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Allylic oxygenated derivatives of himachalenes are highly valued molecules due to their potential applications in perfumery, cosmetics, and pharmaceuticals. Previous attempts at catalyzed allylic oxidation of himachalenes led to the formation of a very stable η3-allyl palladium complex, preventing any further reaction development. Herein, we present the first successful palladium-catalyzed synthesis of a novel allylic acetoxylated derivative of himachalenes. This reaction was achieved by incorporating an aromatic ring into the substrate structure. The resulting intermediate complex was isolated and characterized using nuclear magnetic resonance spectroscopy and X-ray crystallography. Density functional theory (DFT) calculations were performed to compare the reactivity of the newly synthesized complex with previously reported ones. The theoretical results confirm that the introduction of an aromatic ring enhances the reactivity of the η³-allyl palladium complex, thereby facilitating the desired transformation. [ABSTRACT FROM AUTHOR]

A quinoxaline‐based ligand, 6,7‐dimethyl‐2,3‐di(2‐pyridyl)quinoxaline (Me2dpq), and its unique binuclear Co(II)‐Me2dpq complex were prepared and analyzed using single crystal X‐ray diffraction and several spectroscopy techniques. Hirshfeld surface analyses were also used to clarify the Me2dpq ligand and the Co(II)‐Me2dpq crystal packing. The Co(II)‐Me2dpq complex crystallized in triclinic P‐1 space group and exhibited a distorted trigonal bipyramidal geometry around the cobalt(II) ion. Each Co(II) ion coordinated to a Me2dpq ligand through two N donor centers from pyridyl and quinoxaline rings along with a terminal Cl and two bridged Cl atoms. The binding properties of the ligand and its complex with CT‐DNA were studied by several techniques, namely UV–Vis spectroscopy, fluorescence quenching, viscosity measurements, thermal denaturation, and gel electrophoresis. The CT‐DNA binding interaction tests demonstrated that both the Co(II)‐Me2dpq complex and its parent ligand bind to DNA in an intercalative way. The antioxidant studies of the novel Co(II)‐Me2dpq complex illustrated significant activity against DPPH• and OH•· radicals. The in vitro cytotoxic effect of Me2dpq ligand and its Co(II)‐complex on MCF‐7 and Hep‐G2 tumor cell lines was evaluated by using the MTT assay. The studies showed that the Co(II)‐Me2dpq complex had superior activity toward the tested cell lines. Molecular docking studies of synthesized compounds were employed to figure out the way they would associate with a biologically macromolecular target B‐DNA (PDB: 1BNA). Thus, this study is anticipated to provide novel opportunities for the successful utilization of the synthesized compounds in many medical domains. [ABSTRACT FROM AUTHOR]

Twelve spiro thiazolidinone compounds (A–L) were synthesized via either conventional thermal or ultrasonication techniques using Fe2O3 nanoparticles. The modification of the traditional procedure by using Fe2O3 nanoparticles led to enhancement of the yield of the desired candidates to 78–93% in approximately half reaction time compared with 58–79% without catalyst. The products were fully characterized using different analytical and spectroscopic techniques. The structure of the two derivatives 4-phenyl-1-thia-4-azaspirodecan-3-one (A) and 4-(p-tolyl)-1-thia-4-azaspirodecan-3-one (B) were also determined using single crystal X-ray diffraction and Hirshfeld surface analysis. The two compounds (A and B) were crystallized in the orthorhombic system with Pbca and P212121 space groups, respectively. In addition, the crystal packing of compounds revealed the formation of supramolecular array with a net of intermolecular hydrogen bonding interactions. The energy optimized geometries of some selected derivatives were performed by density functional theory (DFT/B3LYP). The reactivity descriptors were also calculated and correlated with their biological properties. All the reported compounds were screened for antimicrobial inhibitions. The two derivatives, F and J, exhibited the highest levels of bacterial inhibition with an inhibition zone of 10–17 mm. Also, the two derivatives, F and J, displayed the most potent fungal inhibition with an inhibition zone of 15–23 mm. Molecular docking investigations of some selected derivatives were performed using a B-DNA (PDB: 1BNA) as a macromolecular target. Structure and activity relationship of the reported compounds were correlated with the data of antimicrobial activities and the computed reactivity parameters. [ABSTRACT FROM AUTHOR]

Two Zn(II) clusters were synthesized by the reaction of Zn(OAc)2·2H2O and 1,2‐bis(2‐hydroxy‐3‐methoxybenzylidene)hydrazine as a N2O4‐donor Schiff base ligand in 1:3 molar ratio. The reaction in methanol gave yellow‐brown needle crystals, while block yellow crystals were achieved in a mixture of methanol:water (50:50 v/v). Investigation of the crystals by single crystal X‐ray analysis showed that solvent has considerable effect on the structure and composition of the products. In methanol, two independent pentanuclear Zn(II) clusters with the same general formula of [Zn5(L)2(μ‐OAc)4(OAc)2(CH3OH)2] but different coordination environments around Zn(II) cores, and bridging mode of the acetate ligands are present in the unit cell. In a mixture of methanol:water, a pentanuclear cluster and a 1D coordination polymer with pentanuclear repetitive unit are simultaneously present in the crystal structure. These compounds were further characterized by spectroscopic techniques, and they were used as catalysts for intramolecular cycloisomerization of 1,4‐diphenylbut‐3‐yn‐1‐one. The results indicated that these Zn(II) clusters can efficiently produce 2,5‐diphenylfuran through catalytic cycloisomerization reaction. [ABSTRACT FROM AUTHOR]

The scope of the heterogeneous catalysts has been greatly expanded in last few decades by the development of various catalysts. In this work a new chitosan-based nanocomposite hydrogel (CS/CuFe 2 O 4 NCH) was synthesized as a high-performance heterogeneous catalyst and then, it was utilized for the green synthesis of substituted 1,2,3-triazoles by a multi-component (azide-alkyne-epoxide) cycloaddition reaction. The synthesized nanocomposite hydrogel was investigated by using various instrumental analyses, including FT-IR, XRD, SEM, EDS, HRTEM, DLS, and TGA. The structure of one of the substituted 1,2,3-triazoles was studied by using single-crystal X-ray diffraction analysis. The nanocomposite hydrogel can be easily regenerate after the catalytic reaction. It can be reused frequently without considerable loss of activity. The high catalytic activity, straightforward reaction, easy recyclability, short reaction time, use of a green solvent, and the simple separation of catalyst are the main advantage of the current method, which offers both financial and environmental benefits., Competing Interests: The authors declare that there is no conflicts of interest., (This journal is © The Royal Society of Chemistry.)