scholarly journals Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

2016 ◽  
Vol 12 ◽  
pp. 5-15 ◽  
Author(s):  
Krzysztof Skowerski ◽  
Jacek Białecki ◽  
Stefan J Czarnocki ◽  
Karolina Żukowska ◽  
Karol Grela
Keyword(s):  
Double Bond ◽  
Filter Paper ◽  
Ruthenium Complex ◽  
High Yield ◽  
Subsequent Reduction ◽  
Solid Supports ◽  
Solid Materials ◽  
One Pot ◽  
Metathesis Catalyst ◽  
Palladium On Carbon

An ammonium-tagged ruthenium complex, 8, was deposited on several widely available commercial solid materials such as silica gel, alumina, cotton, filter paper, iron powder or palladium on carbon. The resulting catalysts were tested in toluene or ethyl acetate, and found to afford metathesis products in high yield and with extremely low ruthenium contamination. Depending on the support used, immobilised catalyst 8 shows also additional traits, such as the possibility of being magnetically separated or the use for metathesis and subsequent reduction of the obtained double bond in one pot.

Synthesis of Highly Functionalized Quinazoline-2,4(1H,3H)-diones from Isocyanides, Aniline and Isocyanate via Cu-Catalyzed Intermolecular C-H Activation Reactions

2020 ◽  
Vol 17 (11) ◽  
pp. 832-836
Author(s):  
Manijeh Nematpour ◽  
Hossein Fasihi Dastjerdi ◽  
Mehdi Jahani ◽  
Sayyed Abbas Tabatabai
Keyword(s):  
13C Nmr ◽  
Reaction Times ◽  
High Yield ◽  
One Pot ◽  
1H And 13C Nmr ◽  
Activation Reaction ◽  
Elemental Analyses

A simple and appropriate procedure for the synthesis of quinazoline-2,4(1H,3H)-dione derivatives from isocyanides, aniline and isocyanate via the Cu-catalyzed intramolecular C-H activation reaction is reported. The advantages of this method are one-pot conditions, accessible starting materials- catalyst, high yield of products, and short reaction times. The structures are confirmed spectroscopically (1H- and 13C-NMR, IR and EI-MS) and by elemental analyses.

One-pot Synthesis of Pyrazolone Sulfones by Iodine-catalyzed Sulfenylation of Pyrazolones with Aryl Sulfonyl Hydrazides Followed by Oxidation in Water

2018 ◽  
Vol 15 (3) ◽  
pp. 380-387
Author(s):  
Xia Zhao ◽  
Xiaoyu Lu ◽  
Lipeng Zhang ◽  
Tianjiao Li ◽  
Kui Lu
Keyword(s):  
Double Bond ◽  
Efficient Method ◽  
Room Temperature ◽  
Sulfonyl Chloride ◽  
Antibacterial Activities ◽  
Oxidation Reactions ◽  
Reaction Conditions ◽  
One Pot ◽  
X Ray ◽  
Amide Form

Aim and Objective: Pyrazolone sulfones have been reported to exhibit herbicidal and antibacterial activities. In spite of their good bioactivities, only a few methods have been developed to prepare pyrazolone sulfones. However, the substrate scope of these methods is limited. Moreover, the direct sulfonylation of pyrazolone by aryl sulfonyl chloride failed to give pyrazolone sulfones. Thus, developing a more efficient method to synthesize pyrazolone sulfones is very important. Materials and Method: Pyrazolone, aryl sulphonyl hydrazide, iodine, p-toluenesulphonic acid and water were mixed in a sealed tube, which was heated to 100°C for 12 hours. The mixture was cooled to 0°C and m-CPBA was added in batches. The mixture was allowed to stir for 30 min at room temperature. The crude product was purified by silica gel column chromatography to afford sulfuryl pyrazolone. Results: In all cases, the sulfenylation products were formed smoothly under the optimized reaction conditions, and were then oxidized to the corresponding sulfones in good yields by 3-chloroperoxybenzoic acid (m-CPBA) in water. Single crystal X-ray analysis of pyrazolone sulfone 4aa showed that the major tautomer of pyrazolone sulfones was the amide form instead of the enol form observed for pyrazolone thioethers. Moreover, the C=N double bond isomerized to form an α,β-unsaturated C=C double bond. Conclusion: An efficient method to synthesize pyrazolone thioethers by iodine-catalyzed sulfenylation of pyrazolones with aryl sulfonyl hydrazides in water was developed. Moreover, this method was employed to synthesize pyrazolone sulfones in one-pot by subsequent sulfenylation and oxidation reactions.

Design, Synthesis, In vitro Cytotoxic Activity Evaluation, and Study of Apoptosis Inducing Effect of New Styrylimidazo[1,2-a]Pyridines as Potent Anti-Breast Cancer Agents

2019 ◽  
Vol 19 (2) ◽  
pp. 265-275 ◽  
Author(s):  
Faeze Khalili ◽  
Sara Akrami ◽  
Malihe Safavi ◽  
Maryam Mohammadi-Khanaposhtani ◽  
Mina Saeedi ◽  
...  
Keyword(s):  
Breast Cancer ◽  
Cytotoxic Activity ◽  
High Yield ◽  
Breast Cancer Cell Lines ◽  
Pyridine Derivatives ◽  
One Pot ◽  
Standard Drug ◽  
Three Component Reaction ◽  
Anti Cancer

Background: This paper reports synthesis, cytotoxic activity, and apoptosis inducing effect of a novel series of styrylimidazo[1,2-a]pyridine derivatives. Objective: In this study, anti-cancer activity of novel styrylimidazo[1,2-a]pyridines was evaluated. Methods: Styrylimidazo[1,2-a]pyridine derivatives 4a-o were synthesized through a one-pot three-component reaction of 2-aminopyridines, cinnamaldehydes, and isocyanides in high yield. All synthesized compounds 4a-o were evaluated against breast cancer cell lines including MDA-MB-231, MCF-7, and T-47D using MTT assay. Apoptosis was evaluated by acridine orange/ethidium bromide staining, cell cycle analysis, and TUNEL assay as the mechanism of cell death. Results: Most of the synthesized compounds exhibited more potent cytotoxicity than standard drug, etoposide. Induction of apoptosis by the most cytotoxic compounds 4f, 4g, 4j, 4n, and 4m was confirmed through mentioned methods. Conclusion: In conclusion, these results confirmed the potency of styrylimidazo[1,2-a]pyridines for further drug discovery developments in the field of anti-cancer agents.

scholarly journals Cathodic hydrodimerization of nitroolefins

2015 ◽  
Vol 11 ◽  
pp. 1163-1174 ◽  
Author(s):  
Michael Weßling ◽  
Hans J Schäfer
Keyword(s):  
Double Bond ◽  
Nitro Group ◽  
Bond Formation ◽  
Cathodic Reduction ◽  
High Yield ◽  
Easy Access ◽  
Electrolysis Cell ◽  
Aldehydes And Ketones ◽  
Nef Reaction

Nitroalkenes are easily accessible in high variety by condensation of aldehydes with aliphatic nitroalkanes. They belong to the group of activated alkenes that can be hydrodimerized by cathodic reduction. There are many olefins with different electron withdrawing groups used for cathodic hydrodimerization, but not much is known about the behaviour of the nitro group. Synthetic applications of this group could profit from the easy access to nitroolefins in large variety, the C–C bond formation with the introduction of two nitro groups in a 1,4-distance and the conversions of the nitro group by reduction to oximes and amines, the conversion into aldehydes and ketones via the Nef reaction and base catalyzed condensations at the acidic CH bond. Eight 1-aryl-2-nitro-1-propenes have been electrolyzed in an undivided electrolysis cell to afford 2,5-dinitro-3,4-diaryl hexanes in high yield. The 4-methoxy-, 4-trifluoromethyl-, 2-chloro- and 2,6-difluorophenyl group and furthermore the 2-furyl and 2-pyrrolyl group have been applied. The reaction is chemoselective as only the double bond but not the nitro group undergoes reaction, is regioselective as a ß,ß-coupling with regard to the nitro group and forms preferentially two out of six possible diastereomers as major products.

The Structure and Synthesis of Cytokinin Metabolites. 1. The 7- and 9-β-D-Glucofuranosides and Pyranosides of Zeatin and 6-Benzylaminopurine

1978 ◽  
Vol 31 (5) ◽  
pp. 1095 ◽  
Author(s):  
DE Cowley ◽  
CC Duke ◽  
AJ Liepa ◽  
JK Macleod ◽  
DS Letham
Keyword(s):  
Pyrimidine Ring ◽  
Ring Closure ◽  
Imidazole Derivative ◽  
High Yield ◽  
Ring Size ◽  
Plant Metabolites ◽  
One Pot ◽  
Synthetic Routes

The structures of the major stable plant metabolites of the cytokinins zeatin and 6-benzylaminopurine have been confirmed by synthesis to be 7- and 9-β-D-glucopyranosides. The small quantities of metabolites initially isolated (< 100 μg) precluded assignment of the glucose ring size or configuration of the anomeric linkage so that synthesis of both the furanose and pyranose forms of 7-β-D- and 9-β-D-glucosylzeatin and 6-benzylaminopurine was undertaken which allowed direct u.v., m.s. and t.l.c. comparison with the metabolites. Numerous synthetic routes to the unusual 7-glucosides of the two cytokinins were explored, the most successful utilizing a one-pot pyrimidine ring closure of an imidazole derivative to afford directly in high yield the required 7-glucosides of zeatin and 6-benzylaminopurine.

scholarly journals Synthesis of deoxymannojirimycin using a Ruthenium-catalysed hydrogen borrowing reaction

2021 ◽  
Author(s):  
◽  
Victoria Skinner
Keyword(s):  
Scale Up ◽  
Ruthenium Catalyst ◽  
High Yield ◽  
One Pot ◽  
Unfolded Protein ◽  
Unit Operations ◽  
Hepatocarcinoma Cells ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Reaction Vessels

<p>1-Deoxymannojirimycin (DMJ) has been investigated as a potential anti-cancer therapy due to its specific inhibition of class I α-mannosidase enzymes, which has been shown to trigger ER stress and the Unfolded Protein Response (UPR) pathway, leading to apoptosis in human hepatocarcinoma cells. Current methods for the synthesis of DMJ consist of multiple steps and often result in poor yields. The objectives of this research project were to develop a scale-up suitable synthesis of deoxymannojirimycin (DMJ), and to assess the feasibility of telescoping key-reactions to reduce the number of unit operations. Synthetic efforts focused on the key conversion of 1 to 2 have previously involved separate oxidation and reduction steps. In our laboratory; attempts to use hydrogen-borrowing chemistry had taken >48hr and not been achieved in high yield. The highlights of this work were that this conversion was ultimately realised in 95% yield in 24hr, and that the final deprotection of (2) could be telescoped into the process removing reaction-workup and chromatographic steps. The ruthenium catalyst used in the hydrogen borrowing reaction was found to be extremely air-sensitive, with reactions taking place in carefully prepared reaction vessels under an atmosphere of dry argon gas. The catalyst was also found to exhibit sensitivities to materials such as metal needles and polymer tubing, preventing sampling and monitoring of the reaction during synthesis. This study demonstrated that a one-pot synthesis is feasible,compressing the final steps in the synthesis of DMJ in excellent yield. The difficulty arises from the sensitive nature of the ruthenium catalyst, and the extreme care required in the preparation of the glassware and reagents used in synthesis. Many aspects of this development require further investigation, including the sampling, monitoring and quality control of each synthetic step.</p>

scholarly journals One pot synthesis of 3, 4-dihydropyrimidine-2(1H)-thiones using orange peel powder under ultrasonic irradiation

2020 ◽  
Vol 9 (1) ◽  
pp. 919-923
Keyword(s):  
Reaction Time ◽  
Ultrasonic Irradiation ◽  
Heterocyclic Compounds ◽  
Multicomponent Reactions ◽  
Orange Peel ◽  
Biologically Active ◽  
High Yield ◽  
Atom Economy ◽  
One Pot ◽  
The Past

Biginelli, an important multicomponent reaction provides an avenue for the synthesis of different biologically active heterocyclic compounds. During the past decade, one pot multicomponent reactions have attracted the attention of organic and medicinal chemists due to high atom economy, time and enery saving convergent nature. The present manuscript reports a simple one pot three component synthesis of 3, 4-dihydroprimidin-2(1H)-thiones from various diversely substituted aldehydes, ethyl acetoacetate and thiourea using a orange peel powder as a natural catalyst on ultrasonic irradiation in aqueous medium as the solvent. The advantages of this reaction are less reaction time, high yield, easy availability of the catalyst and green nature.

scholarly journals Synthesis of deoxymannojirimycin using a Ruthenium-catalysed hydrogen borrowing reaction

2021 ◽  
Author(s):  
◽  
Victoria Skinner
Keyword(s):  
Scale Up ◽  
Ruthenium Catalyst ◽  
High Yield ◽  
One Pot ◽  
Unfolded Protein ◽  
Unit Operations ◽  
Hepatocarcinoma Cells ◽  
The Unfolded Protein Response ◽  
Protein Response ◽  
Reaction Vessels

<p>1-Deoxymannojirimycin (DMJ) has been investigated as a potential anti-cancer therapy due to its specific inhibition of class I α-mannosidase enzymes, which has been shown to trigger ER stress and the Unfolded Protein Response (UPR) pathway, leading to apoptosis in human hepatocarcinoma cells. Current methods for the synthesis of DMJ consist of multiple steps and often result in poor yields. The objectives of this research project were to develop a scale-up suitable synthesis of deoxymannojirimycin (DMJ), and to assess the feasibility of telescoping key-reactions to reduce the number of unit operations. Synthetic efforts focused on the key conversion of 1 to 2 have previously involved separate oxidation and reduction steps. In our laboratory; attempts to use hydrogen-borrowing chemistry had taken >48hr and not been achieved in high yield. The highlights of this work were that this conversion was ultimately realised in 95% yield in 24hr, and that the final deprotection of (2) could be telescoped into the process removing reaction-workup and chromatographic steps. The ruthenium catalyst used in the hydrogen borrowing reaction was found to be extremely air-sensitive, with reactions taking place in carefully prepared reaction vessels under an atmosphere of dry argon gas. The catalyst was also found to exhibit sensitivities to materials such as metal needles and polymer tubing, preventing sampling and monitoring of the reaction during synthesis. This study demonstrated that a one-pot synthesis is feasible,compressing the final steps in the synthesis of DMJ in excellent yield. The difficulty arises from the sensitive nature of the ruthenium catalyst, and the extreme care required in the preparation of the glassware and reagents used in synthesis. Many aspects of this development require further investigation, including the sampling, monitoring and quality control of each synthetic step.</p>

An efficient multicomponent, one-pot synthesis of Betti bases catalyzed by cerium (IV) ammonium nitrate (CAN) at ambient temperature

2016 ◽  
Vol 5 (4) ◽  
Author(s):  
Ramadan Ahmed Mekheimer ◽  
Abdullah Mohamed Asiri ◽  
Afaf Mohamed Abdel Hameed ◽  
Reham R. Awed ◽  
Kamal Usef Sadek
Keyword(s):  
Ambient Temperature ◽  
Environmental Pollution ◽  
Ammonium Nitrate ◽  
Room Temperature ◽  
Catalytic Amount ◽  
High Yield ◽  
Reaction Conditions ◽  
One Pot ◽  
Work Up ◽  
Cerium Iv Ammonium Nitrate

AbstractStarting from readily available 2-naphthol, aldehydes, aryl and alkylamines, a variety of Betti bases were efficiently synthesized utilizing a catalytic amount of cerium (IV) ammonium nitrate (CAN) at room temperature. This protocol has advantages of high yield, mild reaction conditions, no environmental pollution, diversity of reactants and simple work up procedure.

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