Thioacetic Acid Research Articles

ChemInform Abstract: KF/Al2O3/PEG‐400: An Efficient Catalytic System for the Fiesselmann‐Type Synthesis of Thiophene Derivatives.

AbstractA simple protocol is developed to synthesize novel non‐steroidal and steroidal thiophenes via reaction of β‐halo‐α,β‐unsaturated aldehydes with thioacetic acid ethyl ester.

ChemInform Abstract: N‐Alkylsulfonamides as Useful Carbon Electrophiles

AbstractReview: ca. 100 refs.

Convenient Synthesis of Various Substituted Homotaurines from Alk‐2‐enamides

AbstractVarious substituted homotaurines (=3‐aminopropane‐1‐sulfonic acids) 6 were readily synthesized in satisfactory to good yields via the Michael addition of thioacetic acid to alk‐2‐enamides 3 (→4), followed by LiAlH4 reduction (→5) and performic acid oxidation (Scheme 1). The configuration of ‘anti’‐disubstituted homotaurine ‘anti’‐6h was deduced from the 3‐(acetylthio)alkanamide (=S‐(3‐amino‐1,2‐dimethyl‐3‐oxopropyl) ethanethioate)‘anti’‐4h formed in the Michael addition, which was identified via the Karplus equation analysis, and confirmed by X‐ray diffraction analysis. The current route is an efficient method to synthesize diverse substituted homotaurines, including 1‐, 2‐, and N‐monosubstituted, as well as 1,2‐, 1,N‐, 2,N‐, and N,N‐disubstituted homotaurines (Table).

ChemInform Abstract: Organocatalytic Enantioselective Transient Enolate Protonation in Conjugate Addition of Thioacetic Acid to α‐Substituted N‐Acryloyloxazolidinones.

AbstractCTU is found to be the optimal catalyst for the process which affords biologically interesting sulfur compounds.

N-Alkylsulfonamides as Useful Carbon Electrophiles

The cleavage of the sp³ carbon–nitrogen bonds in <i>N</i>-alkylsulfonamides has been utilized for the selective formation of various carbon–carbon and carbon–heteroatom bonds. When <i>N</i>-alkylsulfonamides undergo sp³ carbon–nitrogen bond cleavage in the presence of acid catalysts, the resulting carbocations can react with a broad range of carbon, sulfur, nitrogen, oxygen, or hydride nucleophiles. On the other hand, basic conditions allow<i> N</i>-alkylsulfonamides to act as sp³ carbon electrophiles in reactions with strong nucleophiles. In general, <i>N</i>-benzylic, <i>N</i>-allylic, and <i>N</i>-propargylic sulfonamides serve as suitable substrates, and their reactions with nucleophiles provide ready access to a wide range of functionalized molecules. 1 Introduction 2 Mechanism 3 Reactions with Carbon Nucleophiles 3.1 Active Methylene Compounds 3.2 Ketones and Aldehydes 3.3 Aromatic Compounds 3.4 Alkynes, Alkenes, and Arylallenes 3.5 Silylated Carbon Nucleophiles 3.6 Grignard Reagents 4 Reactions with Sulfur Nucleophiles 4.1 Thiols and Thiophenols 4.2 Thioacetic acid 4.3 Sulfinic Acids 5 Reactions with Nitrogen Nucleophiles 6 Reactions with Oxygen Nucleophiles 7 Reduction 8 Conclusion

Organocatalytic diastereo- and enantioselective sulfa-Michael addition to α,β-disubstituted nitroalkenes

An effective asymmetric sulfa-Michael addition of various S-nucleophiles to a range of α,β-disubstituted nitroalkenes with bifunctional organocatalyst has been developed. The expected adducts could be obtained in high yields with reasonable diastereo- and enantioselectivities. This process provides an easy access to synthetically useful chiral 1,2-aminothiol derivatives bearing two vicinal stereocenters. Importantly, current work represents the first example about the catalytic asymmetric Michael addition of diverse S-nucleophiles except thioacetic acid to less reactive α,β-disubstituted nitroalkenes.

Efficient Functionalization of Oxide-Free Silicon(111) Surfaces: Thiol–yne versus Thiol–ene Click Chemistry

Thiol-yne click (TYC) chemistry was utilized as a copper-free click reaction for the modification of alkyne-terminated monolayers on oxide-free Si(111) surfaces, and the results were compared with the analogous thiol-ene click (TEC) chemistry. A wide range of thiols such as 9-fluorenylmethoxy-carbonyl cysteine, thio-β-d-glucose tetraacetate, thioacetic acid, thioglycerol, thioglycolic acid, and 1H,1H,2H,2H-perfluorodecanethiol was immobilized using TYC under photochemical conditions, and all modified surfaces were characterized by static water contact angle measurements, X-ray photoelectron spectroscopy (including a simulation thereof by density functional calculations), and infrared absorption reflection spectroscopy. Surface-bound TYC proceeds with an efficiency of up to 1.5 thiols per alkyne group. This high surface coverage proceeds without oxidizing the Si surface. TYC yielded consistently higher surface coverages than TEC, due to double addition of thiols to alkyne-terminated monolayers. This also allows for the sequential and highly efficient attachment of two different thiols onto an alkyne-terminated monolayer.

ChemInform Abstract: Squaramide‐Catalyzed Enantio‐ and Diastereoselective sulfa‐Michael Addition of Thioacetic Acid to α,β‐Disubstituted Nitroalkenes.

AbstractThe title reaction affords various biologically important sulfur compounds.

Novel Synthetic Strategy for the Sulfonation of Polybutadiene and Styrene–Butadiene Copolymers

The selective and quantitative sulfonation of polybutadiene (PB) and triblock copolymers polystyrene-b-polybutadiene-b-polystyrene (SBS) has been successfully obtained through a novel procedure consisting of two reaction steps carried out in a single batch: free radical addition of thiolacetic acid to olefinic double bonds followed by autocatalytic oxidation of the thioacetylated polymer with in situ generated organic peracids. The polymers resulting from the two reactions were fully characterized by NMR, FTIR, and elemental analysis; the ion exchange capacity (IEC) of the sulfonated polymers was assessed by elemental analysis and titration with NaOH. Critical desulfonation temperatures of the poly(alkylsulfonate)s were observed in the range 160–270 °C, whereas the thermal decomposition starts at about 380 °C. The TUNA-AFM analysis of a sample of SBS containing 79 mol % of alkylsulfonic groups showed a phase-separated morphology consisting of polystyrene domains of about 28 nm embedded in the sulfonated p...

Synthesis of 1,3-benzothiazol-2(3H)-ones with a carbamate function at the C-6 atom

A new method has been developed for the synthesis of 1,3-benzothiazol-2(3H)-ones with carbamate function based on the adducts of the 1,4-addition of thioacetic acid to 2-R-N,N'-dimethoxycarbonyl-1,4-benzoquinone diimines. Refluxing the 2-thioacetyl-substituted dicarbamates in ethanol in the presence of hydrochloric acid gave 1,3-benzothiazol-2(3H)-ones with methoxycarbonylamine group at the C-6 atom. Modifications of the obtained compounds were performed.

Organocatalytic enantioselective transient enolate protonation in conjugate addition of thioacetic acid to α-substituted N-acryloyloxazolidinones

Organocatalytic conjugate addition of thioacetic acid to a series of α-substituted N-acryloyloxazolidin-2-ones followed by enantioselective protonation has been studied in the presence of thiourea catalysts derived from cinchona alkaloids. Conjugate addition/protonation adducts have been obtained up to 97% ee and high yields. The methodology could serve as an easy and practical route to the syntheses of useful biologically active molecules.

100% thiol-functionalized ethylene PMOs prepared by “thiol acid–ene” chemistry

A novel thiol functionalized bis-silane PMO precursor was synthesized by highly efficient thiol acid-ene chemistry between the double bonds of 1,2-(E)-bis(triethoxysilyl)ethene and thioacetic acid. After aminolysis the self-assembly process of the formed SH-precursor with Pluronic P123 under acidic conditions yields the first 100% thiol-PMO material with good structural ordering.

Reversible Generation of Metastable Enols in the 1,4-Addition of Thioacetic Acid to α,β-Unsaturated Carbonyl Compounds

Addition of thioacetic acid to reactive α,β-unsaturated carbonyl compounds like acrolein or crotonaldehyde in acetone-d(6) generates metastable (E)- and (Z)-1-alkenols, which tautomerize slowly at ambient temperature. The 1,4-addition of thioacetic acid and crotonaldehyde to (Z)-3-(acetylsulfanyl)-1-propen-1-ol is reversible with K(eq) = 5.5 ± 0.5 L/mol. A concerted, cyclic 1,4-addition mode is proposed to explain the preferred (Z)-stereoselectivity in lower polarity, nonprotic solvents.

ChemInform Abstract: Synthesis of Homotaurine and 1‐Substituted Homotaurines from α,β‐Unsaturated Nitriles.

AbstractHomotaurine (VI) and 1‐substituted derivatives (VII) are prepared by Michael addition of thioacetic acid to α,β‐unsaturated nitriles followed by reduction and oxidation.

Sulfidization of Au(111) from Thioacetic Acid: An Experimental and Theoretical Study

We have studied the adsorption of thioacetic acid (TAAH) on Au(111) from solution deposition. The close proximity of the SH groups to CO groups makes this molecule very attractive for exploring the effect of the functional group on the stability of the S-C and S-Au bonds. Although thioacetic acid was supposed to decompose slowly in water by hydrolysis supplying hydrogen sulfide, this behavior is not expected in nonpolar solvents such as toluene or hexane. Therefore, we have used these solvents for TAAH self-assembly on the Au(111) surface. The characterization of the adsorbates has been done by electrochemical techniques, X-ray photoelectron spectroscopy (XPS), and scanning tunneling microscopy (STM). We have found that even in nonpolar solvents thioacetic acid decomposes to S. The results have been discussed on the basis that the adsorbed species suffer a cleavage on the Au surface, leaving the S attached to it. The dissociation is a spontaneous process that reaches the final state very fast once it is energetically favorable, as can be interpreted from DFT calculations. The thioacetic acid adsorption reveals the strong effect that produces a functional group and the key role of the S-H bond cleavage in the self-assembly process.

Synthesis, characterization of conjugated oligo-phenylene-ethynylenes and their supramolecular interaction with β-cyclodextrin for salicylaldehyde detection

Four new conjugated oligo-phenylene-ethynylenes derivatives, N-methyl-4-(4-acetylthiophenylethynyl)-1,8-naphthalimide (1), thioacetic acid S-[4-(4-aminophenyl-ethynyl)phenyl]ester (2), 4-methylthiophenylethynylbenzenamine (3), N-methyl-4-(4-methyl-thiophenyl-ethynyl)-1,8-naphthalimide (4), were synthesized by Sonogashira and Eglinton cross-coupling reactions. The structures of the four compounds were confirmed by 1HNMR, 13CNMR, MS and IR and their spectral characteristics were studied by ultraviolet and visible (UV) spectroscopy as well as fluorescence spectroscopy in different medium. It was found that the fluorescence properties of compounds 2 and 3 were notably improved in aqueous solutions in the presence of β-cyclodextrin (β-CD). Spectral analysis supported the suppositions that the fluorescence intensity enhancement was due to the formation of inclusion complex with β-CD. The supramolecular interaction was investigated in detail and the reaction mechanism was provided. A salicylaldehyde determination method in aqueous medium was established based on the supramolecular complex of compound 3. Under the optimum conditions, the supramolecular complex exhibited a dynamic fluorescence response range for salicylaldehyde from 0.6 to 240×10−6molL−1, with a detection limit of 1×10−8molL−1.

I2 as a mild and efficient catalyst in deoxygenation of sulfoxides with thioacetic acid

An effective procedure for deoxygenation of sulfoxides to sulfides using thioacetic acid as a reducing agent and a catalytic amount of I2 in MeCN at ambient temperature has been developed. Using this protocol, a variety of sulfoxides including benzyl, allyl, alkyl and aryl sulfoxides have been successfully reduced to the corresponding sulfides in excellent yields.

ChemInform Abstract: Enantio‐ and Diastereoselective Addition of Thioacetic Acid to Nitroalkenes via N‐Sulfinyl Urea Catalysis.

AbstractThe sulfinyl group in catalyst NSU is essential to attain high enantioselectivity in the thioacetic acid addition.

Synthesis of Homotaurine and 1-Substituted Homotaurines from α,β-Unsaturated Nitriles

Homotaurine and a series of 1-substituted homotaurines were readily synthesized in satisfactory to good yields via the Michael­ addition of thioacetic acid to aliphatic and aromatic α,β-unsaturated nitriles followed by lithium aluminum hydride mediated reduction and performic acid oxidation. The synthesis of 1,1-disubstituted homotaurines was attempted with β,β-disubstituted acrylonitriles as starting materials but failed due to steric hindrance. The current process is an efficient method for the synthesis of 1-substituted homotaurines.

An efficient and facile synthesis of N-Cbz-β-aminoalkanesulfonamides

An efficient method for the synthesis of N-Cbz-β-aminoalkanesulfonamides was described. N-Cbz-β-aminoalkanesulfona-mides were readily prepared in good yields from a variety of amino alcohols, including optically active ones, via N-Cbz protection with benzyl chloroformate, Mitsunobu esterification reaction with thiolacetic acid, N-chlorosuccinimide oxidation, and ammonolysis process.