1569-69-3Relevant articles and documents
Thiolation of cycloalkenes C5, C6 by redox-activation of hydrogen sulfide
Shinkar, Elena V.,Kudryavtsev, Daniil A.,Pashchenko, Konstantin P.,Berberova, Nadezhda T.,Okhlobystina, Alexandra V.
, p. 180 - 182 (2017)
Direct and indirect redox-activation of H2S in the presence of cyclopentene or cyclohexene in MeCN at 25?°C affords the corresponding cycloalkanethiols.
The benzyl can be selectively removed by visible light or near visible light. Method for protecting allyl and propargyl group
-
Paragraph 0031, (2021/10/16)
The invention provides a method for selectively removing benzyl, allyl and propargyl protecting groups by visible light or near visible light, namely a substrate containing benzyl, allyl or propargyl protecting groups. The method has the advantages of simple operation, safe and clean visible light or near visible light as excitation conditions, cheap and easily available reagents, high reaction yield, high reaction chemistry and regional selectivity, and is suitable for selective removal of benzyl, allyl and propargyl protecting groups in various substrates.
Catalytic Hydrogenation of Thioesters, Thiocarbamates, and Thioamides
Luo, Jie,Rauch, Michael,Avram, Liat,Ben-David, Yehoshoa,Milstein, David
supporting information, p. 21628 - 21633 (2021/01/11)
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.
Chromium(III) and indium(III) 3,6-di-tert-butyl-o-semiquinolate complexes as redox mediators of hydrogen sulfide oxidation in reactions with cycloalkanes
Berberova,Shinkar,Smolyaninov,Shvetsova,Sediki
, p. 578 - 582 (2017/09/23)
The electrochemical oxidation of the chromium(III) and indium(III) complexes with 3,6-di-tert-butyl-o-semiquinolate leading to the formation of active monocationic species is studied by cyclic voltammetry. The reactions of the latter with hydrogen sulfide generate the radical cation of H2S, whose fragmentation affords the proton and thiyl radical. These complexes are proposed for the first time as redox mediators for the one-pot thiolation of inert cycloalkanes C6–C8, which decreases the activation energy of hydrogen sulfide compared to that for direct electrochemical oxidation. The major products of cycloalkane functionalization involving H2S are thiols and organic di- and trisulfides. The yield of the synthesized compounds depends on the type of the mediator: the chromium(III) complex exhibits the highest efficiency in the electrocatalytic transformations.
Insight into the Mechanism of Reversible Ring-Opening of 1,3-Benzoxazine with Thiols
Urbaniak, Tobias,Soto, Marc,Liebeke, Manuel,Koschek, Katharina
, p. 4050 - 4055 (2017/04/27)
The reversible ring-opening addition and fragmentation reaction of p-cresol-based N-phenylbenzoxazine with aliphatic and aromatic thiols was investigated in solvent-mediated and solvent-free reactions. Independently of the used thiol, N-phenylbenzoxazine and the thiols reacted to equilibrium with comparable amounts of reactants and products in aprotic solvent, whereas in protic solvent almost full conversions were reached. In contrast, thiol reactivity was a crucial factor in solvent-free reactions yielding fast and complete conversions for a more acidic thiol and balanced equilibrium concentrations in case of thiols with high pKa values. The strong influence of thiols with low pKa values emphasizes the relevance of the protonation step in the ring-opening reactions of 1,3-benzoxazines with thiols in absence of solvents where acidity predominates nucleophilicity. The reverse reactions, namely adduct dissociation and benzoxazine recovery, were successfully conducted at elevated temperatures and reduced pressure facilitated by the removal of the formed thiols yielding up to 95% recovered 1,3-benzoxazine. These results provide deeper understanding of the reversible ring-opening reaction mechanism of 1,3-benzoxazine with thiols.
Redox mediators of hydrogen sulfide oxidation in reactions with cycloalkanes
Berberova,Shinkar',Smolyaninov,Pashchenko
, p. 295 - 298 (2016/01/12)
An indirect electrochemical method for thiolation of cycloalkanes C5-C7 has been suggested. The method is based on a new approach to activation of hydrogen sulfide by redox mediators.
Flavouring and odorant thiols from renewable natural resources by InIII-catalysed hydrothioacetylation and lipase-catalysed solvolysis
Dia, Reine-Marie,Belaqziz, Rim,Romane, Abderrahmane,Antoniotti, Sylvain,Du?ach, Elisabet
scheme or table, p. 2164 - 2167 (2010/06/13)
A chemoenzymatic access to thiol compounds, including ethyl 3-thiobutanoate, 3-thio-p-menthene and 8-thio-p-menthan-2-one, three compounds of interest in flavour and fragrance chemistry presenting various fruity notes, is proposed. It involves an indium(III)-catalysed hydrothioacetylation of renewable precursors followed by an enzymatic solvolysis of the obtained thioesters by lipases in aqueous or organic solvents.
Process and catalyst for synthesis of mercaptans and sulfides from alcohols
-
Page/Page column 9-10, (2008/06/13)
A process and catalyst blend for selectively producing mercaptans and sulfides from alcohols. The alcohol is reacted with hydrogen sulfide, in the presence of a catalyst blend containing a hydrotreating catalyst and a dehydration catalyst to convert the alcohol to mercaptan or sulfide in one-pass. The alcohols can include primary and secondary alcohols. The mercaptan or sulfide having less than about 30% unreacted alcohol contained therein.
Deacylation of esters, thioesters and amides by a naphthalene-catalysed lithiation
Behloul, Cherif,Guijarro, David,Yus, Miguel
, p. 309 - 314 (2007/10/03)
The reaction of different esters, thioesters and amides derived from pivalic, benzoic and 4-tert-butylbenzoic acids with an excess of lithium and a catalytic amount of naphthalene (8 mol%) led, after methanolysis, to the corresponding alcohols, thiols and amines, respectively, through a reductive non-hydrolytic procedure. This methodology represents a reasonable alternative to other non-reductive protocols. Georg Thieme Verlag Stuttgart.
Desilylation procedure via a naphthalene-catalysed lithiation reaction
Behloul, Cherif,Guijarro, David,Yus, Miguel
, p. 6908 - 6915 (2007/10/03)
The reaction of silyl protected alcohols, amines and thiols with lithium powder and a catalytic amount of naphthalene, in THF, at 0°C led, after hydrolysis, to the recovery of the free alcohols, amines and thiols in very good yields. At least a phenyl group was required in the silyl protecting group for the success of the reaction. Some polyfunctionalised starting materials have successfully been deprotected. The stereochemical outcome of the deprotection of a silylated chiral secondary alcohol has also been studied and no racemization was observed. The process has shown to be a good alternative to the acid-catalysed desilylation procedures, the latter being not useful for the deprotection of some silylated tertiary alcohols.
