Bis Selenide Research Articles

Unexpected Carbon–Selenium Bond Formation in the Reaction of Secondary Phosphine Selenides with Benzoylphenylacetylene

Secondary phosphine selenides reacted as selenating agents with benzoylphenylacetylene in wet acetonitrile (70–72°C) to give bis(2-benzoyl-1-phenylvinyl) selenide in up to 43% yield.

Green Hydroselenation of Aryl Alkynes: Divinyl Selenides as a Precursor of Resveratrol.

A simple and efficient protocol to prepare divinyl selenides has been developed by the regio- and stereoselective addition of sodium selenide species to aryl alkynes. The nucleophilic species was generates in situ, from the reaction of elemental selenium with NaBH4, utilizing PEG-400 as the solvent. Several divinyl selenides were obtained in moderate to excellent yields with selectivity for the (Z,Z)-isomer by a one-step procedure that was carried out at 60 °C in short reaction times. The methodology was extended to tellurium, giving the desired divinyl tellurides in good yields. Furthermore, the Fe-catalyzed cross-coupling reaction of bis(3,5-dimethoxystyryl) selenide 3f with (4-methoxyphenyl)magnesium bromide 5 afforded resveratrol trimethyl ether 6 in 57% yield.

Bis(1,3-dioxolan-2-ylmethyl)selenide

The reaction of selenium dihalides with 2-vinyloxyethanol has been performed for the first time, and the method of preparation of bis(1,3-dioxolan-2-ylmethyl)selenide in quantitative yield has been proposed.

Effective synthesis of bis(1,4-dioxan-2-ylmethyl)selenide and selenoxide

Effective synthesis of bis(1,4-dioxan-2-ylmethyl)selenide and selenoxide

Chalcogenation of 1,3-dichloropropene with elemental chalcogens in the system hydrazine hydrate–base

Sulfur reacts with 1,3-dichloropropene in the system hydrazine hydrate–KOH to form bis(1-chloroprop-1-en-3-yl) sulfide, and in the system hydrazine hydrate–monoethanolamine, bis(1-chloroprop-1-en- 3-yl) disulfide. The reaction of tellurium in the system hydrazine hydrate–KOH leads to diallyl telluride, the product of nucleophilic substitution of the allylic chlorine atom and reductive cleavage of the Сsp2–Cl bond. The reaction of selenium with 1,3-dichloropropene gives a complex mixture of products. At excess KOH (Se: KOH = 1: 5) bis(1-chloroprop-1-en-3-yl) selenide was isolated.

Reactivity Study of a Pyridyl-1-azaallylgermanium(I) Dimer: Synthesis of Heavier Ether and Ester Analogues of Germanium.

The reactivity study of a pyridyl-1-azaallylgermanium(I) dimer LGe-GeL [1; L = N(SiMe3)C(Ph)C(SiMe3)(C5H4N-2)] with different stoichiometric ratios of elemental selenium and tellurium is described. The reactions of 1 with 1 equiv of selenium and tellurium afforded the first examples of heavier ether analogues of germanium, bis(germylene) selenide and telluride LGe(μ-E)GeL [E = Se (2) and Te (3)], respectively. Meanwhile, the reactions of 1 with 2 equiv of selenium and tellurium gave the heavier ester analogues LGe═E(μ-E)GeL [E = Se (4) and (5)]. All compounds have been characterized by X-ray crystallography and multinuclear NMR spectroscopy.

Silver(I) complexes of a new multidentate macrocyclic ligand with N/S/Se donor atoms

The 28 membered macrocyclic ligand L (1) containing S, Se and N donor atoms was obtained by the [2+2] condensation reaction between bis(o-formylphenyl)selenide and bis(2-aminoethyl)sulfane. The reaction between 1 and AgX in a 1:1 molar ratio resulted in the ionic species [LAg]+X− [X=OSO2CF3 (2), PF6 (3) and BF4 (4)]. The NMR spectra of ligand 1 at room temperature suggest a mixture of two invertomers in chlorinated solvents, while the spectra of 1 in C6D6 indicate only one species in solution. The molecular structures of 1 and the silver(I) complexes 2 and 3·2CHCl3 were determined by single-crystal X-ray diffraction. A N,N,S,S,Se,Se coordination behavior of the ligand and a distorted octahedral environment about Ag(I) were observed in the [LAg]+ cation in both complexes.

Synthesis of new functionalized organoselenium compounds by heterocyclization of selenium dihalides with pent-4-en-1-ol

The reaction of selenium dihalides with pent-4-en-1-ol has been carried out for the first time. Efficient procedures for the synthesis of previously unknown bis(tetrahydrofuran-2-ylmethyl) selenide, dihalobis( tetrahydrofuran-2-ylmethyl)-λ4-selanes, and bis(tetrahydrofuran-2-ylmethyl) selenoxide have been developed on the basis of this reaction. The product structures have been studied by 1H, 13C, and 77Se NMR. Bis(tetrahydrofuran-2-ylmethyl) selenide and dihalobis(tetrahydrofuran-2-ylmethyl)-λ4-selanes represent equimolar mixtures of two diastereoisomers which display different signals in the 13C and 77Se NMR spectra. The oxidation of bis(tetrahydrofuran-2-ylmethyl) selenide with sodium periodate in methanol leads to the corresponding selenoxide consisting of 4 diastereoisomers.

ChemInform Abstract: Bis(trimethylsilyl)selenide in the Selective Synthesis of β‐Hydroxy, β‐Mercapto, and β‐Amino Diorganyl Diselenides and Selenides Through Ring Opening of Strained Heterocycles.

AbstractA novel approach to the synthesis of β‐substituted dialkyl diselenides and selenides is described through reaction of bis(trimethylsilyl)selenide with epoxides, thiiranes, and aziridines catalyzed by tetrabutylammonium fluoride.

Synthesis of bis(4-hydroxyphenyl) selenide and epoxide and acrylate monomers on this basis

Reaction of SeCl2 with PhOH has afforded bis(4-hydroxyphenyl) selenide, whose treatment with epichlorohydrin provides a diepoxide that is transformed in bisacrylate and further in tetraacrylate via opening of the epoxide rings with acrylic acid followed by acylation with acryloyl chloride.

Bis(trimethylsilyl)selenide in the Selective Synthesis of β‐Hydroxy, β‐Mercapto, and β‐Amino Diorganyl Diselenides and Selenides Through Ring Opening of Strained Heterocycles

AbstractA novel approach to the synthesis of β‐substituted dialkyl diselenides and selenides is described through reaction of bis(trimethylsilyl)selenide with epoxides, thiiranes, and aziridines catalyzed by tetrabutylammonium fluoride. Selective formation of a wide variety of β‐hydroxy, β‐mercapto, and β‐amino diselenides and selenides is achieved by controlling the reaction conditions in the regioselective attack of the silyl selenide onto the ring‐strained heterocycles. All reactions occur in a highly regioselective and enantioconservative manner, affording the title compounds with good to high yields. Selenium‐77 NMR chemical shifts were measured to verify the selective formation of the β‐substituted diselenides and selenides.

A facile route for CdSe nanoparticles: synthesis and structural characterisation

Semiconducting CdSe nanoparticles of a few nanometers in size were synthesised by solvothermal decomposition of novel, single-source molecular precursor Cd(II) complex of bis(aminoethyl)selenide ((NH2CH2CH2)2Se.CdCl2)) using quinoline as coordinating agent at 200°C. Particle size, structural phase, elemental compositions, morphology and optical bandgap of as-synthesised nanoparticles were characterised using X-ray diffraction (XRD), energy-dispersive X-ray spectroscopy (EDAX), transmission electron microscopy (TEM) and UV–Vis spectroscopy. The XRD pattern revealed that hexagonal CdSe nanocrystallites of ≈7 nm average size can be obtained by the solvothermal decomposition of ((NH2CH2CH2)2Se.CdCl2)) in quinoline. Elemental composition ratio of Cd:Se reveals non-stochiometric phase as confirmed standard less ZAF quantification, where Z, A and F are the matrix correction parameters, describing the atomic number effect (stopping power and backscatter effect), the absorption effect, and the fluorescence effect, respectively, in EDAX. Absorption spectra show blue shift in the absorption in nano particles with respect to their bulk counterpart and the calculated optical bandgap is estimated at 3·94 eV. This method has several advantages such as non-toxic and non-pyroforic single-source precursor, relatively low temperature and avoids the need for inert environment. However, quinoline used as coordinating agent has proved ineffective in capping and dispersing the nanoparticles and need to be further investigated.

Thiosilane‐ and Organoselenosilane‐Mediated Novel Access to 3,7‐Disubstituted‐1,2,5‐ trithiepanes and ‐1,2,5‐dithiaselenepanes

ABSTRACTThe reaction of bis(trimethylsilyl) sulfide with different substituted thiiranes under tetrabutylammonium fluoride (TBAF) catalysis leads to the synthesis of 3,7‐disubstituted‐1,2,5‐trithiepanes, through regioselective reaction of a thiosilane intermediate with another molecule of episulfide, followed by intramolecular oxidation of two sulfur units. When using bis(trimethylsilyl)selenide, the reaction with thiiranes and TBAF affords a smooth access to a novel class of disubstituted‐1,2,5‐dithiaselenepanes.

Selenium- and tellurium-containing binucleophiles in selective synthesis of allene and methylacetylene from 2,3-dichloro-1-propene

Recently, we have shown that pure allene is formed in the reaction of K2Te2 with 2,3-dichloro-1-propene (I) in the hydrazine hydrate – KOH medium [2]. In the case of Se analog (K2Se2), the reaction with compound I does not yield any gaseous products but rather gives bis(2-chloro-1-propene-3-yl)selenide [3]. Extending the studies of chalcogen-containing nucleophiles reactions with I, we here report on the behavior of binucleophilic reagents, potassium 1,3-propaneditellurolate (IIа) and potassium 1,3-propanediselenolate (IIb). Compounds IIа and IIb were prepared by reductive decomposition of the respective poly(trimethylenedichalcogenides) [4, 5] in the hydrazine hydrate–KOH medium. The so obtained salts IIа and IIb were introduced in the reaction with I without isolation.

ChemInform Abstract: Synthesis of Bis(1,2,2‐trichloroethyl) and Bis(dichlorovinyl) Selenides by Electrophilic Reaction of Selenium Dichloride with 1,2‐Dichloroethylene.

AbstractThe reaction of 1,2‐dichloroethylene (I) with selenium dichloride is studied.

Stereoselective reaction of selenium dihalides with hex-3-yne

In recent time, the synthetic potential of new electrophilic reagents, selenium dichloride and selenium dibromide, has attracted much interest [1–6]. These reagents are more selective than selenium tetrahalides used previously [7]. For example, reactions of selenium dichloride and dibromide with acetylene follow stereoselective anti-addition pattern with formation of (E,E)-bis(2-halovinyl) selenides in nearly quantitative yield [2], whereas the addition of selenium tetrahalides to acetylene gives both (E,E)-bis(2-halovinyl) selenides and their halogenation products at one double bond [7]. The addition of selenium dihalides to acetylenic compounds is generally regioand stereoselective; however, the nature of substituents at the triple bond could considerably affect steric configuration of the product [1–5]. For instance, unexpected anti–syn-addition product, (Z,E)-bis(2-chloro-3-trimethylsilylprop1-en-1-yl) selenide was obtained in the reaction of selenium dichloride with 3-trimethylsilylprop-1-yne [3]. It was presumed that the first elementary step of this reaction occurs as anti-addition, but in the second step syn-addition of the primary adduct to the second 3-trimethylsilylprop-1-yne molecule appears to be energetically more favorable than the anti-addition due to strong steric effect of two trimethylsilyl groups [3]. Reactions of selenium dihalides with propargyl alcohols lead to the corresponding syn-addition products, (Z,Z)-bis(1-halo-3-hydroxyprop-1-en-2-yl) selenides [4]. Their steric structure is determined by the hydroxy group which acts as internal nucleophile [4].

Synthesis of bis(1,2,2-trichloroethyl) and bis(dichlorovinyl) selenides by electrophilic reaction of selenium dichloride with 1,2-dichloroethylene

Electrophilic reactions of sulfur dichloride with unsaturated systems underlie one of the most general methods for the synthesis of bis(2-chloroalkyl) sulfides [1]. Reactions of analogous unsaturated compounds with selenium tetrachloride yield the corresponding bis-adducts containing a four-coordinate selenium atom (>SeCl2) [2]. In recent years we performed systematic studies on reactions of SeCl2 with alkenes and their oxygenand sulfur-containing derivatives [3, 4]. Reactions with chlorinated ethylenes, such as chloroethene, 1,1and 1,2-dichloroethenes, and trichloroethene were reported only for SCl2, and they required the presence of Lewis acids as catalyst [5]. Garratt et al. [6] showed that SeCl4 failed to react with 1,2-dichloroethene in the presence of AlCl3 as catalyst. Nevertheless, we succeeded in adding SeCl2 to bis(2-chlorovinyl) selenide (a selenium-containing derivative of 1,2-dichloroethene) in the absence of a catalyst [7]. Sulfur and selenium dichlorides are known to act as chlorinating agents toward alkylsulfanyl derivatives of polychloroethenes, e.g., alkyl 2,2-dichlorovinyl sulfides [8].

Acute Treatment with Bis Selenide, an Organic Compound Containing the Trace Element Selenium, Prevents Memory Deficits Induced by Reserpine in Rats

Taking into account the promising pharmacological actions of (Z)-2,3-bis(4-chlorophenylselanyl) prop-2-en-1-ol) (bis selenide), an organic compound containing the trace element selenium, and the constant search for drugs that improve the cognitive performance, the objective of the present study was to investigate whether bis selenide treatment ameliorates memory deficits induced by reserpine in rats. For this aim, male adult rats received a single subcutaneous injection of reserpine (1mg/kg), a biogenic amine-depleting agent used to induce memory deficit. After 24h, bis selenide at doses of 25 and 50mg/kg was administered to rats by intragastric route, and 1h later, the animals were submitted to behavior tasks. The effects of acute administration of bis selenide on memory were evaluated by social recognition, step-down passive avoidance, and object recognition paradigms. Exploratory and locomotor activities of rats were determined using the open-field test. Analysis of data revealed that the social memory disruption caused by reserpine was reversed by bis selenide at both doses. In addition, bis selenide, at the highest dose, prevented the memory deficit resulting from reserpine administration to rats in step-down passive avoidance and object recognition tasks. No significant alterations in locomotor and exploratory behaviors were found in animals treated with reserpine and/or bis selenide. Results obtained from distinct memory behavioral paradigms revealed that an acute treatment with bis selenide attenuated memory deficits induced by reserpine in rats.

Synthesis of bis(2-pyridylmethyl)selenide and solid-state structural characterization of bis-tridentate zinc triad perchlorate chelates

Bis-tridentate chelates of Cd(ClO4)2 and Hg(ClO4)2 with N4Se2 metal coordination environments were isolated by slow evaporation from methanol/n-butanol solutions containing two equivalents of bis(2-methylpyridyl)selenide (L). The ligand L was obtained through a previously unexplored pathway to symmetric selenoethers involving selenoacetamide. Although no structurally characterized complexes of the harder group 12 metal ions Zn(II) or Cd(II) with selenoether ligands have had M–SeR2 bonds and numerous attempts to crystallize a bis-tridentate chelate of Zn(II) were unsuccessful, the distorted trans facial octahedral complex [CdL2](ClO4)2 was characterized. In addition, X-ray crystallographic characterization of [HgL2](ClO4)2 revealed a mononuclear structure with distorted trigonal prismatic coordination geometry, the highest coordination number Hg(II) complex with selenoether ligands yet reported.

Organoselenium Bis Selenide Attenuates 3-Nitropropionic Acid-Induced Neurotoxicity in Rats

This study was designed to evaluate the effects of bis selenide on Huntington disease (HD)-like signs induced by 3-nitropropionic acid (3-NP) in rats. To this aim, rats were treated for 4days with bis selenide (5 or 20mg/kg/day, per oral) 30min before 3-NP (20mg/kg/day, intraperitoneally). The body weight gain, locomotor activity, motor coordination, and biochemical parameters in striatal preparations were assessed 24h after the last injection of 3-NP. The highest dose of bis selenide was effective in protecting against body weight loss and motor coordination deficit induced by 3-NP. The impairment of locomotor activity caused by 3-NP was abolished by bis selenide at both doses. Bis selenide (5 and 20mg/kg) partially restored succinate dehydrogenase activity inhibited after 3-NP exposure. The dose of 20mg/kg of bis selenide recovered partially δ-aminolevulinic acid dehydratase activity, and totally Na(+), K(+)-ATPase activity, two sulfhydryl enzymes sensitive to oxidizing agents, which had their activities inhibited by 3-NP. Also, 3-NP led to an increase in protein carbonyl levels and glutathione reductase activity and inhibited catalase activity-alterations that were reversed by bis selenide administration at both doses. The highest dose of bis selenide was effective against the increase of RS levels, the depletion of reduced glutathione content, and the inhibition of glutathione peroxidase activity induced by 3-NP. Bis selenide was not effective against inhibition of SOD activity caused by 3-NP. These findings demonstrate that bis selenide elicited protective effects against HD-like signs induced by 3-NP in rats.