The azide-alkyne cycloaddition (Huisgen reaction) is one of the most powerful and widely used copper-mediated reactions. In many such reactions, use of metal or metal oxide nanoparticles as the ...catalyst is more appealing because of the increased catalytic activity attributed to the large surface to volume ratio. However, the nano/micro particles are synthesized often in the presence of long chain organic molecules as capping or stabilizing agents. These organic molecules cover the active centers and restrict or reduce their catalytic activity. Therefore, we have synthesized the copper sulfide (sf-CuS) nano/micro particles without having organic surfactant molecules as the capping agent. These particles with a flower-like architecture (micro flowers, mf) were obtained readily under the supersaturated condition at room temperature. In these particles, the surface was freely available for adsorption and desorption reactions. When utilized as a catalyst in multicomponent cycloaddition reactions, the sf-CuS mf exhibited excellent catalytic activity compared with some other nanoparticles with surfactants. This sf-CuS mf catalyzed the one-pot synthesis of 1,2,3-triazole and β-hydroxy-1,2,3-triazole effectively from a variety of benzyl bromide derivatives epoxides respectively. Both these reactions proceeded in the presence of azide and phenylacetylene in the water at room temperature. The catalyst was reusable, and there was no catalyst leaching observed during reactions. Synthesis of β-hydroxy triazoles and 1,2,3-triazoles under exceptionally mild conditions with high yields proved the sf-CuS mf as the catalyst as a robust and recyclable catalyst.
The copper sulfide (sf-CuS) micro flowers (mf) without having any organic surfactant molecules as the capping agent have been synthesized. These sf-CuS mf exhibited excellent catalytic activity in multicomponent cycloaddition reactions compared with some other nanoparticles with surfactants. Synthesis of β-hydroxy triazoles and 1,2,3-triazoles under exceptionally mild conditions with high yields proved sf-CuS mf as a robust and recyclable catalyst. Display omitted
•The catalysis by nano/micro particles is dependent on the adsorption of molecules on the surface of the catalyst. Therefore, it is essential to study the impact of organic surfactant-free nano/micro particles in heterogeneous catalysis.•The azide-alkyne cycloaddition (Huisgen reaction) is one of the most powerful and widely applied copper-mediated reactions. Organic surfactant-free CuS nano/micro particles have been found to effectively catalyze the multicomponent, one-pot synthesis of 1, 2, 3-triazole from a variety of benzyl bromide derivatives and β-hydroxy-1, 2, 3-triazole through the ring opening of a variety of epoxides.•The surfactant-free copper sulfide micro flowers (sf-CuS mf) exhibited excellent catalytic activity compared with some other nanoparticles with the surfactants. Thus the synthesis of β-hydroxy triazoles and 1,2,3-triazoles was achieved under exceptionally mild conditions with high yields.•The catalyst described here, i.e., sf-CuS mf is a robust and reusable catalyst system. And there was no leaching of catalyst observed during reactions, which is a significant finding for the nanomaterial-based catalysis.•The synthesis described here was performed in water at room temperature, and so it was safer, greener, and uses inexpensive materials.
The present study deals with a highly efficient and regioselective synthesis of 7-aryl-5-methyl- and 5-aryl-7-trifluoromethyl-2-amino-3-(4′-arylazo)-pyrazolo1,5-
a
pyrimidines
via
multicomponent ...reaction of hydrazine hydrate, 2-(arylhydrazono)malononitrile and
β
-diketones in presence of
p
-toluenesulphonic acid under solvent-free condition. The structure of the isolated products was established on the basis of NMR (
1
H,
13
C, and
19
F) and IR spectral data. The scope of the reaction was studied using various
β
-diketones
viz.,
aliphatic, aromatic, heteroaromatic, and trifluoromethyl-
β
-diketones. The protocol has several advantages, such as mild conditions, atom economy, practical simplicity, shorter reaction times, and avoidance of multi-step procedures. Seventeen diversely substituted pyrazolo1,5-
a
pyrimidines were screened against two breast cancer cell lines, named MCF-7 and BT474, and two leukemia cell lines, named NALM-6 and SB-ALL, using the MTT cytotoxicity assay. Preliminary results reveal that compound 2-amino-5-(4-bromophenyl)-3-(4-methoxyphenylazo)-7-(trifluoromethyl)pyrazolo1,5-
a
pyrimidine was identified as the most effective compound against all the four cancer cell lines with 65-49% cell survival.
Graphical abstract
An efficient regioselective synthesis of 7-aryl-5-methyl- and 5-aryl-7-trifluoromethyl-2-amino-3-(4′-arylazo)-pyrazolo1,5-
a
pyrimidines is developed using solvent-free sequential multicomponent reaction of hydrazine hydrate, 2-(arylhydrazono)malononitrile with unsymmetrical
β
-diketones.
Multicomponent reactions are crucial for operating organic synthesis. In today's world, chemists concentrate on greener methodologies that cater to rising environmental concerns. Most conventional ...organic solvents are harsh on the environment, which can be addressed by environmentally and pocket‐friendly Deep eutectic solvents (DES). Organic synthesis via MCR in the presence of DES has resulted in the blend of green methodology and green solvent for organic transformations. Forasmuch as addressing the environmental concerns and developing higher heterocycles, our review focuses on the literature published on the DES‐mediated Multicomponent synthesis of N‐Heterocyclic compounds.
Multicomponent reactions (MCRs) are important in organic synthesis, and there is a focus on using greener methodologies and solvents to address environmental concerns. Deep eutectic solvents (DES) are an example of a greener solvent that can be used in MCRs to synthesize heterocyclic compounds while also addressing environmental concerns. The review focuses on literature on the use of DES in MCRs for the synthesis of N‐heterocyclic compounds.
Carbon dots (CDs), defined by their size of less than 10 nm, are a class of photoluminescent (PL) and electrochemiluminescent (ECL) nanomaterials that include a variety of carbon‐based nanoparticles. ...However, the control of their properties, especially ECL, remains elusive and afflicted by a series of problems. Here, the authors report CDs that display ECL in water via coreactant ECL, which is the dominant mechanism in biosensing applications. They take advantage of a multicomponent bottom‐up approach for preparing and studying the luminescence properties of CDs doped with a dye acting as PL and ECL probe. The dependence of luminescence properties on the surface chemistry is further reported, by investigating the PL and ECL response of CDs with surfaces rich in primary, methylated, or propylated amino groups. While precursors that contribute to the core characterize the PL emission, the surface states influence the efficiency of the excitation‐dependent PL emission. The ECL emission is influenced by surface states from the organic shell, but states of the core strongly interact with the surface, influencing the ECL efficiency. These findings offer a framework of pre‐ and post‐synthetic design strategies to improve ECL emission properties, opening new opportunities for exploring biosensing applications of CDs.
Pre‐ and post‐synthetic strategies enhance the electrochemiluminescence (ECL) of carbon dots (CDs). By using a fluorophore and ECL emitter in the bottom‐up synthesis, the major contribution of the surface emitting states to the ECL emission and the role from the states of the core are revealed. These findings have implications for advancing the ECL applications of CDs.
A multicomponent strategy was applied to the synthesis of chiral bidentate unsaturated hydroxyalkyl‐ and carboxyalkyl‐N‐heterocyclic carbene (NHC) precursors. The newly developed low‐cost chiral ...ligands derived from amino alcohols and amino acids were evaluated in copper‐catalyzed asymmetric conjugated addition and asymmetric allylic alkylation, which afforded the desired tertiary and quaternary carbon stereocenters with excellent regio‐ and enantioselectivities (up to 99:1 e.r.).
Bifunctional ligands: A multicomponent strategy was applied to the synthesis of chiral bidentate unsaturated hydroxyalkyl‐ and carboxyalkyl‐N‐heterocyclic carbene (NHC) precursors. The newly developed low‐cost chiral bifunctional ligands were evaluated in copper‐catalyzed asymmetric conjugated addition (ACA) and asymmetric allylic alkylation (AAA; see scheme).
An efficient synthetic methodology for the preparation of 3-amino 1,5-dihydro-2H-pyrrol-2-ones through a multicomponent reaction of amines, aldehydes, and pyruvate derivatives is reported. In ...addition, the densely substituted lactam substrates show in vitro cytotoxicity, inhibiting the growth of carcinoma human tumor cell lines HEK293 (human embryonic kidney), MCF7 (human breast adenocarcinoma), HTB81 (human prostate carcinoma), HeLa (human epithelioid cervix carcinoma), RKO (human colon epithelial carcinoma), SKOV3 (human ovarian carcinoma), and A549 (carcinomic human alveolar basal epithelial cell). Given the possibilities in the diversity of the substituents that offer the multicomponent synthetic methodology, an extensive structure-activity profile is presented. In addition, both enantiomers of phosphonate-derived γ-lactam have been synthesized and isolated and a study of the cytotoxic activity of the racemic substrate vs. its two enantiomers is also presented. Cell morphology analysis and flow cytometry assays indicate that the main pathway by which our compounds induce cytotoxicity is based on the activation of the intracellular apoptotic mechanism.
Display omitted
•PET and limestone can be easily converted to carbon-based catalysts by heating.•Polluting plastic residues are used for production of CaO supported on porous carbons.•PET/CAL ...efficiently catalyzes synthesis 2-amino-4H-chromenes under mild conditions.•The reaction is strongly favored in the presence of the CaO-containing catalysts.
Novel series of calcium oxide (calcium hydroxide)/carbon composites applied to the green and efficient synthesis of 2-amino-4H-chromenes, from salicylaldehydes and ethyl cyanoacetate, under mild and free-solvent conditions, is herein reported for the first time. These basic hybrid materials are easily prepared by direct thermal pyrolysis of limestone and PET. Different Ca-phases, CaO or Ca(OH)2, were independently detected, since CaO/carbon composites initially formed can be easily hydrated, under atmospheric conditions, but also dehydrated by re-calcination. CaO-containing samples present enhanced catalytic performance, the observed reactivity being attributed to the catalyst basicity.
The reaction under study catalyzed by CaO probably occurs by cascade reactions through aldolization – heterocyclization – dehydration – Michael addition sequence, strongly favored by the presence of the truly active phase, CaO, as experimental and theoretical demonstrated.
The methodology herein reported can be framed in circular economy domain opening the possibility of synthetizing valuable compounds from carbon-based catalysts prepared by using plastic residues as PET source.
A highly efficient and catalyst-free green synthetic protocol is developed for the synthesis of two series of poly-functionalized pyran derivatives via the one-pot reaction of aromatic aldehydes, ...malononitrile, and either dimedone or 1,3-dimethyl barbituric acid with EtOH: H
2
O (1:1 v/v) as solvent under ultrasound irradiation. Excellent yields (90-99%) of desired pyran derivatives were obtained for rapid reaction time 5 min. The structural features of the synthesized compounds were fully characterized by spectroscopic techniques (IR, HRMS
1
H, and
13
C NMR). A simple workup, clean reaction profile, short reaction times, excellent yields, 95% atom economy, and 100% carbon efficiency are the benefits of the proposed protocol. In addition, the circumvention of the chromatographic separations is the further advantage of the procedure.
Cathepsin B represents a group of lysosomal-encapsulated cellular cysteine proteases, whose upregulation is the critical risk factor for cancer progression and in the regulation of degenerative ...processes like apoptosis. Therefore, cysteine cathepsins are used as effective biomarkers for cancers and other neurodegenerative disorders and have become specific targets in drug designing. To diversify the pharmacological potential of aurones, a total of eighteen novel 1,2,3-triazole decorated aurone hybrids were synthesized in very good yields, utilizing click chemistry and an ultrasound-assisted one-pot, multicomponent and greener protocol, straight from hydroxy-substituted aurones. These hybrids have been evaluated as useful cathepsin B inhibitors and further explored their in-vitro study over AGS cell line using MTT assay. The in-vitro cathepsin B inhibitory potential of the synthesized hybrids revealed that the hybrid 3p possesses a very significant inhibition (% inhibition = 85.02) at the concentration of 10−6 M compared to the standard aspirin (% inhibition = 48.21 at 10−7 M) and curcumin (% inhibition = 57.72 at 10−7 M), which further supported by the in-silico studies. In addition to this, the cytotoxic assay of the hybrids showed that the hybrids 3d (IC50 = 24 μM), 3i (IC50 ≈ 24 μM), and 3m (IC50 = 26 μM) exhibit comparable anti-tumor activity against AGS cell line than the standard, oxaliplatin (IC50 = 29 μM). The results suggested that the reported novel aurone-1,2,3-triazole hybrids are a promising candidate for the development of new cathepsin B inhibitors as well as anti-cancer leads.
Display omitted
•US-promoted aqueous media domino synthesis of eighteen novel 1,2,3-triazole incorporated aurone hybrids.•Hybrids 3p displayed good inhibition towards cathepsin B with % inhibition of 85.02% at micromolar range.•In-silico drug modeling studies supports the in-vitro cathepsin B inhibitory evaluation.•Hybrids 3d(IC50=24 μM) and 3i(IC50=24 μM) exhibited significant activity against AGS cell line, compared to the standard Oxaliplatin (29 μM).
PDF
