Catalytic Method for the Synthesis of Deuterium-Labeled N-Heterocyclic Carbenes Enabled by a Coordinatively Unsaturated Ruthenium N-Heterocyclic Carbene Catalyst

Cyclotriarsanes are rare and limited synthetic approaches have hampered reactivity studies on these systems. Described in here is a scalable synthetic protocol towards (AsAr)3 (Ar = Dip, 2,6-iPr2-C6H3; Tip, 2,4,6-iPr3-C6H2), which allowed to study their reactivity towards [Cp2Ti(C2(SiMe3)2], affording titanocene diarsene complexes and towards N-heterocyclic carbenes (NHCs) to give straightforward access to a variety of NHC-arsinidene adducts. The electronic structure of the titanium diarsene complxes has been studied and they are best described as Ti(IV) species with a doubly reduced As2Ar2 ligand. These findings will make (AsAr)3 valuable precursors in the synthetic inorganic and organic chemistry.

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Nickel-Catalyzed Regioselective Hydroalkylation of 1,3-Dienes with Hydrazones

10.26434/chemrxiv.8266643.v1 ◽

2019 ◽

Author(s):

Leiyang Lv ◽

Dianhu Zhu ◽

Zihang Qiu ◽

Jianbin Li ◽

Chao-Jun Li

Keyword(s):

Catalytic Method ◽

Unsaturated Hydrocarbons ◽

Carbon Nucleophiles ◽

Aryl Aldehydes ◽

Aldehydes And Ketones ◽

Sterically Hindered

Hydroalkylation of unsaturated hydrocarbons with unstablized carbon nucleophiles is difficult and remains a major challenge. The disclosed examples so far mainly focused on the involvement of heteroatom and/or stabilized carbon nucleophiles as efficient reaction partners. Reported here is an unprecedented regioselective nickel-catalyzed hydroalkylation of 1,3-dienes with hydrazones, generated in situ from abundant aryl aldehydes and ketones and acted as both the sources of unstabilized carbanions and hydride. With this strategy, both terminal and sterically hindered internal dienes are hydroalkylated efficiently in a highly selective manner, thus providing a novel and reliable catalytic method to construct challenging C(sp3)-C(sp3) bonds.

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SO3H-functionalized Zeolite-Y as an Efficient Nanocatalyst for the Synthesis of Nbenzimidazole- 2-aryl-4-thiazolidinones and tri-substituted Imidazoles

Current Organic Synthesis ◽

10.2174/1570179417666200115170019 ◽

2020 ◽

Vol 17 (2) ◽

pp. 117-130 ◽

Cited By ~ 1

Author(s):

Mehdi Kalhor ◽

Zohre Zarnegar ◽

Zahra Seyedzade ◽

Soodabeh Banibairami

Keyword(s):

Zeolite Y ◽

Internal Standard ◽

Acid Catalyst ◽

Aromatic Aldehydes ◽

Reaction Rates ◽

Ambient Conditions ◽

Catalytic Method ◽

Efficient Catalyst ◽

Bet Analysis ◽

Ft Ir

Background: SO3H-functionalized zeolite-Y was prepared and used as a catalyst for the synthesis of 2-aryl-N-benzimidazole-4-thiazolidinones and tri-substituted imidazoles at ambient conditions. Objective: The goals of this catalytic method include excellent yields and high purity, inexpensive procedure and ease of product isolation, the use of nontoxic and heterogeneous acid catalyst, shorter reaction times and milder conditions. Materials and Methods: NMR spectra were recorded on Brucker spectrophotometer using Me4Si as internal standard. Mass spectra were recorded on an Agilent Technology 5975C VL MSD with tripe-axis detector. FTIR spectra were obtained with KBr disc on a galaxy series FT-IR 5000 spectrometer. The surface morphology of nanostructures was analyzed by FE-SEM (EVO LS 10, Zeiss, Carl Zeiss, Germany). BET analysis were measured at 196 °C by a Japan Belsorb II system after the samples were vacuum dried at 150°C overnight. Results: The NSZ was characterized by FT-IR, FESEM, EDX, XRF, and BET. The catalytic activity of NSZ was investigated for synthesis of 1,3-tiazolidin-4-ones in H2O/Acetone at room temperature. Moreover, NSZ was used for synthesis of tri-substituted imidazoles at 60 °C via solvent-free condensation. Different kinds of aromatic aldehydes were converted to the corresponding of products with good to excellent yields. Conclusion: Sulfonated zeolite-Y was as an efficient catalyst for the preparation of N-benzimidazole-2-aryl-1,3- thiazolidin-4-ones and 2,4,5-triaryl-1H-imidazoles. High reaction rates, elimination toxic solvent, simple experimental procedure and reusability of the catalyst are the important features of this protocol.

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Application of Nitrogen Heterocyclic Carbenes in Organocatalysis

Current Catalysis ◽

10.2174/2211544709999201201120617 ◽

2020 ◽

Vol 09 ◽

Author(s):

Minita Ojha ◽

R. K. Bansal

Keyword(s):

Asymmetric Catalysis ◽

Building Blocks ◽

Structural Features ◽

Heterocyclic Carbenes ◽

Stetter Reaction ◽

Metal Pollutants ◽

Synthetic Strategy ◽

Wide Range ◽

Benzoin Condensation ◽

Nitrogen Heterocyclic

Background: During the last two decades, horizon of research in the field of Nitrogen Heterocyclic Carbenes (NHC) has widened remarkably. NHCs have emerged as ubiquitous species having applications in a broad range of fields, including organocatalysis and organometallic chemistry. The NHC-induced non-asymmetric catalysis has turned out to be a really fruitful area of research in recent years. Methods: By manipulating structural features and selecting appropriate substituent groups, it has been possible to control the kinetic and thermodynamic stability of a wide range of NHCs, which can be tolerant to a variety of functional groups and can be used under mild conditions. NHCs are produced by different methods, such as deprotonation of Nalkylhetrocyclic salt, transmetallation, decarboxylation and electrochemical reduction. Results: The NHCs have been used successfully as catalysts for a wide range of reactions making a large number of building blocks and other useful compounds accessible. Some of these reactions are: benzoin condensation, Stetter reaction, Michael reaction, esterification, activation of esters, activation of isocyanides, polymerization, different cycloaddition reactions, isomerization, etc. The present review includes all these examples published during the last 10 years, i.e. from 2010 till date. Conclusion: The NHCs have emerged as versatile and powerful organocatalysts in synthetic organic chemistry. They provide the synthetic strategy which does not burden the environment with metal pollutants and thus fit in the Green Chemistry.

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Efficient and selective catalytic hydroxylation of unsaturated plant oils: a novel method for producing anti-pathogens

BMC Chemistry ◽

10.1186/s13065-021-00748-z ◽

2021 ◽

Vol 15 (1) ◽

Author(s):

Ahmed M. Senan ◽

Binru Yin ◽

Yaoyao Zhang ◽

Mustapha M. Nasiru ◽

Yong‐Mei Lyu ◽

...

Keyword(s):

Antimicrobial Agents ◽

In Vitro Study ◽

Functional Method ◽

Plant Oils ◽

Main Process ◽

Catalytic Method ◽

Novel Method ◽

Pharmaceutical Industries ◽

Increasing Demand

AbstractWith the increasing demand for antimicrobial agents and the spread of antibiotic resistance in pathogens, the exploitation of plant oils to partly replace antibiotic emerges as an important source of fine chemicals, functional food utility and pharmaceutical industries. This work introduces a novel catalytic method of plant oils hydroxylation by Fe(III) citrate monohydrate (Fe3+-cit.)/Na2S2O8 catalyst. Methyl (9Z,12Z)-octadecadienoate (ML) was selected as an example of vegetable oils hydroxylation to its hydroxy-conjugated derivatives (CHML) in the presence of a new complex of Fe(II)-species. Methyl 9,12-di-hydroxyoctadecanoate 1, methyl-9-hydroxyoctadecanoate 2 and methyl (10E,12E)-octadecanoate 3 mixtures is produced under optimized condition with oxygen balloon. The specific hydroxylation activity was lower in the case of using Na2S2O8 alone as a catalyst. A chemical reaction has shown the main process converted of plantoils hydroxylation and (+ 16 Da) of OH- attached at the methyl linoleate (ML-OH). HPLC and MALDI-ToF-mass spectrometry were employed for determining the obtained products. It was found that adding oxidizing agents (Na2S2O8) to Fe3+ in the MeCN mixture with H2O would generate the new complex of Fe(II)-species, which improves the C-H activation. Hence, the present study demonstrated a new functional method for better usage of vegetable oils.Producing conjugated hydroxy-fatty acids/esters with better antipathogenic properties. CHML used in food industry, It has a potential pathway to food safety and packaging process with good advantages, fundamental to microbial resistance. Lastly, our findings showed that biological monitoring of CHML-minimum inhibitory concentration (MIC) inhibited growth of various gram-positive and gram-negative bacteria in vitro study. The produced CHML profiles were comparable to the corresponding to previousstudies and showed improved the inhibition efficiency over the respective kanamycin derivatives.

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Reversal of Polarity by Catalytic SET Oxidation: Synthesis of Azabicyclo[m.n.o]alkanes via Chemoselective Reduction of Amidines

Organic & Biomolecular Chemistry ◽

10.1039/d1ob00416f ◽

2021 ◽

Author(s):

Sundarababu Baskaran ◽

Kirana D V ◽

Kanak Kanti Das

Keyword(s):

Electron Transfer ◽

Stereoselective Synthesis ◽

Single Electron ◽

Single Electron Transfer ◽

Catalytic Method ◽

One Pot ◽

Oxidative System ◽

Oxidation Synthesis

A one-pot catalytic method has been developed for the stereoselective synthesis of cyclopropane-fused cyclic amidines using CuBr2/K2S2O8 as an efficient single electron transfer (SET) oxidative system. The generality of this...

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