Search

This article discusses the development of a practical method for Fischer indolization, a commonly used synthetic approach in chemistry. The researchers used bench-stable sodium arylhydrazine sulfonates as a substitute for arylhydrazine, which is typically used in Fischer indolization. The sodium arylhydrazine sulfonates were easily obtained from substituted anilines and could be used directly in the reaction without further purification. The method was successful in synthesizing various tetrahydrocarbazoles and tryptamine-based pharmaceutical molecules. The researchers believe that this method has potential applications in the synthesis of indole-based pharmaceutical compounds. [Extracted from the article]

cis-5-Arylpyrrolidine-2-carboxylates, obtained by 1,3-dipolar cycloaddition reactions from glycine aryl aldimines and vinyl sulfones, undergo oxidative aromatization under the action of Mn(IV) oxide to form the corresponding 5-arylpyrrole-2-carboxylates in high yields. Factors responsible for the retention of the sulfonyl substituent in the pyrrole backbone were determined. [ABSTRACT FROM AUTHOR]

We have developed a highly N 2-regioselective method for direct construction of amide bond from N -sulfonyl-1,2,3-triazoles and carboxylic acids in the presence of bases at 60 °C in air. The developed reaction provides the corresponding products with high yields (up to 90 %) and a broad substrate compatibility including aryl acids, heterocyclic acids, and alkyl acids. Mechanistic studies show that the reaction proceeds through a direct nucleophilic attack of N -sulfonyl-1,2,3-triazoles to carboxylate anions via a base- and water-involved synergistic desulfonation process. This work presents an unusual water-involved example for direct synthesis of amides utilizing readily available starting materials under mild conditions. [Display omitted] • Direct construction of amide bonds from N -sulfonyl azoles and carboxylic acids under mild conditions. • The developed reaction provides high yields (up to 90%) of the corresponding products with broad substrate compatibility. • This reaction is facilitated by a synergistic water- and base-involved desulfonation process. [ABSTRACT FROM AUTHOR]

[Display omitted] • The mechanism of flavin MsuD monooxygenase was studied by DFT calculations. • Mechanism A, involving FlN 5 -OO− with O 2 bound at the flavin N 5 atom, is feasible. • It involves electron transfer, N O formation, proton transfer, and O O cleavage. • Mechanism B containing FlC 4 -OO− is ruled out, due to inaccessible hydroxy rebound. • Both FlN 5 -OO− and FlC 4 -OO− intermediates may appear in the MsuD reaction. MsuD, a flavin-dependent monooxygenase, catalyzes the conversion of methanesulfonate (MS−) into formaldehyde and sulfite, playing a crucial role in the organic sulfur cycle. Using density functional calculations, we have demonstrated that the MsuD reaction uses mechanism A involving a FlN 5 -OO− intermediate. It mainly includes electron transfer from the N 5 atom of deprotonated reduced flavin to O 2 , N O bond formation yielding FlN 5 -OO−, deprotonation of MS− methyl by FlN 5 -OO− forming FlN 5 -OOH and MS2− carbanion, and hydroxy rebound from FlN 5 -OOH to MS2− accompanying with immediate C S bond dissociation producing sulfite and formaldehyde. In contrast, mechanism B containing FlC 4 -OO− is ruled out due to the inaccessible hydroxy rebound from FlC 4 -OOH to MS2−, although the FlC 4 -OO− species, a common intermediate in the family of flavin-dependent monooxygenases, may also appear in MsuD. Our research provides insights into the enzymatic C S bond cleavage and confirms the potential of the flavin N 5 site to facilitate various chemical reactions. [ABSTRACT FROM AUTHOR]

The presence of the sulfonic acid group in sulfonated anthraquinones (SAs) resulted in the difficulty in the mineralization of anthraquinone ring. Little information is available on the removal pathway of the sulfonic acid group of SAs under aerobic/anaerobic conditions. Herein, sodium 1-aminoanthraquinone-2-sulfonate (ASA-2) was used as an important intermediate of SAs. A novel Pseudomonas nitroreducens WA capable of ASA-2 desulfonation was isolated from the Reactive Blue 19-degrading consortium WRB. Anaerobic desulfonation efficiency of 0.165 mM ASA-2 by strain WA reached 99% in 36 h at pH 7.5 and 35 ℃ using glucose as an electron donor. Further analysis showed that ASA-2 as an electron acceptor could be anaerobically transformed into 1-aminoanthraquinone and sulfite via the cleavage of C-S bond. Strain WA could also desulfonate sodium 1-amino-4-bromoanthraquinone-2-sulfonate and sodium anthraquinone-2-sulfonate. Under denitrification conditions, the formed sulfite could be oxidized to sulfate by nitrite via a chemical reaction, which was beneficial for nitrite removal. This phenomenon was observed in consortium WRB-amended system. Moreover, the consortium WRB could reduce the formed sulfite to sulfide due to the presence of Desulfovibrio. These results provide a theoretical basis for the anaerobic biodesulfonation of SAs along with nitrate removal and support for the development of sulfite-based biotechnology. [Display omitted] • A novel Pseudomonas nitroreducens WA capable of ASA-2 desulfonation was isolated. • ASA-2 was transformed into AAQ-1 and sulfite via the cleavage of C-S bond. • Strain WA could utilize ASA-2 as an electron acceptor to produce more ATP. • The formed sulfite could be oxidized to sulfate by nitrite via a chemical reaction. • Consortium WRB containing Desulfovibrio reduced sulfite to sulfide. [ABSTRACT FROM AUTHOR]

To utilize the lignin generated by the paper industry and reduce the cost of poly(lactic acid) (PLA), PLA/lignin composites were prepared from PLA and different ratios of lignosulfonate (LS) or desulfonated lignosulfonate (DLS) particles using a casting method. The physicochemical properties of the lignins were characterized by Fourier transform infrared spectroscopy (FTIR), thermogravimetric analysis (TGA), differential scanning calorimetry (DSC), gel permeation-high performance liquid chromatography (GPC), and elementary analysis. The results indicate that the sulfur content of the original LS was successfully reduced to half by desulfonation to produce DLS, which was found to have a higher thermal stability and a lower average molecular weight than LS. Additionally, the thermal stability, crystallization, compatibility, mechanical, hydrophobicity, and optical properties of the PLA/lignin composites were also meticulously evaluated. Comparison of the PLA/DLS and PLA/LS composites revealed that the incorporation of DLS into PLA improved compatibility, thermal stability (T5% and Tmax), and hydrophobicity, while the mechanical properties remained almost unchanged. In addition, both PLA/DLS and PLA/LS exhibited UV light absorption capacity. Finally, the low-rate addition of both LS (10%) and DLS (5%) accelerated the crystallization of PLA, but crystallization was delayed with higher lignin content. [ABSTRACT FROM AUTHOR]

The linear low-density polyethylene (LLDPE) fibers were sulfonated in 95 % concentrated sulfuric acid. The structure composition and thermal stability of the polyethylene (PE) fibers sulfonated for various times were determined by Fourier transform infrared spectroscopy (FTIR), resonance Raman spectra, elemental analysis, X-ray photoelectron spectroscopy (XPS) and thermogravimetric analysis (TGA). It was confirmed that substitution, oxidation and desulfonation took place in succession during sulfonation. The initial increase of sulfonic acid and hydroxyl groups, as an indication of the substitution reaction, led to a proposal that the reaction was initiated by the abstraction of hydrogen by HSO to give PE radical, which reacted with HSO to give HSO· and HO· radical, and terminated by the formation of PE-SOH and PE-OH. The subsequent decrease of hydroxyl groups and generation of carbonyl groups were attributed to the oxidation reaction. The formation of C=C double bonds and the decrease of sulfur and sulfonic acid groups later on implied that the desulfonation reaction proceeded to induce intermolecular cross-linking. The cross-linked and conjugated polyenes derived from the desulfonation probably attributed to the high char yield for sulfonated LLDPE fibers. [ABSTRACT FROM AUTHOR]

Thin film and bulk, sulfonated poly(ether ether ketone) (SPEEK) have been subjected to a thermal treatment at 160-250 °C for up to 15 h. Exposing the films to 160 °C already causes partial desulfonation, and heating to temperatures exceeding 200 °C results in increased conjugation in the material, most likely via a slight cross-linking by H-substitution. It is well-known that the sulfonate proton plays a major role in the desulfonation reactions, and exchanging the protons with other cations can inhibit both protodesulfonation as well as electrophilic cross-linking reactions of the sulfonate group with other chains. Yet, the implications of such ion-exchange for the thermal processing of sulfonated polymer films has not been recognized. Our study demonstrates that the ion exchange stabilizes thin films and bulk SPEEK up to temperatures exceeding 200 °C, opening up ways for the thermal processing of SPEEK in the temperature range of 160-220 °C without adverse effects. [ABSTRACT FROM AUTHOR]

Abstract: Background: Total (i.e. free+sulfated) metanephrines in plasma is a biomarker for the diagnosis of pheochromocytoma/paraganglioma. Sulfated metanephrines must be completely deconjugated by perchloric acid hydrolysis or sulfatase treatment prior to analytical measurement to enable quantification by current techniques. In this report, we compare the yield and efficiency of both methods. Methods: The deconjugation rate of synthetic sulfated metanephrines (normetanephrine (S-NMN), metanephrine (S-MN) and methoxytyramine (S-MT)) spiked in charcoal-stripped plasma was determined by boiling perchloric acid and compared to sulfatase treatment. Total plasma metanephrines (MN, NMN and MT) were also determined in patient samples by both methods. Results: The complete deconjugation of sulfated metanephrines is achieved after 30min incubation with 0.1M boiling perchloric acid or upon sulfatase treatment. Ten minutes of acid hydrolysis (gold-standard) leads to a 30% underestimation of metanephrine concentrations. The enzyme hydrolysis is time and amount of sulfatase dependent. The rate of hydrolysis is analyte-dependent (MT>>NMN>MN), although it must contain at least 0.8 U/ml of sample. The Deming regression curves comparing acid versus enzyme hydrolysis on patient samples assessed that both methods gave similar unbiased concentrations. Conclusion: Enzyme and acid treatments are equivalent and efficient for removing sulfate from metanephrines as long as the optimal protocol is used for each method. However, the gold standard method for acid hydrolysis at 10min established more than 20 years ago was not satisfactory regarding the hydrolysis of metanephrines in plasma. [Copyright &y& Elsevier]

Abstract: We report a method which protects sulfonated hydrocarbon based proton exchange membranes at the interface between active and non-active area and in the gas inlet/outlet areas, where stresses are maximal during fuel cell operation. The sensitive membrane regions are subjected to a locally confined heat treatment using a stainless steel frame, under which desulfonation and/or crosslinking reactions occur. While modifications in air limit the reaction temperature to 180°C, inert atmosphere allows to raise the temperature and thus to shorten the necessary reaction time from 24h to less than 30min. Membranes are prepared from a commercially available copolymer (SES0005, AquafoneTM), which has a high IEC (2.08meqg−1) and a water uptake of 64%. As expected, modified membranes show reduced IEC values, reduced water uptake, and increased dimensional stability. Catalyst coated membranes (CCMs) are assembled into single cells for fuel cell testing. A membrane modified on all edges shows a stable performance in H2/air fuel cell operation and an H2 crossover current density of 0.52mAcm−2, while a membrane modified only on two edges fails within 50h. Tensile and fuel cell tests show that the interface between modified and pristine area is not the preferred breaking point. [Copyright &y& Elsevier]

Abstract: Sulphonates are often the major form of sulphur in soils where sulphate usually represents less than 5% of the total sulphur. The use of sulphonates as a S source is limited to a functional bacterial guild. However, fungi may assist bacteria in sulphonate desulphurization. In this study, grassland turfs were watered periodically with a modified Hoagland's solution that was i) sulphur free, ii) contained low molecular weight sulphonate iii) or high molecular weight sulphonate. DNA fingerprint analyses of fungal and bacterial communities revealed significant differences between the rhizosphere soil and the bulk soil. Sulphonate treatments had only significant effects on the bacterial and desulphonating bacterial communities and no significant effects on the fungal communities. However, sequencing of the fungal ITS region identified the presence of potentially endophytic fungi in sulphonate amended turfs. Analysis of the sulphur species in soil suggested that the added toluenesulphonate–sulphur was transformed despite the fact that the number of the desulphonating bacteria remained unchanged indicating no sulphonate limitation. The results showcase a robust fungal community in grassland turfs where only the bacterial community with its desulphonating bacterial guild is predominantly responding to the sulphonate amendment. [Copyright &y& Elsevier]

The title compound (2-ammonio-4-chloro-5-methylbenzenesulfonate), C 7H 8ClNO 3S, 1, is an intermediate in the synthesis of laked red and yellow azo pigments. Heating 1 in 2-picoline, quinoline and N,N′-dimethylacetamide (DMAc) [or N-methyl-2-pyrrolidone (NMP)] resulted in the formation of three different compounds: a 2-picolinium hydrate ( 2), a quinolinium quinoline solvate ( 3), and a sulfate of the desulfonated title compound ( 4). The three new compounds were structurally characterised using single-crystal diffraction data and chemically using thermal analysis (DTA/TGA), elemental analysis and spectroscopic methods (IR and NMR). By heating 2, 3 and 4 in the solid state, compound 1 is obtained again. In the case of 4, this corresponds to a desulfonation-resulfonation reaction in subsequent steps, which is rarely observed as such. Graphical Abstract: The title compound 2-ammonio-4-chloro-5-methylbenzenesulfonate was heated in 2-picoline, quinoline and N,N′-dimethylacetamide (DMAc) resulting in the formation of three different compounds: a 2-picolinium hydrate ( 2), a quinolinium quinoline solvate ( 3), and a sulfate of the desulfonated title compound ( 4 see Figure). Heating 2, 3 and 4 in the solid state, compound 1 is obtained again. In the case of 4, this corresponds to a desulfonation-resulfonation reaction in subsequent steps, which is rarely observed as such.[Figure not available: see fulltext.] [ABSTRACT FROM AUTHOR]

Abstract: Poly(ether ether ketone) (PEEK) was dissolved in conc. H2SO4 and its chloromethylation was achieved in presence of paraformaldehyde, trimethylchlorosilane and Lewis acid catalyst, obtained about 35–75% degree of chloromethylation (DCM). This idea is based on partial sulfonation of PEEK to make it soluble and further complete replacement of –SO3H with –CH2Cl groups. Alkaline membranes (AMs) were prepared by quaternization of chloromethylated PEEK (CMPEEK). The reported method is a “green” alternative for the production of AEM without the use of hazardous chemicals (such as chloromethyl methyl ether, chloromethyloctylether, bis(chloromethyl) ether etc.). Chronopotentiometry study of prepared membranes confirmed their homogeneous and alkaline nature suitable for methanol fuel cells. The AMs exhibit a splendid chemical stability at 10M KOH. Alkaline conductivity of quaternized poly(ether ether ketone) membrane with 75% DCM (QPEEK-75) (14.63mScm−1) in equilibration with deionized water was relatively high in compare with other AMs reported in the literature. For the H2/air single fuel cell at 50°C with QPEEK-75 membrane, about 1.02V OCV and 48.09mWcm−2 power density at 109.3mAcm−2 current density were obtained. [Copyright &y& Elsevier]

Abstract: Background: The quantification of total (free+sulfated) metanephrines in urine is recommended to diagnose pheochromocytoma. Urinary metanephrines include metanephrine itself, normetanephrine and methoxytyramine, mainly in the form of sulfate conjugates (60–80%). Their determination requires the hydrolysis of the sulfate ester moiety to allow electrochemical oxidation of the phenolic group. Commercially available urine calibrators and controls contain essentially free, unhydrolysable metanephrines which are not representative of native urines. The lack of appropriate calibrators may lead to uncertainty regarding the completion of the hydrolysis of sulfated metanephrines, resulting in incorrect quantification. Methods: We used chemically synthesized sulfated metanephrines to establish whether the procedure most frequently recommended for commercial kits (pH 1.0 for 30min over a boiling water bath) ensures their complete hydrolysis. Results: We found that sulfated metanephrines differ in their optimum pH to obtain complete hydrolysis. Highest yields and minimal variance were established for incubation at pH 0.7–0.9 during 20min. Conclusion: Urinary pH should be carefully controlled to ensure an efficient and reproducible hydrolysis of sulfated metanephrines. Synthetic sulfated metanephrines represent the optimal material for calibrators and proficiency testing to improve inter-laboratory accuracy. [Copyright &y& Elsevier]

Abstract: This paper deals with the desulfonation properties of some strong acid cation-exchange resins. The sulfate concentration in solution is continuously increased when a strong acid cation-exchange resin is mixed with water. The leaching of sulfate results from the desulfonation of the fixed group, and the amount of leached sulfate depends on the counter ion charge, the crosslinking degree and the exchanger matrix. The effects of the counter ion charge on the desulfonation rate suggested that the counter ion induces the nucleophilic attack of a water molecule on the sulfo group. This interpretation was supported by semiempirical molecular orbital calculations for the C6H5SO3 −M m+ (M m+ = Na+, Mg2+ and Al3+) systems, and the transition state of the Na+ system was successfully predicted by DFT calculations. The crosslinking degree influenced the desulfonation rate, which can be related to the decreasing hydration number of each counter ion in the resin phase with the increasing crosslinking degree. Furthermore, different exchanger matrices produced the differences in the rates, which may be derived from the electron-density donation from the exchanger matrix to the sulfo group. The desulfonation is governed by the electron-density of the sulfur atom and the water activity in the solid phase. [Copyright &y& Elsevier]

Abstract: Sulfonates are major soil sulfur components that can be desulfurized by certain soil-borne bacteria as a sulfur source, but application of sulfate through fertilization could affect this natural sulfur mobilizing process. This study investigates the effects of sulfate treatments on bacterial communities in semi-natural grasslands. Agrostis stolonifera-dominated turfs with their autochthonous bacteria from Woburn Experimental Farm, UK, were incubated with and without additional sulfate over a period of eight weeks and compared to soil and rhizosphere samples taken from the field directly. Cultivable rhizobacteria able to desulfurize toluenesulfonate were dominated by strains affiliated to the Variovorax, Polaromonas and Rhodococcus genera. The betaproteobacteria communities (16S rRNA gene-based denaturing gradient gel electrophoresis) and the desulfonating bacterial communities (asfA based terminal restriction fragment length polymorphism) revealed clear differences between field rhizospheres and bulk soil and the two types of incubated rhizospheres. Clone libraries of asfA from the sulfate-limited treatment were dominated by a new AsfA type, affiliated to Polaromonas. The results from this study suggest that the community of desulfonating bacteria in the Agrostis rhizosphere adapts quickly to changing levels of inorganic sulfate. [Copyright &y& Elsevier]

The preparation of 5-bromo-2-naphthol (4) in three steps from 5-amino-2- naphthol (1) is described. A sulfonic acid group is introduced at the 1-position as an activating and protecting group for the Sandmeyer reaction. The sulfonate group allows for the use of only water and sulfuric acid as solvents. The sulfonic acid is introduced with three equivalents of sulfuric acid, and it is removed in 20% aq. sulfuric acid. [ABSTRACT FROM AUTHOR]

Aerobic enrichment cultures with taurocholate or alkanesulfonates as sole sources of carbon and energy for growth were successful and yielded nine bacterial isolates, all of which utilized taurocholate. Growth was complex and involved not only many, usually transient, excretion products but also sorption of taurocholate and cholate to cells. Three metabolic strategies to dissimilate taurocholate were elucidated, all of which involved bile salt hydrolase cleaving taurocholate to cholate and taurine. Comamonas testosteroni KF-1 utilized both the taurine and the cholate moieties for growth. Pseudomonas spp., e.g. strain TAC-K3 and Rhodococcus equi TAC-A1 grew with the cholate moiety and released taurine quantitatively. Delftia acidovorans SPH-1 utilized the taurine moiety and released cholate. [ABSTRACT FROM AUTHOR]

Abstract: Red HE7B (RHE7B, 100mgl−1), a sulfonated azo dye, was decolorized at static condition by Pseudomonas desmolyticum NCIM 2112 in 72h with 71% reduction in chemical oxygen demand (COD). Extracellular lignin peroxidase (LiP) has played a crucial role in breakdown of the dye by asymmetric cleavage and reductases in the initial 24h incubation to break azo bonds of some dye molecules. Dye also induced the activity of aminopyrine N-demethylase, one of the enzymes of mixed function oxidase system. Decolorization and degradation were analyzed by using UV–vis and high-pressure liquid chromatography (HPLC). The Fourier transform infrared spectroscopy (FTIR) analysis revealed that P. desmolyticum preferred C–N and So break down the RHE7B. GC–MS identification of 8-amino-naphthalene-1,3,6,7-tetraol and 2-hydroxyl-6-oxalyl-benzoic acid as final metabolites supports the degradation of RHE7B by desulfonation before and after ring cleavage. Aerobic degradation of amines and reduced phytotoxicity increased the applicability of this microorganism for dye removal. Scientific relevance of the paper: This is the first report on degradation of Red HE7B by oxidative enzymes and on further degradation by desulfonation before and after ring cleavage. [Copyright &y& Elsevier]

The naturally occurring sulfonate N-acetyltaurine was synthesized chemically and its identity was confirmed. Aerobic enrichment cultures for bacteria able to utilize N-acetyltaurine as sole source of fixed nitrogen or as sole source of carbon were successful. One representative isolate, strain NAT, which was identified as a strain of Delftia acidovorans, grew with N-acetyltaurine as carbon source and excreted stoichiometric amounts of sulfate and ammonium. Inducible enzyme activities were measured in crude extracts of this organism to elucidate the degradative pathway. Cleavage of N-acetyltaurine by a highly active amidase yielded acetate and taurine. The latter was oxidatively deaminated by taurine dehydrogenase to ammonium and sulfoacetaldehyde. This key intermediate of sulfonate catabolism was desulfonated by the known reaction of sulfoacetaldehyde acetyltransferase to sulfite and acetyl phosphate, which was further degraded to enter central metabolism. A degradative pathway including transport functions is proposed. [ABSTRACT FROM AUTHOR]

Cysteate and sulfolactate are widespread natural products in the environment, while propanesulfonate, 3-aminopropanesulfonate and propane-1,3-disulfonate are xenobiotics. While some understanding of the bacterial assimilation of cysteate sulfur has been achieved, details of the dissimilation of cysteate and sulfolactate by microbes together with information on the degradation of the xenobiotics have only recently become available. This minireview centres on bacterial catabolism of the carbon moiety in these C3-sulfonates and on the fate of the sulfonate group. Three mechanisms of desulfonation have been established. Firstly, cysteate is converted via sulfopyruvate to sulfolactate, which is desulfonated to pyruvate and sulfite; the latter is oxidized to sulfate by a sulfite dehydrogenase and excreted as sulfate in Paracoccus pantotrophus NKNCYSA. Secondly, sulfolactate can be converted to cysteate, which is cleaved in a pyridoxal 5′-phosphate-coupled reaction to pyruvate, sulfite and ammonium ions; in Silicibacter pomeroyi DSS-3, the sulfite is excreted largely as sulfite. Both desulfonation reactions seem to be widespread. The third desulfonation mechanism is oxygenolysis of, e.g. propanesulfonate(s), about which less is known. [ABSTRACT FROM AUTHOR]

We investigated the laser photolysis of tetrasodium 1,3,6,8-pyrene-tetrasulfonate (Na4PS4) and sodium 1-pyrenesulfonate (NaPS) in aqueous and reverse micellar solutions. The photoproducts as well as their yields were found to strongly depend on the reaction parameters such as pH, dissolved gases and the size of water pool. The primary reaction in aqueous solution was commonly presented by laser-induced formation of the cation radicals followed by hydroxylation of them. In the case of PS44−, pyranine was efficiently and highly selectively formed, possibly via desulfonation of the cation radical, P⋅+S44−, followed by the hydroxylation. On the other hand, from PS−, hydroxypyrenesulfonate (PSOH) was initially formed in alkaline solution and desulfonation occurred secondarily, leading to the formation of hydoxypyrene. These photoreactions were markedly suppressed within a small water pool of the reverse micelle. As the size of water pool increased similar photochemical reactions occurred depending on the dissolved gases. The observed micellar effects could be explained based on the pH of water pool and the nature of the cation radicals in it. [Copyright &y& Elsevier]

6:2 fluorotelomer sulfonic acid (6:2 FTSA) is one per- and poly-fluoroalkyl substances commonly detected in the environment. While biotransformation of 6:2 FTSA has been reported, factors affecting desulfonation and defluorination of 6:2 FTSA remain poorly understood. This study elucidated the effects of carbon and sulfur sources on the gene expression of Rhodococcus jostii RHA1 which is responsible for the 6:2 FTSA biotransformation. While alkane monooxygenase and cytochrome P450 were highly expressed in ethanol-, 1-butanol-, and n-octane-grown RHA1 in sulfur-rich medium, these cultures only defluorinated 6:2 fluorotelomer alcohol but not 6:2 FTSA, suggesting that the sulfonate group in 6:2 FTSA hinders enzymatic defluorination. In sulfur-free growth media, alkanesulfonate monooxygenase was linked to desulfonation of 6:2 FTSA; while alkane monooxygenase, haloacid dehalogenase, and cytochrome P450 were linked to defluorination of 6:2 FTSA. The desulfonation and defluorination ability of these enzymes toward 6:2 FTSA were validated through heterologous gene expression and in vitro assays. Four degradation metabolites were confirmed and one was identified as a tentative metabolite. The results provide a new understanding of 6:2 FTSA biotransformation by RHA1. The genes encoding these desulfonating- and defluorinating-enzymes are potential markers to be used to assess 6:2 FTSA biotransformation in the environment. [Display omitted] • High expression of alkane monooxygenase gene linked to high 6:2 FTOH defluorination. • Desulfonation of 6:2 FTSA is a necessary prior to its defluorination. • Alkanesulfonate monooxygenase-producing strain RHA1 desulfonated 6:2 FTSA. • Three defluorinating enzymes involved in defluorination of 6:2 FTSA were identified. • PFHpA was a new metabolite of 6:2 FTSA biotransformation by strain RHA1. [ABSTRACT FROM AUTHOR]

A simple and efficient preparation of biaryl derivatives from arylsulfonyl hydrazides has been developed using Pd(OAc)2 as the catalyst in a mixed solvent of DMA and THF and without the use of any ligand and base. [ABSTRACT FROM AUTHOR]

• nNiFeo-AC particles transformed both L- and Br-PFOS isomers. • PFOS transformation highest at 50 °C at 94 % (40–60 °C investigated). • Fluoride and sulfite generation accounted for nearly all the PFOS decomposed. • Several organic transformation products were identified in particle extracts. Degradation of linear (L) and branched (Br) perfluorooctanesulfonate (PFOS) using nNiFe° particles supported on activated carbon (AC) and heat is demonstrated for the first time and with several lines of evidence. At 60 °C, PFOS degradation plateaued at 50 ± 6%, while at 50 °C, 94 ± 4.1 % PFOS transformed. The accelerated iron corrosion at the higher temperature is attributed to the lower PFOS transformation at 60 °C. However, at both temperatures, ≥ 97 % of the PFOS transformed was accounted for by the moles of fluoride generated. At 60 °C, PFOS degradation rates were estimated at 0.028 ± 0.003 h−1 and fluoride and sulfite generation rates of 0.70 ± 0.165 h−1 and 0.62 ± 0.157 h−1, respectively, with no differences between L-PFOS and total Br-PFOS. Using time-of-flight mass spectrometry, some organic products were identified in the particle extracts from the 60 °C reaction. Products included single-bonded C8 polyfluoroalkyl sulfonates (F 16 to F 7) and alkyl acids (PFCAs, C 4 -C 8) and one perfluorinated C 8 desulfonated product supporting both defluorination and desulfonation pathways. Most of the organic products were gone after the first 25 h. High PFOS mineralization using nNiFe°-AC technology warrants further investigation for its use in permeable reactive barriers. [ABSTRACT FROM AUTHOR]

An abstract of the article "Visible-Light Photoredox-Catalyzed Coupling Reaction of Azoles with α-Carbamoyl Sulfides" by Lucie Jarrige, Guillaume Levitre, and Géraldine Masson is presented.

Review: 418 refs. [ABSTRACT FROM AUTHOR]

The one-pot synthesis of secondary benzylic alcohols proceeds via radical desulfonylation of β-ketosulfones and sequential Bouveault-Blanc reduction of the resulting ketones. [ABSTRACT FROM AUTHOR]

Cross-coupling reactions of unactivated aryl sulfides with alkynylmagnesium chloride are invented to afford 1-aryl-1-alkynes with the aid of a palladium/N-heterocyclic carbene complex. [ABSTRACT FROM AUTHOR]

Chemical equations for the article "Metal-Free Mediated Meerwein-Type Reaction: A Radical Cascade Arylation/Aryl Migration/Desulfonylation of Conjugated Alkenes" by Z. Nu and others, which published in 2016 issue of journal "Organic Letter " is presented.

A graphical abstract of the article "Iron Trichloride and Air Mediated Guanylation of Acylthioureas. An Ecological Route to Acylguanidines: Scope and Mechanistic Insights" by S. Pape et al. is presented.

A graphical abstract of the study "Arylative Desulfonation of Diarylmethyl Phenyl Sulfone With Arenes Catalyzed by Scandium Triflate" by N. Mazakazu and colleagues is presented.

The addition of sulfonyl radicals to the double bond of acrylamides triggers a domino 5-exo-trig cyclization, desulfonylation, and aryl migration sequence, affording a series of sulfonylated amides. [ABSTRACT FROM AUTHOR]

Desulfurization reactions of thioureas using KICl2 in the presence of amines result in the formation of acyclic and cyclic guanidine salts. [ABSTRACT FROM AUTHOR]

An abstract of the article "Palladium-Catalyzed C-3 Desulfitative Arylation of Indolizines with Sodium Arylsulfinates and Arylsulfonyl Hydrazides," by C. Wang and colleagues is presented.

An abstract of the article "Synthesis of Symmetrical and Unsymmetrical 1,3-Diheteroarylbenzenes Through Palladium-Catalyzed Direct Arylation of Benzene-1,3-disulfonyl Dichloride and 3-Bromobenzenesulfonyl Chlorides" by Imane Idris, Fazia Derridj and Safia Djebbar, et al. is presented.

Various β-ketothioamides are treated with arylglyoxals under conditions A) to produce highly substituted furan structures as important synthons in natural product and medicinal chemistry. [ABSTRACT FROM AUTHOR]

Review: [79 refs. [ABSTRACT FROM AUTHOR]

Fused thiazoles are synthesized through title reaction of thiazolidine-2-thiones either with boronic acids or with boronic acid pinacol esters. [ABSTRACT FROM AUTHOR]

Gold-catalyzed oxidation of alkynyl sulfonamides (I) with pyridine N-oxides produces acyl gold carbene intermediates by in situ expulsion of sulfur dioxide. [ABSTRACT FROM AUTHOR]

An abstract of the article "Desulfitative palladium-catalyzed direct C-3 arylation of indolizines with arylsulfonyl chlorides," by W. Zhang and colleagues is presented.

Optimized conditions allow the preparation of various 2-cyclopentenone structures with high yields. [ABSTRACT FROM AUTHOR]

The method is highly chemoselective and applied to the reduction of a wide range of sulfides, including benzyl and alkyl sulfides, and dithianes. [ABSTRACT FROM AUTHOR]

An abstract of the article "Versatile Synthesis of N-Substituted Lactopyranosil Formamides by Desulfurization of the Corresponding Thiocarbamides" by G. S. Patkar and colleagues is presented.

An abstract of the article "Synthesis of Substituted Benzenes via Bi(OTf)3-Mediated Intramolecular Carbonyl Allylation of α-Prenyl or α-Geranyl β-Arylketosulfones" by M.-Y. Change and colleagues is presented.

affording alkynylated quinoline derivatives [ABSTRACT FROM AUTHOR]

Review: [173 refs. [ABSTRACT FROM AUTHOR]

A simple and efficient method for the arylsulfonylation of N-acryl-N-substituted benzenesulfonamides with arylsulfonic acids is developed using environmentally friendly oxygen in air as the oxidant. [ABSTRACT FROM AUTHOR]