Synthetic Organic Transformations of Transition‐Metal Nanoparticles as Propitious Catalysts: A Review

Abstract

Nanotechnology has produced compelling evidences in the field of catalysis, construction, electronics, energy, food, imaging, medical, packaging, pharmaceutical sectors and in water treatment. Nanoparticles of transition metal origin are enticing in catalytic applications due to their lowlying empty orbitals for bonding and can offer a distinct ability to expand the coordination sphere. This coupled with ease of synthesis, recyclability and occurrence in abundance staples them as unique industrial materials. Transition metals such as Gold, Palladium, Silver, Copper, Iron, Ruthenium, Rhodium and hetero-bimetallic versions have been in demand for various organic transformations. The sharp rise in number of literature reports justifies the stand in catalytic property. A unique ability to form Covalent and/or Van der Waals interactions with solid supports and activate the substrates through close functional group interactions renders them as effective entities in organic transformations. In this review, we present the new developments in this niche in the past five years with a retreat on the mechanistic aspects along with parameters involved in nanoparticle characterizations through advances in spectroscopy.

Expeditious entry into carbocyclic and heterocyclic spirooxindoles

“…Earlier, we reported transition-metal nanometal particle mediated diastereoselective reactions in general. 42 We here provide a glimpse into the advances in the synthesis, characterization, and utility of nanometal particles in diastereoselective cascade and multicomponent reactions leading to oxindole spirocycles. By and large, the multicomponent reactions of isatin, malononitrile and activated carbonyl compounds are covered.…”

Solvent‐Free Synthesis of Pyrroles: An Overview

“…The literature reports explicitly indicate the catalytic property of metals in various organic transformations [70] . Transition metals as well as rare earth metals are explored for their catalytic activity in solvent‐free protocols [71] .…”

“…The literature reports explicitly indicate the catalytic property of metals in various organic transformations. [70] Transition metals as well as rare earth metals are explored for their catalytic activity in solvent-free protocols. [71] Solvent-free synthetic methodology for pyrroles has utilized a wide range of metals in the form of nanoparticles, magnetic particles, metal triflates [72] as well as metal ion incorporated heterogeneous catalysts.…”

Novel self‐doped Pd/Cu bimetals in CMC/PANI composites: Efficient heterogeneous catalyst for cooperative Sonogashira and Sonogashira‐cyclization tandem reactions

“…Therefore, a broad range of solid matrix has been adopted for tethering bimetallic catalysts. [30][31][32][33][34] Among these materials, sodium carboxymethylcellulose (CMC-Na) is a linear cellulose derivative consisting of multiple carboxylic (-CH 2 COO À ) and hydroxyl (-OH) functional groups with outstanding features such as low-cost, high-water solubility, nontoxicity, biocompatibility, and excellent coordination with various transition metal ions. 35,36 Furthermore, polyaniline (PANI) possesses a superior affinity for metal ions, attributed to the lone electron pair on nitrogen atoms and highly delocalized π-π conjugated systems, making it an effective supportive material for the fabrication of PANI-based metal catalysts.…”