Dibenzothiophene Dioxide Research Articles

Transition-metal-free synthesis of 2-arylphenol via SNAr reaction of dibenzothiophene dioxide with KOH

Transition-metal-free synthesis of 2-arylphenol via SNAr reaction of dibenzothiophene dioxide with KOH

Charge Mobility of Substituted Donor-Acceptor Compounds Based on Diphenylamines and Dibenzothiophene Dioxides in OLED Structures

Charge Mobility of Substituted Donor-Acceptor Compounds Based on Diphenylamines and Dibenzothiophene Dioxides in OLED Structures

9-Phenyl-9-phosphafluorene oxide based organic ligands synthesized via successive SNAr reactions and their symmetric phosphorescent Ir(III) complexes for highly efficient solution-processed OLEDs

Three organic ligands with 9-phenyl-9-phosphafluorene oxide (PhFlPO) group have been synthesized via successive nucleophilic aromatic substitution (SNAr) reactions between dibenzothiophene dioxides and PhPH2-KOH under mild reaction conditions at room temperature. In this way, the novel PhFlPO-type organic ligands can be easily obtained without either highly sensitive Grignard or organolithium reagents of noble metal catalysts. Using these PhFlPO-type organic ligands, cyclometalated Ir(III) phosphorescent complexes with PhFlPO groups have been developed through well-accepted two-step strategy. To the best of our knowledge, these complexes represent the unprecedented examples of symmetric cyclometalated Ir(III) phosphorescent complexes bearing PhFlPO group. It has been found that electron-density on the coordinated carbon atom in the PhFlPO unit can exert a significant influence on the metal-to-ligand charge transfer transition (MLCT) processes and phosphorescent emission behavior of these cyclometalated Ir(III) phosphorescent complexes. In addition, the electroluminescent potential of these new cyclometalated Ir(III) phosphorescent complexes with PhFlPO groups has been characterized in solution-processed organic light-emitting diodes (OLEDs). They can show very impressively high external quantum efficiency (ηext), current efficiency (ηL) and power efficiency (ηP) of 20.0%, 71.7 cd A−1 and 56.1 lm W−1, respectively. These encouraging research results can furnish critical information for developing new PhFlPO-based Ir(III) phosphorescent emitters.

Construction of 5H‐Dibenzo[c,e]azepine Framework from Dibenzothiophene Dioxides andN‐Benzylimines through SNAr Reactions

AbstractTreatment of a mixture of dibenzothiophene dioxides and benzaldehydeN‐benzylimines with potassium hexamethyldisilazide induces sequential intermolecular and intramolecular SNAr reactions to eventually form the corresponding 5H‐dibenzo[c,e]azepines without any formation of the conceivable five‐membered fluorene derivatives.

Synthesis of N-Alkyl and N-H-Carbazoles through SN Ar-Based Aminations of Dibenzothiophene Dioxides.

Alkyl amines have become available for the synthesis of diverse N-alkyl carbazoles through twofold SN Ar aminations of dibenzothiophene dioxides by using alkali metal bases. Of particular importance is the choice of counter cations on alkali metal bases, that is, i) the use of Li base for the efficient intermolecular reaction and ii) the sequential addition of heavier alkali metal bases (Na, K, or Cs) to promote intramolecular cyclization in a one-pot manner. This protocol also enables the cascade synthesis of N-H-carbazoles by using 2-phenylethylamine by removal of the 2-phenethyl group from N-(2-phenethyl) carbazoles in a single operation.

Dibenzothiophene Dioxide Based Conjugated Microporous Polymers for Visible-Light-Driven Hydrogen Production

Conjugated microporous polymers (CMPs) have gained much recent attention as a kind of metal-free organic photocatalyst for photocatalytic hydrogen generation. However, the development of a visible-light-driven CMP photocatalyst with high photocatalytic activity is still a big challenge. Here, we report dibenzothiophene dioxide containing CMP photocatalysts and demonstrate the influence of the cross-linker length on the photocatalytic performance for hydrogen production. The most active photocatalyst of DBTD-CMP1 with a short cross-linker of benzene exhibits a high hydrogen evolution rate (HER) of 2460 μmol h–1 g–1 under visible light without Pt cocatalyst. Remarkably, the Pt-loaded DBTD-CMP1 shows an attractive HER of 9200 μmol h–1 g–1 under UV–vis light illumination. This result demonstrates that these dibenzothiophene dioxide containing CMPs are competitive with the most reported porous organic polymer photocatalysts.

KHMDS mediated synthesis of 9-arylfluorenes from dibenzothiophene dioxides and arylacetonitriles by tandem SNAr-decyanation-based arylation.

A straightforward KHMDS mediated synthetic route to 9-arylfluorenes from readily available starting materials has been developed. This reaction involves SNAr reactions of dioxide with arylacetonitriles, followed by decyanation reaction. The proposed transformation can also be used to furnish a densely arylated indene.

Synthesis of Dibenzophosphole Oxides from Dibenzothiophene Dioxides and Phenylphosphine by Two Successive SNAr Reactions

AbstractOne‐pot treatment of dibenzothiophene dioxides with phenylphosphine and KOH in DMSO at ambient temperature provides the corresponding dibenzophosphole oxides after oxidative workup. Substitution of the endocyclic SO2 unit with PPh could proceed via an intermolecular SNAr reaction of the dioxides with potassium phenylphosphide followed by another SNAr reaction in an intramolecular fashion. Various dibenzophospholes have been synthesized from readily available dibenzothiophene dioxides and were investigated from a photophysical viewpoint.

Novel Diazole/Triazole and Dibenzothiophene Dioxide Containing Pentacyclic Systems with Promising Biological Activities

The aim of the current work is to synthesize the new heterocyclic pentacyclic condensed systems that combine benzothiophen and benzimidazole/triazole into one molecule. The dibenzothiophene was taken as an initial compound and by consistent “extension” was annihilated the imidazole and triazole nucleuses. As a result two new pentacyclic systems were produced: 3H-, 7H-diimidazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide and 3H-, 7H-ditriazole[4,5-b][5,4-g] dibenzothiophene-5,5-dioxide with the promising antimi-crobial activity. Their spectral characteristics were studied.

A Promising PET Tracer for Imaging of α7 Nicotinic Acetylcholine Receptors in the Brain: Design, Synthesis, and in Vivo Evaluation of a Dibenzothiophene-Based Radioligand

Changes in the expression of α7 nicotinic acetylcholine receptors (α7 nAChRs) in the human brain are widely assumed to be associated with neurological and neurooncological processes. Investigation of these receptors in vivo depends on the availability of imaging agents such as radioactively labelled ligands applicable in positron emission tomography (PET). We report on a series of new ligands for α7 nAChRs designed by the combination of dibenzothiophene dioxide as a novel hydrogen bond acceptor functionality with diazabicyclononane as an established cationic center. To assess the structure-activity relationship (SAR) of this new basic structure, we further modified the cationic center systematically by introduction of three different piperazine-based scaffolds. Based on in vitro binding affinity and selectivity, assessed by radioligand displacement studies at different rat and human nAChR subtypes and at the structurally related human 5-HT3 receptor, we selected the compound 7-(1,4-diazabicyclo[3.2.2]nonan-4-yl)-2-fluorodibenzo-[b,d]thiophene 5,5-dioxide (10a) for radiolabeling and further evaluation in vivo. Radiosynthesis of [18F]10a was optimized and transferred to an automated module. Dynamic PET imaging studies with [18F]10a in piglets and a monkey demonstrated high uptake of radioactivity in the brain, followed by washout and target-region specific accumulation under baseline conditions. Kinetic analysis of [18F]10a in pig was performed using a two-tissue compartment model with arterial-derived input function. Our initial evaluation revealed that the dibenzothiophene-based PET radioligand [18F]10a ([18F]DBT-10) has high potential to provide clinically relevant information about the expression and availability of α7 nAChR in the brain.

Transition-Metal-Free Synthesis of Carbazoles and Indoles by an SNAr-Based “Aromatic Metamorphosis” of Thiaarenes

Dibenzothiophene dioxides, which are readily prepared through oxidation of the parent dibenzothiophenes, undergo nucleophilic aromatic substitution with anilines intermolecularly and then intramolecularly to yield the corresponding carbazoles in a single operation. The “aromatic metamorphosis” of dibenzothiophenes into carbazoles does not require any heavy metals. This strategy is also applicable to the synthesis of indoles. Since electron-deficient thiaarene dioxides exhibit interesting reactivity, which is not observed for that the corresponding electron-rich azaarenes, a combination of a thiaarene-dioxide-specific reaction with the SNAr-based aromatic metamorphosis allows transition-metal-free construction of difficult-to-prepare carbazoles.

Transition-Metal-Free Synthesis of Carbazoles and Indoles by an SN Ar-Based "Aromatic Metamorphosis" of Thiaarenes.

Dibenzothiophene dioxides, which are readily prepared through oxidation of the parent dibenzothiophenes, undergo nucleophilic aromatic substitution with anilines intermolecularly and then intramolecularly to yield the corresponding carbazoles in a single operation. The "aromatic metamorphosis" of dibenzothiophenes into carbazoles does not require any heavy metals. This strategy is also applicable to the synthesis of indoles. Since electron-deficient thiaarene dioxides exhibit interesting reactivity, which is not observed for that the corresponding electron-rich azaarenes, a combination of a thiaarene-dioxide-specific reaction with the SN Ar-based aromatic metamorphosis allows transition-metal-free construction of difficult-to-prepare carbazoles.

Phosphotungstic acid containing ionic liquid immobilized on magnetic mesoporous silica rod catalyst for the oxidation of dibenzothiophene with H2O2

Abstract We have synthesized phosphotungstic acid (PA) containing ionic liquid 1-methyl-3-[(triethoxysilyl) propyl] imidazolium chloride (IL) immobilized on magnetic mesoporous silica rod to catalyze dibenzothiophene (DBT) for producing dibenzothiophene monoxide (DBTO) and dibenzothiophene dioxide (DBTO2). The effects of reaction time and reaction temperature on the conversion of DBT were studied. It was demonstrated that the catalyst was extremely effective for the reaction and the catalyst could be easily separated from the reaction solution by applying an external magnetic field and recycled several times.

Synthesis and Structure-Linear and Structure-Nonlinear Optical Properties of Multi-Dipolar Zigzag Oligoaryleneethynylenes

A novel series of monodisperse, multi-dipolar zigzag oligoaryleneethynylenes DA(n) and D-Ar-A(n), bearing electron-donating dibenzothiophene and electron-accepting dibenzothiophene dioxide as arenes, with up to six charge-transfer (dipolar) units have been designed and synthesized by palladium-catalyzed Sonogashira coupling reactions. The linear and nonlinear optical properties of these multi-dipolar oligoaryleneethynylenes can easily be modified or enhanced by incorporating/extending with various central aryleneethynyl moieties such as phenylethynyl, oligo(9,9-dibutylfluorenyl)ethynyl, and oligothienylethynyl within the donor-acceptor units. Interestingly, the absorption and emission of these zigzag oligoaryleneethynylenes are not dependent on the number of covalently linked dipolar chromophores; however, the fluorescence quantum efficiencies consistently decrease with increased number of covalently linked dipolar units. These zigzag oligoaryleneethynylenes exhibit a linear increase in the two-photon absorption (TPA) cross-sections with increased number of covalently linked dipolar units without red-shifting the absorption and emission spectra. In addition, very large TPA cross-sections in the femtosecond regime (sigma(800) = 1306 GM in DMF or sigma(750) = 1522 GM in CH(2)Cl(2)) were obtained for D-TF-A(4) despite the moderate strength of the donor-acceptor pair. Our results suggest that the TPA properties of these zigzag oligoaryleneethynylenes including TPA wavelength and TPA cross-section can easily be tuned by means of modifying the central aryleneethynylene units and increasing the number of dipolar units, respectively. This approach provides an alternative means to tune or enhance the TPA cross-section at a specific wavelength.

Oxidation of dibenzothiophene by hydrogen peroxide or monopersulfate and metal–sulfophthalocyanine catalysts: an easy access to biphenylsultone or 2-(2′-hydroxybiphenyl)sulfonate under mild conditions

A catalytic system consisting of metal–sulfophthalocyanines (MPcS) and monopersulfate or hydrogen peroxide as oxidants was effective in the dibenzothiophene oxidative desulfurization with various yields and selectivities. Oxidations were conducted at room temperature in acetonitrile–water mixed solvent. The dibenzothiophene oxidation involved the step by step formation of dibenzothiophene dioxide and biphenylsultone (dibenzo-1,2-oxathiine 2,2-dioxide), followed by hydrolysis to 2(2′-hydroxybiphenyl)sulfonate and finally catalytic desulfurization to 2-hydroxybiphenyl (2-phenylphenol) and sulfuric acid; all the intermediate compounds were identified. Moreover, catalytic over-oxidation of 2-hydroxybiphenyl, with ring fission and formation of various oxidation products, among them carbon dioxide, oxalic and benzoic acid, was also observed. Among the various MPcS catalysts examined (M = Fe, Co and Ru), the ruthenium derivative exhibited the best performances with persulfate and iron derivative with hydrogen peroxide; in both cases the slow step of the process consisted in the oxidation of dibenzothiophene dioxide to biphenylsultone.

Electrochemical evidence for an unusual base-catalysed chain mechanism in an intramolecular homolytic arylation

Cyclic voltammetry and controlled-potential electrolysis of the disulphone (1a) in dimethyl sulphoxide show that its transformation into the dibenzothiophene dioxide (2a), in the presence of a base, is an efficient electrocatalytic process.

The decomposition of dibenzothiophene dioxide and related compounds in the presence of molten alkali

A detailed study was carried out on the decomposition of dibenzothiophene dioxide in the presence of both sodium and potassium hydroxide at 200–300°. Our results show that the stability of the dibenzothiophene nucleus is markedly dependent on the oxidation state of the S-atom. The products formed in the decomposition reaction vary with temperature, contact time, and the initial ratio of base to dioxide. In the presence of excess base at 300°, dibenzothiophene dioxide was converted to dibenzofuran in high yield. The formation of the furan apparently proceeds by a multistep reaction sequence in which 2-phenylbenzene sulfonic acid and 2-phenylphenol are unstable intermediates. We also investigated the decomposition of dibenzothiophene monoxide, benzothiophene dioxide, n-octyl sulfoxide and sulfone, and diphenyl sulfoxide and sulfone under these conditions. The aliphatic S-derivatives decomposed by a typical beta-elimination reaction. The products formed from the other oxidized S-derivatives suggest that the decomposition process involves a complex series of addition, cleavage, and elimination reactions.

Studies in mass spectrometry—XV : Mass spectra of sulphoxides and sulphones. The formation of CC and CO bonds upon electron impact

Although dialkyl sulphoxides and sulphones behave relatively simply upon electron impact, aromatic sulphoxides and sulphones show a pronounced tendency to undergo CO bond formation, as evidence by a number of decomposition pathways which involve the elimination of carbon monoxide. For example, dibenzothiophene dioxide (XV) decomposes from its molecular ion by successive eliminations of carbon monoxide.

The Formation of Substituted Dibenzothiophene Dioxides by Sulfonation of meta- and para-Terphenyls

ADVERTISEMENT RETURN TO ISSUEPREVArticleNEXTThe Formation of Substituted Dibenzothiophene Dioxides by Sulfonation of meta- and para-TerphenylsJAMES A. VanALLANCite this: J. Org. Chem. 1956, 21, 10, 1152–1155Publication Date (Print):October 1, 1956Publication History Published online1 May 2002Published inissue 1 October 1956https://doi.org/10.1021/jo01116a024RIGHTS & PERMISSIONSArticle Views181Altmetric-Citations12LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (378 KB) Get e-Alerts Get e-Alerts