Imidazolium salts and [Pt(cod)2]: from NHC hydrido complexes to the unprecedented olefinic tetrahedral cluster [Pt4(μ-H)(cod)4]BF4

2021 ◽  
Vol 57 (78) ◽  
pp. 10039-10042
Author(s):  
Fengkai He ◽  
Christophe Gourlaouen ◽  
Huan Pang ◽  
Pierre Braunstein
Keyword(s):  
Imidazolium Salts ◽  
Tetrahedral Cluster ◽  
Imidazolium Salt ◽  
Potential Precursor

Whereas the bis(imine)imidazolium salt 1·Cl yielded with [Pt(cod)2] the PtII-hydrido NHC complex 3, the unprecedented, tetrahedral cluster [Pt4(μ-H)(cod)4]BF4 (7) was unexpectedly obtained from 1·BF4.

Intramolecular Diels Alder reactions in highly organized imidazolium salt-based ionic liquid crystals

RSC Advances ◽  
2015 ◽  
Vol 5 (1) ◽  
pp. 635-639 ◽  
Author(s):  
Tien Dat Do ◽  
Andreea R. Schmitzer
Keyword(s):  
Ionic Liquid ◽  
Liquid Crystals ◽  
Diels Alder ◽  
Imidazolium Salts ◽  
Imidazolium Salt ◽  
New Family ◽  
Ionic Liquid Crystals

This paper describes the development of a new family of ionic liquid crystals based on imidazolium salts and their applications as media for intramolecular Diels Alder reactions.

Synthesis, Characterization, and Biological Activity of Anthraquinone-Substituted Imidazolium Salts for the Treatment of Bladder Cancer

2020 ◽  
Vol 6 (4) ◽  
pp. 471-479
Author(s):  
Michael L. Stromyer ◽  
David J. Weader ◽  
Uttam Satyal ◽  
Philip H. Abbosh ◽  
Wiley J. Youngs
Keyword(s):  
Bladder Cancer ◽  
Cell Line ◽  
Cell Lines ◽  
Cancer Cell ◽  
High Grade ◽  
Imidazolium Salts ◽  
Muscle Invasive Bladder Cancer ◽  
Imidazolium Salt ◽  
Muscle Invasive

BACKGROUND: Bladder cancer is one of the most common types of cancer diagnosed each year, and more than half of patients have non-muscle invasive bladder cancer (NMIBC). The standard of care for patients with high-grade NMIBC is Bacillus Calmette-Guerin (BCG). Unfortunately, multiple BCG shortages have limited access to this treatment. Available alternatives using intravesical administration of chemotherapy have some efficacy, but lack prospective validation and long-term outcomes. Development of novel intravesical therapies may provide more active alternatives to BCG for patients with high-grade NMIBC. OBJECTIVE: To develop an optimal imidazolium salt for the intravesical treatment of NMIBC and determine preliminary in vitro activity of anthraquinone-substituted imidazolium salts. METHODS: The development of the anthraquinone-substituted imidazolium salts was undertaken in an attempt to increase the potency of this class of compounds by incorporating the quinone functional group observed in the chemotherapeutics doxorubicin, valrubicin, and mitomycin. All compounds were characterized by 1H and 13C NMR spectroscopy and infrared spectroscopy. Furthermore, these imidazolium salts were tested for in vitro cytotoxicity by the Developmental Therapeutics Program (DTP) on the NCI-60 human tumor cell line screening. Additional in vitro testing was performed against diverse bladder cancer cell lines (RT112, TCCSUP, J82, and UMUC13) using CellTiter-Glo® assays and colony-forming assays. RESULTS: The NCI-60 cell line screening indicated that compound 7 had the highest activity and was concluded to be the optimal compound for further study. Using CellTiter-Glo® assays on bladder cancer cell lines, 50% growth inhibitory concentration (IC50) values were determined to range from 32–50μM after an exposure of 1 h, for compound 7. Further evaluation of the compound by colony-forming assays showed the complete inhibition of growth at 10 days post a 100μM dose of compound 7 for 1 h. CONCLUSIONS: The most active lipophilic anthraquinone imidazolium salt, compound 7, could be a viable treatment for non-muscle invasive bladder cancer as it exhibits a cell-killing effect at a 1 h time period and completely inhibits cancer regrowth in colony-forming assays.

scholarly journals An efficient Pd–NHC catalyst system in situ generated from Na2PdCl4 and PEG-functionalized imidazolium salts for Mizoroki–Heck reactions in water

2017 ◽  
Vol 13 ◽  
pp. 1735-1744 ◽  
Author(s):  
Nan Sun ◽  
Meng Chen ◽  
Liqun Jin ◽  
Wei Zhao ◽  
Baoxiang Hu ◽  
...  
Keyword(s):  
Catalytic Activity ◽  
Imidazole Ring ◽  
Catalyst System ◽  
Water Soluble ◽  
Imidazolium Salts ◽  
Heck Reactions ◽  
Imidazolium Salt ◽  
Simple Method ◽  
Wide Range

Three PEG-functionalized imidazolium salts L1–L3 were designed and prepared from commercially available materials via a simple method. Their corresponding water soluble Pd–NHC catalysts, in situ generated from the imidazolium salts L1–L3 and Na2PdCl4 in water, showed impressive catalytic activity for aqueous Mizoroki–Heck reactions. The kinetic study revealed that the Pd catalyst derived from the imidazolium salt L1, bearing a pyridine-2-methyl substituent at the N3 atom of the imidazole ring, showed the best catalytic activity. Under the optimal conditions, a wide range of substituted alkenes were achieved in good to excellent yields from various aryl bromides and alkenes with the catalyst TON of up to 10,000.

scholarly journals Scalable Synthesis of 1,3,4,5-Tetraaryl Imidazolium Salts as Precursors of Sterically Demanding N-Heterocyclic Carbenes

SynOpen ◽  
2020 ◽  
Vol 04 (01) ◽  
pp. 01-11
Author(s):  
Cengiz Azap ◽  
Anna Christoffers ◽  
Renat Kadyrov
Keyword(s):  
Large Scale ◽  
Oxidative Desulfurization ◽  
Heterocyclic Carbenes ◽  
Imidazolium Salts ◽  
Imidazolium Salt ◽  
Available N ◽  
Sterically Demanding ◽  
Cost Efficient ◽  
Scalable Synthesis ◽  
Electron Donation

A convenient, large-scale, and cost-efficient synthesis of 4,5-diarylsubstituted N,N-diarylimidazolium salts is described. A variety of 1,3,4,5-tetraaryl imidazolium salts with increasing electron donation and steric bulk of the N-aryl groups was synthesized in good yields. In the key step, readily available N,N′-diarylthioureas and benzoin/anisoin are coupled to give imidazole-2-thiones, followed by imidazolium salt formation by oxidative desulfurization. In this way, N,N-diarylimidazolium salts with 2-methoxy, 2-methyl, and 2-isopropyl substituents could be obtained; the synthesis of their 2-tert-butyl, 2,6-dimethyl, and 2,6-diisopropyl analogues failed.

scholarly journals Microbiota potentialized larvicidal action of imidazolium salts against Aedes aegypti (Diptera: Culicidae)

2019 ◽  
Vol 9 (1) ◽  
Author(s):  
Harry Luiz Pilz-Junior ◽  
Alessandra Bittencourt de Lemos ◽  
Kauana Nunes de Almeida ◽  
Gertrudes Corção ◽  
Henri Stephan Schrekker ◽  
...  
Keyword(s):  
Mass Spectrometry ◽  
Molecular Markers ◽  
Aedes Aegypti ◽  
Bacterial Communities ◽  
Blood Feeding ◽  
Imidazolium Salts ◽  
Imidazolium Salt ◽  
Chemical Products ◽  
Laboratory Breeding

Abstract Mosquitoes are important vectors of pathogens due to their blood feeding behavior. Aedes aegypti (Diptera: Culicidae) transmits arboviruses, such as dengue, Zika, and Chikungunya. This species carries several bacteria that may be beneficial for its biological and physiological development. Therefore, studying the response of its microbiota to chemical products could result in vector control. Recently, imidazolium salts (IS) were identified as effective Ae. aegypti larvicides. Considering the importance of the mosquito microbiota, this study addressed the influence of IS on the bacteria of Ae. aegypti larvae. After exposition of larvae to different IS concentrations, the cultured microbiota was identified through culturomics and mass spectrometry, and the non-cultivated microbiota was characterized by molecular markers. In addition, the influence of the IS on axenic larvae was studied for comparison. There was an alteration in both cultivable species and in their diversity, including modifications in bacterial communities. The axenic larvae were less susceptible to the IS, which was increased after exposing these larvae to bacteria of laboratory breeding water. This highlights the importance of understanding the role of the larval microbiota of Ae. aegypti in the development of imidazolium salt-based larvicides. Such effect of IS towards microbiota of Ae. aegypti larvae, through their antimicrobial action, increases their larvicidal potential.

Selective di- and monochlorination of pyridazine-annelated bis(imidazolium) salts

2016 ◽  
Vol 71 (6) ◽  
pp. 659-666 ◽  
Author(s):  
Benjamin Raible ◽  
Doris Kunz
Keyword(s):  
Molecular Structure ◽  
Steric Hindrance ◽  
Acetyl Chloride ◽  
Synthetic Route ◽  
Imidazolium Salts ◽  
Imidazolium Salt ◽  
Trichloroisocyanuric Acid ◽  
The Ideal

AbstractA synthetic route for the selective di- and monochlorination of pyridazine annelated bis(imidazolium) salts at the formamidinium moieties with trichloroisocyanuric acid (TCCA) is presented. Due to the steric hindrance, the molecular structure of the dichlorobis(imidazolium) salt shows a pronounced torsion from planarity as well as a deviation of the C–Cl bond vectors from the ideal bisecting line of the respective NCN angles such as to avoid each other. The monochlorinated bis(imidazolium) salt is free of steric hindrance and therefore shows less deviation from the parent bis(imidazolium) salt. In the presence of acetate the chloroimidazolium salt acts as a chlorination agent for acetate leading to formation of acetyl chloride and the respective urea.

Pd(II) Complexes of N-Allyl Substituted N-Heterocyclic Carbenes

2004 ◽  
Vol 59 (11-12) ◽  
pp. 1519-1523 ◽  
Author(s):  
F. Ekkehardt Hahn ◽  
Beate Heidrich ◽  
Thomas Lügger ◽  
Tania Pape
Keyword(s):  
Allyl Bromide ◽  
Heterocyclic Carbenes ◽  
Ethyl Bromide ◽  
Imidazolium Salts ◽  
Imidazolium Salt ◽  
Butyl Lithium ◽  
X Ray ◽  
Square Planar

The unsymmetrically substituted imidazolium salt 1-ethyl-3-allyl-imidazolium bromide 1 was synthesized by treatment of imidazole with one equivalent each of n-butyl lithium and ethyl bromide followed by treatment with one equivalent of allyl bromide. The symmetrically substituted derivatives 1,3-diallyl-imidazolium bromide 2 and 1,3-bis(3-methyl-2-butenyl)-imidazolium bromide 3 were obtained from imidazole and two equivalents of allyl bromide or 4-bromo-2-methyl-2-butenyl bromide, respectively, in the presence of sodium hydrogencarbonate as a base. The imidazolium bromides 1- 3 react with Pd(OAc)2 to afford the palladium(II) dicarbene complexes trans-[PdBr2(L)2] (L = 1- ethyl-3-allyl-imidazolin-2-ylidene, 4; L = 1,3-diallyl-imidazolin-2-ylidene, 5; L = 1,3-di(3-methyl-2- butenyl)imidazolin-2-ylidene, 6) by in situ deprotonation of the imidazolium salts. The X-ray structure analyses of 4- 6 show all three complexes to be mononuclear with palladium(II) coordinated in a square-planar fashion by two carbene and two bromo ligands.

1,3,4,5-Tetramethyl-2-methylenimidazolin - ein Olefin mit Ylid-artigen Eigenschaften [1] / 1,3,4,5-Tetramethyl-2-methylenimidazoline - an Olefin with Ylidic Properties [1]

1996 ◽  
Vol 51 (9) ◽  
pp. 1267-1278 ◽  
Author(s):  
Norbert Kuhna ◽  
Hans Bohnena ◽  
Gerald Henkel ◽  
Jörg Kreutzberg
Keyword(s):  
Charge Transfer ◽  
Imidazolium Salts ◽  
Facile Synthesis ◽  
Imidazolium Salt ◽  
Imidazolium Ion

A facile synthesis of l,3,4,5-tetramethyl-2-methylenimidazoline 5 (Im) starting from the pentamethylimidazolium ion (8) and KH is described. Boranes react with 5 to give the adducts ImBHi3 (11) and ImBF3 (18). With Mel and CH3C(O)Cl the imidazolium salts ImMe+ (19) and ImC(O)Me+ (20) are obtained. CS2 gives the zwitterionic compound ImCS2 (24) which is transformed into the cationic thiocarboxylic ester ImC(S)SCH2Cl+ on treatment with CH2Cl2. Reaction with chlorotrimethylsilane gives the imidazolium ion ImSiMe+3 (26) which may be transferred into the disilylated imidazolium ion 28 via deprotonation and subsequent silylation, the silylated olefin 27 being the intermediate. Similarly, the cations ImSiR2Cl+ (29; R = Me, Ph) are obtained from 5 and the silanes R2SiCl2. The neutral adduct ImSnPh2Cl2 (32) is formed in the reaction of 5 with Ph2SnCl2. Iodine reacts with 5 to give the charge-transfer adduct Iml2 (35), which can be further transferred into the imidazolium salt Iml+I-3 (36).

scholarly journals Identification and in Silico Characterization of Novel and Conserved MicroRNAs in Methyl Jasmonate-Stimulated Scots Pine (Pinus sylvestris L.) Needles

Forests ◽  
2020 ◽  
Vol 11 (4) ◽  
pp. 384
Author(s):  
Baiba Krivmane ◽  
Ilze Šņepste ◽  
Vilnis Šķipars ◽  
Igor Yakovlev ◽  
Carl Gunnar Fossdal ◽  
...  
Keyword(s):  
Methyl Jasmonate ◽  
Scots Pine ◽  
Target Genes ◽  
Regulation Of Gene Expression ◽  
Stem Loop ◽  
Protein Coding ◽  
Stem Loop Structure ◽  
In Silico Characterization ◽  
Potential Precursor

MicroRNAs (miRNAs) are non-protein coding RNAs of ~20–24 nucleotides in length that play an important role in many biological and metabolic processes, including the regulation of gene expression, plant growth and developmental processes, as well as responses to stress and pathogens. The aim of this study was to identify and characterize novel and conserved microRNAs expressed in methyl jasmonate-treated Scots pine needles. In addition, potential precursor sequences and target genes of the identified miRNAs were determined by alignment to the Pinus unigene set. Potential precursor sequences were identified using the miRAtool, conserved miRNA precursors were also tested for the ability to form the required stem-loop structure, and the minimal folding free energy indexes were calculated. By comparison with miRBase, 4975 annotated sequences were identified and assigned to 173 miRNA groups, belonging to a total of 60 conserved miRNA families. A total of 1029 potential novel miRNAs, grouped into 34 families were found, and 46 predicted precursor sequences were identified. A total of 136 potential target genes targeted by 28 families were identified. The majority of previously reported highly conserved plant miRNAs were identified in this study, as well as some conserved miRNAs previously reported to be monocot specific. No conserved dicot-specific miRNAs were identified. A number of potential gymnosperm or conifer specific miRNAs were found, shared among a range of conifer species.

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