Ionic Liquids Immobilized Synthesis of New Xanthenes Derivatives and their Antiproliferative, Molecular Docking, and Morphological Studies

BACKGROUND

Xanthenes and benzoxanthenesare are highly valuable compounds in organic chemistry and medicinal chemistry. Xanthene derivatives were found to have many applications in medicinal chemistry.

OBJECTIVE

This work aims to explore the synthesis of xanthene derivatives with various substituents and find the possibility of their uses as anticancer agents.

METHOD

The basic starting compound through this work was the 2,3-dihydro-1H-xanthen-1-one (3), which was synthesized from the reaction of cyclohexan-1,3-dione and 2-hydroxybenzaldehyde. Compound 3 synthesized new thiophene, pyrimidine, isoxazole, and thiazole derivatives based on the xanthenes nucleus. Fused xanthene derivatives were obtained through further heterocyclization reactions. Multicomponent reactions expressed in this work were carried out in the presence of solvent catalyzed by Et3N and in solvent-free ionic liquid immobilized catalyst.

RESULTS

Cytotoxicity for the newly synthesized compounds toward cancer cell lines was measured, and the results revealed that many compounds exhibited high inhibitions.

CONCLUSION

The antiproliferative activity of the synthesized compounds was studied on six selected cancer cell lines. The nature of the heterocyclic ring and the variations of substituted groups showed a high effect through the inhibitions of the tested compound.

Multicomponent Synthesis of 4-Aryl-4,9-dihydro-1H-pyrazolo[3,4-b]quinolines Using L-Proline as a Catalyst-Does It Really Proceed?

Looking for effective synthetic methods for 1H-pyrazolo[3,4-b]quinolines preparation, we came across a procedure where, in a three-component reaction catalysed by L-proline, 4-aryl-4,9-dihydro-1H-pyrazolo[3,4-b]quinolines are formed. These compounds can be easily oxidised to a fully aromatic system, which gives hope for a synthetic method that could replace, e.g., Friedländer condensation, often used for this purpose, even though severely limited by the availability of suitable substrates. However, after careful repetition of the procedures described in the publication, it turned out that the compounds described therein do not form at all. The actual compounds turned out to be 4,4-(phenyl-methylene)-bis-(3-methyl-1-phenylpyrazol-5-oles). Therefore, 4-Aryl-4,9-dihydro-1H-pyrazolo[3,4-b]quinolines were prepared by another method and used as standards to compare the products formed in the original procedure.

Recent Developments in Multi-component Synthesis of Lawsone Derivatives

BACKGROUND

2-Hydroxy-1,4-Naphthoquinone (HNQ; Lawsone) is one of the most useful and the simplest naturally occurring naphthoquinones and has stimulated a resurgence of interest in the past decades due to a wide range of pharmacological activities.

INTRODUCTION AND METHODS

This activity has led to the unusually large emphasis being placed on the design of more efficient multi-component reactions (MCRs) in the synthesis of bioactive lawsone derivatives.

RESULTS AND CONCLUSION

This review highlights the recent developments in multi-component synthesis of biologically relevant naphthoquinone linked and fused heterocyclic derivatives carried out from 2015 till now.

Novel 3-phenyl-1- (alkylphenyl)-9-oxa-4-azaphenanthren-10-ones as inhibitors of some enzymes: synthesis, characterization, biological evaluation and molecular docking studies

A series of novel 3-phenyl-1-(alkylphenyl)-9-oxa-4-azaphenanthren-10-ones and (E)-1-phenyl-3-(aryl)prop-2-en-1-ones were synthesized and characterized by IR, 1H NMR, 13C spectroscopy and elemental analysis. The synthesized Compounds 5a-f were subjected to molecular docking simulation with three proteins, namely, tyrosyl-tRNA synthetase, heme oxygenase 1 and acetylcholinesterase to evaluate the antibacterial, antioxidant and acetylcholinesterase inhibition, respectively. Moreover, the docked poses of all compounds inside the proteins were subjected to further dynamic simulation through the calculation of the binding free energy using MM-GBSA analysis. Compound 5d exhibits high potential inhibition against antibacterial, antioxidant and acetylcholinesterase activities. Compounds 3d, 3f, 5a and 5d recorded an important scavenging activity in DPPH and ABTS assays. Investigation of the anti-acetylcholinesterase activity of the synthesized compounds showed that Compounds 5a and 3d are the most potent inhibitors against AchE, with percent inhibition values of 38 and 30%, respectively.Communicated by Ramaswamy H. Sarma.

Recent Progresses in the Multicomponent Synthesis of Dihydropyridines by Applying Sustainable Catalysts Under Green Conditions

The synthesis of dihydropyridines, valuable molecules with diverse therapeutic properties, using eco-friendly heterogeneous catalysts as a green alternative received significant consideration. By selecting appropriate precursors, these compounds can be readily modified to induce the desired properties in the target product. This review focused on synthesising diverse dihydropyridine derivatives in single-pot reactions using magnetic, silica, and zirconium-based heterogeneous catalytic systems. The monograph describes preparation techniques for various catalyst materials in detail. It covers facile and benign magnetic, silica, zirconium-based, and ionic liquid catalysts, exhibiting significant efficacy and consistently facilitating excellent yields in short reaction times and in a cost-effective way. Most of the designated protocols employ Hantzsch reactions involving substituted aldehydes, active methylene compounds, and ammonium acetate. These reactions presumably follow Knoevenagel condensation followed by Michael addition and intra-molecular cyclisation. The multicomponent one-pot protocols using green catalysts and solvents have admirably increased the product selectivity and yields while minimising the reaction time. These sustainable catalyst materials retain their viability for several cycles reducing the expenditure are eco-friendly.

Three-Component Reaction to 1,4,2-Diazaborole-Type Heteroarene Systems

The borane FmesBH₂ reacts in a three-component reaction with an isonitrile and a small series of organonitriles to give rare examples of the class of dihydro-1,4,2-diazaborole derivatives. In a related way, annulated BN-indolizine derivatives became conveniently available, as were dihydro-1,4,2-oxaza- or thiazaborole derivatives. The nucleophilic framework of a dihydro-1,4,2-diazaborole example allowed for an uncatalyzed acylation reaction. It also served as a 1,3-dipolar reagent and underwent a [3+2] cycloaddition/[4+2] cycloreversion sequence when treated with methyl propiolate to give the respective pyrrole product. The [3+2] cycloaddition product of a dihydro-1,4,2-diazaborole derivative with N-phenylmaleimide was isolated and its heterobicyclo[2.2.1]heptane derived structure characterized by X-ray diffraction.

One-Step Synthesis of Photoaffinity Probes for Live-Cell MS-Based Proteomics

We present a one-step Ugi reaction protocol for the expedient synthesis of photoaffinity probes for live-cell MS-based proteomics. The reaction couples an amine affinity function with commonly used photoreactive groups, and a variety of handle functionalities. Using this technology, a series of pan-BET (BET: bromodomain and extra-terminal domain) selective bromodomain photoaffinity probes were obtained by parallel synthesis. Studies on the effects of photoreactive group, linker length and irradiation wavelength on photocrosslinking efficiency provide valuable insights into photoaffinity probe design. Optimal probes were progressed to MS-based proteomics to capture the BET family of proteins from live cells and reveal their potential on- and off-target profiles.

New Approaches for the Synthesis of Fused Thiophene, Pyrazole, Pyran and Pyridine Derivatives with Anti-Proliferative Together with c-Met Kinase and Prostate Cancer Cell Inhibitions

BACKGROUND

Recently multi-component reactions producing pyran and pyridine derivatives acquired a special attention due to their wide range of pharmacological activities, especially therapeutic activities. Through the market, it was found that many pharmacological drugs containing the pyran and pyridine nucleus were known.

OBJECTIVE

We are aiming in this work to synthesize target molecules possess not only anti-tumor activities but also kinase inhibitors. The target molecules were obtained starting from cyclohexane-1,3-dione followed by its heterocyclization reactions to produce anticancer target molecules.

METHODS

This work demonstrated multi-component reactions of cyclohexan-1,3-dione with aromatic aldehydes and diethylmalonate using triethylamine as a catalyst to give the 7,8-dihydro-4H-chromen-5(6H)-one derivatives 4a-c. The reaction of compounds 4a-c with either of hydrazine hydrate of phenylhydrazine gave the chromeno[2,3-c]pyrazole derivatives 5a-f, respectively. In addition, further heterocyclization reactions were adopted to give the chromeno[3,2-d]isoxazole, chromene-3-carboxamide derivatives. Moreover, the multicomponent reaction of cyclohexan-1,3-dione (1) with either of aromatic aldehydes and diethylmalonate using a catalytic amount of ammonium acetate gave the 1,4,5,6,7,8-hexahydroquinoline derivatives 13a-c. The antiproliferative activities of the synthesized compounds toward the six cancer cell lines namely A549, H460, HT- 29, MKN-45, U87MG, and SMMC-7721 were studied. In addition, the c-Met enzymatic activities and inhibition toward the prostate cancer cell PC-3 were measured.

RESULTS

Anti-proliferative evaluations, c-Met enzymatic activities and inhibition toward the prostate cancer cell PC-3 were measured, and the results obtained in most cases indicated that the presence of electronegative Cl group through the molecule favour the inhibitions.

CONCLUSION

The compounds with high anti-proliferative activity towards the cancer cell lines were 4a, 4b, 6d, 6e, 6f, 10e, 10f, 12c, 14e, 14f, 15c, 16d, 16e, 16f, 19c and 20c. Compounds 4b, 6c, 6d, 8b, 10c, 10d, 12b, 13b, 14c, 14d, 15b, 16c, 16d, 17b, 17c, 19b, 20b and 20c exhibited high potency against c-Met kinase and compounds 4a, 4b, 6b, 6c, 6d, 6f, 8b, 8c, 10c, 10d, 10e, 12b, 12c, 13a, 13b, 13c, 14c, 14d, 14e, 14f, 15b, 15c, 16b, 16c, 16d, 17b, 17c, 19c, 19d, 20a, 20b and 20c displayed high inhibitions toward PC-3 cell line.

Synthesis and Anti-Proliferative Evaluations of New Heterocyclic Derivatives Using 5,6,8,9-Tetrahydropyrazolo[5,1-b]quinazolin-7(3H)-one Derivatives Derived from Cyclohexa-1,4-dione

BACKGROUND

Recentlty, pyrazoloquinazoline derivatives acquired a special attention due to their wide range of pharmacological activities, especially therapeutic. Through the market, it was found that many pharmacological drugs containing the quinazoline nucleus were known.

OBJECTIVE

The aim of this work is to synthesize target molecules possessing not only anti-tumor activities but also kinase inhibitors. The target molecules were obtained through the synthesis of a series of 5,6,8,9- tetrahydropyrazolo[5,1-b]quinazolin-7(3H)-one derivatives 4a-i using the multi-component reactions of cyclohexane- 1,4-dione (1), the 5-amino-4-(2-arylhydrazono)-4H-pyrazol-3-ol derivatives 2a-c, the aromatic aldehydes 3a-c, respectively. The synthesized compounds were evaluated against c-Met kinase, PC-3 cell line, and different kinds of cancer cell lines together with normal cell line, tyrosine kinases, and Pim-1 kinase.

METHODS

Multi-component reactions were adopted using compound 1 to get different 5,6,8,9- tetrahydropyrazolo[5,1-b]quinazolin-7(3H)-one derivatives which underwent further heterocyclization reactions. The c-Met kinase activity of all compounds was evaluated using Homogeneous Time-Resolved Fluorescence (HTRF) assay, taking foretinib as the positive control. The anti-proliferative activity of all target compounds against the human prostatic cancer PC-3 cell line was measured using MTT assay using SGI-1776 as the reference drug. All the synthesized compounds were assessed for inhibitory activities against A549 (non-small cell lung cancer), H460 (human lung cancer), HT-29 (human colon cancer), and MKN-45 (human gastric cancer) cancer cell lines together with foretinib as the positive control by an MTT assay.

RESULTS

Antiproliferative evaluations and c-Met kinase, Pim-1 kinase inhibitions were performed for the synthesized compounds, where the varieties of substituents through the aryl ring and the thiophene moiety afforded compounds with high activities.

CONCLUSION

The compounds with high antiproliferative activity were tested towards c-Met and the results showed that compounds 4e, 4f, 4g, 4i, 6i, 6k, 6l, 8f, 8i, 10d, 10e, 10f, 10h, 12e, 12f, 12g, 12h, 12i, 14f, 14g, 14h, and 14i were the most potent compounds. A further selection of compounds for the Pim-1 kinase inhibition activity showed that compounds 4f, 6i, 6l, 8h, 8i, 8g, 10d, 12i, and 14f were the most active compounds to inhibit Pim-1.

Multi-Component Reactions of Cyclohexan-1,3-dione: Synthesis of Fused Pyran, Pyridine, Thiophene and Pyrazole Derivatives with c-Met, AntiProliferative Activities

BACKGROUND

Recently products of multi-component reactions (MCR's) acquired a special attention due to their wide range of pharmacological activities especially the therapeutic activities. Through the market it was found that many pharmacological drugs containing the pyran and pyridine nucleus that were produced through MCR's were known.

OBJECTIVE

We are aiming in this work to synthesize target molecules not only possess anti-tumour activities but also cMet and prostate cancer inhibitors. The target molecules were obtained starting from cyclohexan-1,3-dione through its multi-component reactions to produce anticancer target molecules.

METHODS

Cyclohexan-1,3-dione underwent different multi-component reactions to produce fused pyran, pyridine and thiophene derivatives. The anti-proliferative activity of the newly synthesized compounds among the synthesized compounds toward the six cancer cell lines namely A549, H460, HT-29, MKN-45, U87MG, and SMMC-7721 was studied. In addition, inhibitions toward c-Met kinase and prostate cancer cell line were studied. Antitumor evaluations toward seventeen cancer cell lines subpanel according the diseases, for certain compounds were also demonstrated. Pim-1 kinase inhibitions of the most active compounds were also measured.

RESULTS

Anti-proliferative evaluations, c-Met and Pim-1 kinase inhibitions were performed for most of the synthesized compounds where the varieties of substituent through the aryl ring and the heterocyclic ring afforded compounds with high activities.

CONCLUSION

Compounds 4b, 6b, 8b, 9a, 11b, 12b, 17b, 18b, 19, 22c, 23b and 25b were the most cytotoxic compounds toward the six cancer cell lines. Inhibitions toward c-Met kinase and prostate cancer cell showed that the presence of the electronegative Cl group within the molecule was responsible for its high activity. In addition, inhibitions toward Pim-1 kinase exhibited that most of tested compounds showed high inhibitions.

1,5-Phosphonium betaines from N-triflylpropiolamides, triphenylphosphane, and active methylene compounds

N-Phenyl-N-(trifluoromethylsulfonyl)propiolamides react with triphenylphosphane in the presence of various active methylene compounds CH₂XY in a 1:1:1 molar ratio to furnish 1-phosphonium-5-oxabetaines, Ph₃P⁺-C(R)=CH-C(O^-)=CXY. These betaines are formed preferentially, but not exclusively, as E-diastereoisomers with respect to the vinylic double bond. In some cases, separation of the two diastereoisomers was achieved by fractionating crystallization. Structure determination by X-ray diffraction analysis revealed marked conformational differences around the CH-C(O^-) single bond of E and Z-isomers and extended charge delocalization in the anionic part.

Multi-Component Synthesis of Rare 1,3-Dihydro-1,3-azaborinine Derivatives: Application of a Bora-Nazarov Type Reaction

The twofold hydroboration products of (Fmes)BH₂ ⋅SMe₂ with a series of alkynes (2-butyne, arylethynes) react with two molar equiv of 2,6-dimethylphenyl isocyanide (CN-Xyl) at 80 °C to give rare examples of 1,3-azaborinine derivatives. A mechanistic study revealed a reaction course involving insertion of one isonitrile followed by a bora-Nazarov type ring-closure reaction and subsequent isonitrile insertion to give the respective 1,3-dihydro-1,3-azaborinines 5.

Glycoconjugates via phosphorus ylides

A facile, high yielding access to rare chimeric compounds combining phosphorus ylides with complex glycosyl formamides is described. We determined x-ray structures gaining structural insight into this compounds class. In addition, data mining of similar compounds deposited within the Cambridge Structural Database was performed. These derivatives could be used either as synthetic intermediates via the ylide functionalization and glyco chemical biology synthons or improving the pharmacokinetic properties of a potential bioactive molecule, exploiting the glycosyl moiety.

Kinetics Studies on a Multicomponent Knoevenagel-Michael Domino Reaction by an Automated Flow Reactor

The optimization of complex chemical reaction systems is often a troublesome and time‐consuming process. The application of modern technologies, including automated reactors and analytics, opens the avenue for generating large data sets on chemical reaction processes in a short period of time. In this work, an automated flow reactor is used to present detailed kinetics and mechanistic studies about an amine‐catalyzed Knoevenagel−Michael domino reaction to yield tetrahydrochromene derivatives. High‐performance monoliths as catalyst supports and online coupled HPLC analysis allow for time‐efficient data generation. We show that the two‐step multicomponent domino reaction does not follow the kinetics of consecutive reaction steps proceeding independently from each other. Instead, the starting materials of both individual reactions compete for the active sites on the heterogeneous catalyst, which lowers the rate constants of both steps. This knowledge was used to implement a more efficient experimental setup which increased the turnover numbers of the catalyst, without adjusting common reaction parameters like temperature, reaction time, and concentrations.

A Simple and Efficient Synthesis of Highly Substituted Indeno[1,2-b]pyrrole and Acenaphtho[1,2-b]pyrrole Derivatives by Tandem Three-Component Reactions

A green, convenient and tandem procedure for the efficient synthesis of highly substituted indeno[1,2-b]pyrrole and acenaphtho[1,2-b]pyrrole derivatives by domino three-component reaction of tryptamine/benzylamine, 1,3-dicarbonyl compounds and ninhydrin/ acenaphthenequinone is described. The significant features of this procedure were characterized by mild reaction conditions, high yields, operational simplicity and it being environmentally benign.

p-TSA-promoted syntheses of 5H-benzo[h] thiazolo[2,3-b]quinazoline and indeno[1,2-d] thiazolo[3,2-a]pyrimidine analogs: molecular modeling and in vitro antitumor activity against hepatocellular carcinoma

In our efforts to address the rising incidence of hepatocellular carcinoma (HCC), we have made a commitment to the synthesis of novel molecules to combat Hep-G2 cells. A facile and highly efficient one-pot, multicomponent reaction has been successfully devised utilizing a p-toluenesulfonic acid (p-TSA)-catalyzed domino Knoevenagel/Michael/intramolecular cyclization approach for the synthesis of novel 5H-benzo[h]thiazolo[2,3-b]quinazoline and indeno[1,2-d] thiazolo[3,2-a]pyrimidine analogs bearing a bridgehead nitrogen atom. This domino protocol constructed one new ring by the concomitant formation of multiple bonds (C-C, C-N, and C=N) involving multiple steps without the use of any metal catalysts in one-pot, with all reactants effi-ciently exploited. All the newly synthesized compounds were authenticated by means of Fourier transform infrared spectroscopy, liquid chromatography-mass spectrometry, proton nuclear magnetic resonance spectroscopy, and carbon-13 nuclear magnetic resonance spectroscopy, together with elemental analysis, and their antitumor activity was evaluated in vitro on a Hep-G2 human cancer cell line by sulforhodamine B assay. Computational molecular modeling studies were carried out on cancer-related targets, including interleukin-2, interleukin-6, Caspase-3, and Caspase-8. Two compounds (4A and 6A) showed growth inhibitory activity comparable to the positive control Adriamycin, with growth inhibition of 50% <10 μg/mL. The results of the comprehensive structure-activity relationship study confirmed the assumption that two or more electronegative groups on the phenyl ring attached to the thiazolo[2,3-b]quinazoline system showed the optimum effect. The in silico simulations suggested crucial hydrogen bond and π-π stacking interactions, with a good ADMET (absorption, distribution, metabolism, excretion, and toxicity) profile and molecular dynamics, in order to explore the molecular targets of HCC which were in complete agreement with the in vitro findings. Considering their significant anticancer activity, 4A and 6A are potential drug candidates for the management of HCC.

The Flögel-three-component reaction with dicarboxylic acids - an approach to bis(β-alkoxy-β-ketoenamides) for the synthesis of complex pyridine and pyrimidine derivatives

An extension of the substrate scope of the Flögel-three-component reaction of lithiated alkoxyallenes, nitriles and carboxylic acids is presented. The use of dicarboxylic acids allowed the preparation of symmetrical bis(β-ketoenamides) from simple starting materials in moderate yields. Cyclocondensations of these enamides to 4-hydroxypyridine derivatives or to functionalized pyrimidines efficiently provided symmetrically and unsymmetrically substituted fairly complex (hetero)aromatic compounds containing up to six conjugated aryl and hetaryl groups. In addition, subsequent functionalizations of the obtained heterocycles by palladium-catalyzed couplings or by oxidations are reported. We also describe the simple synthesis of a structurally interesting macrocyclic bispyrimidine derivative incorporating a 17-membered ring, whose configuration was elucidated by DFT calculations and by subsequent reactions.

Intercepted Decarboxylative Allylations of Nitroalkanoates

Using palladium-catalyzed decarboxylation, several cascade reactions of allyl and prenyl nitroalkanoates that lead to nitro-containing chemical building blocks are described. A nitronate Michael addition/Tsuji-Trost allylation cascade was developed, leading to functionally dense chemical building blocks. Likewise, a Tsuji-Trost/decarboxylative protonation sequence was developed for the synthesis of orthogonally functionalized 2° nitroalkanes. The latter method provides rapid access to the indolizidine core.

Enaminones in a multicomponent synthesis of 4-aryldihydropyridines for potential applications in photoinduced intramolecular electron-transfer systems

An efficient three component reaction with enaminones, primary amines and aldehydes resulted in easy access to 1,4-dihydropyridines with different substituents at the 1-, 3-, 4- and 5-positions. Microwaves improved the reaction yield, reducing also considerably the reaction time and the amount of solvent used. Chiral primary amines gave chiral 1-substituted-1,4-dihydropyridines. The 4-(1-naphthyl) and 4-(phenanthren-9-yl)dihydropyridine derivatives exhibited an interesting photoluminescence behavior, which suggests their potential application as suitable photoinduced intramolecular electron-transfer systems.