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An efficient B(C6F5)3-catalyzed aerobic oxidative C-S cross-coupling reaction of thiophenol with indoles was developed, affording a wide range of diaryl sulfides in good yields. An electron donor-acceptor complex between B(C6F5)3 and indoles was formed, facilitating the photoinduced single-electron transfer (SET) from indole substrates to the B(C6F5)3 catalyst. This protocol demonstrates a new reaction model using B(C6F5)3 as a single-electron oxidant.

A metal-free, photocatalyst-free, photochemical system was developed for the direct alkylation of thiophenols via electron donor-acceptor (EDA) complexes (KEDA = 145 M-1) between two reactants, N-hydroxyphthalimide esters as acceptors and thiophenol anions as donors, in the presence of a tertiary amine. The EDA complexes in the reaction system have a broad range of visible-light absorption (400-650 nm) and can trigger the reaction effectively under sunlight.

Abstract— Derivatives of sesquiterpene lactones modified at the lactone ring with a thiophenol residue have been synthesized. The resulting conjugates with thiophenol have capacity for the oxidation–elimination reaction by the action of ROS of a tumor cell with the release of initial cytotoxic lactones. It has been proposed to use the resulting sulfur-containing conjugates as ROS-activated prodrugs of sesquiterpene lactones. The antiproliferative properties of the conjugates have been examined on tumor and pseudonormal cell lines. The cytotoxicity of the conjugates is lower than that of parent lactones; however, in some cases, as with the conjugates of alantolactone with artemisiten, it remains moderate in all tumor cell lines tested.

We describe a simple and efficient procedure for nucleophilic borylation of imines in the absence of a photoredox catalyst. Visible light irradiation of an acetonitrile solution of an imine, an NHC-borane, and diphenyl disulfide (10 mol %) provides various stable α-amino NHC-boranes in good yields. The reaction proceeds via addition of a nucleophilic boryl radical to an imine, followed by hydrogen abstraction from thiophenol, which is generated from NHC-borane and diphenyl disulfide.

We present an efficient and versatile visible light-driven methodology to transform aryl aldehydes and ketones chemoselectively either to alcohols or to pinacol products with CdSe/CdS core/shell quantum dots as photocatalysts. Thiophenols were used as proton and hydrogen atom donors and as hole traps for the excited quantum dots (QDs) in these reactions. The two products can be switched from one to the other simply by changing the amount of thiophenol in the reaction system. The core/shell QD catalysts are highly efficient with a turn over number (TON) larger than 4 X 10(4) and 4 X 10(5) for the reduction to alcohol and pinacol formation, respectively, and are very stable so that they can be recycled for at least 10 times in the reactions without significant loss of catalytic activity. The additional advantages of this method include good functional group tolerance, mild reaction conditions, the allowance of selectively reducing aldehydes in the presence of ketones, and easiness for large scale reactions. Reaction mechanisms were studied by quenching experiments and a radical capture experiment, and the reasons for the switchover of the reaction pathways upon the change of reaction conditions are provided.

Ternary catalyst systems (TCSs) are an emerging type of catalyst for the synthesis of multiblock copolymers of lactide (LA), epoxides and CO2. For our previous TCS (SalenCoIII-dinitrophenol (DNP), SalenCoII and PPNCl; TCS I), although multiblock copolymers could be successfully prepared from mixed monomers, the low activity from SalenCoII prevents TCS I from being further applied. In this work, a new homogeneous TCS (TCS III) is presented with two substitution strategies of SalenCoII. TCS IIIa consists of SalenCoIII-DNP, SalenCoIII-difluorothiophenol (DFTP) and PPNCl, while TCS IIIb contains SalenCoIII-DNP, oxygen and PPNCl. Compared to TCS I, TCS III showed higher activity (for TCS IIIa, TOFPO increased from 27 h−1 to 231 h−1), and remained active even under diluted conditions ([Cat] : [PO] = 1 : 5000), while TCS I lost activity when the ratio was over 1 : 2500. The microstructure of the resultant copolymer was analyzed in detail, the low average chain length being consistent with its thermal property. SalenCoIII-DFTP is different from SalenCoIII-DNP in the X-axial ligands: the thiophenol endows SalenCoIII with special catalytic property, contributing to the higher activity of TCS IIIa. In TCS IIIb, SalenCoII is replaced by the cocatalyst of oxygen, which is beneficial for reduction of SalenCo loading. The results of the TCSs provide key insights into the copolymerization mechanism of LA, epoxide and CO2, and show promising implications for the design of future catalytic systems.

Heterocyclic compounds such as pyrazolines, pyrimidines, oxazole and isoxazole exhibit different pharmacological activities. The current study involves synthesis of new 2-pyrazolines. The synthesis involves the cyclocondensation reaction of substituted chalcones with (4-fluorophenylthio)acetic acid hydrazide (FTAH) under reflux. The chalcones (C1-C7 / 1a-1g) were synthesized from the reaction of substituted acetophenone with substituted benzaldehyde and FTAH was prepared from 4-fluro thiophenol. New 2-pyrazolines were obtained in good yields (60-70 %). All the compounds were characterized by FT-IR, 1H, 13C NMR and mass spectra. PASS analysis was carried out for the 2-pyrazolines synthesized (P1-P7 / 3a-3g).

BACKGROUND: Aromatic thioether derivatives exist widely in natural products and have significant applications in modern synthesis and the pharmaceutical industry; for example, 2‐sulfanylphenols and arylthioquinones are important intermediates in the processing of anticancer, antibiotic, antivirus and antimalarial drugs. Direct C─H hydroxylation was considered as one of the efficient methods for the synthesis of these compounds. Homogeneous transition metal catalysts usually were used through a cross‐coupling of halogen‐substituted phenols with thiophenols. However, from the perspectives of sustainable development and easy recovery, it is necessary to develop an efficient and recoverable catalytic system to realize the synthesis of aromatic thioether derivatives with good efficiency and recyclability. RESULTS: The heterogeneous catalyst [Cu(binap)I]₂@HT in the present work showed good catalytic activity for the C─H hydroxylation of benzenethiol and phenylboronic acid. The catalytic system was tolerant to various substituents including alkyl, alkoxy, ester, halogen or trifluoromethyl on the phenyl ring of the thiophenols or arylboric acids. In addition to electron‐donating groups, the products with strong electron‐withdrawing groups, such as methyl formylate and trifluoromethyl also were achieved with good yields at 90 °C for 12 h (68% and 66%, respectively). Repeated experiment results showed that the catalyst could be reused at least five times without obvious decrease in catalytic activity. CONCLUSION: A BINAP‐Cu complex supported on hydrotalcite was prepared and used as a heterogeneous catalyst for the C─H activation of thiophenol under mild reaction conditions. Through a cascade C─H hydroxylation and further oxidation process, 2‐Sulfanylphenols and arylthioquinones could be obtained with moderate‐to‐good yields for a series of 2‐(phenylthio)phenol derivatives using the heterogeneous catalyst [Cu(binap)I]₂@HT. In addition, this heterogeneous catalyst showed good recylbility. © 2020 Society of Chemical Industry

Surface plasmon can trigger or accelerate many photochemical reactions, especially useful in energy and environmental industries. Recently, molecular adsorption has been proved effective in modulating the plasmon-mediated photochemistry, however the realized chemical reactions are limited and the mechanism behind is still unclear. Herein, by using in situ dark-field optical microscopy, the plasmon-mediated oxidative etching of silver nanoparticles (Ag NPs), a typical hot-hole-driven reaction, is monitored continuously and quantitatively. The presence of thiol or thiophenol molecules is found essential in the silver oxidation. In addition, the rate of silver oxidation is modulated by the choice of different thiol or thiophenol molecules. Compared with the molecules having electron donating groups, the ones having electron accepting groups accelerate the silver oxidation dramatically. The thiol/thiophenol modulation is attributed to the modulation of the charge separation between the Ag NPs and the adsorbed thiol or thiophenol molecules. This work demonstrates the great potential of molecular adsorption in modulating the plasmon-mediated photochemistry, which will pave a new way for developing highly efficient plasmonic photocatalysts.

ortho-Quinone methides, very reactive transient intermediates, are utilized successfully in synthesizing complex organic molecules of natural and biological significance. Among several synthetic protocols, the acid catalyzed generation of ortho-quinone methides from suitably substituted phenols is a promising method for further exploitation in organic synthesis. Such an interesting reactive species is conveniently employed in the synthesis of conformationally restricted triarylmethane derivatives such as 12/9-arylxanthenes/arylthioxanthenes starting from symmetrical/unsymmetrical 2-(hydroxydiarylmethyl)phenol/thiophenol, respectively, using SiO2–NaHSO4. Conformationally restricted 12/9-arylxanthenes/arylthioxanthenes were obtained in 52 to 96% yields using this protocol, which is believed to involve the formation of o-quinone methides followed by electrocyclic ring closure and isomerization at elevated temperature. Photophysical studies of selected examples in acidic media showed turn-on fluorescence by hydride ion transfer mediated π-conjugated xanthylium salt formation and suggested the application potential in bio-imaging and fluorescent sensors.

A novel six-step synthesis of 7,8-difluoro-6,11-dihydrodibenzo[b,e]thiepin-11-ol (1) is described. Starting with 3,4-difloro-2-methylbenzoic acid and using diphenyl disulfide as an ideal sulfur sou...

Recently [11C]mG4P012 (previously [11C]KALB012 and presently named as [11C]PXT012253 by Prexton Therapeutics) had been used as a biomarker during the preclinical development of a potential therapeutic drug, PXT0002331 (an mGluR4 PAM), for PD and l -dopa-induced dyskinesia. [11C]mG4P012 was shown to be a promising PET radioligand for mGluR4 in the monkey brain and for further development in human subjects. However, the previously reported multi-step synthesis of the thiophenol precursor suffered from low yields and difficult workup procedures. To support the translational research of [11C]mG4P012 and the other potential applications, we have developed a new route for synthesis of the thiophenol precursor and optimized the reaction conditions. The synthesis of N-(4-chloro-3-mercaptophenyl)picolinamide from 1-chloro-4-nitrobenzene has been greatly improved from 8% to 52% total yield with easy handling and in gram scales.

A novel Fmoc-SPPS compatible peptide thioester generation method leveraging Knorr pyrazole synthesis was reported recently. C-terminal peptide hydrazides, pentane-2,4-dione and excess arylthiol were added in one-pot to efficiently produce peptide thioesters in acidic aqueous solution at room temperature. To elucidate the detailed mechanism of this reaction and the origin of the effect of solution acidity, a theoretical investigation on the Knorr pyrazole synthesis-thioester generation reaction was carried out. Our computational results suggest that the reaction generally proceeds through three stages: hydrazone formation, pyrazole formation and thioester formation. The rate-determining step is the C O bond cleavage step in the pyrazole formation stage. The formed pyrazole is readily converted to thioester in the presence of excess thiophenol. The effect of solution acidity originates from the need for protonation of oxygen atoms to increase the electrophilicity of carbonyl group or the leaving ability of hydroxyl group.

A highly selective NHC-catalyzed Michael addition of alkanethiols or thiophenol to 2-nitro-d-galactal compounds for the synthesis of 2-nitro-thiogalactoside derivatives has been developed for the first time. A wide variety of 1,2-cis-2-nitro-thiogalactosides can be prepared in good to excellent yields and high to excellent α-selectivities.

The copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid is reported. The procedure operates under simple conditions to afford the corresponding aryl cyclopropyl sulfides in moderate to excellent yields. The reaction tolerates substitution in ortho-, meta- and para-substitution as well as electron-donating and electron-withdrawing groups. The S-cyclopropylation of a thiophenol was also accomplished using potassium cyclopropyl trifluoroborate.

Radical anti-Markovnikov hydro- and deuteroamidation of unactivated alkenes was achieved by merging photoredox and thiol catalysis. Reactions proceed by addition of the electrophilic CbzHN-radical (Cbz=carbobenzyloxy), readily generated by single-electron-transfer (SET) oxidation of an α-Cbz-amino-oxy acid to an alkene. The adduct radical is reduced by thiophenol added as an organic polarity reversal cocatalyst, which mediates the H transfer from H2 O to the alkyl radical intermediate. Accordingly, deuteroamidation of alkenes was realized with excellent D incorporation by using D2 O as the stoichiometric formal radical-reducing reagent. The reaction features low redox catalyst loading, excellent anti-Markovnikov selectivity, and the use of a large alkene excess is not required. Diverse Cbz-protected primary amines, including β-deuterated amines, can be obtained by applying this method.

With the importance of sulfur-containing organic molecules, developing methodologies toward C–S bond formation is a long-standing goal, and, to date, considerable progress has been made in this area. Recent electrochemical oxidative cross-coupling reactions for C–S bond formation allow the synthesis of sulfur-containing molecules from more effective synthetic routes with high atom economy under mild conditions. In this review, we highlight the vital progress in this novel research arena with an emphasis on the synthetic and mechanistic aspects of the organic electrochemistry reactions.1 Introduction2 Electrochemical Oxidative Sulfonylation for the Formation of C–S Bonds2.1 Applications of Sulfinic Acid Derivatives for the Formation of C–S Bonds2.2 Applications of Sulfonylhydrazide Derivatives for the Formation of C–S Bonds3 Electrochemical Oxidative Thiolation for the Formation of C–S Bonds3.1 Applications of Disulfide Derivatives for the Formation of C–S Bonds3.2 Applications of Thiophenol Derivatives for the Formation of C–S Bonds4 Electrochemical Oxidative Thiocyanation for the Formation of C–S Bonds5 Electrochemical Oxidative Cyclization for the Formation of C–S Bonds6 Conclusion

Thiophenol and its derivatives easily cause damage to aquatic bioorganisms, animals and even human being, therefore, fluorescent probes for detecting thiophenol with sensitive and selective characters are highly popular. In this study, a highly sensitive and selective porphyrin-based fluorescent sensor (M1) was reported for detection of thiophenol based on the steric hindrance effect, where the recognition unit, 7-nitrobenzo[c][1,2,5]oxadiazolyl group is linked to aromatic ortho-position in the porphyrin, and correspondingly the fluorescence of fluorescein is efficiently quenched. Its time of fluorescence response for thiophenol was only 60s, and its fluorescence responses for the other anions/molecules were all far lower than the relative fluorescence ratio values for thiophenol, which means that the porphyrin-based fluorescent sensor is rapid, sensitive and selective to detection of thiophenol. This approach offers some useful insights for designing sensitive and selective fluorescent turn-on sensors in the detection assays for other analytes.

A novel, visible-light-mediated method for the synthesis of 2-sulfenylindenones from easily available thiophenols (2.0 equiv.) and 1, 3-diarylpropynones (1.0 equiv.) in the presence of eosin Y (0.02 equiv.) under air atmosphere has been developed. The reaction proceeded smoothly, for a wide range of derivatives of thiophenols and 3-diarylpropynones, to give the expected products in moderate to good yields. Compared with traditional methods, this method is more convenient and avoids using stoichiometric amounts of I2 and K2S2O8.

Three alkoxyamines based on imidazoline radicals with a pyridine functional group&mdash, potential initiators of nitroxide-mediated, controlled radical polymerization&mdash, were synthesized. Electron Paramagnetic Resonance (EPR) measurements reveal biexponential kinetics for the thermolysis for diastereomeric alkoxyamines and monoexponential kinetics for an achiral alkoxyamine. For comparison, the thermolysis of all three alkoxyamines was studied by NMR in the presence of three different scavengers, namely tetramethylpiperidine-N-oxyl (TEMPO), thiophenol (PhSH), and &beta, mercaptoethanol (BME), and detailed analysis of products was performed. NMR differentiates between N-inversion, epimerization, and homolysis reactions. The choice of scavenger is crucial for making a reliable and accurate estimate of the true homolysis rate constant.

We report the synthesis of 4-thioferulic acid (TFA), a new ferulic acid (FA) derivative, and highlight the differences between the two compounds concerning rate and mechanism of radical scavenging activity, redox potential, acidity of the phenol/thiophenol moieties, cytotoxicity in differentiated SH-SY5Y cells, and neuroprotection against hydrogen peroxide (H2O2) and tert-butyl hydroperoxide (t-BHP) in the same cellular model.

Silica-bonded 1,4-diaza-bicyclo[2.2.2]octane-acetic acid bromide (SBDBAAB) as a novel nanostructured catalyst was prepared and fully characterized by several techniques including fourier transform infrared spectroscopy (FT-IR), X-ray diffraction (XRD), thermal gravimetric analysis (TGA), differential thermal gravimetric (DTG), scanning electron microscope (SEM), transmission electron microscopy (TEM), energy dispersive X-ray analysis (EDX), Brunauer-Emmett-Teller (BET) surface area analysis and Barrett-Joyner-Halenda (BJH) pore size and volume analysis. SBDBAAB was successfully tested on the synthesis of α-aryloxy alcohols as new compounds by the reaction of phenol or thiophenols with various epoxides. The structure of α-aryloxy alcohols were fully characterized by FT-IR, 1H NMR and 13C NMR as well as mass spectra.

Background: The sulfinic esters are important and useful building blocks in organic synthesis. Objective: The aim of this study was to develop a simple and efficient method for the synthesis of sulfinic esters. Materials and Methods: Constant current electrolysis from thiols and alcohols was selected as the method for the synthesis of sulfinic esters. Results and Discussion: A novel electrochemical method for the synthesis of sulfinic esters from thiophenols and alcohols has been developed. Up to 27 examples of sulfinic esters have been synthesized using the current methods. This protocol shows good functional group tolerance as well as high efficiency. In addition, this protocol can be easily scaled up with good efficiency. Notably, heterocycle-containing substrates, including pyridine, thiophene, and benzothiazole, gave the desired products in good yields. A plausible reaction mechanism is proposed. Conclusion: This research not only provides a green and efficient method for the synthesis of sulfinic esters but also shows new applications of electrochemistry in organic synthesis. It is considered that this green and efficient synthetic protocol used to prepare sulfinic esters will have good applications in the future.

Two‐dimensional (2D) molybdenum disulfide (MoS2) holds great promise in electronic and optoelectronic applications owing to its unique structure and intriguing properties. The intrinsic defects such as sulfur vacancies (SVs) of MoS2 nanosheets are found to be detrimental to the device efficiency. To mitigate this problem, functionalization of 2D MoS2 using thiols has emerged as one of the key strategies for engineering defects. Herein, we demonstrate an approach to controllably engineer the SVs of chemically exfoliated MoS2 nanosheets using a series of substituted thiophenols in solution. The degree of functionalization can be tuned by varying the electron‐withdrawing strength of substituents in thiophenols. We find that the intensity of 2LA(M) peak normalized to A1g peak strongly correlates to the degree of functionalization. Our results provide a spectroscopic indicator to monitor and quantify the defect engineering process. This method of MoS2 defect functionalization in solution also benefits the further exploration of defect‐free MoS2 for a wide range of applications., Non‐defective defects: Plot of the intensity of the 2LA(M) peak normalized to A1g peak (I450/I404) as a function of the degree of functionalization. This phenomenological relationship between I450/I404 and the degree of functionalization can potentially serve as a spectroscopic indicator to monitor and quantify the defect engineering process. The inset model depicts the structure of defect‐functionalized MoS2 nanosheets. The R in the model structure is corresponding to the para‐substituent on the phenyl ring.

Using sulfinamides as a new reagent for preparation of asymmetrical thioethers has been developed under metal-free conditions. The reactions proceeded smoothly without the use of stinky thiophenol, highly toxic sulfonyl chloride or oxidant. Such a simple, efficient transformation provides an attractive approach to various diaryl sulfides in good to excellent yields.

A selective four-electron reduction of CO2 with thiophenol using NaBH4 as a reductant is described to access dithioacetals. This reaction provides a novel synthetic method for the highly selective conversion of CO2 into methylene, and a new access to molecular structures via formation of C–S bonds using CO2 as the C1 source.

WOS: 000446500100013 Sulfenamide and its derivatives (S-N bond) have been synthesized with classical method in the literature. However, microwave-assisted synthesis of a series of N-(substituted phenylthio), N-(benzylthio), N-(cyclothio), and N-(2-mercaptobenzimidazolyl)amines has been not in the literature yet. They have been obtained from treating some amines (4 mmol) with thioph-thalimides (PhthSR, 1 mmol) using sulfur transfer reagent in the presence of 2-ethoxyethanol (beta-ee, neat) under microwave irradiation at 50 degrees C. The scope of this reaction was shown by the efficient synthesis of sulfenamides in good to excellent yields of 70-98% under free catalyst and ligand. Nine of the synthesized sulfenamide derivatives are novel. All of the thiols react with morpholine to give corresponding sulfenamides in excellent yields of 78-98%. Thiophenol, 4-methylthiophenol, 4-chlorothiophenol, and 4-fluorothiophenol react with cyclohexylamine to give corresponding sulfenamides in high yields 81-92%. Thiophenol, 4-methylthiophenol, 4-chlorothiophenol react with pyrrolidine to give corresponding sulfenamides in good yields of 70-76%. We observed that the reaction of t-butylamine with N-(phenylthio)phthalimide gave desired sulfenamide under microwave irradiation in the presence of DPPH as radical scavenger reagent in high yield of 93% Aniline, benzylamine, 1-hexylamine, ethanolamine, diethylamine, N-ethyl-n-butylamine, N-ethylaniline, N-benzylmethylamine, t-butylamine react with thiols to give symmetrical disulfides instead of desired products under microwave irradiation, 2-ethoxyethanol as a solvent (neat), and at 50 degrees C. In this study, microwave-assisted synthesis method was compared with the classical method. All the products obtained were purified with chromatographic method and the analysis of these products was confirmed with IR, H-1 NMR, C-13 NMR spectroscopy, MS spectrometry, and elemental methods. [GRAPHICS] . Ondokuz Mayis UniversityOndokuz Mayis University [PYO.FEN.1904.10.024] We would like to thank Ondokuz Mayis University (Grant No. PYO.FEN.1904.10.024) for its financial support of this work.

CdSe/CdS core/shell quantum dots (QDs) can be used as stable and highly active photoredox catalysts for efficient transfer hydrogenation of imines to amines with thiophenol as a hydrogen atom donor. This reaction proceeds via a proton-coupled electron transfer (PCET) from the QDs conduction band to the protonated imine followed by hydrogen atom transfer from the thiophenol to the α-aminoalkyl radical. This precious metal free transformation is easy to scale up and can be carried out by a one-pot protocol directly from aldehyde, amine, and thiophenol. Additional advantageous features of this protocol include a wide substrate scope, high yield of the amine products, extremely low catalyst loading (0.001 mol %), high turnover number (105), and the mild reaction conditions of using visible light or sun light at room temperature in neutral media.

The mechanism of action of the selenenamide 1 as a mimic of the glutathione peroxidase (GPx) was investigated by the density functional theory. The solvent-assisted proton exchange procedure was applied to model the catalytic behavior and antioxidant activity of this mimic. To have an insight into the charge transfer effect, different aromatic thiols, including electron donating substituents on the phenyl ring were considered. The catalytic behavior of the selenenamide was modeled in a four-step mechanism, described by the oxidation of the mimic, the reduction of the obtained product, selenoxide, the reduction of the selenenylsulfide and dehydration of selenenic acid. On the basis of the activation parameters, the final step of the proposed mechanism is the rate determining states of the catalytic cycle. Turnover frequency (TOF) analysis showed that the electron donating groups at the para-position of the phenyl ring of the PhSH do not affect the catalytic activity of the selenenamide in contrast to p-methyl thiophenol which indicates the highest nucleophilicity. The evaluation of the electronic contribution of the various donating groups on the phenyl ring of the aromatic thiols shows that the antioxidant activity of the selenenamide sufficiently increases in the presence of the electron-donating substitutions. Finally, the charge transfer process at the rate-determining state was investigated based on the natural bond orbital analysis.

Cyclic homodetic peptides are very appealing for medicinal chemistry programs. In addition to the high efficiency and selectivity inherently associated with peptides, a cyclic structure totally formed by amide bonds increases their stability under physiological conditions. Here Fmoc-MeDbz-resin was studied for the preparation of these peptides. Our results demonstrate the usefulness of this strategy for the preparation of cyclic “head-to-side chain” peptides through cyclative cleavage (simultaneous cyclization and release from the resin). In contrast, for the synthesis of the “head-to-tail” counterparts, the cyclization-cleavage should be carried out in the presence of thiophenol.

Thia-Michael addition of thiophenol to α,α′-di[(E)-benzyl­idene]alkanones of both cyclic (six-membered) and acyclic varieties using anhydrous K2CO3 or amberlyst-15 as catalyst has been found to be highly diastereoselective at 15 °C. A one-pot protocol was developed for such reactions by a tandem aldol-thia-Michael process. The stereochemistry of the products was confirmed by X-ray crystallographic studies and in all cases formation of a meso product was observed.

Garratt-Braverman (GB) cyclization, two C C bond forming reaction in a single step, has been utilized to construct several isoindoline and phthalan derivatives. The precursors were the bispropargyl protected amines and ethers with one of the propargyl arm substituted with an alkene moiety. The GB cyclizations were generally carried out in presence of DBU in refluxing toluene. In case of the bispropargyl amine systems with the alkene arm substituted with electron withdrawing ester group, the cyclization occurred at room temperature. The yields of cyclization ranged from 64 to 86% which are acceptable considering the formation of two C C bonds. The protected isoindolines could be successfully deprotected by treatment with thiophenol in presence of triethyl amine and the corresponding free amines were isolated as the TFA salts.

Copper acetate - iodine co-mediated regioselective ortho-arylthiolation of 2-arylpyridines has been accomplished with inexpensive and convenient thiophenol as the arylthiolating reagent. This protocol features excellent functional group tolerance, generating thioarylated products in moderate-to-high yields. © 2021 Elsevier Science. All rights reserved.

A series of novel carbohydrate-derived thiochromans has been successfully synthesized in order to investigate the influence of alkyl substituents on the aromatic ring of the thiophenol moiety in addition to the effect of protecting groups and stereochemistry on the sugar component of the target molecules. Results from the evaluation of the thiochromans for their antimalarial activity against the chloroquine-sensitive (3D7) strain of Plasmodium falciparum suggest that the presence of short chain alkyl substituents, a benzyl ether protecting group and equatorial orientation of the C-4 substituent on the sugar moiety are crucial structural features that impart high antimalarial activity.

A protocol for the synthesis of allylic sulfides from simple allylic hydrocarbons with thiophenol derivatives via a DDQ-mediated oxidative dehydrogenation strategy is described. This reaction possesses good functional group compatibility, broad substrate scope, and high atom- and step-economy. Moreover, the synthetic utility of this method can be highlighted by its application in the synthesis of versatile organo-sulfur compounds.

A series of ordered meso/macrostructured phosphotungstic acid (HPW)/SiO 2 materials were synthesized by evaporation-induced self-assembly (EISA) method using nonionic surfactant (P123) and monodispersed polystyrene (PS) spheres as templates. SEM images displayed close-packed ordered macropores with an average pore size of 210 nm. TEM, small-angle XRD and N 2 adsorption-desorption isotherms confirmed the existence of two-dimensional (2D) hexagonal ( p6mm ) mesostructure, embedded in the wall of macropores. The wild-angle XRD and FT-IR spectra proved that the Keggin-type HPW were finely dispersed in a silica matrix. The composite materials were used as catalysts for oxidative desulfurization of model oil (ODS). Compared with the ordered meso/macroporous HPW/SiO 2 catalyst and ordered macroporous HPW/SiO 2 catalyst prepared by colloidal crystal template method, ordered meso/macroporous HPW/SiO 2 catalysts synthesized through EISA method displayed much higher catalytic activity of thiophenol, dibenzothiophene (DBT) and its alkyl derivatives, achieving the thiophenol, BT, DBT, 4-MDBT and 4,6-DMDBT conversions of 100%, 83.3%, 99.3%, 89.1% and 86.5% within 40 min under the optimum conditions. This feature may be attributed to the larger mesoporous specific surface area and peculiar hierarchically meso/macroporous structural characteristics of the catalyst. Moreover, the catalytic activity has no obviously decreased even after sixth cycle of uses.

The kinetics and mechanism of the thermally activated dynamic covalent exchange of thiol-Michael adducts is investigated. A model system of thiol-Michael adducts between thiophenol and phenylvinylketone derivatives and adducts between 2-mercaptoethanol phenylvinylketone derivatives in N,N-dimethylformamide (DMF) at elevated temperatures is used to probe the underlying exchange mechanism. The kinetic data show negligible free Michael acceptor, which is consistent with the highly efficient thiol-Michael reaction being a "click"-like reaction that significantly favors the adduct form. At elevated temperatures of 90 °C in DMF the thiol-Michael adducts reach equilibrium after 24 h, although equilibration did not occur within 24 h at 60 °C or 75 °C, and negligible exchange occurs under ambient conditions. A kinetic model was developed to describe the dynamic covalent exchange and equilibration. The experimental and simulation kinetic data of dynamic covalent exchange are consistent with the thiol-Michael adducts undergoing a retro-Michael reaction, followed by subsequent addition of a free thiol to the liberated Michael acceptor. Kinetic analysis is consistent with the fragmentation, or retro-Michael reaction, being the rate-determining step in the dynamic covalent exchange. This suggests that the key step in dynamic covalent exchange is not enhanced by addition of free thiol or free Michael acceptor, since the addition reaction is much faster than the retro-Michael reaction. This fundamental study will guide the design of organic compounds, materials, and bioconjugates that utilize the thermally activated dynamic covalent thiol-Michael linkages.

Three-component reactions of alkylglyoxals, 1,3-dicarbonyl compounds, and a nucleophile were performed under aqueous and catalyst-free conditions, which produced 1,4-diketone scaffolds in a straightforward way. Many compounds, such as indole, azaindole, pyrrole, 2-methylfuran, N,N-dimethylaniline, N-methylaniline, thiophenol, and benzyl mercaptan, were all able to act as nucleophiles to react with alkylglyoxal and 1,3-dicarbonyl compounds. The mechanim of this reaction was also investigated. The obtained 1,4-diketones can be easily converted to many valuable chemicals.

This review is based on the analysis of recent developments on cyanation reactions for the synthesis of nitriles (RCN) through transition metal mediated cyanation reaction as well as by using non-metal like iodine (transition metal free system). In this regard, various catalyzed systems were reviewed to find the most efficient method having acceptable reaction system with surely less cost, mild conditions with easy handling. For the synthesis of nitriles; Copper, Palladium, Rhodium, and Iodine-based catalyzed systems have been explored for various aryl halides, arenes, pyridine, quinolone, imidazole, thiophenol, β -keto esters/amides, 2-arylbenzothiazoles etc. These reactions underwent with different time rates having the corresponding nitriles leading to natural products derivative in moderate to good yields.

An environmentally benign and straightforward synthetic approach for the assembly of a new class of diverse symmetrical substituted di-aromatic-fused 2,8-dioxa/dithiabicyclo[3,3,1]nonane derivatives containing methylene-bridged bicyclic framework via reusable cross-linked polystyrene-supported p-toluenesulfonic acid-catalyzed tandem reactions of substituted phenols/selected thiophenol with 1,1,3,3-tetramethoxypropane under neat conditions has been reported in which four new chemical bonds (two C–C/two C–O)-(two C–C/two C–S), two new six-membered cycles, and two new stereogenic tertiary carbon centers were constructed in a single operation. The synthetic utility of this method was also demonstrated. In addition, this present protocol could be successfully extended to the selected naphthols and dihydroxynaphthalenes as the enol partner of phenols with high efficiency. The developed transformation featured high efficiency, the use of commercially accessible feedstocks, excellent regioselectivity, simple operation, gram-scale synthesis, and good functional group compatibility. Furthermore, the solvent-free conditions, easily recoverable catalyst, and efficient recycling render the protocol green, economic and sustainable.