Nanotechnology is the creation, manipulation and use of materials at the nanometre size scale (1 to 100 nm). At this size scale there are significant differences in many material properties that are normally not seen in the same materials at larger scales. Although nanoscale materials can be produced using a variety of traditional physical and chemical processes, it is now possible to biologically synthesize materials via environment-friendly green chemistry based techniques. In recent years, the convergence between nanotechnology and biology has created the new field of nanobiotechnology that incorporates the use of biological entities such as actinomycetes algae, bacteria, fungi, viruses, yeasts, and plants in a number of biochemical and biophysical processes. The biological synthesis via nanobiotechnology processes have a significant potential to boost nanoparticles production without the use of harsh, toxic, and expensive chemicals commonly used in conventional physical and chemical processes. The aim of this review is to provide an overview of recent trends in synthesizing nanoparticles via biological entities and their potential applications.

/pdf/green-synthesis-of-metallic-nanoparticles-via-biological-2qqcskkgq6.pdf

Green Synthesis of Metallic Nanoparticles via Biological Entities

Understanding active species in catalytic transformations: From molecular catalysis to nanoparticles, leaching, “Cocktails” of catalysts and dynamic systems

During this study, we report the green synthesis of palladium nanoparticles using Hippophae rhamnoides Linn leaf extract and their application as heterogeneous catalysts for the Suzuki–Miyaura coupling in water. The synthesized nanoparticles are characterized by XRD, SEM, TEM and UV–vis techniques. This method has the advantages of high yields, simple methodology, and elimination of ligand, organic solvent and homogeneous catalysts and easy work-up. Furthermore, the catalyst exhibits high catalytic activity, superior cycling stability and excellent substrate applicability.

Green synthesis of palladium nanoparticles using Hippophae rhamnoides Linn leaf extract and their catalytic activity for the Suzuki–Miyaura coupling in water

We report a one step and environment-friendly synthesis of cellulose nanocrystal (CN)-supported palladium nanoparticles (Pd NPs) without employing any other reductants, capping or dispersing agents. CNs played a dual role as a supporting matrix and a reductant and they were used to obtain stable dispersions of Pd NPs. The obtained hybrid material exhibited much higher activities than the unsupported and other polymer-supported Pd NPs in the catalyzed reduction of methylene blue and 4-nitrophenol. The approach presented in this paper promotes the use of renewable natural resources to prepare a variety of hybrid inorganic–organic materials for the purpose of catalysis, sensors, and other potential applications.

A novel reagentless approach for synthesizing cellulose nanocrystal-supported palladium nanoparticles with enhanced catalytic performance

This work reports on the green synthesis of Pd/Fe 3 O 4 nanoparticles using Euphorbia condylocarpa M. bieb root extract as reducing agents and stabilizers and their catalytic applications in ligand- and copper-free Sonogashira and Suzuki coupling reactions. This method has such advantages as high yields, simple methodology and easy work up. In addition, the catalyst can be recovered by using a magnet and reused several times without significant loss of its catalytic activity. The catalyst was characterized using UV–vis, powder XRD, SEM and EDS techniques.

Green synthesis of Pd/Fe3O4 nanoparticles using Euphorbia condylocarpa M. bieb root extract and their catalytic applications as magnetically recoverable and stable recyclable catalysts for the phosphine-free Sonogashira and Suzuki coupling reactions

Palladium nanoparticles catalyzed Suzuki cross-coupling reactions in ambient conditions

Palladium nanoparticles (PdNPs) were used as a catalyst for the one-pot synthesis of a variety of benzofurans by Sonogashira cross-coupling reactions under ambient conditions. The catalyst could be recycled without significant loss in its activity.

/pdf/palladium-nanoparticles-catalyzed-synthesis-of-benzofurans-3ymgdz5vub.pdf

Palladium Nanoparticles Catalyzed Synthesis of Benzofurans by a Domino Approach

Palladium nanoparticles catalyzed Sonogashira reactions for the one-pot synthesis of symmetrical and unsymmetrical diarylacetylenes

We developed an iodine-mediated cascade strategy to synthesize amino pyrazole thioether derivatives (11) in the absence of metals as well as solvents. The present approach provides amino pyrazole thioethers in a highly selective manner without the formation of diaryl sulfide and sulfenyl-enaminonitrile with broad substrate scope. The reactivity of nine sulfenylation sources and synthetic applications of the synthesized compounds have been demonstrated. Thus, the overall iodine-mediated multicomponent reaction (MCR) is more economically feasible, efficient, and environmentally benign.

Metal- and Solvent-Free Cascade Reaction for the Synthesis of Amino Pyrazole Thioether Derivatives.

A facile one-pot synthesis of mono(hpp)- or di(hpp)-substituted N -heterocyclic ligands from halogenated N -heterocycles and 1,3,4,6,7,8-hexahydro-2 H -pyrimido[1,2- a ]pyrimidine (H-hpp) is presented. N , N -Bidentate and N , N , N -tridentate ligands incorporating electron-donating and electron-withdrawing substituents can also be readily synthesized using this method.

Pavan Kumar Mandali

Papers

Palladium nanoparticles catalyzed Suzuki cross-coupling reactions in ambient conditions

Palladium Nanoparticles Catalyzed Synthesis of Benzofurans by a Domino Approach

Palladium nanoparticles catalyzed Sonogashira reactions for the one-pot synthesis of symmetrical and unsymmetrical diarylacetylenes

Metal- and Solvent-Free Cascade Reaction for the Synthesis of Amino Pyrazole Thioether Derivatives.

A Facile Route to Substituted Bidentate and Tridentate Ligands Capable of Forming Six-membered Chelate Rings with Transition-Metal Ions