Thio Derivatives Research Articles

Recent Advances in Organocatalytic Asymmetric Synthesis of Bicyclo[3.3.1]nonane Frameworks

The bicyclo[3.3.1]nonane ring represents an attractive yet challenging synthetic targets in the field of organic synthesis, especially in a stereocontrolled fashion. Over the past two decades, organocatalysis has emerged as an enabling technology for the facile construction of enantioenriched molecules with remarkably increasing complexity and diversity, and a myriad of chiral architectures containing bicyclo[3.3.1]nonane units were elegantly assembled through organocatalytic asymmetric transformations. This review summarizes recent advancements on this topic (mainly from 2010 to 2023), emphasizing the reaction types such as desymmetrization and cascade reactions of different prochiral starting materials toward various chiral bicyclo[3.3.1]nonanes as well as their aza, oxa and thio derivatives. Meanwhile, the synthetic strategy, reaction mechanism, substrate scope and synthetic applications of these catalytic reactions are also discussed. We hope that this review will motivate further development and application of organocatalytic asymmetric synthesis of bicyclo[3.3.1]nonane frameworks.

Thio and Seleno Derivatives of Angelicin as Efficient Triplet Harvesting Photosensitizers: Implications in Photodynamic Therapy.

Photodynamic therapy (PDT) is widely accepted in medical practice for its targeted induction of apoptosis in cancerous cells. Angelicin (Ang) has traditionally been known for its efficacy in cancer treatment and its capability to enter a photoexcited triplet state. This study has comprehensively assessed the effects of substituting individual chalcogen atoms at three specific positions in Angelicin, with the objective of facilitating access to this elusive triplet state to enhance its role as a photosensitizer in PDT. The study scrutinizes various enhancements and factors that are crucial for efficient triplet harvesting. The decrease in singlet-triplet energy gap (ΔEST) and increased spin-orbit coupling (SOC) values present numerous viable pathways for intersystem crossing (ISC), leading to the triplet manifold. The lifetime of ISC, thus, decreases from 10-5 s-1 in Ang to 10‑8 s-1 in thioangelicin (TAng) and finally to 10-9 s-1 in selenoangelicin (SeAng). Additionally, this study investigates the two-photon absorption properties of thio and seleno-substituted Angelicin for their potentialities as non-UV photosensitizers. The interplay between electron-withdrawing and electron-donating substitutions in these derivatives significantly enhances the two-photon absorption cross-sections (σ) to as high as 49.3 GM while shifting the absorption wavelengths towards the infrared region enabling them as efficient PDT photosensitizers.

Inhibition of dengue viruses by N-methylcytisine thio derivatives through targeting viral envelope protein and NS2B-NS3 protease

Dengue virus (DENV) is a significant global health threat, causing millions of cases worldwide each year. Developing antiviral drugs for DENV has been a challenging endeavor. Our previous study identified anti-DENV properties of two (-)-cytisine derivatives contained substitutions within the 2-pyridone core from a pool of 19 (-)-cytisine derivatives. This study aimed to expand on the previous research by investigating the antiviral potential of N-methylcytisine thio (mCy thio) derivatives against DENV, understanding the molecular mechanisms of antiviral activity for the active thio derivatives. The inhibitory assays on DENV-2-induced cytopathic effect and infectivity revealed that mCy thio derivatives 3 ((1R,5S)-3-methyl-1,2,3,4,5,6-hexahydro-8H-1,5-methanopyrido[1,2-a][1,5]diazocine-8-thione) and 6 ((1S,5R)-3-methyl-2-thioxo-1,2,3,4,5,6-hexahydro-8H-1,5-methanopyrido[1,2-a][1,5]diazocin-8-one) were identified as the active compounds against both DENV-1 and DENV-2. Derivative 6 displayed robust antiviral activity against DENV-2, with EC50 values ranging from 0.002 to 0.005 μM in different cell lines. Derivative 3 also exhibited significant antiviral activity against DENV-2. The study found that these compounds are effective at inhibiting DENV-2 at both the entry stage (including virus attachment) and post-entry stages of the viral life cycle. The study also investigated the inhibition of the DENV-2 NS2B-NS3 protease activity by these compounds. Derivative 6 demonstrated notably stronger inhibition compared to mCy thio 3, revealing its dual antiviral action at both the entry and post-entry stages. Molecular docking simulations indicated that mCy thio derivatives 3 and 6 bind to the domain I and III of the DENV E protein, as well as the active of NS2B-NS3 protease, suggesting their molecular interactions with the virus. The study demonstrates the antiviral efficacy of N-methylcytisine thio derivatives against DENV. It provides valuable insights into the potential interactions between these compounds and viral target proteins, which could be useful in the development of antiviral drugs for DENV.

SYNTHESIS OF TERMINAL 2-ALKENYL(ALKYNYL)THIO-5-CYANO-6-(p-DIMETHYLAMINOPHENYL)PYRIMIDIN-4-ONES

Functionalized pyrimidines possess a wide spectrum of biological activity. In particular, they have antitumor, antiviral, and anticonvulsant activities, exhibit anti-inflammatory and analgesic effects, and they are inhibitors of aldose reductase, SecA ATPase, azide, and plant growth. The search for methods of synthesis of new functionalized and condensed pyrimidine derivatives is an urgent problem.
 Alkenyl-functionalized mono- and polycyclic pyrimidines are promise substrates for studying the regioselectivity of electroph ilic heterocyclization reactions under the influence of halogen-containing electrophilic agents, and halogen- and chalcogen-functionalized cyclization products showed high antibacterial, antifungal, and antimalarial activity. The introduction of new functional groups capable to modification into such alkenylpyrimidines can significantly affect their reactivity and change/enhance the biological activity of the halocyclization products. We proposed the synthesis of 2-alkenyl(alkynyl)thio derivatives of 5-cyano-6-(p-dimethylaminophenyl)-pyrimidin-4-one containing a cyano group labile to functionalization. As a result of alkylation of 2-thioxo-5-cyano-6-(p-dimethylaminophenyl)pyrimidin-4-one with unsaturated alkyl halides in an alkaline medium, the terminal alkenyl (allyl, methallyl) and alkynyl (propargyl) thioethers of cyanopyrimidine were obtained, promising for heterocyclization with halogen-containing electrophilic reagents .
 Keywords: 2-thioxo-5-cyano-pyrimidin-4-one; alkylation; alkenylthiopyrimidinone; alkynylthiopyrimidinone.

On the efficiency of barbituric acid and its thio derivatives as aluminium corrosion inhibitors: A computational study

The corrosion inhibition efficiency of the barbituric acid and its thio derivatives were herein monitored by the execution of a variety of density functional theory (DFT) computations. The 1,3-diazinane-2,4,6-trione (BA); 6-sulfanylidene-1,3-diazinane-2,4-dione (1S); 2,6-bis(sulfanylidene)-1,3-diazinan-4-one (2S); and 1,3-diazinane-2,4,6-trithione (3S) compounds were devoted as aluminum corrosion inhibitors. Global and local quantum descriptors were determined for the neutral and protonated forms of the modelled inhibitors in gas and aqueous phases. As the global indices indicated, reverse and proportional correlations were noticed between the number of S atoms in the studied inhibitors and their ionization potential and electron affinity. Accordingly, the inhibition efficiency of the studied compounds generally increased in the order BA < 1S < 2S < 3S. In the same line, the obtained values of local nucleophilic and electrophilic Fukui function indices affirmed the further favorability of the 3S compound over other studied analogs. Utilizing molecular dynamics simulations, the most favorable configurations for inhibitor∙∙∙aluminium (Al)(111) complexes were characterized. Binding energy calculations revealed the efficiency of the corrosion inhibition increased in the order BA∙∙∙Al (−0.95 eV) < 1S∙∙∙Al (−1.71 eV) < 2S∙∙∙Al (−2.16 eV) < 3S∙∙∙Al (−2.49 eV). Upon the presented findings, the current work would be a sufficient linchpin for future research related to the aluminium corrosion inhibition process, particularly with the incorporation of acids and their thio derivatives.

Cumulative impact of classical, weak and sulfur-centered H-bonds on structure and energetic: Homodimers of formic acid and its thio derivatives

An extensive computational investigation for homodimers of formic acid along with its mono- and di-thio derivatives has been carried out. Geometries and binding energies have been calculated at CCSD(T)-F12/cc-pVTZ-F12//ωB97X-D/aug-cc-pV(D+d)Z level. The findings are in very good agreement with existing experimental and high-level theoretical results. A total of 99 distinguishable stable conformers have been predicted for all four studied homodimers. Sixteen different noncovalent interactions, including ten types of H-bonds, have been identified. Structures and energetics of the dimers show systematic changes with sequential replacement of the two O atoms by S atoms. Caged structures become more favored over cyclic and linear ones with increasing S atoms. Hydroxyl/thiol groups were found to dictate dimeric properties rather than carbonyl/thiocarbonyl groups.

Photoprocesses in Guest–Host Complexes of a Styryl Dye Thio Derivative with Cucurbiturils

Photoprocesses in Guest–Host Complexes of a Styryl Dye Thio Derivative with Cucurbiturils

Photoprocesses in Guest–Host Complexes of a Styryl Dye Thio Derivative with Cucurbiturils

Photoprocesses in aqueous solutions of the styryl dye 1-ethyl-4-{(E)-2-[4(methylthio)phenyl]vinyl}pyridinium perchlorate (1) and its complexes with cucurbit[n]urils (CB[n], n = 6–8) have been studied using the methods of stationary and time-resolved optical spectroscopy. The fluorescence intensity increases by approximately 3 times in 1 : 1 complexes of 1 and CB[6], whereas CB[7] has almost no effect on the fluorescence intensity. In 2 : 1 complexes with CB[8], the photocycloaddition reaction does not occur, with strong fluorescence quenching being associated with the formation of nonreactive dimers. The fluorescence decay kinetics of 1 has two characteristic times, 1.4 and ~130 ps, and changes little in the complexes. The photoinduced intramolecular charge transfer in 1 is an order of magnitude smaller than in the wellknown dye DASPI.

Enantiomeric separation of newly synthesized amino, thio, and oxy derivatives of monoterpene lactones, amides, and ester applying polysaccharide-based chiral stationary phases in normal-phase mode

New amino, thio, and oxy derivatives of monoterpene lactones, amides, and esters have been synthesized and their enantioselective separations were investigated on seven covalently immobilized polysaccharide-based chiral stationary phases. The effects of basic additives, different short-chain alcohols, and the influence of the temperature on the chromatographic behavior were studied. In addition, relationships between the structure of selector and selectand and the chromatographic parameters were explored to reveal mechanistic details of chiral recognition. Experiments were performed in the temperature range 10–50°C and thermodynamic parameters were calculated from plots of lnα versus 1/T. The separations were generally enthalpy-controlled, but entropy-driven separation was also observed. Special attention has been paid to the enantiomer elution order and several examples are shown how the structural characteristics of the selector, the nature, and the concentration of the polar modifier induce reversal of the enantiomer elution order in the case of the polysaccharide-based selectors.

Enantioselective Povarov Reactions: An Update of a Powerful Catalytic Synthetic Methodology

AbstractThe enantioselective Povarov reaction is one of the most powerful synthetic strategy to synthesize chiral, highly functionalized 1,2,3,4‐tetrahydroquinolines. The present Minireview aims to collect the most significant successful examples of highly efficient enantioselective catalytic protocols for this reaction, since 2014. A comprehensive discussion of different catalytic strategies employed in recent years to realize the enantioselective Povarov reaction is provided; the use of chiral phosphoric acids, thio(urea) and proline derivatives, as well as transition metal complexes will be presented. Additionally, this Minireview critically discusses the intriguing and yet obscure mechanistic pathways of this well‐known reaction, the controversial dispute between a concerted or a polar two‐step process.

Synthesis of 4-Selanyl- and 4-Tellanyl-1H-isochromen-1-ones Promoted by Diorganyl Dichalcogenides and Oxone

A new method was developed for the synthesis of 4-chalcogenyl-1H-isochromen-1-ones through the 6-endo-dig electrophilic cyclization of 2-alkynylaryl esters and diorganyl dichalcogenides under ultrasound irradiation. The reactions were performed under mild conditions, using Oxone as a green oxidant to promote the cleavage of the chalcogen-chalcogen bond in diorganyl diselenides and ditellurides to generate electrophilic species in situ. A total of 25 compounds were selectively obtained after 30-70 min, in good to excellent yields (74-95%). This procedure was extended to prepare 5H-selenopheno[3,2-c]isochromen-5-ones. Additionally, for the first time, the 4-chalcogenyl-1H-isochromen-1-ones were used as substrates in the thionation reaction, using Lawesson's reagent and microwave irradiation under solvent-free conditions, obtaining the thio derivatives in yields of up to 99% in only 15 min.

Synthesis and biological profiling of novel isocoumarin derivatives and related compounds

In the continuation of our study of substituted isocoumarins a series of novel 3-azolyl isocoumarin and their thio derivatives, including some related lactone compounds was prepared and biologically profiled against C. albicans showing moderate activity with MIC values in range of 4?60 ?g mL-1, in general. The additional characterisation of selected compounds was carried out by exploring their activity on CYP3A4 and CYP2D6 enzymes, while experiments on mutagenicity were performed by AMES test. The representative isocoumarins 3b, 4a and 4b showed lower inhibitory activity on CYP enzymes, when compared to the reference inhibitors, ketoconazole and quinidine. Compound 4a showed a higher mutagenic potential than the other two compounds. Further characterization included cytotoxicity profiling against normal MRC5 cells.

Scaffolding-Induced Property Modulation of Chemical Space.

Physicochemical property switching of chemical space is of great importance for optimization of compounds, for example, for biological activity. Cyclization is a key method to control 3D and other properties. A two-step approach, which involves a multicomponent reaction followed by cyclization, is reported to achieve the transition from basic moieties to charge neutral cyclic derivatives. A series of multisubstituted oxazolidinones, oxazinanones, and oxazepanones as well as their thio and sulfur derivatives are synthesized from readily available building blocks with mild conditions and high yields. Like a few other methods, MCR and cyclization allow for the collective transformation of a large chemical space into a related one with different properties.

Synthesis and antioxidant properties of (dodecylsulfanyl)methyl quercetin derivatives

Mono-, bis-, and tris[(dodecylsulfanyl)methyl]-substituted quercetin derivatives were obtained by the reaction of quercetin with (N,N-diethylaminomethyl) dodecyl sulfide. These compounds under the conditions of AIBN-initiated oxidation of styrene (37 °C) terminated oxidation chains with a stoichiometric inhibition coefficients of 2.0±0.1 and rate constants of 5.1 · 105, 4.8 · 105, and 2.9 · 105 L mol-1 s-1, respectively. Based on the rate constants, the O-H bond energy values in the molecules of quercetin and its mono-, bis-, and tris- [(dodecylsulfanyl) methyl]-substituted derivatives were calculated and found to be equal to 334.4, 341.4, 341.7, and 344.7 kJ mol-1, respectively. It was established that the ability of the synthesized thio derivatives of quercetin to inhibit thermal autooxidation of lard (133 °C) is 1.3-2.7 times higher than that of the reference antioxidants (a-tocopherol, BHT, and BHA). According to the in silico assessment of acute toxicity for rats, the synthesized derivatives are low-toxic and non-toxic compounds.

Inclusion ability and selectivity of ethylenediamine derivatives for pyridine in the presence of methylpyridine isomers

The inclusion behaviour of compounds N,N′-bis(9-cyclohexyl-9-xanthenyl)ethylenediamine (OED) and N,N′-bis(9-cyclohexyl-9-thioxanthenyl)ethylenediamine (SED) was assessed in the presence of pyridine (PYR) and its three methylpyridine isomers (2MP, 3MP and 4MP). PYR, 3MP and 4MP were each enclathrated by OED when it was recrystallized independently from each guest solvent, but failed to include 2MP. The thio host derivative, SED, was less efficient, forming a complex only with PYR. When these guests were mixed in equimolar amounts and each host recrystallized from the mixture, OED constantly displayed a significantly enhanced preference for 4MP (near-complete in many instances), while complexation failed under these circumstances for SED, even when PYR was present in the guest mixture (despite PYR having been included in the single solvent experiment). A selectivity order of 4MP (92.8%) ≫ PYR (6.0%) > 3MP (0.9%) > 2MP (0.3%) was noted for OED when it was recrystallized from the equimolar quaternary mixed solvent system. The selectivity of OED towards 4MP was investigated using single crystal diffraction (SCXRD) and thermal (TA) analyses: interestingly, only 4MP experienced a strong classical hydrogen bond with OED, in direct relation to the enhanced selectivity of OED for 4MP while, additionally, this complex displayed an increased thermal stability relative to the other two complexes with OED.

Synthesis, characterization, and biological evaluation of a set of new alkylthio substituted plastoquinones containing ester group

In the present investigation, fourteen new alkylthio substituted 5,6-dimethyl-1,4-benzoquinone derivatives were synthesized as potential antimicrobial and antifungal agents. First, 2,3-dichloro-5,6-dimethyl-1,4-benzoquinone was reacted with alkyl thiols containing ester group to yield its mono- and bis(thio) derivatives and then these compounds were investigated for their antibacterial and antifungal activities. In vitro studies were carried out using four Gram-negative bacteria (Pseudomonas aeruginosa ATCC 27853, Escherichia coli ATCC 25922, Klebsiella pneumoniae ATCC 4352, Proteus mirabilis ATCC 14153), three Gram-positive bacteria (Enterococcus faecalis ATCC 29212, Staphylococcus epidermidis ATCC 12228, Staphylococcus aureus ATCC 29213), and two fungi (Candida albicans ATCC 10231, Candida parapsilosis ATCC 22019) by using the microbroth dilutions technique. Most of the synthesized compounds (3a-c, 3f, 4b-c, and 4e) exhibited good antibacterial activities with MIC values between 9.76 and 78.12 μg/mL. Compound 4e was identified as a hit compound with antibacterial efficiency against P. aeruginosa and E. faecalis with MIC value of 9.76 and 19.53 μg/mL, respectively.

LONG-CHAIN SCHIFF'S BASICS BASED ON QUINOLINE

Azomethines with heterocyclic fragment in its composition are used as pigments of dyes, catalysts, intermediates in organic synthesis and as stabilizers in the production of high molecular weight compounds. Known examples of using Schiff bases to obtain transition metal complexes what are important for analytical chemistry. Also, azomethines show a wide range of biological activity: they exhibit anti-inflammatory, anti-fungal, antibacterial and anticonvulsant activity.The introduction of a quinoline cycle to the azomethine moiety may increase the bioactivity of the latter, as it is known that functional quinoline derivatives exhibit a wide range of biological activity.The purpose of this work is to synthesize new azomethines based on quinoline. The interaction of long-chain amines with 2-chloroquinoline was carried out in the environment of pyridineThe reaction results were obtained condensation products of 1- (2-chloroquinolin-3-yl) -N-alkylmethanimines. A large hydrocarbon chain near iminium nitrogen increases the lyophilicity of azomethines, which may potentially affect the rate of pharmacological action.The condensation reactions of 2-chloroquinoline-3-carbaldehyde were carried out with hexanoic and octanoic acid hydrazides in ethanol, allowing to obtain high yields hydrazones. It should be noted that the reaction produces a mixture of syn- and anti-isomers.To determine the effect of the substituent at position 2 quinoline, condensations of synthetically available 2-thioquinoline-3-carbaldehyde with amines and acid hydrazides were conducted. The interaction between thioquinolinecarbaldehyde and octylamine in an ethyl alcohol environment results in the formation of a condensation product of 3 - [(octylimino) methyl] quinoline-2-thiol. In the case of condensation of 2-thioquinoline-3-carbaldehyde with octanoic acid hydrazide, hydrazone is formed, which is a mixture of syn- and anti-isomers in a ratio of 1: 1.2.It should be noted that the obtained long-chain thio derivatives of quinoline can be used as complexing agents for the determination of metals.The structure of the obtained compounds was proved by the spectra of nuclear magnetic resonance.

Synthesis and In Vitro Antibacterial Activity of New C-3-Modified Carbapenems

New C-3 modified carbapenems have been synthesized by the AdNE-substitution of the enol phosphate group of 4-nitrobenzyl (4R)-3-[(diphenylphosphoryl)oxy]-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-en-2-carboxylate by the corresponding thiols in acetonitrile in the presence of diisopropylethylamine (DIPEA). Mercaptoacetic acid methyl ester, furan-1-methylthiol, methyl N-(mercaptoacetyl)methioninate, and 2-(4-methylpiperazin-1-yl)-2-oxoethanethiol as thiols have been used. As a result, we have obtained the expected 4-nitrobenzyl esters of 3-[(2-methoxy-2-oxoethyl)thio]-, 3-[(2-furylmethyl)thio], 3-{[2-(4-methylpiperazin-1-yl)-2-oxoethyl]thio}, and 3-[((2-(S)-1-methoxy-4-methylthio-1-oxopropan-2-yl)amino)-2-oxoethyl]thio derivatives of (4R,5S,6S)-6-[(1R)-1-hydroxyethyl]-4-methyl-7-oxo-1-azabicyclo[3.2.0]hept-2-ene-2-carboxylic acid in yields of 67–87% after purification by column chromatography. The p-nitrobenzyl (pNb) esters of carbapenems have been converted to the corresponding acids by hydrogenolysis over 10% Pd/C in methanol. The antibacterial activity of the resulting carbapenems and their preceding pNb-esters has been studied against microorganisms of Escherichia coli, Pseudomonas aeruginosa, Candida albicans, and Streptococcus oralis. The compounds that have been found exceed in their activity the known drugs Meropenem and Cilapenem.

Compounds N,N′-bis(9-cyclohexyl-9-xanthenyl)ethylenediamine and its thio derivative, N,N′-bis(9-cyclohexyl-9-thioxanthenyl)ethylenediamine, as potential hosts in the presence of xylenes and ethylbenzene: Conformational analyses and molecular modelling considerations

Two novel crystalline compounds, N,N′-bis(9-cyclohexyl-9-xanthenyl)ethylenediamine (OED) and its thio derivative, N,N′-bis(9-cyclohexyl-9-thioxanthenyl)ethylenediamine (SED), were designed and synthesized in our laboratories, and assessed for their potential as host compounds for the four C8 aromatic compounds, namely o-, m- and p-xylene (o-Xy, m-Xy, p-Xy), and ethylbenzene (EB). Despite the only difference between the two compounds being the heteroatoms in their B rings, immense behaviour differences were noted: only OED displayed host behaviour in these conditions, clathrating all but m-Xy, while SED failed to form complexes with any of the four organic solvents. These observations prompted an investigation into the conformations of OED and SED through single crystal diffraction (SCXRD) analyses as well as computational studies with surprising results. SCXRD was also employed to analyse the three complexes that successfully formed with OED, and thermal analyses (TA) assisted in understanding the selectivity behaviour of OED when presented with mixed guests.

Synthesis, antimicrobial activity and quantum calculations of Novel sulphonamide derivatives

The reactivity of 2-bromo-N-(phenylsulfonyl)acetamide derivatives 3a-c towards some nitrogen-based nucleophiles was studied in this investigation and gave the corresponding aminothiazole 6a-c, amino-oxazole 7a-c, quinazoline-2-yl 10a-c; respectively. Furthermore, the reaction of acetamide derivatives 3a-c with aminopyridine gave pyridine-4-ylamino 12a-c. Reaction of acetamide derivatives 3a-c with benzo-2-thiol derivatives afforded benzo [d] thiazol-2-ylthio 14a-c and 1H-benzo[d]imidazol-2-yl)thio derivatives 16a-c; respectively. The synthesized compounds displayed good antimicrobial activity. Additionally, compounds 12a and 14a exhibited high activity towards most of the strains. The computational calculations for 12a and 14a were carried out via HF/6-31G(d) and DFT B3LYP/6-31G(d) basis sets and the corresponding results of HOMO–LUMO energy gap and Mulliken atomic charges were tabulated. This correlation between experimental and theoretical calculations provided a good confirmation for anticipated new compounds.