- Catalytic Hydrogenation of Thioesters, Thiocarbamates, and Thioamides
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Direct hydrogenation of thioesters with H2 provides a facile and waste-free method to access alcohols and thiols. However, no report of this reaction is documented, possibly because of the incompatibility of the generated thiol with typical hydrogenation catalysts. Here, we report an efficient and selective hydrogenation of thioesters. The reaction is catalyzed by an acridine-based ruthenium complex without additives. Various thioesters were fully hydrogenated to the corresponding alcohols and thiols with excellent tolerance for amide, ester, and carboxylic acid groups. Thiocarbamates and thioamides also undergo hydrogenation under similar conditions, substantially extending the application of hydrogenation of organosulfur compounds.
- Luo, Jie,Rauch, Michael,Avram, Liat,Ben-David, Yehoshoa,Milstein, David
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supporting information
p. 21628 - 21633
(2021/01/11)
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- [FeFe]-Hydrogenase H-Cluster Mimics with Various -S(CH2)nS- Linker Lengths (n = 2-8): A Systematic Study
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The effect of the nature of the dithiolato ligand on the physical and electrochemical properties of synthetic H-cluster mimics of the [FeFe]-hydrogenase is still of significant concern. In this report we describe the cyclization of various alkanedithiols to afford cyclic disulfide, tetrasulfide, and hexasulfide compounds. The latter compounds were used as proligands for the synthesis of a series of [FeFe]-hydrogenase H-cluster mimics having the general formulas [Fe2(CO)6{μ-S(CH2)nS}] (n = 4-8), [Fe2(CO)6{μ-S(CH2)nS}]2 (n = 6-8), and [Fe2(CO)6{(μ-S(CH2)nS)2}] (n = 6-8). The resulting complexes were characterized by 1H and 13C{1H} NMR and IR spectroscopic techniques, mass spectrometry, and elemental analysis as well as X-ray analysis. The purpose of this research was to study the influence of the systematic increase of n from 2 to 7 on the redox potentials of the models and the catalytic ability in the presence of acetic acid (AcOH) by applying cyclic voltammetry.
- Abul-Futouh, Hassan,Almazahreh, Laith R.,Harb, Mohammad Kamal,G?rls, Helmar,El-Khateeb, Mohammad,Weigand, Wolfgang
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p. 10437 - 10451
(2017/09/12)
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- Reduction of thiokols in the system hydrazine hydrate-base as a new route to alkanedithiols
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A new procedure for preparative synthesis of alkanedithiols from simple commercially available products is based on reduction of the S-S bond in appropriate polyalkylene disulfides (thiokols) in the system hydrazine hydrate-base. Thiokols were prepared by reaction of dihaloalkanes with Na2S2 or K2S2 generated from elemental sulfur and alkali in aqueous hydrazine hydrate. Reaction of 1,2-dibromocyclohexane with sodium or potassium disulfide yields bis(2-bromocyclohexyl) sulfide as the only product.
- Alekminskaya,Russavskaya,Korchevin,Deryagina,Trofimov
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p. 732 - 737
(2007/10/03)
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- One pot rapid synthesis of thiols from alcohols under mild conditions
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Thiols are prepared in high yields from corresponding alcohols using Ph3P, NBS in acetone and followed by addition of polymer supported hydrosulfide under mild condition.
- Bandgar,Sadavarte
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p. 908 - 910
(2007/10/03)
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- A Reagent for Reduction of Disulfide Bonds in Proteins That Reduces Disulfide Bonds Faster Than Does Dithiothreitol
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We have synthesized a new reagent - N,N'-dimethyl-N,N'-bis(mercaptoacetyl)hydrazine (DMH) - for the reduction of disulfide bonds in proteins.DMH reduces disulfide bonds 7 times faster than does dithiothreitol (DTT) in water at pH 7.DMH reduces mixed disulfides of cysteine proteases (papain and ficin) especially rapidly (30 times faster than DTT).DMH (ε0 = -0.300 V) reduces noncyclic disulfides completely, although it is less strongly reducing than DTT (ε0 = -0.356 V).
- Singh, Rajeeva,Whitesides, George M.
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p. 2332 - 2337
(2007/10/02)
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- Process for the preparation of organic thiosulphates
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The invention provides a process for the preparation of a compound of general formula, M-O-O2S-S-X-S-SO2-O-M (I), where X represents an alkylene radical, and M represents a monovalent metal, the equivalent of a multivalent metal, a monovalent ion derived by the addition of a proton to a nitrogenous base, or the equivalent of a multivalent ion derived by the addition of two or more protons to a nitrogenous base or M represents the equivalent of a complex cation of nickel or cobalt with an amine, which process comprises reacting a dithiol of general formula, H-S-X-S-H (II), where X is as defined above with a sulphur trioxide-base complex of formula, SO3.A (III), where A is a nitrogenous base selected from optionally substituted pyridine, optionally substituted quinoline and tertiary amines of formula NR1R2R3 wherein R1, R2 and R3 are independently selected from C1-20alkyl, phenyl and benzyl groups, to produce a compound of formula I wherein M represents a monovalent ion AH , optionally followed by reaction with an alkali metal hydroxide to produce a compound of formula I wherein M represents an alkali metal, optionally followed by conversion of the compound of formula I wherein M represents an alkali metal into another compound of formula I wherein M is as defined above.
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- Polyfunctional disulfide compounds having S--S exchange reactivity
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A polyfunctional disulfide compound, useful as a cross-linking reagent having S--S exchange reactivity, of the formula STR1 wherein R is 2-benzothiazolyl or 2-pyridyl-N-oxide and X is a spacer group having an alkylene group directly bonded to each S--S group.
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- Ethylenic silicon compounds and thermoplastic elastomers obtained therefrom
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The invention provides organosilicon compounds of the formula: STR1 in which: N IS 1, 2 OR 3; Each R, which may be identical or different, is a monovalent organic group which contains a carbon-carbon double bond and from 2 to 10 carbon atoms; Each R1, which may be identical or different, is a straight or branched alkyl radical optionally substituted by one or more halogen atoms or cyano groups; an aryl radical or an alkylaryl radical optionally substituted by one or more halogen atoms; R2 is a straight or branched divalent alkylene or alkylidene radical possessing up to 4 carbon atoms; X is a divalent radical consisting of, or containing, at least one hetero-atom selected from oxygen, sulphur and nitrogen atoms, the radical being attached to the radical R2 via a said hetero-atom; G is an organic radical of valency (m+ l) possess from 1 to 30 carbon atoms; m is 1, 2 or 3; And each Y, which may be identical or different, is a functional group selected from: --NO2, STR2 --COOM (where M represents a sodium, potassium or lithium atom); --COOR4 ; STR3 --COCl; --OH; --OR4 ; STR4 --SH; --SR4 ; STR5 --CONH2 ; --CSNH2 ; --CN; --CH2 --NH2 ; --CHO; STR6 --NCO; STR7 wherein R3 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 6 carbon atoms and R4 represents an alkyl radical possessing up to 4 carbon atoms, with the proviso that two Y groups can together constitute an imide group STR8 wherein R5 represents a hydrogen atom or a straight or branched alkyl radical possessing up to 4 carbon atoms. These are useful intermediates in the preparation of disilanes and silicon polymers, in particular of polyethylenic silicon compounds which can be polymerized with an α, ω-dihydrogenopolysiloxane to give thermoplastic elastomers.
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