- Regio- And stereoselective synthesis of new ensembles of diversely functionalized 1,3-thiaselenol-2-ylmethyl selenides by a double rearrangement reaction
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The reaction of 2-(bromomethyl)-1,3-thiaselenole with potassium selenocyanate proceeded via a rearrangement with ring expansion, leading to a six-membered 2,3-dihydro-1,4-thiaselenin-2-yl selenocyanate (kinetic product) which in turn underwent rearrangement with ring contraction to a 1,3-thiaselenol-2-ylmethyl selenocyanate (thermodynamic product). These rearrangements occurred by a nucleophilic attack of the selenocyanate anion at two different carbon atoms of the seleniranium intermediate. The efficient regioselective synthesis of alkyl, allyl, 2-propynyl, benzyl, 4-fluorobenzyl, and 2-pyridinylmethyl 1,3-thiaselenol-2-ylmethyl selenides was developed based on the generation of sodium 1,3-thiaselenol-2-ylmethylselenolate from 1,3-thiaselenol-2-ylmethyl selenocyanate or bis(1,3-thiaselenol-2-ylmethyl) diselenide followed by nucleophilic substitution reactions. Sodium 1,3-thiaselenol-2-ylmethylselenolate underwent nucleophilic addition to alkyl propiolates in a regio- and stereoselective manner affording 1,3-thiaselenol-2-ylmethyl vinyl selenides in high yields predominantly with Z-configuration. Not a single representative of the 1,3-thiaselenol-2-ylmethyl selenide scaffold has been previously described in the literature.
- Albanov, Alexander I.,Amosova, Svetlana V.,Filippov, Andrey A.,Makhaeva, Nataliya A.,Potapov, Vladimir A.
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- Synthesis of some new selenonitrone compounds
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The carbonyl selenonitrile and dicarbonyl diselane compounds were prepared by using the inorganic reagent such as potassium selenocyanate. New nitrone compounds were synthesized from the condensation of carbonyl group in the selenocarbonyl compounds with substituted N-phenylhydroxylamine and N-benzyl hydroxylamine. The resulting products were identified by physical properties such as melting point (M.p.), retardation factor (Rf) and color. Also compounds showed the expected data in identification techniques such as FTIR, 1H NMR, 13 C NMR, mass spectroscopy and Elemental analysis (CHN). The results proved the validity of the expected chemical structures of synthesized compounds.
- Haddad, Batool Saleh
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- A Comprehensive Study on the Full Series of Alkali-Metal Selenocyanates AI[SeCN] (AI=Li?Cs)
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The full series of quasibinary alkali-metal selenocyanates was synthesized either by oxidation of the respective cyanides (A=Li?Rb) or by metathesis (A=Cs). For Li[SeCN] only ball-milling and subsequent annealing led to the isolation of the quasibinary selenocyanate. Their structures were refined from single-crystal and powder X-ray data. The respective solid-state IR and Raman spectra were interpreted with the aid of solid-state quantum-mechanical calculations and DSC-TGA measurements allowed for extraction of melting points. Only for Li[SeCN] a possible phase transition was observed that is discussed on the basis of VT-PXRD experiments. It is also the only quasibinary selenocyanate to form a hydrate (Li[SeCN] ? 2H2O).
- Shlyaykher, Alena,Ehmann, Marvin,Karttunen, Antti J.,Tambornino, Frank
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- Cytotoxicity of new selenoimine, selenonitrone, and nitrone derivatives against human breast cancer MDA-MB231 cells
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A series of new nitrone, selenoimine and selenonitrone derivatives were synthesized. Nitrone and selenonitrone derivatives were synthesized through the condensation reaction between N-mono substitutedhydroxylamine and carbonyl compounds substituted with electron donating groups, such as di(4-methoxy)benzoyl diselenide, 4-(N, N-dimethylamino) benzoyl selenonitrile and 4, 4'-di(N, N- dimethylamino)benzil, afforded a variety of new nitrone and selenonitrone compounds. Selenoimine derivative was synthesized through the condensation reaction between tert-butyl amine and (4-methoxybenzoyl selenonitrile). The yield of synthesized compounds (N1, N2, N3, N4 and N5 were (66, 60, 61, 62 and 45) %, respectively. The structures of the synthesized compounds were characterized by FT-IR, 1H-NMR, 13C-NMR, and mass spectra. Cytotoxicity of selenonitrone (N1) and selenoimine (N3) derivatives against breast cancer cells (MDA-MB231) were evaluated for 24 and 48 h via MTT assay. The IC50 value of compound N1 was 1.714 and 1.897 μM for 24 h and 48 h, respectively. The IC50 value of compound N3 was 1.438 and 2.469 μM for 24 h and 48 h, respectively. The results suggested selenonitrone (N1) and selenoimine (N3) as anti-breast cancer potential lead compound with future merit investigations.
- Haddad, Batool Saleh,Al-Shawi, Ali A.A.
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p. 4607 - 4613
(2020/12/11)
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- A Scalable Process for the Synthesis of 1,2-Dialkyldiselanes and 1-Alkaneselenols
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A four-step telescoped process for the synthesis of 1-alkaneselenols entails (1) the rapid formation of potassium selenocyanate from potassium cyanide and selenium in methanol, (2) the nucleophilic substitution of bromoalkanes or alkyl tosylates with potassium selenocyanate, (3) the mild base-catalyzed conversion of the resultant 1-alkaneselenocyanates to 1,2-dialkyldiselanes (the Krief reaction), and (4) the reduction of the resultant 1,2-dialkyldiselanes with hypophosphorous acid to give the desired 1-alkaneselenols. The process has been used to produce 1-octaneselenol on a 10.4 mol scale. Nine examples of the process are described.
- Cooksey, John P.,Kocieński, Philip J.,Blacker, A. John
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supporting information
p. 2571 - 2575
(2019/11/14)
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- Selective Synthesis of 1,3-Thiaselenol-2-ylmethyl Selenocyanate
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2-Bromomethyl-1,3-thiaselenole reacted with potassium selenocyanate in acetonitrile at room temperature to give in 5 min 97% of 1,3-thiaselenol-2-ylmethyl selenocyanate.
- Potapov,Filippov,Amosova
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p. 957 - 958
(2018/07/31)
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- Synthesis, structures, EPR and ENDOR investigations on transition metal complexes of N,N-diisobutyl-N′-(2,6-difluoro)benzoyl selenourea
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The synthesis and the structures of the NiII and PdII complexes of the ligand N,N-diisobutyl-N′-(2,6-difluoro)benzoylselenourea HBui2dfbsu are reported. The ligands coordinate bidentately forming bis-chelates. The structure of the ligand could not be obtained, however, the structure of its O-ethyl ester will be reported. Attempts to prepare the CuII complex result only in the formation of oily products. However, the CuII complex could be incorporated into the corresponding NiII and PdII compounds. From this diamagnetically diluted powder and single-crystal samples were obtained being suitable for EPR-ENDOR measurements. We report X- and Q-band EPR investigations on the systems [Cu/Ni(Bui2dfbsu)2] and [Cu/Pd(Bui2dfbsu)2] as well as a single-crystal X-band EPR study for [Cu/Ni(Bui2dfbsu)2]. The obtained 63,65Cu and 77Se hyperfine structure tensors allow a determination of the spin-density distribution within the first coordination sphere. In addition, orientation selective 19F Q-band pulse ENDOR investigations on powder-samples of [Cu/Ni(Bui 2dfbsu)2] have been performed. The hyperfine structure tensors of two intramolecular 19F atoms could be determined. According to the small 19F couplings only a vanishingly small spin-density of 19F atoms.
- Kampf, Michael,Richter, Rainer,Griebel, Jan,Weller, Anke,Kirmse, Reinhard
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p. 698 - 708
(2008/10/09)
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