A simple and straightforward strategy for expedient access to benzoxazoles using chemically engineered 2D magnetic graphene oxide nanosheets as an eco-compatible catalyst.

Two-dimensional (2D) graphene oxide nanosheets serve as an excellent support material for immobilizing metal complexes to deal with the drawbacks of homogeneous catalysis. In this work, we report a magnetically retrievable graphene oxide (MGO) based copper nanocatalytic system that has been efficiently exploited for obtaining a series of pharmaceutically and biologically active benzoxazole scaffolds. The nanocatalyst was designed by covalent immobilization of dehydroacetic acid (DHA) onto a magnetic amino-silanized graphene oxide nanosupport which was accompanied by its metallation with copper acetate.

Preparation and characterization of the -BN/FeO/APTES-AMF/Cu nanocomposite as a new and efficient catalyst for the one-pot three-component synthesis of 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4-chromene-3-carbonitriles.

The intriguing features of surface-engineered hexagonal two-dimensional boron nitride (-BN) nanostructures have captivated the immense interest of researchers working in the arena of materials science. Inspired by striking attributes exhibited by -BN nanosheets as the support material, we devoted our efforts towards synthesizing a novel magnetically retrievable -BN/FeO/APTES-AMF/Cu catalytic system, which was then comprehensively characterized using various techniques including SEM, TEM, EDX, SEM-based elemental mapping, ED-XRF, AAS, XRD, FT-IR, VSM, XPS, TGA, and BET. Further, the catalytic potential of -BN/FeO/APTES-AMF/Cu nanocomposites was investigated in the one-pot multicomponent coupling reaction to gain access to a library of biologically active 2-amino-4-aryl(or heteroaryl)-7,7-dimethyl-5-oxo-5,6,7,8-tetrahydro-4-chromene-3-carbonitriles under ambient conditions.

An Earth-abundant cobalt based photocatalyst: visible light induced direct (het)arene C-H arylation and CO capture.

In this work, we have reported a noble metal free heterogeneous photocatalyst to carry out direct (het)arene C-H arylation and solvent-free CO capture single-electron transfer processes at room temperature and under pressure. The catalytic system comprises a cobalt(III) complex grafted over the silica coated magnetic support for the efficient recovery of the photocatalytic moiety without hampering its light-harvesting capability. The novel Earth-abundant cobalt(III) based photocatalyst possesses various fascinating properties such as high surface area to volume ratios, large pore volume, crystalline behaviour, high metal loading, excellent stability and reusability.

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.

Silver nanomaterials: synthesis and (electro/photo) catalytic applications.

In view of their unique characteristics and properties, silver nanomaterials (Ag NMs) have been used not only in the field of nanomedicine but also for diverse advanced catalytic technologies. In this comprehensive review, light is shed on general synthetic approaches encompassing chemical reduction, sonochemical, microwave, and thermal treatment among the preparative methods for the syntheses of Ag-based NMs and their catalytic applications. Additionally, some of the latest innovative approaches such as continuous flow integrated with MW and other benign approaches have been emphasized that ultimately pave the way for sustainability.

Aldehydes: magnificent acyl equivalents for direct acylation.

From the viewpoint of meeting the current green chemistry challenges in chemical synthesis, there is a need to disseminate how the cocktail of acylation and activation can play a pivotal role in affording bioactive acylated products comprising substituted ketone motifs in fewer reaction steps, with higher atom-economy and improved selectivity. In recent years, a significant number of articles employing the title compounds "aldehydes" as magnificent acylation surrogates which are less toxic and widely applicable have been published. This review sheds light on the compounds use for selective acylation of arene, heteroarene and alkyl (sp3, sp2 and sp) C-H bonds by proficient utilization of the C-H activation strategy.

Harnessing the Untapped Catalytic Potential of a CoFeO/Mn-BDC Hybrid MOF Composite for Obtaining a Multitude of 1,4-Disubstituted 1,2,3-Triazole Scaffolds.

Metal-organic frameworks derived nanostructures with extraordinary variability, and many unprecedented properties have recently emerged as promising catalytic materials to address the challenges in the field of modern organic synthesis. In this contribution, the present work reports the fabrication of an intricately designed magnetic MOF composite based on Mn-BDC (manganese benzene-1,4-dicarboxylate/manganese terephthalate) microflakes via a facile and benign in situ solvothermal approach. Structural information about the as-synthesized hybrid composite has been obtained with characterization techniques such as TEM, SEM, XRD, FT-IR, AAS, EDX, ED-XRF, and VSM analysis.

Triptycene-Based and Schiff-Base-Linked Porous Networks: Efficient Gas Uptake, High CO/N Selectivity, and Excellent Antiproliferative Activity.

A set of unique triptycene-based and organic Schiff-base-linked polymers (s) are conveniently synthesized in which triptycene motifs are connected with 1,3,5-triformylphloroglucinol units via Schiff-base linkages. s are amorphous, thermally stable with a reasonable surface area (SA up to 649 m/g), and have abundant nanopores (pore size < 100 nm). s are good sorbents for small gas molecules (such as CO, H, and N) and they can selectively capture CO over N.

Design and Exploration of Catalytic Activity of Two-Dimensional Surface-Engineered Graphene Oxide Nanosheets in the Transannulation of N-Heterocyclic Aldehydes or Ketones with Alkylamines.

In this work, pharmaceutically and biologically important compounds containing imidazo[1,5-]pyridine nuclei have been synthesized via transannulation of N-heteroaryl aldehydes or ketones with alkylamines using a graphene oxide-supported copper catalyst. The nanocatalyst was fabricated by the covalent immobilization of 4-aminoantipyrine onto an amine-functionalized graphene oxide nanosupport followed by its metallation with copper acetate. Structural analysis by transmission electron microscopy, scanning electron microscopy, X-ray photoelectron spectroscopy (XPS), and X-ray diffraction demonstrates that the two-dimensional sheet-like structure of graphene oxide is maintained even after the chemical modifications, whereas XPS revealed crucial information related to elemental composition and surface electronic states of the metal present in the catalyst.

Expanding the Horizon of Multicomponent Oxidative Coupling Reaction via the Design of a Unique, 3D Copper Isophthalate MOF-Based Catalyst Decorated with Mixed Spinel CoFeO Nanoparticles.

This work discloses the first ever magnetically retrievable copper isophthalate-based metal-organic framework (MOF) decorated with surface-modified cobalt ferrite (CoFeO) nanoparticles that have been utilized as catalytic reactors for obtaining a relatively large number of biologically active benzimidazole scaffolds. A facile one-pot solvothermal approach was employed for obtaining spherical and monodisperse CoFeO nanoparticles, which were subsequently modified using suitable protecting and functionalizing agents. Finally, these functionalized magnetic nanoparticles were anchored onto the three-dimensional copper isophthalate MOF via a covalent immobilization methodology.

Fabrication of Core-Shell-Structured Organic-Inorganic Hybrid Nanocatalyst for the Expedient Synthesis of Polysubstituted Oxazoles via Tandem Oxidative Cyclization Pathway.

The quest for designing efficient heterogeneous catalytic systems for tandem oxidative cyclization reactions has provided a great impetus to research efforts, as it enables the step-economic construction of complex heterocyclic molecules as well as confers the benefits of a facile catalytic recovery. In the present study, we disclose a new core-shell-structured organic-inorganic hybrid copper nanocatalyst fabricated via the covalent grafting of 2,2'-dipyridyl ketone ligand on amine-functionalized silica-encapsulated magnetite nanoparticles, followed by its metallation with cupric acetate for the tandem oxidative cyclization of amines and β-ketoesters, leading to the production of biologically active polysubstituted oxazole moieties. This programmed catalytic protocol proceeds via the formation of intermolecular C-C and C-N bonds by single-step synthesis and accommodates a broad combination of reaction coupling partners.

Quinoline-2-carboimine copper complex immobilized on amine functionalized silica coated magnetite nanoparticles: a novel and magnetically retrievable catalyst for the synthesis of carbamates via C-H activation of formamides.

In the present study, we report the synthesis of a highly efficient and magnetically retrievable catalytic system (Cu-2QC@Am-SiO2@Fe3O4) through the covalent immobilization of quinoline-2-carboxaldehyde (2QC) on an amine functionalized silica coated ferrite nanosupport followed by metallation with copper acetate. The structure of the organic-inorganic hybrid nanomaterial has been confirmed using various physicochemical techniques such as Powder X-Ray Diffraction (XRD), Fourier Transform Infrared Spectroscopy (FT-IR), Scanning Electron Microscopy (SEM), Transmission Electron Microscopy (TEM), Energy Dispersive X-Ray Spectroscopy (EDS), Energy Dispersive X-Ray Fluorescence Spectroscopy (ED-XRF), Atomic Absorption Spectroscopy (AAS), Inductively Coupled Plasma Spectroscopy (ICP) and Vibrating Sample Magnetometry (VSM). The resulting nanocatalyst exhibits a remarkable catalytic efficacy in the synthesis of industrially and pharmaceutically significant carbamates via the C-H activation of formamides under solvent free conditions.

New water resistant biomaterial biocide film based on guar gum.

This work was aimed to develop water resistant biocide film from renewable resources for applications in food and water technology. Guar gum, a polymeric galactomannan, was intrinsically modified to a new guar gum benzamide. Benzoylation was carried out by benzoyl chloride reaction in water medium and a propyl amine spacer was used to impart a high degree of hydrophobicity.