- Additive-Free Green Light-Induced Ligation Using BODIPY Triggers
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Photochemical ligation is important in biomaterials engineering for spatiotemporal control of biochemical processes. Such reactions however generally require activation by high energy UV or short wavelength blue light, which can limit their use as a consequence of the potential of these high energy light sources to damage living cells. Herein, we present an additive-free, biocompatible, chemical ligation triggered by mild visible light. BODIPY dyes with a pendant thioether attached at the meso-position undergo photolysis of the [C?S] bond under green light (λ=530 nm) excitation, producing an ion pair intermediate that can react specifically with a propiolate group. The utility of this photochemical ligation in materials science is demonstrated by the fabrication of hydrogels with specific architectures, photo-immobilization of biomacromolecules, and live cell encapsulation within a hydrogel scaffold.
- Li, Ming,Dove, Andrew P.,Truong, Vinh X.
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- Secondary Deuterium Isotope Effects on Formyl Transfer Reactions between Sulfur and Oxygen Nucleophiles
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Secondary deuterium isotope effects have been measured for formyl and deuterioformyl transfer between oxygen and sulfur nucleophiles at 25 deg C in aqueous solution.Most data were obtained on p-nitrophenyl formate and deuterioformate, and on p-nitrothiophenyl formate and deuterioformate.The nucleophiles that were used are a series of aromatic and aliphatic thiol anions and oxy anions having a broad range of pKa values.The value of kD/kH is larger for oxy anion attack (ca. 1.22) on esters than for thiol anion attack (ca. 1.00).The effects on kD/kH of changing from an aryl to an alkyl anion nucleophile are discussed.No measurable effect on kD/kH is observed with changing nucleophile basicity, suggesting little "Hammond postulate" type of change in transition-state structure.This lack of change is found even in regions were βnuc varies substantially for oxy anions.Data are presented which suggest that the use of absolute values of kD/kH for determining transition-state bond orders can give values much different than other indexes of transition-state structure.The possibility that changes in frequencies other than C-H stretching and bending modes may result in a variation in kD/kH is considered.
- Pohl, Eric R.,Hupe D.J.
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- Thiol–Anhydride Dynamic Reversible Networks
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The reaction of thiols and anhydrides to form ring opened thioester/acids is shown to be highly reversible and it is accordingly employed in the fabrication of covalent adaptable networks (CANs) that possess tunable dynamic covalent chemistry. Maleic, succinic, and phthalic anhydride derivatives were used as bifunctional reactants in systems with varied stoichiometries, catalyst, and loadings. Dynamic characteristics such as temperature-dependent stress relaxation, direct reprocessing and recycling abilities of a range of thiol–anhydride elastomers, glasses, composites and photopolymers are discussed. Depending on the catalyst strength, 100 % of externally imposed stresses were relaxed in the order of minutes to 2 hours at mild temperatures (80–120 °C). Pristine properties of the original materials were recovered following up to five cycles of a hot-press reprocessing technique (1 h/100 °C).
- Podgórski, Maciej,Mavila, Sudheendran,Huang, Sijia,Spurgin, Nathan,Sinha, Jasmine,Bowman, Christopher N.
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- Method and device for continuously producing thiopropionate series compounds through pipeline type
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The invention discloses a method and a device for continuously producing thiopropionate series compounds through pipeline type, and can simultaneously or separately prepare thiodipropionate compounds. Dithionate type compounds and mercapto ester compounds. The method is simple to operate, low in cost and high in yield, and is suitable for industrial production.
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Paragraph 0085; 0088-0090
(2021/11/27)
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- Method for preparing methyl 3-mercaptopropionate by utilizing reactive distillation technology
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The invention relates to the technical field of organic synthesis, in particular to a method for preparing methyl 3-mercaptopropionate by utilizing a reactive distillation technology. The method comprises the following steps: mixing reactants 3-thiohydracrylic acid and methanol, and pre-reacting through a fixed bed reactor filled with a catalyst to obtain a methyl 3-thiohydracrylate crude product; feeding the crude product to the middle of a reactive distillation tower through a feeding pump to be input, feeding fresh methanol and a water-carrying agent from the lower part of the reactive distillation tower, wherein the lower part of the reactive distillation tower is filled with a catalyst; and carrying out a reaction on the unreacted 3-mercaptopropionic acid in the crude product and methanol continue in a catalyst bed layer of the reactive distillation tower; after the reaction is finished, withdrawing excessive methanol, the water-carrying agent and water from the upper part of the reactive distillation tower, and withdrawing the product methyl 3-mercaptopropionate from the bottom of the tower. By means of the reaction rectification technology, methyl 3-mercaptopropionate and water are separated from a reaction system in time, the reaction time is shortened, the reaction efficiency is improved, and the effect is obvious.
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Paragraph 0022-0027
(2021/09/04)
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- Unusual multistep reaction of C70Cl10 with thiols producing C70[SR]5H
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We report a reaction of the chlorofullerene C70Cl10 with thiols producing C70[SR]5H with all organic addends attached around one central pentagon at the pole of the C70 cage. This reaction was shown to proceed via a complicated radical pathway, presumably involving addition, substitution, rearrangement, and/or elimination steps. The obtained C70[SR]5H products were shown to be very unstable and undergo quantitative decomposition to pristine C70, RSSR, and RSH at elevated temperatures (e.g., 50 °C). Quantum chemical calculations and NMR spectroscopy data showed that cleavage of organic addends from the fullerene cage could be induced by solvation effects in solution.
- Khakina, Ekaterina A.,Peregudov, Alexander S.,Yurkova, Anastasiya A.,Piven, Natalya P.,Shestakov, Alexander F.,Troshin, Pavel A.
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p. 1215 - 1219
(2016/03/01)
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- A method for preparing thiol compounds
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The invention provides a preparation method of a thiol compound. According to the preparation method, gas-liquid reaction is carried out on sulfuretted hydrogen and an organic compound containing carbon-carbon double bonds in a solid base catalyst and a reaction solvent through Michael addition under the conditions that the temperature is 20-80 DEG C and the pressure is 0.10-0.12MPa, so as to prepare the thiol compound. The preparation method is mild in reaction condition; the adopted solid base catalyst is strong in alkalinity; the alkaline catalysis position has relatively strong steric hindrance, and the applicability is wide; the solid base catalyst is easy to filter and recover, and can be repeatedly used after being activated; the reaction conversion rate and the selectivity are high; the side reaction is reduced; and the atomic economic utilization rate of the reaction is high.
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Paragraph 0044-0045
(2017/05/12)
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- METHOD OF PREPARING METHYL 3-MERCAPTOPROPIONATE AND DIMETHYL 3,3’-THIOPROPIONATE
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The present invention relates to a manufacturing method of methyl 3-mercaptopropionate comprises a step of reacting hydrogen sulfide with a mixture containing an organic solvent and methyl acrylate, in the presence of a catalyst containing a quaternary ammonium salt compound, wherein the organic solvent has heat of dissolution below 9.2 kcal/mol (room temperature, 1 atm) with respect to the methyl acrylate. In addition, the present invention relates to a manufacturing method of dimethyl 3,3andprime;-thiopropionate comprises a step of reacting methyl 3-mercaptopropionate with a mixture containing an organic solvent and methyl acrylate, in the presence of a catalyst containing a quaternary ammonium salt compound, wherein the organic solvent has heat of dissolution below 9.2 kcal/mol (room temperature, 1 atm) with respect to the methyl acrylate.COPYRIGHT KIPO 2016
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Paragraph 0070; 0071; 0072
(2016/10/09)
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- PREPARATION OF 3-MERCAPTOPROPIONATES
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Disclosed is a process for preparing 3-mercapto propionates, comprising adding Na2SO3 during a reaction of H2S with S2R2, wherein R= -CH2CH2COOR1, R1 is C1-8 alkyl, aryl C1-8 alkyl or C3-8 cycloalkyl. The process has some advantages such as relatively high yield of the target product, high recovery of materials, reducing the danger of reaction procedures and the like.
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Paragraph 0030
(2014/01/23)
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- SEMICONDUCTING THIN [60]FULLERENE FILMS AND THEIR USE
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?The present invention relates to the use of soluble pentakis(alkylthio)derivatives of [60] fullerene as precursors for semiconducting thin [60] fullerene films by thermal decomposition and organic electronic devices using these films.
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Page/Page column 12; 13
(2013/07/25)
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- Synthesis of a derivative of a pentasaccharide repeating unit of the O-antigenic polysaccharide of the bacterium Klebsiella pneumoniae O3 as a benzoylated 2-methoxycarbonylethyl thioglycoside
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Block synthesis of a fully benzoylated derivative of the pentasaccharide α-d-Manp-(1→3)-α-d-Manp-(1→2)-α-d-Manp-(1→2) -α-d-Manp-(1→2)-α-d-Manp-SCH2CH2CO 2Me, the glycoside of the repeating unit of the O-antigenic polysaccharide of the bacterium Klebsiella pneumoniae O3, was performed.
- Abronina,Galkin,Backinowsky,Grachev
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experimental part
p. 457 - 467
(2010/07/08)
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- METHOD OF PRODUCING β-MERCAPTOCARBOXYLIC ACIDS
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The invention relates to a method for efficiently producing β-mercaptocarboxylic acids using a solid acid catalyst such as zeolite, which product corresponds to respective starting materials selected from α, β-unsaturated carboxylic acids (α, β-unsaturated carboxylic acid, a, β-unsaturated carboxylic acid ester, ex, β-unsaturated amide, a, β-unsaturated aldehide and α, β-unsaturated ketone) and hydrogen sulfides (hydrogen sulfide, sulfide salt and hydrosulfide salt), wherein a solvent compatible with water is used in the reaction. According to the invention, β-mercaptocarboxylic acids which are useful as additives in synthetic materials for pharmaceutical or agricultural agents and in polymer compounds can be industrially produced efficiently by using easily available a, β-unsaturated carboxylic acid (such as crotonic acid) at high yield.
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Page/Page column 31-32
(2009/04/25)
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- Combinatorial synthesis of libraries of macrocyclic compounds useful in drug discovery
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A library of macrocyclic compounds of the formula (I) where part (A) is a (CH2)y—NH— bivalent radical, a —(CH2)y— bivalent radical or a covalent bond; where part (B) is a (CH2)z—NH— bivalent radical, a —(CH2)z— bivalent radical, or a covalent bond; where part (C) is a (CH2)t—NH— bivalent radical, a —(CH2)t— bivalent radical, or a covalent bond; and where part (T) is a —Y-L-Z— radical wherein Y is CH2 or CO, Z is NH or O and L is a bivalent radical. These compounds are useful for carrying out screening assays or as intermediates for the synthesis of other compounds of pharmaceutical interest. A process for their preparation of these compounds in a combinatorial manner, is also disclosed.
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Page/Page column 6
(2010/02/11)
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- A thioesterase for chemoselective hydrolysis of S-acyl sulfanylalkanoates.
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[figure: see text] A thioesterase, isolated from a strain of Alcaligenes sp. ISH108, chemoselectively hydrolyzes thiol esters. The application of the enzyme has been demonstrated in the preparation of the antihypertensive agent captopril.
- Kumar,Jolly
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p. 283 - 285
(2007/10/03)
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- The Selective Deprotection of Thioesters Using Titanium(IV) Chloride/Zinc
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A new method for deprotection of thioesters using TiCl4/Zn at 0-25 deg C is described. The procedure chemoselectively cleaves the S-CO bond in thioesters in the presence of other carbonyl functional groups and other protecting groups to cleanly produce thiols.
- Jin, Chung Keun,Jeong, Hyung Jae,Kim, Min Kyu,Kim, Ju Young,Yoon, Yong-Jin,Lee, Sang-Gyeong
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p. 1956 - 1958
(2007/10/03)
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- Acid-catalyzed breakdown of alkoxide and thiolate ion adducts of benzylidene Meldrum's acid, methoxybenzylidene Meldrum's acid and thiomethoxybenzylidene Meldrum's acid
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A kinetic study of the acid-catalyzed loss of alkoxide and thiolate ions from alkoxide and thiolate ion adducts, respectively, of benzylidene Meldrum's acid (1-H), methoxybenzylidene Meldrum's acid (1-OMe), and thiomethoxybenzylidene Meldrum's acid (1-SMe) is reported. The reactions appear to be subject to general acid catalysis, although the catalytic effect of buffers is weak and the bulk of the reported data refers to H+-catalysis. α-Carbon protonation and, in some cases, protonation of one of the carbonyl oxygens to form an enol compete with alkoxide or thiolate ion expulsion. This rendered the kinetic analysis more complex but allowed the determination of pK(a) values and of proton-transfer rate constants at the α-carbon. In conjunction with previously reported data on the nucleophilic addition of alkoxide and thiolate ions to the same Meldrum's acid derivatives, rate constants for nucleophilic addition by the respective neutral alcohols and thiols could also be calculated. Various structure-reactivity relationships are discussed that help define transition-state structures. Comparisons with similar reactions of alkoxide ion adducts of β-alkoxy-α-nitrostilbenes provide additional insights.
- Bernasconi, Claude F.,Ketner, Rodney J.,Brown, Shoshana D.,Chen, Xin,Rappoport, Zvi
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p. 8829 - 8839
(2007/10/03)
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- Kinetics of the reactions of methoxybenzylidene Meldrum's acid with thiolate ions, alkoxide ions, OH-, and water in aqueous DMSO. Detection and kinetic characterization of the S(N)V intermediate
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The nucleophilic vinylic substitution (S(N)V) reactions of methoxybenzylidene Meldrum's acid (5-OMe) follow the common two-step mechanism involving a tetrahedral intermediate. With thiolate and alkoxide ions, this intermediate is shown to accumulate to detectable levels and a detailed kinetic study allowed the determination of the rate constants of the various elementary steps. With OH- as the nucleophile, the intermediate cannot be observed; it is shown that this is the result of the intermediate rapidly breaking down to products by a pathway not available in the reactions with the thiolate or alkoxide ions. Comparison of structure-reactivity data for the reactions of 5-OMe with those of benzylidene Meldrum's acid (5-H) and β-methoxy-α-nitrostilbene (4-OMe) reveal a complex interplay of steric effects, π-donor and π-acceptor resonance effects, and anomeric effects.
- Bernasconi, Claude F.,Ketner, Rodney J.,Chen, Xin,Rappoport, Zvi
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p. 7461 - 7468
(2007/10/03)
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- NO-Group transfer (transnitrosation) between S-nitrosothiols and thiols. Part 2
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The kinetics of NO-group transfer have been measured for the reaction between a nitrosothiol (HOCH2CH2SNO) and nine thiols, mostly based on the cysteine structure.The reaction is second-order and there is evidence for a steric effect for thiols containing 1,1-dimethyl substituents (penicillamine derivatives).Reaction occurs via the thiolate anion as shown by the pH-rate constant profile, and a full kinetic analysis for the reactions of two thiols (N-acetylcysteine and glutathione) is quantitatively in agreement with this mechanism.Variation of the nitrosothiol structure for reaction with N-acetylcysteine shows that electron-withdrawing substituents in the nitrosothiol promote reaction; there is a similarity with the corresponding reactions of alkyl nitrites.
- Barnett, D.Jonathan,Rios, Ana,Williams, D. Lyn H.
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p. 1279 - 1282
(2007/10/03)
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- A NEW SYNTHESIS OF OPTICALLY ACTIVE β-MERCAPTOCARBOXYLIC ACID ESTERS
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Synthesis of optically active β-mercaptocarboxylic acid esters has been achieved by a new method utilizing optically active N-methoxycarbonylpiperidine derivative as a template which can be prepared from L-lysine by anodic oxidation.
- Shono, Tatsuya,Matsumura, Yoshihiro,Fujita, Tetsuhiro
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p. 6723 - 6726
(2007/10/02)
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- Mitomycin derivatives
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Novel mitomycin derivatives are characterized by a substituent on the C6 -methyl group. The mitomycin derivatives exhibit anti-tumor and antibacterial activity and have low toxicity.
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- CONVENIENT METHOD FOR THE PREPARATION OF 3-(2-PYRIDYL DITHIO) PROPIONIC ACID N-HYDROXY SUCCINIMID ESTER
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A new efficient and simple method for the preparation of 3-(2-pyridyl dithio) propionic acid N-hydroxy succinimid ester using diethyl azo dicarboxylate, is described.
- Loccufier, J.,Schacht, E.
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p. 535 - 540
(2007/10/02)
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- 4-oxo-benzopyran carboxylic acids
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Compounds of the Formula I: STR1 and pharmaceutically acceptable salts thereof are leukotriene antagonists. These compounds inhibit SRS-A and leukotriene synthesis and are antagonists of SRS-A and are thus useful in the treatment of asthma, allergic disorders, inflammation, skin diseases and certain cardiovascular disorders.
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- Preparation of dialkyl dithiodialkanoates
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A method for obtaining dialkyl dithiodialkanoates in which mercaptoalkyl esters are contacted with a halogen in an inert hydrocarbon solvent to produce a heavy liquid phase of dialkyl dithiodialkanoate and a separate liquid phase of hydrocarbon solvent. These phases are easily separated into the product dialkyl dithiodialkanoate and hydrocarbon solvent which can be recycled without further treatment. In an embodiment of the invention the dialkyl dithiodialkanoate is further contacted with alkylene oxide to neutralize residual acidic by-products in the reaction mixture.
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- Pesticidal compositions containing phosphoric esters and divalent sulphur compounds
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Pesticidal composition comprising: a pesticidal, phosphoric ester the molecule of which has at least one alkyl group of 1 to 3 carbon atoms, 0.05 to 10% of an agent stabilizing the said ester against decomposition by protonisation, together with adjuvants characterized in that the stabilizing agent comprises at least one sulphur compound containing per molecule at least one divalent sulphur atom of which one valence is bonded to an atom chosen from sulphur, carbon, nitrogen, hydrogen, and metals capable of giving a salt, the other valence being bonded to an atom chosen from hydrogen, the carbon atom already noted, a second carbon atom, the nitrogen atom already noted, a second nitrogen atom, the metal atom already noted in the case of a metal of valence greater than one, a second atom of metal and oxygen when the first valence is not attached to an atom of hydrogen, the proportion of sulphur calculated with reference to the weight of the sulphur compound being between 5 and 99%. Process for stabilizing a phosphoric ester of which the molecule possesses at least one alkyl group containing 1 to 3 carbon atoms characterized in that there is added to the phosphoric ester or to a mixture which contains it, 0.05 to 10% calculated on the weight of the phosphoric acid ester of an agent capable of stabilizing the said phosphoric ester against protonisation and comprising at least one sulphur compound such as that defined thereupon.
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