6996-92-5Relevant academic research and scientific papers
The polyhedral nature of selenium-catalysed reactions: Se(iv) species instead of Se(vi) species make the difference in the on water selenium-mediated oxidation of arylamines
Capperucci, Antonella,Dalia, Camilla,Tanini, Damiano
, p. 5680 - 5686 (2021/08/16)
Selenium-catalysed oxidations are highly sought after in organic synthesis and biology. Herein, we report our studies on the on water selenium mediated oxidation of anilines. In the presence of diphenyl diselenide or benzeneseleninic acid, anilines react with hydrogen peroxide, providing direct and selective access to nitroarenes. On the other hand, the use of selenium dioxide or sodium selenite leads to azoxyarenes. Careful mechanistic analysis and 77Se NMR studies revealed that only Se(iv) species, such as benzeneperoxyseleninic acid, are the active oxidants involved in the catalytic cycle operating in water and leading to nitroarenes. While other selenium-catalysed oxidations occurring in organic solvents have been recently demonstrated to proceed through Se(vi) key intermediates, the on water oxidation of anilines to nitroarenes does not. These findings shed new light on the multifaceted nature of organoselenium-catalysed transformations and open new directions to exploit selenium-based catalysis.
Arylseleninic acid as a green, bench-stable selenylating agent: Synthesis of selanylanilines and 3-selanylindoles
Abenante, Laura,Anghinoni, Jo?o M.,Lenard?o, Eder J.,Padilha, Nathalia B.,Penteado, Filipe,Rosati, Ornelio,Santi, Claudio,Silva, Marcio S.
supporting information, p. 5210 - 5217 (2020/07/23)
Arylseleninic acids were used as an electrophilic selenium source in aromatic substitution reactions, using N,N-substituted anilines and indoles as nucleophiles at 70 °C for 6-15 h. A total of fourteen 4-selanylanilines and five 3-selanylindoles were selectively obtained in good to excellent yields. The starting benzeneseleninic acids are easily prepared from the respective diselenides, are bench stable and easy to handle, affording water as the only waste at the end of the reaction. This journal is
Modelling the Inhibition of Selenoproteins by Small Molecules Using Cysteine and Selenocysteine Derivatives
Reddy, Kishorkumar M.,Mugesh, Govindasamy
, p. 8875 - 8883 (2019/06/17)
Small molecule-based electrophilic compounds such as 1-chloro-2,4-dinitrobenzene (CDNB) and 1-chloro-4-nitrobenzene (CNB) are currently being used as inhibitors of cysteine- and selenocysteine-containing proteins. CDNB has been used extensively to determine the activity of glutathione S-transferase and to deplete glutathione (GSH) in mammalian cells. Also, CDNB has been shown to irreversibly inhibit thioredoxin reductase (TrxR), a selenoenzyme that catalyses the reduction of thioredoxin (Trx). Mammalian TrxR has a C-terminal active site motif, Gly-Cys-Sec-Gly, and both the cysteine and selenocysteine residues could be the targets of the electrophilic reagents. In this paper we report on the stability of a series of cysteine and selenocysteine derivatives that can be considered as models for the selenoenzyme–inhibitor complexes. We show that these derivatives react with H2O2 to generate the corresponding selenoxides, which undergo spontaneous elimination to produce dehydroalanine. In contrast, the cysteine derivatives are stable towards such elimination reactions. We also demonstrate, for the first time, that the arylselenium species eliminated from the selenocysteine derivatives exhibit significant redox activity by catalysing the reduction of H2O2 in the presence of GSH (GPx (glutathione peroxidase)-like activity), which suggests that such redox modulatory activity of selenium compounds may have a significant effect on the cellular redox state during the inhibition of selenoproteins.
Synthesis of 4-Organoselanyl-1H-pyrazoles: Oxone -Mediated Electrophilic Cyclization of α,β-Alkynyl Hydrazones by Using Diorganyl Diselenides
Perin, Gelson,Nobre, Patrick C.,Mailahn, Daniela H.,Silva, Márcio S.,Barcellos, Thiago,Jacob, Raquel G.,Lenard?o, Eder J.,Santi, Claudio,Roehrs, Juliano A.
, p. 2293 - 2304 (2019/05/24)
A simple and efficient method for the synthesis of 4organoselanyl-1 H -pyrazoles has been developed, taking place under metal- and halogen-free conditions. Electrophilic species of selenium were easily generated in situ by the reaction of diorganyl diselenides with Oxone in ethanol as solvent in an open-flask at 70 °C. These electrophilic selenium species were employed in the selenylation/cyclization of α,β-alkynyl hydrazones, giving the title compounds in moderate to excellent yields. The final species of selenium obtained from the reaction of diphenyl diselenide with Oxone were characterized by 77 Se NMR spectroscopy and high-resolution mass spectrometry (HRMS).
Green and Practical Oxidative Deoximation of Oximes to Ketones or Aldehydes with Hydrogen Peroxide/Air by Organoselenium Catalysis
Jing, Xiaobi,Yuan, Dandan,Yu, Lei
, p. 1194 - 1201 (2017/04/13)
Organoselenium-catalyzed oxidative deoximations afforded ketones and aldehydes under mild conditions. The reactions employ hydrogen peroxide and air as clean oxidants and lead to a waste-free and metal-free deprotection protocol for carbonyl protection strategies as well as the green synthesis of ketones and aldehydes. The mechanisms of this interesting organoselenium-catalyzed reaction have been investigated by control experiments as well as the selenium 77 nuclear magnetic resonance (77Se NMR) tests. This novel reaction largely expands the application scope of organoselenium catalysis. (Figure presented.).
Fused Selenazolinium Salt Derivatives with a Se-N+ Bond: Preparation and Properties
Arsenyan, Pavel,Vasiljeva, Jelena,Belyakov, Sergey,Liepinsh, Edvards,Petrova, Marina
, p. 5842 - 5855 (2015/09/15)
Convenient methods for the preparation of stable, fused selenazolinium salt systems with a Se-N+ bond have been developed. The mechanism for the formation of the selenazole cycle was investigated in detail by conducting multinuclear NMR experiments. The ability of these compounds to form stable inner salts was demonstrated. We have shown the glutathione peroxidase (GPx) like properties of selenazolopyridinium salts by oxidizing sulfur-containing natural amino acids, as well as aromatic and heteroaromatic aldehydes. The molecular structures of most of the compounds were confirmed by X-ray diffraction studies.
A photo-responsive catalytic vesicle with GPx activity
Xiao, Ruiqing,Zhou, Lipeng,Dong, Zeyuan,Gao, Yuzhou,Liu, Junqiu
, p. 37 - 43 (2014/02/14)
Glutathione peroxidase (GPx) is a vital antioxidant enzyme involved in the reduction of reactive oxygen species and protects cells from oxidative damage. Consequently enormous efforts have been devoted to developing artificial catalysts with GPx function. Besides the research on enhancing the catalytic activity of GPx mimics, the design and construction of smart GPx models has also inspired great interest. Herein, a novel photo-responsive selenium-containing vesicular GPx model was successfully constructed by supramolecular self-assembly of the cationic surfactant PyC10AzoC10Py with benzeneseleninic acid (PhSeO2H) through hydrophobic and electrostatic interactions in aqueous media. This selenium-containing vesicular catalyst showed remarkable GPx-like activity, which is 692 times more effective than PhSeO2H for the reduction of cumene hydroperoxide (CUOOH) by 4-nitrobenzenethiol (NBT). Interestingly, when an equimolar amount of α-CD was added, the GPx-like activity of the catalytic vesicle declines remarkably due to the vesicle disaggregation in the presence of α-CD. Whereas the biomimetic system was irradiated by UV light at 365 nm, the catalytic vesicle was formed again and the GPx-like activity recovered. Copyright
Facile synthesis of 2-methylenecyclobutanones via Ca(OH) 2-catalyzed direct condensation of cyclobutanone with aldehydes and (PhSe)2-catalyzed Baeyer-Villiger oxidation to 4-methylenebutanolides
Yu, Lei,Wu, Yulan,Cao, Hongen,Zhang, Xu,Shi, Xinkang,Luan, Jie,Chen, Tian,Pan, Yi,Xu, Qing
supporting information, p. 287 - 293 (2014/01/06)
2-Methylenecyclobutanones (2-MCBones), used to be difficult to access, but can now be easily achieved by a green and stereospecific Ca(OH) 2-catalyzed direct and simple aldol condensation of cyclobutanone and aldehydes under mild conditions. The obtained (E)-2-MCBones should be a class of potentially useful building blocks in synthesis as they could readily undergo an interesting (PhSe)2-catalyzed Baeyer-Villiger (BV) oxidation with H2O2 at room temperature to give the versatile 4-methylenebutanolides. Mechanistic studies revealed that the BV reaction most possibly proceeded via the initial formation of benzeneseleninoperoxoic anhydride [PhSe(O)O]2O, which then converted to benzeneseleninoperoxoic acid PhSe(O)OOH as the active oxidant, followed by its selective addition to the CO bond of 2-MCBones and then a selective C-C bond cleavage and rearrangement to give 4-methylenebutanolides.
One-pot synthesis of 1-(E)-phenylethenyl-1,2,3-triazoles by sequential click-elimination reaction from 2-azido-1-phenyl-1-(Phenylseleno)ethane
Su, Hai-You,Sheng, Shou-Ri,Zhang, Xiao-Lan,Ding, Xiao-Ying,Cai, Ming-Zhong
, p. 1591 - 1598 (2013/10/21)
A new convenient one-pot, two-step procedure involving sequential click chemistry and oxidation-elimination reaction for the preparation of 1,4-disubstituted 1,2,3-triazoles bearing 1-(E)-phenylethenyl group from 2-azido-1-phenyl-1-(phenylseleno)ethane is described. The prominent features of this protocol are mild reaction conditions, operational simplicity, and good to high yields of products, as well as avoidance of the isolation of the selenated intermediate. Supplementary materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements for the following free supplemental files: Additional figures.
Intramolecular displacement of phenylselenone by a hydroxy group: Stereoselective synthesis of 2-substituted tetrahydrofurans
Minuti, Lucio,Barattucci, Anna,Bonaccorsi, Paola Maria,Di Gioia, Maria Luisa,Leggio, Antonella,Siciliano, Carlo,Temperini, Andrea
, p. 3906 - 3909 (2013/09/02)
An efficient and stereocontrolled synthesis of 2-substituted tetrahydrofurans has been achieved. The approach employs the asymmetric reduction of γ-phenylseleno ketones obtained by three different procedures that are peculiarly applied to the synthesis of such compounds. Finally, the intramolecular substitution of the phenylselenone residue by the oxygen atom of a hydroxy group gives the tetrahydrofuran ring.
