycles via Groebke–Blackburn–Bienaymè reaction catalyzed by LaCl3·7H2O

A highly efficient and mild protocol for the synthesis of imidazo-fused polyheterocycles via Groebke–Blackburn–Bienaymè reaction under the influence of catalytic amount of lanthanum chloride heptahydrate has been described. A wide range of nitrogen-enriched polyheterocycles are synthesized with high yields under neat conditions.