Soumen Payra

One-pot multicomponent synthesis of highly functionalized bio-active pyrano[2,3-c]pyrazole and benzylpyrazolyl coumarin derivatives using ZrO2 nanoparticles as a reusable catalyst

A facile one-pot multicomponent protocol for the synthesis of bio-active pyrano[2,3-c]pyrazole and benzylpyrazolyl coumarin derivatives has been demonstrated using ZrO2 nanoparticles as a catalyst at room temperature. The reactions are very fast and high-yielding. The catalytic activity and tetragonal plane of the ZrO2 nanoparticles remained unchanged after the 10th cycle.

On water synthesis of pyran–chromenes via a multicomponent reactions catalyzed by fluorescent t-ZrO2 nanoparticles

Here, we have demonstrated fluorescent tetragonal ZrO2 nanoparticle (t-ZrO2 NP) catalyzed green one-pot multicomponent protocol for the synthesis of diverse pyran-fused chromene analogues such as 2-aminochromene, dihydropyrano[3,2-c]chromene, and chromeno[4,3-b]chromene derivatives in water. The rate of the reactions and yields of the products increased significantly in water. In addition, t-ZrO2 NPs showed a higher reactivity than monoclinic ZrO2 NPs. The t-ZrO2 NPs were recycled and the gradual decrease in yield of the product using recycled catalyst could possibly be due to the decrease in Zr-content associated with a decrease in the oxygen vacancies which was evident from fluorescence and atomic absorption studies. However, the tetragonal phase of the catalyst remained intact even at the 10th cycle.

Nano-NiFe2O4 as an efficient catalyst for regio- and chemoselective transfer hydrogenation of olefins/alkynes and dehydrogenation of alcohols under Pd-/Ru-free conditions

Here, we have demonstrated the magnetic nano-NiFe2O4 catalyzed transfer hydrogenation of olefins/alkynes using isopropyl alcohol as a source of hydrogen under ligand/base/Pd-/Ru-metal-free conditions, and dehydrogenation of alcohols under oxidant-free conditions.

In silico binding affinity to cyclooxygenase-II and green synthesis of benzylpyrazolyl coumarin derivatives

Here, we have reported for the first time, in silico binding affinity prediction of benzylpyrazolyl coumarin scaffolds to cyclooxygenase-II (COX-II) enzyme and a green synthetic route to access these scaffolds using a neutral ionic liquid, [pmIm]Br as the reusable catalyst and reaction media under metal-free conditions. The integrated scaffolds, benzylpyrazolyl coumarins exhibited stronger binding affinity to COX-II inhibitor than their individual moieties, 3-benzyl coumarins and pyrazolones. Moreover, 4-((4-hydroxy-2-oxo-2H-chromen-3-yl)(4-nitrophenyl)methyl)-5-methyl-2-phenyl-1H-pyrazol-3(2H)-one (3c) has shown even better binding affinity than the marketed anti-inflammatory drug, celecoxib.

On-water magnetic NiFe2O4 nanoparticle-catalyzed Michael additions of active methylene compounds, aromatic/aliphatic amines, alcohols and thiols to conjugated alkenes

Here, we have demonstrated the Michael addition of active methylene compounds, aromatic/aliphatic amines, thiols and alcohols to conjugated alkenes using magnetic nano-NiFe2O4 as reusable catalyst in water. Nano-NiFe2O4 efficiently catalyzed the formation of C–C and C–X (X = N, S, O etc.) bond through 1,4-addition reactions.

Direct CuO nanoparticle-catalyzed synthesis of poly-substituted furans via oxidative C–H/C–H functionalization in aqueous medium

Here, we have reported synthesis of 3,4-dicarbonyl substituted poly-functionalized furan derivatives via direct functionalization of α,β-unsaturated carbonyl compounds through conjugate addition initiated domino reactions using CuO nanoparticles as a reusable catalyst in aqueous ethanol.

Synthesis of smart bimetallic nano-Cu/Ag@SiO2 for clean oxidation of alcohols

Here, we have demonstrated the synthesis and characterization of silica supported bimetallic copper/silver nanoparticles (Cu/Ag@SiO2 NPs) and their application in the clean oxidation of benzoins/benzyl alcohols in the presence of tert-butyl hydroperoxide as a mild oxidant. All the reactions were very fast (4 h) and high yielding (95–99%), and the Cu/Ag@SiO2 NPs were very stable under the reaction conditions. The catalyst was recovered simply by filtration and reused eight times without loss of its catalytic performance.

Fe–SBA-15 catalyzed synthesis of 2-alkoxyimidazo[1,2-a]pyridines and screening of their in silico selectivity and binding affinity to biological targets

Here, we have demonstrated regioselective three-component synthesis of 2-alkoxyimidazopyridines using mesoporous Fe–SBA-15 as the catalyst and screened their in silico selectivity and binding affinity to different biological targets viz. farnesyl diphosphate synthase, phosphodiesterase III, GABAa and chemokine receptor CXCR4 using molecular docking simulations. Fe–SBA-15 has been characterized by nitrogen absorption–desorption, powder XRD, SEM, TEM studies and atomic absorption spectroscopic analysis. Fe–SBA-15 was very efficient in synthesizing imidazopyridines. The binding affinity study revealed that the 2-butoxy-3-(4-methoxyphenyl)-7-methylH-imidazo[1,2-a] pyridine (4g) moiety has exhibited even better affinity in terms of MolDock, re-rank and steric scores than the marketed anti-inflammatory drug, olprinone.

In-water facile synthesis of poly-substituted 6-arylamino pyridines and 2-pyrrolidone derivatives using tetragonal nano-ZrO2 as reusable catalyst

Here, we report a facile synthetic protocol to access a series of ethyl 5-cyano-2-methyl-4-aryl-6-(arylamino)nicotinates and ethyl 4-hydroxy-2-(4-nitroaryl)-5-oxo-1-aryl-2,5-dihydro-1H-pyrrole-3-carboxylates using tetragonal nano-ZrO2 as reusable catalyst. It was observed that the ZrO2 nanoparticles were stable during reaction and apparently no leaching of Zr-content occurred when the catalyst was recycled eight times.

On Water Cu@g-C3N4 Catalyzed Synthesis of NH-1,2,3-Triazoles Via [2+3] Cycloadditions of Nitroolefins/Alkynes and Sodium Azide

Here, we have reported fabrication of graphitic polymeric C3N4 supported CuCl2 (Cu@g‐C3N4) and characterized by powder X‐ray diffraction, field emission scanning electron microscopy, high resolution transmission electron microscopy, X‐ray photoelectron spectroscopy studies. An efficient and regioselective protocol for the on water synthesis of 4‐aryl‐NH‐1,2,3‐triazole derivatives via 1,3‐diipolar cycloaddition reactions of nitroolefins/phenylacetylenes to sodium azide were demonstrated by using Cu@g‐C3N4 as robust and reusable catalyst.