- Highly selective radical isothiocyano-chalcogenization of alkenes with NH4SCN in water
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In the presence of catalytic amounts of molecular iodine and stoichiometric potassium persulfate, a green, highly chemoselective, regioselective and cis-selective radical isothiocyano-chalcogenization of alkenes with NH4SCN in water is disclosed. This three component reaction features high selectivities, an environmentally benign process, mild conditions, high yields, excellent functional-group tolerance, and broad substrate scope. The resulting products can be further transformed into other molecules with structural similarities of these compounds to bioactive analogs.
- He, Ze,Kang, Xiaokang,Xu, Chao,Zeng, Qingle
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supporting information
p. 7544 - 7548
(2021/10/12)
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- Catalyst-Controlled Regioselective Chlorination of Phenols and Anilines through a Lewis Basic Selenoether Catalyst
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We report a highly efficient ortho-selective electrophilic chlorination of phenols utilizing a Lewis basic selenoether catalyst. The selenoether catalyst resulted in comparable selectivities to our previously reported bis-thiourea ortho-selective catalyst, with a catalyst loading as low as 1%. The new catalytic system also allowed us to extend this chemistry to obtain excellent ortho-selectivities for unprotected anilines. The selectivities of this reaction are up to >20:1 ortho/para, while the innate selectivities for phenols and anilines are approximately 1:4 ortho/para. A series of preliminary studies revealed that the substrates require a hydrogen-bonding moiety for selectivity.
- Dinh, Andrew N.,Maddox, Sean M.,Vaidya, Sagar D.,Saputra, Mirza A.,Nalbandian, Christopher J.,Gustafson, Jeffrey L.
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p. 13895 - 13905
(2020/11/03)
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- Transition metal-free coupling reactions of benzylic trimethylammonium salts with di(hetero)aryl disulfides and diselenides
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A new protocol was developed to synthesize (enantioenriched) thioethers and selenoethers from (chiral) benzylic trimethylammonium salts and di(hetero)aryl disulfides or diselenides. These syntheses were promoted by the presence of weak base and did not require the use of any transition metal, and resulted in the target products with good to excellent yields (72-94%). Using quaternary ammonium salts synthesized from enantiomerically enriched amines led to highly enantiopure benzylic thioethers and selenoethers (94-99% ee) with configurations reversed from those of their enantioenriched quaternary ammonium salts. This journal is
- Li, Fuhai,Wang, Dan,Chen, Hongyi,He, Ze,Zhou, Lihong,Zeng, Qingle
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supporting information
p. 13029 - 13032
(2020/11/07)
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- Preparation method for diphenyl diselenium compound
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The invention discloses a preparation method for a diphenyl diselenium compound. According to the method, an arylboronic acid compound and elemental selenium serve as reaction raw materials, an organic solvent serves as a reaction solvent, under the effect of a silver catalyst, reaction is carried out so as to obtain the diphenyl diselenium compound, the reaction temperature is 100-140 DEG C, thereaction equation is shown in the specification, wherein R is a benzene ring, a naphthalene ring, a heterocyclic ring or a substituted benzene ring. The method has the beneficial effects that the tolerance of functional groups of substrates is high, and the range of the substrates is wide; and the raw materials and the catalyst are cheap and easily available, the conditions are mild, the post-treatment is simple, the yield and purity of a product are high, and the method is suitable for large-scale industrial production.
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Paragraph 0069-0071
(2018/06/28)
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- Synthesis, structure and reactivity of Ni site models of [NiFeSe] hydrogenases
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A series of structural models of the Ni centre in [NiFeSe] hydrogenases has been developed which exhibits key structural features of the Ni site in the H2 cycling enzyme. Specifically, two complexes with a hydrogenase-analogous four-coordinate 'NiS3Se' primary coordination sphere and complexes with a 'NiS2Se2' and a 'NiS 4' core are reported. The reactivity of the complexes towards oxygen and protons shows some relevance to the chemistry of [NiFeSe] hydrogenases. Exposure of a 'NiS3Se' complex to atmospheric oxygen results in the oxidation of the selenolate group in the complex to a diselenide, which is released from the nickel site. Oxidation of the selenolate ligand on Ni occurs approximately four times faster than oxidation with the analogous sulfur complex. Reaction of the complexes with one equivalent of HBF4 results in protonation of the monodentate chalcogenolate and the release of this ligand from the metal centre as a thiol or selenol. Unrelated to their biomimetic nature, the complexes serve also as molecular precursors to modify electrodes with Ni-S-Se containing particles by electrochemical deposition. The activated electrodes evolve H2 in pH neutral water with an electrocatalytic onset potential of -0.6 V and a current density of 15 μA cm-2 at -0.75 V vs. NHE.
- Wombwell, Claire,Reisner, Erwin
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p. 4483 - 4493
(2014/03/21)
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- Solid state, structural and solution studies on bis(2-methylbenzyl)-selenide, methyl(2,4,6-tri-t-butylphenyl)-selenide, bis(2,4,6-tri-methylphenyl)-diselenide, and bis(2,4,6-tri-t-butylphenyl)-diselenide
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Two selenides, (2-MeBz)2Se (1) and MeMes*Se (2) and two diselenides, Mes2Se2 (3) and Mes*2Se2 (4) have been prepared and characterized by single-crystal X-ray diffraction and by NMR spectroscopy. The
- Dickson, Paul M.,McGowan, Margaret A.D.,Yearwood, Burl,Heeg, Mary Jane,Oliver, John P.
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- Sterically Hindered Chalcogenolato Complexes. Mono- and Di-meric Thiolates and Selenolates of Zinc and Cadmium; Structure of t3-2,4,6)2>2>, the First Three-co-ordinate Cadmium-Selenium Complex
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Protolysis of M2 (M = Zn or Cd) with arenechalcogenols 2,4,6-R3C6H2EH (E = S or Se; R = Me, Pri or But) gives the corresponding chalcogenolato complexes M(EC6H2R3-2,4,6)2 in high yield.Complexes with R = Me form co-ordinat
- Bochmann, Manfred,Webb, Kevin J.,Hursthouse, Michael B.,Mazid, Muhammed
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p. 2317 - 2323
(2007/10/02)
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- Synthese und Koordinationsverhalten von Selenoalkinylen R-Se-CC-R'
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Synthesis and Coordination Ability of Selenoalkynes R-Se-CC-R' Several synthetic methods for the preparation of selenoalkynes R-Se-CC-R'(1) are discussed. 1 reacts with octacarbonyl dicobalt to yield the η2-?-side-on coordinated alkyne complexes R-Se2-CC-R')Co2(CO)6> (8) which contain a sterically hindered carbon-cobalt tetrahedrane cluster unit.The identity of compounds 1 and 8 is documented by analytical and spectroscopic (IR, MS, 1H-, 77Se-, and 13C-NMR) data as well as by X-ray analysis of C6H5-Se2-CC-C6H5)Co2(CO)6> (8a).
- Lang, Heinrich,Keller, Holger,Imhof, Wolfgang,Martin, Sabine
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p. 417 - 422
(2007/10/02)
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- Metathesis of N-Silyl Compounds with Selenenyl Chlorides. First Preparation of a Selenenyl Azide and a Triselenenamide
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The reaction of trimethylsilyl azide with mesityleneselenenyl chloride afforded mesityleneselenenyl azide, and tris(trimethylsilyl)amine reacted with benzeneselenenyl chloride to produce tribenzeneselenenamide.
- Back, Thomas G.,Kerr, Russell G.
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p. 134 - 135
(2007/10/02)
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- Asymmetric Synthesis with Organo-Selenium Compounds: A Facile Entry to Optically Active 4-Substituted 2-Cyclohexenones by Asymmetric Selenenylation of Ketones with Chiral Selenenamides
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A convenient route to optically active 4-methyl- and 4-t-butyl-2-cyclohexenone using the chiral areneselenenamides, readily generated in situ, to form the 2-areneselenenyl ketones which are subsequently subjected to oxidative selenoxide elimination, is de
- Hiroi, Kunio,Sato, Shuko
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p. 635 - 638
(2007/10/02)
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- Improved Synthesis of Aromatic Diselenides
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The reaction of aromatic and heterocyclic lithio derivatives with elemental selenium, followed by dimethylthiocarbamyl chloride, gives highly crystalline and readily purified Se-aryl N,N-dimethylselenothiocarbamates.Alkaline hydrolysis of the latter, followed by ferricyanide oxidation, affords diselenides.Overall yields and purity of the diselenides are superior to those obtained by the standard direct selenation-oxidation method.
- Jen, Kwan-Yue,Cava, Michael P.
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p. 1449 - 1451
(2007/10/02)
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- Oxidation of Alcohols with tert-Butyl Hydroperoxide and Diaryl Diselenide
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Treatment of alcohols with tert-butyl hydroperoxide in the presence of diaryl diselenide in refluxing benzene gives the corresponding aldehydes or ketones.Although some allylic alcohols undergo oxidation in the presence of 10-15 mol percent of bis(p-chlorophenyl) diselenide, use of 0.5 equiv of bis(2,4,6-trimethylphenyl) diselenide gives satisfactory results in almost all cases.The procedure can be used for selective oxidation of alcohols bearing a phenylthio or phenylseleno group, which usually survives the reaction conditions to give the corresponding carbonyl compounds.
- Kuwajima, Isao,Shimizu, Makoto,Urabe, Hirokazu
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p. 837 - 842
(2007/10/02)
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