Thiopyran Derivatives Research Articles

Reactivity Study of 4-Hydroxythiocoumarin: A Novel Synthetic Route to Fused Chromono-thiophene and -thiopyran Derivatives through Solvent-dependent Thio-Claisen Rearrangement

The alkylation of 4-hydroxythiocoumarins (1a-f) was carried out with various allyl bromides as well as propargyl bromides using K2CO3 (2 equiv.) in anhydrous acetone at room temperature, and the corresponding...

Anti-cancer effects of bis-oxidized thiopyran derivatives on non-small cell lung cancer: rational design, synthesis, and activity evaluation

A series of bis-oxidized thiopyran derivatives were designed, synthesized and evaluated for their activity against 4 cancer cell lines.

C-H arylation of thiopyran derivatives with aryl halides.

A C-H arylation of thiopyran derivatives with aryl halides has been developed. Under the catalysis of Pd(OAc)2/Ag2CO3, the C-H arylation takes place at the α-position of the thiopyran ring. When dibromo-substituted compounds are used as reactants, double C-H arylations may occur on the same thiopyran ring at its α- and β-positions.

Sc(OTf)3-catalyzed diastereoselective [4 + 2] cycloaddition reaction of 3-benzylideneindoline-2-thiones with alkylidene malonates

A Sc(OTf)3-catalyzed diastereoselective [4 + 2] cycloaddition reaction of 3-benzylideneindoline-2-thiones with 2-alkylidene malonates has been realized, leading to biologically important indole-annulated thiopyran derivatives in moderate to good yields. Moreover, a gram-scale reaction and chemical transformation of the cycloadduct into a sulfone were carried out to further extend the synthetic utility.

Reducing Contact Resistance in Organic Field-Effect Transistors: A Comprehensive Comparison between 2D and Microrod Single Crystals.

A comprehensive comparison of organic single crystals based on a single material but with different dimensions provides a unique approach to probe their carrier injection mechanism. In this report, both two-dimensional (2D) and microrod single crystals with the same crystalline structure of an identical thiopyran derivative, 7,14-dioctylnaphtho[2,1-f:6,5-f']bis(cyclopentane[b]thiopyran) (C8-SS), are grown on a glycerol surface with the space-confined method. Organic field-effect transistors (OFETs) based on the 2D C8-SS single crystal exhibit superior performance compared with those based on the microrod single crystal, particularly in their contact resistance (RC). It is demonstrated that the resistance of the crystal bulk in the contact region plays a key role in RC of the OFETs. Thus, among the 30 devices tested, the microrod OFETs typically appear contact-limited, whereas the 2D OFETs possess significantly reduced RC arising from the tiny thickness of the 2D single crystal. The 2D OFETs show high operational stability and high channel mobility up to 5.7 cm2/V·s. The elucidation of the contact behavior highlights the merits and great potential of 2D molecular single crystals in organic electronics.

Microwave-mediated stereocontrolled annulations of diazo(aryl)methyl(diaryl)phosphine oxides with pyridinium 1,4-zwitterionic thiolates.

Chemoselective annulations of phosphoryl carbenes generated from diazo(aryl)methyl(diaryl)phosphine oxides with pyridinium 1,4-zwitterionic thiolates were performed under microwave irradiation, affording 1-diarylphosphoryl-1H-benzo[c]thiopyran derivatives via [3+3] annulation and indolizine derivatives via ([1+5]-1) annulation with P-Cope elimination as the key step. The annuloselectivity was controlled by the steric hindrance of pyridiniums in pyridinium 1,4-zwitterionic thiolates.

Three-Component Synthesis and Crystal Structure of 2-Amino-3-cyano-4H-pyran and -thiopyran Derivatives

Three-Component Synthesis and Crystal Structure of 2-Amino-3-cyano-4H-pyran and -thiopyran Derivatives

Facile Synthesis of S‐Fused Multi‐Membered Polycyclic Heterocycles: A Construction Strategy towards Thermally Stable Thiepine Derivatives

Comprehensive SummaryS‐fused heterocycles have become popular building blocks to construct functional polycyclic compounds. In contrast to the abundant synthetic methodologies for thiophene‐fused aromatics, the synthesis of S‐heterocycles containing six‐membered thiopyran and seven‐membered thiepine rings is much less reported owing to their unfavorable synthetic protocols and the thermal instabilities. Herein, a series of thiepine‐containing polycyclic S‐heterocycles have been successfully synthesized via different synthetic routes which involve initial construction of sulfur bridges and final ring‐closure reactions. Therefore, the dilithium intermediates are excluded, which facilitates the fusion on the thiepine ring with different S‐heterocycles, including thiophene and thiopyran derivatives. Typically, a S‐fused multi‐membered polycyclic compound simultaneously involving thiophen, thiopyran, and thiepine rings has been successfully prepared. Interestingly, nucleus‐independent chemical shift calculations reveal that the incorporated thiopyran and thiepine rings demonstrate aromatic and nonaromatic characteristics, respectively. Moreover, the thermal stabilities of the thiepine derivatives have been tremendously improved after the fusion on the three vinyl groups in the thiepine unit, which is attributed to the enhancements of the activation energies for the S‐extrusion reactions, as revealed by density functional theory calculations. Therefore, our findings not only provide a facile synthetic methodology for S‐fused multi‐membered polycyclic heterocycles, but also furnish a novel construction strategy towards thermally stable thiepine derivatives.

Facile one-pot, multi-component reaction to synthesize spirooxindole-annulated thiopyran derivatives under environmentally benevolent conditions

An efficient and facile one-pot, five-component reaction for the synthesis of 2,6-diamino-1-alkyl-2-oxospiro[indoline-3,4′-thiopyran]-3,5-dicarbonitrile derivatives has been reported by a reaction between primary amines, carbon disulfide, malononitrile, and isatin derivatives. The major advantages of this procedure are high yields of products in relatively short reaction time, scalability, mild conditions, multi-component synthetic procedure, low catalyst loading, no column separation and simple reaction work-up. As a consequence, this synthetic procedure provided an efficient access to spirooxindole-annulated thiopyran derivatives.

Multi-Component One-Pot Assisted Synthesis, Anti-bacterial Capabilities, and Scanning Electron Microscopy of Novel Corticosteroid Thiopyran.

Corticosteroids are an important group of polycyclic compounds having a wide range of pharmacological and physiological properties. Thiopyran derivatives are important building blocks of many biologically active compounds. Keeping in mind the wide range of applications of corticosteroids and thiopyran, herein we intend to develop a simple and efficient strategy to synthesize steroidal thiopyran derivatives starting with different commercially available corticosteroids and study their biological properties. To achieve our aim, we employed a one-pot multi-component synthesis of steroidal thiopyran derivatives by the reaction of corticosteroids, malononitrile, and carbon disulphide in the presence of triethylamine as a catalyst. An array of novel thiopyran compounds was obtained with the highest product yield using Et3N. Scanning electron microscopy analysis manifested agglomeration pertaining to brick-shaped crystals of corticosteroid thiopyran. Synthesized compounds were also found to be active as anti-bacterial agents. We describe a facile one-pot multi-component synthesis of corticosteroid thiopyran derivatives, which are found to possess anti-bacterial activity. Excellent yields of the products, simple work-up, easily available starting materials, and non-chromatographic purification are some of the main advantages of this protocol.

Sulfhydryl-Directed Iridium-Catalyzed C-H/Diazo Coupling and Tandem Annulation of Naphthalene-1-thiols.

The first sulfhydryl-directed iridium-catalyzed C-H/diazo coupling and tandem annulation of naphthalene-1-thiols has been developed. The framework of naphtho[1,8-bc]thiopyrans was constructed in a one-step reaction with good yields. This transformation provides a practical synthetic route for the widely used naphtho[1,8-bc]thiopyran derivatives.

A thiopyran derivative with low murine toxicity with therapeutic potential on lung cancer acting through a NF-κB mediated apoptosis-to-pyroptosis switch

Pyroptosis is a novel manner of cell death that can be mediated by chemotherapy drugs. The awareness of pyroptosis is significantly increasing in the fields of anti-tumor research and chemotherapy drugs. Invoking the occurrence of pyroptosis is an attractive prospect for the treatment of lung cancer. Here, the compound L61H10 was obtained as a thiopyran derivative to compare its activity with curcumin. It was indicated that L61H10 exhibited good anti-tumor activity both in vitro and in vivo via the switch of apoptosis-to-pyroptosis, which was associated with the NF-κB signaling pathway. In addition, L61H10 had no obvious side effects both in vitro and in vivo. In brief, L61H10 is shown to be a potential anti-lung cancer agent and research on its anti-tumor mechanism provides new information for chemotherapy drug research.

From Colorless to Near-Infrared S-Heteroarene Isomers: Unexpected Cycloaromatization of Cyclopenta[b]thiopyran Catalyzed by PtCl2

S-heteroarenes containing cyclopenta[ b]thiopyran moieties were synthesized via intramolecular ring-expanding cycloisomerization from 1-acetyl-2-thienyl-substituted precursors catalyzed by PtCl2. In comparison to the other two S-heteroarene isomers experiencing common 6-endo and 5-exo cyclization processes, the aromatic cyclopenta[ b]thiopyran derivative demonstrates intriguing photophysical and electrochemical properties, such as near-infrared absorption, low oxidation potential, and excellent electrochemical stability. Therefore, this work provides an effective pathway to incorporate cyclopenta[ b]thiopyran as building blocks for organic semiconductors with unique properties.

Synthesis and characterization of sulfide, sulfoxide and sulfone derivatives of thiopyran: antimicrobial evaluation

A series of thiopyran derivatives and their oxidized analogous forms were synthesized and characterized by FT-IR, 1H, 13C, 31P NMR and mass spectroscopy techniques. The antibacterial and antifungal activities of these synthesized materials were evaluated against Staphylococcus aureus and Bacillus subtilis, as Gram-positive bacteria, and Escherichia coli and Pseudomonas aeruginosa, as Gram-negative bacteria, as well as the fungus Candida albicans. The results revealed that thiopyran S,S-dioxides are the most effective against all the bacteria studied in this work. Furthermore, thiopyran S-oxides showed excellent antifungal activity against Candida albicans.

ChemInform Abstract: An Efficient One‐Pot Regioselective Approach Towards the Synthesis of Thiopyrano[2,3‐d]thiazole‐2‐thiones Catalyzed by Basic Ionic Liquid under Microwave Irradiation.

AbstractA green method for preparation of the title thiopyran derivatives by cyclocondensation of (thioxo)thiazolidinone, benzaldehydes, and β‐oxodithioesters using ionic liquid as catalyst and solvent is developed.

Organosulfur phosphonium salt-mediated synthesis of functionalized thiopyran derivatives

GRAPHICAL ABSTRACT

Sulfur-assisted ring contraction of polyfluoroalkylthiopyran derivatives as a route to functionalized fluorine-containing thiophenes

A synthetic route to functionalized α-(polyfluoroalkyl)thiophenes based on the reactions of ring contraction of polyfluoroalkyl substituted thiopyran derivatives has been explored. Potent 6-membered precursors for the preparation of thiophenes were obtained by the addition of bromine to the double bonds of 2-chloro-2-(trifluoromethyl)-3,6-dihydro-2H-tetrahydrothiopyran and 6-(polyfluoroalkyl)-2H-thiopyrans. The reactions of the resulted 4,5-dibromo-2-chloro-2-(trifluoromethyl)tetrahydrothiopyrans and trans-3,4-dibromo-6-(polyfluoroalkyl)-3,4-dihydro-2H-thiopyrans with sodium acetate in acetic acid produced 2-(acetoxymethyl)-5-(polyfluoroalkyl)thiophenes. Base-catalyzed methanolysis of the acetoxymethyl derivatives allowed preparing the corresponding 2-(hydroxymethyl)-5-(polyfluoroalkyl)thiophenes. The mechanism, which includes formation and nucleophilic cleavage of thiiranium cations, has been suggested for the transformation of dibromothiopyran derivatives to substituted thiophenes.

ChemInform Abstract: Hetero‐Diels—Alder Reactions of Hetaryl and Aryl Thioketones with Acetylenic Dienophiles.

Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones.

Hetero-Diels-Alder reactions of hetaryl and aryl thioketones with acetylenic dienophiles.

Selected hetaryl and aryl thioketones react with acetylenecarboxylates under thermal conditions in the presence of LiClO4 or, alternatively, under high-pressure conditions (5 kbar) at room temperature yielding thiopyran derivatives. The hetero-Diels–Alder reaction occurs in a chemo- and regioselective manner. The initially formed [4 + 2] cycloadducts rearrange via a 1,3-hydrogen shift sequence to give the final products. The latter were smoothly oxidized by treatment with mCPBA to the corresponding sulfones.

ChemInform Abstract: Solvent‐Free Synthesis of Substituted Thiopyrans via Multicomponent Reactions of α‐Haloketones.

Abstract A straightforward and efficient method for the synthesis of thiopyran derivatives via three-component reaction of alkyl propiolate, benzoylisothiocyanate or its derivatives and α -haloketones in the presence of triphenylphosphine under solvent-free conditions at 70 °C without using any catalyst is reported. The method offers several advantages including high yields of products and an easy work-up procedure.