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1.
Daria Kupczyk Renata Studziska Szymon Baumgart Rafa Bilski Tomasz Kosmalski Renata Koodziejska Alina Wo
niak 《Molecules (Basel, Switzerland)》2021,26(9)
Tumors are currently more and more common all over the world; hence, attempts are being made to explain the biochemical processes underlying their development. The search for new therapeutic pathways, with particular emphasis on enzymatic activity and its modulation regulating the level of glucocorticosteroids, may contribute to the development and implementation of new therapeutic options in the treatment process. Our research focuses on understanding the role of 11β-HSD1 and 11β-HSD2 as factors involved in the differentiation and proliferation of neoplastic cells. In this work, we obtained the 9 novel N-tert-butyl substituted 2-aminothiazol-4(5H)-one (pseudothiohydantoin) derivatives, differing in the substituents at C-5 of the thiazole ring. The inhibitory activity and selectivity of the obtained derivatives in relation to two isoforms of 11β-HSD were evaluated. The highest inhibitory activity for 11β-HSD1 showed compound 3h, containing the cyclohexane substituent at the 5-position of the thiazole ring in the spiro system (82.5% at a conc. 10 µM). On the other hand, the derivative 3f with the phenyl substituent at C-5 showed the highest inhibition of 11β-HSD2 (53.57% at a conc. of 10 µM). A low selectivity in the inhibition of 11β-HSD2 was observed but, unlike 18β-glycyrrhetinic acid, these compounds were found to inhibit the activity of 11β-HSD2 to a greater extent than 11β-HSD1, which makes them attractive for further research on their anti-cancer activity. 相似文献
2.
Six new, sterically demanding bis(benzimidazolium) salts (2a–f) as NHC precursors have been synthesized and characterized. These salts, in combination with palladium acetate, provide active catalysts for the cross‐coupling of aryl chlorides and bromides under mild conditions in aqueous media. Copyright © 2006 John Wiley & Sons, Ltd. 相似文献
3.
Emine
zge Karaca Osman ifti lknur
zdemir Gül Yakali Muhittin Aygün Nevin Gürbüz smail
zdemir 《应用有机金属化学》2019,33(7)
Platinum (II) complexes bearing N‐heterocyclic carbene (NHC) ligands have been widely used in catalytic chemistry, but there are very few reports of biological properties of this type of complexes. A series of [PtCl2(NHC)(PEt3)] complexes were synthesized. The structures of all compounds were characterized by 1H‐NMR, 13C‐NMR, IR and elemental analysis techniques, which supported the proposed structures. The single crystal structures of complexes 1a and 1e were determined. The title complexes show slightly distorted square‐planar coordination around the platinum (II) metal center. The cytotoxic properties of the platinum (II)–NHC complexes have been assessed in various human cancer lines, including cisplatin‐sensitive and resistant cells. IC50 values of these four complexes were determined by the MTS‐based assay on three human cell lines—brain (SHSY5Y), colon (HTC116) and liver (HEP3B). These complexes have been highlighted cancer therapeutic agent with unique structures and functions. 相似文献
4.
a-Oxo ketene dithioacetals, methyl 2-(1,3-dithian/dithiolan-2-ylidene)-3-oxobutanoate (2a/2b) prepared in nearly quantitative yields simply from methyl acetylacetate, carbon disulfide and 1,3-dibromopropane/1,2-dibromoethane in the presence of potassium carbonate, were investigated in the thioacetalization with various carbonyl compounds 3. It has been demonstrated that methyl 2-(1,3-dithian-2-ylidene)-3-oxobutanoate (2a) could act as a nonthiolic, odorless and practical thioacetalization reagent. A range of aldehydes and ketones 3 were converted into the corresponding dithioacetals 4 in high yields (up to 91%) in the presence of 2a. Moreover, 2a showed high chemoselectivity between aldehyde and ketone in thioacetalization. 相似文献
5.
1,3‐Diarylsubstituted imidazolinium salts, (NHC‐H)Cl, 3, containing hydrogen or alkyl groups at the 4,5‐positions of the imidazolidine ring, served as precursors to rhodium(I) complexes [RhCl(NHC)COD], 4, which were converted into cis‐[RhCl(NHC)(CO)2] complexes, 5. All compounds prepared were characterized by elemental analyses, 1H NMR and 13C NMR. The relative σ‐donor/π‐acceptor strength of the NHC ligands was determined by means of IR spectroscopy of 5. The ability of NHCs in 4 to enchance activity was explored in the 1,2‐addition of phenylboronic acid to aldehydes. A good correlation was observed between catalytic activity and the electron‐donating power of the NHC ligands. Copyright © 2010 John Wiley & Sons, Ltd. 相似文献
6.
Grzegorz Mlosto Marcin Jasiski Anthony Linden Heinz Heimgartner 《Helvetica chimica acta》2006,89(7):1304-1316
The reaction of 1,4,5‐trisubstituted 1H‐imidazole‐3‐oxides 1 with 2,2‐bis(trifluoromethyl)ethene‐1,1‐dicarbonitrile ( 7 , BTF) yielded the corresponding 1,3‐dihydro‐2H‐imidazol‐2‐ones 10 and 2‐(1,3‐dihydro‐2H‐imidazol‐2‐ylidene)malononitriles 11 , respectively, depending on the solvent used. In one example, a 1 : 1 complex, 12 , of the 1H‐imidazole 3‐oxide and hexafluoroacetone hydrate was isolated as a second product. The formation of the products is explained by a stepwise 1,3‐dipolar cycloaddition and subsequent fragmentation. The structures of 11d and 12 were established by X‐ray crystallography. 相似文献
7.
Synthesis of palladium complexes derived from imidazolidin‐2‐ylidene ligands and used for catalytic amination reactions
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Emine Özge Karaca Nevin Gürbüz Onur Şahin Orhan Büyükgüngör İsmail Özdemir 《应用有机金属化学》2016,30(12):1050-1055
N‐Aryl amination and the Buchwald–Hartwig reaction are of great synthetic and industrial interest and scientists accept their usefulness and versatility for obtaining arylamines. In this study Ag–N‐heterocyclic carbene complexes were used as transmetallation reagents for the synthesis of Pd–N‐heterocyclic carbene complexes. The new Pd–N‐heterocyclic carbene complexes were characterized using elemental analysis and 1H NMR, 13C NMR and infrared spectroscopies. The crystal structure of one, namely dichlorobis[1,3‐bis(2‐methylbenzyl)imidazolidin‐2‐yliden]palladium(II), is presented. The activity of the Pd(II) complexes in the coupling reaction of anilines or amines with bromobenzene was investigated. These complexes exhibited high catalytic activities in the direct synthesis of triarylamines and secondary amines in a single step. Copyright © 2016 John Wiley & Sons, Ltd. 相似文献
8.
9.
Dr. Patrick Hemberger Dr. Andras Bodi Dr. Thomas Gerber Dr. Max Würtemberger Prof. Dr. Udo Radius 《Chemistry (Weinheim an der Bergstrasse, Germany)》2013,19(22):7090-7099
The photoionization and dissociative photoionization of Im(iPr)2, 1,3‐diisopropylimidazolin‐2‐ylidene, was investigated by imaging photoelectron photoion coincidence (iPEPICO) with vacuum ultraviolet (VUV) synchrotron radiation. A lone‐pair electron of the carbene carbon atom is removed upon ionization and the molecular geometry changes significantly. Only 0.5 eV above the adiabatic ionization energy, IEad=7.52±0.1 eV, the carbene cation fragments, yielding propene or a methyl radical in parallel dissociation reactions with appearance energies of 8.22 and 8.17 eV, respectively. Both reaction channels appear at almost the same photon energy, suggesting a shared transition state. This is confirmed by calculations, which reveal the rate‐determining step as hydrogen‐atom migration from the isopropyl group to the carbene carbon center forming a resonance‐stabilized imidazolium ion. Above 10.5 eV, analogous sequential dissociation channels open up. The first propene‐loss fragment ion dissociates further and another methyl or propene is abstracted. Again, a resonance‐stabilized imidazolium ion acts as intermediate. The aromaticity of the system is enhanced even in vertical ionization. Indeed, the coincidence technique confirms that a real imidazolium ion is produced by hydrogen transfer over a small barrier. The simple analysis of the breakdown diagram yields all the clues to disentangle the complex dissociative photoionization mechanism of this intermediate‐sized molecule. Photoelectron photoion coincidence is a promising tool to unveil the fragmentation mechanism of larger molecules in mass spectrometry. 相似文献
10.
A highly effective, easy to handle and environmentally benign process for palladium‐mediated Suzuki cross‐coupling is developed. The in situ prepared three‐component system Pd(OAc)2–1,3‐bis(alkyl)imidazolinium chlorides (2a–f) and Cs2CO3 catalyses quantitatively the Suzuki cross‐coupling of deactivated aryl chlorides. Copyright © 2005 John Wiley & Sons, Ltd. 相似文献