Propargylamine and its derivatives are important skeletal structure for synthesis of many nitrogen containing active biological and pharmaceutical compounds. They are classically prepared from aldehyde, amine and alkyne (A3 coupling) which proved to be an exciting method since water is the only byproduct with the desired compound. Three component coupling strategies are very attractive research domain in organic chemistry during the past two decades for the synthesis of highly functionalized organic molecules. Molecular diversity in three component reactions ends up with several methods for drug discovery process towards the synthesis of structurally tailored heterocyclic compounds. These one pot transformation processes do involve simultaneous addition of reactants, reagents and catalyst. The reactions are generally carried out by employing several transition metal catalysts. Nanoparticles have shown their potential as catalysts in several fields of chemical research in modern era. Now, they have taken entry in multicomponent reaction system for playing the role of a catalyst. This review highlights a library of metal nanoparticles which have been used in recent years for synthesis of propargylamine and its derivatives via A3 coupling reactions.
Phenolic Schiff bases derived from o-, m-, and p-hydroxybenzaldehydes and 4, 4Ј-diaminodiphenyl ether were subjected to polycondensation reaction with formaldehyde. The resins were found to form polychelates readily with several metal ions. The materials were characterized by elemental analysis, GPC, IR, UV-Vis, 1 H-NMR, XRD, and thermal analyses like TG, DTG, and DSC studies. The 1 H-NMR spectra of the resins provided evidence of polycondensation with well-defined peaks for bridging methylene and terminal methylol functions. The metal-ligand bonds were registered in the IR spectra of the polychelates. The thermal analysis data provided the kinetic parameters like activation energy, frequency factor, and entropy changes associated with the thermal decomposition. These data indicated the resins to be more stable than the polychelates. The DSC and XRD data indicated that the incorporation of metal ions significantly enhanced the crystallinity of the polymers. The resins could adsorb several metal ions from dilute aqueous solutions. Adsorption characteristics of the resins towards Cu(II) and Ni(II) were studied spectrophotometrically both in competitive and noncompetitive conditions. The effects of pH, contact time, quantity of the sorbent, concentration of the metal ions in a suitable buffer medium were studied. The resins were found to be selective for Cu(II) leading to its separation from a mixture of Cu(II) and Ni(II).
Abstract. The advantages of using mesh free simulation methods such as SPH are demonstrated for elastic and elastoplastic deformation and for brittle fracture. The accuracy of SPH for deformation problems is demonstrated using a uniaxial test. An industrial example of forging is shown.
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