Synthesis of (E)-2-(1H-tetrazole-5-yl)-3-phenylacrylenenitrile derivatives catalyzed by new ZnO nanoparticles embedded in a thermally stable magnetic periodic mesoporous organosilica under green conditions

ZnO nanoparticles embedded in a magnetic isocyanurate-based periodic mesoporous organosilica (Fe₃O₄@PMO–ICS–ZnO) were prepared through a modified environmentally-benign procedure for the first time and properly characterized by appropriate spectroscopic and analytical methods or techniques used for mesoporous materials. The new thermally stable Fe₃O₄@PMO–ICS–ZnO nanomaterial with proper active sites and surface area as well as uniform particle size was investigated for the synthesis of medicinally important tetrazole derivatives through cascade condensation and concerted 1,3-cycloaddition reactions as a representative of the Click Chemistry concept. The desired 5-substituted-1H-tetrazole derivatives were smoothly prepared in high to quantitative yields and good purity in EtOH under reflux conditions. Low catalyst loading, short reaction time and the use of green solvents such as EtOH and water instead of carcinogenic DMF as well as easy separation and recyclability of the catalyst for at least five consecutive runs without significant loss of its activity are notable advantages of this new protocol compared to other recent introduced procedures.

Modified chitosan-zeolite supported Pd nanoparticles: A reusable catalyst for the synthesis of 5-substituted-1H-tetrazoles from aryl halides

A novel heterogeneous catalyst has been developed using chitosan-zeolite supported Pd nanoparticles (PdNPs@CS-Zeo) and used in an efficient synthesis of 5-substituted-1H-tetrazoles from aryl halides with high yields for relatively short reaction times with an easy work-up procedure. In this method, highly effective and reusable PdNPs@CS-Zeo catalyst was used in the reaction of various aryl iodides/bromides with K₄[Fe(CN)₆] as a non-toxic cyanide source to catalyze the [2 + 3] cycloaddition of the corresponding aryl nitriles with NaN₃ in the sequential one-pot preparation of 5-substituted-1H-tetrazoles. The synthesized PdNPs@CS-Zeo nanocatalyst was characterized using XRD, FTIR, TEM, HRTEM, XPS, Raman, TG-DTG, ICP-OES, BET, and EDS mapping. Additionally, the nanocatalyst could be effectively separated by filtration and reused for multiple times without significant decrease of catalytic activity.

Enhanced catalysis through structurally modified hybrid 2-D boron nitride nanosheets comprising of complexed 2-hydroxy-4-methoxybenzophenone motif

Tuning the structural architecture of the pristine two dimensional hexagonal boron nitride (h-BN) nanosheets through rational surface engineering have proven advantageous in the fabrication of competent catalytic materials. Inspired by the performance of h-BN based nanomaterials in expediting key organic transformations, we channelized our research efforts towards engineering the inherent surface properties of the exclusively stacked h-BN nanosheets through the incorporation of a novel competent copper complex of a bidentate chelating ligand 2-hydroxy-4-methoxybenzophenone (BP). Delightfully, this hybrid nanomaterial worked exceptionally well in boosting the [3 + 2] cycloaddition reaction of azide and nitriles, providing a facile access to a diverse variety of highly bioactive tetrazole motifs. A deep insight into the morphology of the covalently crafted h-BN signified the structural integrity of the exfoliated h-BN@OH nanosheets that exhibited lamellar like structures possessing smooth edges and flat surface. This interesting morphology could also be envisioned to augment the catalysis by allowing the desired surface area for the reactants and thus tailoring their activity. The work paves the way towards rational design of h-BN based nanomaterials and adjusting their catalytic potential by the use of suitable complexes for promoting sustainable catalysis, especially in view of the fact that till date only a very few h-BN nanosheets based catalysts have been devised.

Retraction: Highly monodisperse Pt(0)@AC NPs as highly efficient and reusable catalysts: the effect of the surfactant on their catalytic activities in room temperature dehydrocoupling of DMAB

Retraction of ‘Highly monodisperse Pt(0)@AC NPs as highly efficient and reusable catalysts: the effect of the surfactant on their catalytic activities in room temperature dehydrocoupling of DMAB’ by Betül Çelik et al., Catal. Sci. Technol., 2016, 6, 1685–1692, DOI: 10.1039/C5CY01371B.

Formation of microns long thin wire networks with a controlled spatial distribution of elements

By controlling the spatial distribution of elements using a simple self-assembly process, the catalytic performance can be enhanced.

Highly monodispersed palladium-ruthenium alloy nanoparticles assembled on poly(N-vinyl-pyrrolidone) for dehydrocoupling of dimethylamine-borane: An experimental and density functional theory study

This study reports on one of the best heterogeneous catalysts for the dehydrogenation of dimethylamine-borane (DMAB). This new catalytic system consists of highly monodisperse Pd and Ru alloy nanoparticles supported by poly(N-vinyl-pyrrolidone) (PdRu@PVP). The prepared heterogeneous catalyst can be reproducibly formed using an ultrasonic reduction technique for DMAB dehydrogenation under mild conditions. For the characterization of PdRu@PVP nanomaterials, several spectroscopic and microscopic techniques were used. The prepared PdRu@PVP nanomaterials with an average particle size of 3.82 ± 1.10 nm provided an 808.03 h^-1 turnover frequency (TOF) in the dehydrogenation of DMAB and yielded 100% of the cyclic product (Me₂NBH₂)₂ under mild conditions. Furthermore, the activities of catalysts were investigated theoretically using DFT-B3LYP calculations. The theoretical results based on density functional theory were in favorable agreement with the experimental data.

Composites of Palladium-Nickel Alloy Nanoparticles and Graphene Oxide for the Knoevenagel Condensation of Aldehydes with Malononitrile

Herein, we have described uniformly dispersed palladium-nickel nanoparticles furnished on graphene oxide (GO-supported PdNi nanoparticles) as a powerful heterogeneous nanocatalyst for the promotion of Knoevenagel reaction between malononitrile and aromatic aldehydes under mild reaction conditions. The successful characterization of PdNi nanoparticles on the GO surface was shown by X-ray diffraction, X-ray photoelectron spectroscopy, high-resolution transmission electron microscopy (HR-TEM), and TEM. GO-supported PdNi nanoparticles, which are used as highly efficient, stable, and durable catalysts, were used for the first time for the Knoevenagel condensation reaction. The data obtained here showed that the GO-supported PdNi nanocatalyst had a unique catalytic activity and demonstrated that it could be reused five times without a significant decrease in the catalytic performance. The use of this nanocatalyst results in a very short reaction time under mild reaction conditions, high recyclability, excellent catalytic activity, and a straightforward work-up procedure for Knoevenagel condensation of malononitrile and aromatic aldehydes.

Fe3O4@L-arginine as a Reusable Catalyst for the Synthesis of Polysubstituted 2-Pyrrolidinones

Background:

This research introduces an effective and green method for the synthesis of polysubstituted 2-pyrrolidinone derivatives as biologically-active heterocyclic compounds using multi- component reactions using Fe3O4@L-arginine as a reusable organocatalyst.

Material and Method:

The Fe3O4@L-arginine nanoparticles were prepared by a facile one-step approach and the structure elucidation of the magnetic nanocatalyst has been done using various spectroscopy techniques.

Results:

L-arginine-functionalized magnetite nanoparticles were obtained with particle sizes around 10 nm. Fe3O4@L-arginine exhibited strong catalytic activity to obtain some polysubstituted 2- pyrrolidinone.

Conclusion:

The considerable advantages of this research are short reaction times, excellent yields, simple workup procedure and reusability of the nanocatalyst which is in good agreement with green chemistry disciplines. The study on the reusability of the Fe3O4@L-arginine nanoparticles showed that the recovered catalyst could be reused six consecutive times.

Facilitating charge transfer via a giant magnetoresistance effect for high-efficiency photocatalytic hydrogen production

CoCu alloy magnetic unit was implanted in photocatalytic system to improve photoinduced charge separation efficiency by regulating electron transfer pathway via giant magnetoresistance (GMR) effect, achieving significantly H₂ production activity.

Sustainable Generation of Ni(OH)2 Nanoparticles for the Green Synthesis of 5-Substituted 1H-Tetrazoles: A Competent Turn on Fluorescence Sensing of H2O2

A mutually correlated green protocol has been devised that originates from a sustainable production of β-Ni(OH)₂ nanoparticles which is used for an efficient catalytic synthesis of versatile substituted tetrazoles, under mild reaction conditions in water via a simple, one-pot, eco-friendly method. The synthesis is followed by derivatization into a highly fluorescence active compound 9-(4-(5-(quinolin-2-yl)-1H-tetrazol-1-yl)phenyl)-9H-carbazole that can be used at tracer concentrations (0.1 μM) to detect as well as quantify hydrogen peroxide down to 2 μM concentration. The nanocatalyst was synthesized by a simple, proficient, and cost-effective methodology and characterized thoroughly by UV-vis absorption and Fourier transform infrared spectra, N₂ adsorption/desorption, high resolution transmission electron microscopy, powder X-ray diffraction pattern, field emission scanning electron microscopy, and thermogravimetric analysis. Broad substrate scope, easy handling, higher efficiency, low cost, and reusability of the catalyst are some of the important features of this heterogeneous catalytic system. The strong analytical performance of the resultant derivative in low-level quantification of potentially hazardous hydrogen peroxide is the key success of the overall green synthesis procedure reported here.

Investigation of the effect of pomegranate extract and monodisperse silver nanoparticle combination on MCF-7 cell line

In this study, we aimed to investigate whether the combination therapy of pomegranate extract and silver nanoparticle is effective on MCF-7 cell culture. The pomegranate extract was mixed and incubated with silver nitrate for the microwave assisted green synthesized of silver nanoparticle. Obtained nanoparticles were investigated using X-ray diffraction (XRD), Fourier Transform Infrared Spectroscopy (FTIR), UV-vis, Field Emission Scanning Electron Microscopy (FESEM), and Transmission Electron Microscopy (TEM) methods The spectroscopic and morphological studies of the monodisperse Ag NPs which have particle size of 15.4nm indicate the highly crystalline form, well dispersity, and colloidally stable NPs. After fully characterization of prepared nanoparticles, the effectiveness of Ag NPs was determined by evaluating cell viability, nuclear degradation and cell cycle parameters. The results obtained demonstrate that biosynthesized Ag NPs can inhibit the proliferation of human breast cancer cell line MCF-7 in the IC50 at a dose of 12.85μg/mL and inhibit the proliferation of Ag NPs against anti-growth arresting MCF-7 cell line. This case demonstrates that it may exert its proliferative effect by reducing DNA synthesis and apoptosis-inducing cell cycle stages.

Microwave assisted synthesis of novel tetrazole/sulfonamide derivatives based on octahydroacridine, xanthene and chromene skeletons as inhibitors of the carbonic anhydrases isoforms I, II, IV and VII

The synthesis of novel tetrazole/sulfonamide derivatives based on octahydroacridine, xanthene and chromene scaffold by using microwave (MW) assisted techniques is reported in this study. These synthesized hybrid compounds were assayed for the inhibition of carbonic anhydrase (CA, EC 4.2.1.1). The inhibitory activities were determined against three cytosolic human isoforms (hCA I, II and VII) and one membrane-associated (hCA IV) isoform. Some of the newly synthesized sulfonamides showed micromolar to nanomolar inhibitory activity against these enzymes.

One-pot synthesis of Hantzsch dihydropyridines using a highly efficient and stable PdRuNi@GO catalyst

The method for the synthesis of 1,4-dihydropyridine compounds in the presence of Pd–Ni–Ru@GO was developed, which is simple, effective and productive.

A comparative study between heterogeneous stannous chloride loaded silica nanoparticles and a homogeneous stannous chloride catalyst in the synthesis of 5-substituted 1H-tetrazole

Heterogeneous SnCl₂–nano-SiO₂efficiently catalyzed 5-substituted 1H-tetrazole synthesis with excellent yield. It is widely applicable on aliphatic, aromatic, heteroaromatic and sterically hindered nitriles with five times recyclability. ​

Carbon black hybrid material furnished monodisperse platinum nanoparticles as highly efficient and reusable electrocatalysts for formic acid electro-oxidation

Carbon black hybrid material supported monodisperse Pt NPs/TPr have been used as a novel catalyst for formic acid electro-oxidation reduction.

Self-assembly synthesis of reduced graphene oxide-supported platinum nanowire composites with enhanced electrocatalytic activity towards the hydrazine oxidation reaction

Pt-NWs-P can self-assemble on the GO@NH₂ surface. After NaBH₄ reduction, Pt-NWs/RGO show improved electrocatalytic activity for the hydrazine oxidation reaction.

Monodispersed palladium–cobalt alloy nanoparticles assembled on poly(N-vinyl-pyrrolidone) (PVP) as a highly effective catalyst for dimethylamine borane (DMAB) dehydrocoupling

Monodispersed PdCo@PVP NPs showed record catalytic activity, giving the best catalytic performance yet with a very high turnover frequency.

A rapid and novel method for the synthesis of 5-substituted 1H-tetrazole catalyzed by exceptional reusable monodisperse Pt NPs@AC under the microwave irradiation

Monodisperse Pt NPs@AC catalyst showed excellent yield, one of the shortest reaction time for the synthesis of 5-substituted 1H-tetrazoles under the microwave irradiation.