A Convenient Synthesis of 4,4′-Dimethylaminodiphenyl Diselenide and 4,4′-Dinitrodiphenyl Diselenide

A simple, rapid and efficient synthesis of 4,4′-dimethylamino-diphenyl diselenide 1 and 4,4′-dinitrodiphenyl diselenide 2 is described. The method consists of the reductive cleavage of the Se-CN linkage in the corresponding aryl selenocyanates by sodium borohydride followed by air oxidation of the resulting seleno-lates. The diselenides 1 and 2 are readily obtained in a state of high purity, in 89 and 80% yield, respectively.     

Light-Driven Diselenide Metathesis in Peptides

Peptides containing selenocysteine moieties are susceptible to non-catalytic reactions of diselenide bonds metathesis induced by visible light. In contrast to previously reported radical metathesis of disulfide bridges in cysteine derivatives, this newly developed reaction is fast and clean, and proceeds without decomposition of peptides and without formation of side products. The diselenide bond in peptides was reported in literature to be more stable than the disulfide one and also less susceptible to metathesis induced by thiols and reducing reagents. We demonstrated that visible light induces fast metathesis of Se−Se bonds in peptides. This reaction is important for the folding of peptides containing selenocysteine residues and may find application in designing dynamic combinatorial libraries of peptides responsive to external influence.     

Synthesis of a Selenium-Substituted Diselenide

Abstract

A wide range of diselenides as precursors for selenium electrophiles is already known, but the development of reagents with higher selectivity is still ongoing. Herein we report the first synthesis of selenium-stabilized diselenides together with some preliminary reactions of these reagents in stereoselective selenenylation reactions.     

Stereoselective Addition of Dimethyl Diselenide to Trimethylethynylsilane

Russian Journal of General Chemistry -     

Physicochemical and Biochemical Profiling of Diphenyl Diselenide

The objective of the present study was to evaluate the physicochemical and biochemical profiling of diphenyl diselenide (PhSe)₂, a selenoorganic compound with biological activity. Experimental protocols were established for chemical stability in isotonic phosphate buffer (PBS) pH 7.4 and in simulated gastric and intestinal fluids, biological stability (bovine serum albumin (BSA) and plasma), solubility in PBS pH 7.4, distribution coefficient (Log D) in octanol/PBS, and determination of free (PhSe)₂ concentrations in BSA and plasma by using liquid chromatography with ultraviolet detection and tandem mass spectrometry. (PhSe)₂ was found to be chemically stable and not susceptible to degradation in plasma. The aqueous solubility was 0.98?±?0.072 μM and the Log D in octanol/PBS system was found to be 3.13. The percentage of unbound fractions of (PhSe)₂ obtained by equilibrium dialysis from BSA and plasma incubated with 100 μM (PhSe)₂ were 0.69?±?0.12 and 0.44?±?0.09 %, respectively. The findings indicated that (PhSe)₂ presents chemical and biological stability. Though, the compound showed low aqueous solubility, high Log D value and high binding to plasmatic protein. These data contribute to the knowledge of the toxicokinetic properties of (PhSe)₂ and further explain its low bioavailability in experimental models.     

两亲性双硒聚合物的制备及其聚集体形成

由于Se-Se键相对活泼, 对外部氧化和还原环境敏感, 双硒聚合物在药物控释系统有广泛的应用. 采用双硒二醇, 异佛尔酮二异氰酸酯和低分子壳聚糖为原料制备出了两亲性的双硒聚合物. 这种共聚物能够在水中发生自组装现象, 形成稳定的以PU为核, 壳聚糖为壳的球形纳米聚集体, 粒径约为130 nm. 并探索了该聚集体在氧化还原条件下的响应性, 发现不管在弱氧化还是弱还原环境下, 这种双硒聚合物都能发生Se-Se键断裂, 使得装载在聚集体中的正电荷药物盐酸阿霉素达到控制释放的效果.     

Reaction of Diethyl Diselenide with Dihaloalkanes in an Alkaline Reductive Medium

Bis(ethylseleno)alkanes were obtained by reductive cleavage of the Se-Se bond in diethyl diselenide with the system hydrazine hydrate-alkali, followed by alkylation with dihaloalkanes. A general preparative method of synthesis of bis(alkylseleno)alkanes of various structure was proposed.     

三正丁基膦参与的二苯联硒与吖啶及环氧化合物的开环反应

Aziridines and epoxides were reacted with diphenyl diselenide in the presence of a stoichiometric amount of （n-Bu）3P, respectively, giving β-amino- or β-hydroxy selenides in moderate to excellent yields under mild conditions. In the reactions the （n-Bu）3P might act as a reductant though it was a nucleophilic catalyst in other similar ring-opening reactions.     

A Diselenide Turn-On Fluorescent Probe for the Detection of Thioredoxin Reductase

We report the first diselenide-based probe for the selective detection of thioredoxin reductase (TrxR), an enzyme commonly overexpressed in melanomas. The probe design involves conjugation of a seminaphthorhodafluor dye with a diselenide moiety. TrxR reduces the diselenide bond, triggering a fluorescence turn-on response of the probe. Kinetic studies reveal favorable binding of the probe with TrxR with a Michaelis–Menten constant (K_m) of 15.89 μm . Computational docking simulations predict a greater binding affinity to the TrxR active site in comparison to its disulfide analogue. In vitro imaging studies further confirmed the diselenide probe exhibited improved signaling of TrxR activity compared to the disulfide analogue.     

A Convenient New Method for the Preparation of Diaryl Diselenide1

Diaryliodonium salts react with sodium O, O- diethyl phosphoroselenoate in ethanol-IMF at 70–80° C then hydrolyzed in basic medium and oxidized at room temperature to afford symmetric diaryl diselenides in better yields.     

Intercalated Iridium Diselenide Electrocatalysts for Efficient pH‐Universal Water Splitting

Developing bifunctional catalysts for both hydrogen and oxygen evolution reactions is a promising approach to the practical implementation of electrocatalytic water splitting. However, most of the reported bifunctional catalysts are only applicable to alkaline electrolyzer, although a few are effective in acidic or neutral media that appeals more to industrial applications. Here, a lithium‐intercalated iridium diselenide (Li‐IrSe₂) is developed that outperformed other reported catalysts toward overall water splitting in both acidic and neutral environments. Li intercalation activated the inert pristine IrSe₂ via bringing high porosities and abundant Se vacancies for efficient hydrogen and oxygen evolution reactions. When Li‐IrSe₂ was assembled into two‐electrode electrolyzers for overall water splitting, the cell voltages at 10 mA cm^?2 were 1.44 and 1.50 V under pH 0 and 7, respectively, being record‐low values in both conditions.     

Synthesis of Poly(amidoamine) Dendrimer with a Diphenyl Diselenide Core

Abstract

We succeeded in the synthesis of a novel poly(amidoamine) dendrimer having diphenyl diselenide at the core. Modification of the dendrimer diselenide by the reaction with glucono-δ-lactone in methanol gave a water-soluble dendrimer diselenide having chiral terminal groups. The structures of dendrimers were satisfactorily confirmed by MAIDI-TOF MS spectrometry, elemental analysis, and NMR spectroscopy. Interestingly, induced circular dichroism (ICD) of the interaction between the diphenyl diselenide core and D-gluconamide periphery of the dendrimer was observed at 300 nm.

Supplemental materials are available for this article. Go to the publisher's online edition of Phosphorus, Sulfur, and Silicon and the Related Elements to view the free supplemental file.

GRAPHICAL ABSTRACT     

Dynamic Diselenide Bonds: Exchange Reaction Induced by Visible Light without Catalysis

Dynamic covalent bonds are extensively employed in dynamic combinatorial chemistry. The metathesis reaction of disulfide bonds is widely used, but requires catalysis or irradiation with ultraviolet (UV) light. It was found that diselenide bonds are dynamic covalent bonds and undergo dynamic exchange reactions under mild conditions for diselenide metathesis. This reaction is induced by irradiation with visible light and stops in the dark. The exchange is assumed to proceed through a radical mechanism, and experiments with 2,2,6,6‐tetramethylpiperidin‐1‐yloxyl (TEMPO) support this assumption. Furthermore, the reaction can be conducted in different solvents, including protic solvents. Diselenide metathesis can also be used to synthesize diselenide‐containing asymmetric block copolymers. This work thus entails the use of diselenide bonds as dynamic covalent bonds, the development of a dynamic exchange reaction under mild conditions, and an extension of selenium‐related dynamic chemistry.     

Iodosobenzene Diacetate and Diphenyl Diselenide: An Electrophilic Selenenylating Agent of Double Bonds

Phenylseleno-acetoxylation, hydroxylation, etherification and lactonization products are obtained in good yields from the reaction of alkenes with diphenyl diselenide and iodosobenzene diacetate, in acetonitrile.

     

Highly Stable Passively Q-Switched Erbium-Doped All-Fiber Laser Based on Niobium Diselenide Saturable Absorber

A saturable absorber (SA) based on niobium diselenide (NbSe₂), which is a layered transition metal dichalcogenide (TMD) in the VB group, is fabricated by the optically driven deposition method, and the related nonlinear optical properties are characterized. The modulation depth, saturable intensity, and nonsaturable loss of the as-prepared NbSe₂ nanosheet-based SA are measured to be 16.2%, 0.76 MW/cm², and 14%, respectively. By using the as-fabricated NbSe₂ SA, a highly stable, passively Q-switched, erbium-doped, all-fiber laser is realized. The obtained shortest pulse width is 1.49 μs, with a pulse energy of 48.33 nJ at a center wavelength of 1560.38 nm. As far as we know, this is the shortest pulse duration ever obtained by an NbSe₂ SA in a Q-switched fiber laser.     

Thermal Addition of Diphenyl Disulfide to Ethynyltrimethylsilane in the Presence of Dimethyl Diselenide

Russian Journal of General Chemistry -