Browse
Submit Data
Databases
API
Help

Dataset Information

20 Views

0 Connections

0 Citations

0 Reanalyses

0 Downloads

Omics score: 0

Formation of intramolecular dimer radical ions of diphenyl sulfones.

ABSTRACT: Dimer radical ions of aromatic molecules in which excess charge is localized in a pair of rings have been extensively investigated. While dimer radical cations of aromatics have been previously produced in the condensed phase, the number of molecules that form dimer anions is very limited. In this study, we report the formation of intramolecular dimer radical ions (cations and anions) of diphenyl sulfone derivatives (DPs) by electron beam pulse radiolysis in the liquid phase at room temperature. The density functional theory (DFT) calculations also showed the formation of the dimer radical ions. The torsion barrier of the phenyl ring of DPs was also calculated. It was found that the dimer radical ions show the larger barrier than the neutral state. Finally, stability of the dimer radical anion is dependent on not only the inductive effect of the sulfonyl group but the conjugation involving the d-orbital of the S atom and the phenyl rings.

SUBMITTER: Okamoto K

PROVIDER: S-EPMC7666127 | biostudies-literature | 2020 Nov

REPOSITORIES: biostudies-literature

ACCESS DATA

Json Xml

Publications

Formation of intramolecular dimer radical ions of diphenyl sulfones.

Okamoto Kazumasa K Kawai Shunpei S Kozawa Takahiro T

Scientific reports 20201113 1

Dimer radical ions of aromatic molecules in which excess charge is localized in a pair of rings have been extensively investigated. While dimer radical cations of aromatics have been previously produced in the condensed phase, the number of molecules that form dimer anions is very limited. In this study, we report the formation of intramolecular dimer radical ions (cations and anions) of diphenyl sulfone derivatives (DPs) by electron beam pulse radiolysis in the liquid phase at room temperature. ...[more]

PMID: 33188267

Similar Datasets

Base-Mediated Radical Borylation of Alkyl Sulfones.

Project description:A practical and direct method was developed for the production of versatile alkyl boronate esters via transition metal-free borylation of primary and secondary alkyl sulfones. The key to the success of the strategy is the use of bis(neopentyl glycolato) diboron (B2 neop2 ), with a stoichiometric amount of base as a promoter. The practicality and industrial potential of this protocol are highlighted by its wide functional group tolerance, the late-stage modification of complex compounds, no need for further transesterification, and operational simplicity. Radical clock, radical trap experiments, and EPR studies were conducted which show that the borylation process involves radical intermediates.

| S-EPMC9299846 | biostudies-literature

Formation of 4-hydroxynonenal from cardiolipin oxidation: Intramolecular peroxyl radical addition and decomposition.

Project description:We report herein that oxidation of a mitochondria-specific phospholipid tetralinoleoyl cardiolipin (L(4)CL) by cytochrome c and H(2)O(2) leads to the formation of 4-hydroxy-2-nonenal (4-HNE) via a novel chemical mechanism that involves cross-chain peroxyl radical addition and decomposition. As one of the most bioactive lipid electrophiles, 4-HNE possesses diverse biological activities ranging from modulation of multiple signal transduction pathways to the induction of intrinsic apoptosis. However, where and how 4-HNE is formed in vivo are much less understood. Recently a novel chemical mechanism has been proposed that involves intermolecular dimerization of fatty acids by peroxyl bond formation; but the biological relevance of this mechanism is unknown because a majority of the fatty acids are esterified in phospholipids in the cellular membrane. We hypothesize that oxidation of cardiolipins, especially L(4)CL, may lead to the formation of 4-HNE via this novel mechanism. We employed L(4)CL and dilinoleoylphosphatidylcholine (DLPC) as model compounds to test this hypothesis. Indeed, in experiments designed to assess the intramolecular mechanism, more 4-HNE is formed from L(4)CL and DLPC oxidation than 1-palmitoyl-2-linoleoylphosphatydylcholine. The key products and intermediates that are consistent with this proposed mechanism of 4-HNE formation have been identified using liquid chromatography-mass spectrometry. Identical products from cardiolipin oxidation were identified in vivo in rat liver tissue after carbon tetrachloride treatment. Our studies provide the first evidence in vitro and in vivo for the formation 4-HNE from cardiolipin oxidation via cross-chain peroxyl radical addition and decomposition, which may have implications in apoptosis and other biological activities of 4-HNE.

| S-EPMC3014443 | biostudies-literature

Palladium-Catalyzed Intramolecular Oxidative Arylations for the Synthesis of Fused Biaryl Sulfones.

Project description:This study unveils palladium-catalyzed intramolecular oxidative cyclizations in biaryl and heterobiaryl sulfones providing direct access to fused biaryl sulfones (dibenzothiophene-5,5-dioxides). Variously substituted dibenzothiophene-5,5-dioxides could be readily prepared in good to excellent yields under optimized conditions. In addition, bromination afforded dibromo derivative of dibenzothiophene-5,5-dioxides, providing platform for late-stage diversification. The translational applications of this current protocol have successfully been demonstrated in the synthesis of 2,8-diamino derivative of dibenzothiophene-5,5-dioxides, a α7-nicotinic acetylcholine receptor agonist analogue, and novel single fluorene-tethered dibenzothiophene-5,5-dioxide, an organic emitter.

| S-EPMC6641745 | biostudies-literature

Quantitative constraints on autoxidation and dimer formation from direct probing of monoterpene-derived peroxy radical chemistry.

Project description:Organic peroxy radicals (RO2) are key intermediates in the atmospheric degradation of organic matter and fuel combustion, but to date, few direct studies of specific RO2 in complex reaction systems exist, leading to large gaps in our understanding of their fate. We show, using direct, speciated measurements of a suite of RO2 and gas-phase dimers from O3-initiated oxidation of α-pinene, that ∼150 gaseous dimers (C16-20H24-34O4-13) are primarily formed through RO2 cross-reactions, with a typical rate constant of 0.75-2 × 10-12 cm3 molecule-1 s-1 and a lower-limit dimer formation branching ratio of 4%. These findings imply a gaseous dimer yield that varies strongly with nitric oxide (NO) concentrations, of at least 0.2-2.5% by mole (0.5-6.6% by mass) for conditions typical of forested regions with low to moderate anthropogenic influence (i.e., ≤50-parts per trillion NO). Given their very low volatility, the gaseous C16-20 dimers provide a potentially important organic medium for initial particle formation, and alone can explain 5-60% of α-pinene secondary organic aerosol mass yields measured at atmospherically relevant particle mass loadings. The responses of RO2, dimers, and highly oxygenated multifunctional compounds (HOM) to reacted α-pinene concentration and NO imply that an average ∼20% of primary α-pinene RO2 from OH reaction and 10% from ozonolysis autoxidize at 3-10 s-1 and ≥1 s-1, respectively, confirming both oxidation pathways produce HOM efficiently, even at higher NO concentrations typical of urban areas. Thus, gas-phase dimer formation and RO2 autoxidation are ubiquitous sources of low-volatility organic compounds capable of driving atmospheric particle formation and growth.

| S-EPMC6275546 | biostudies-literature

Superoxide-mediated formation of tyrosine hydroperoxides and methionine sulfoxide in peptides through radical addition and intramolecular oxygen transfer.

Project description:The chemistry underlying superoxide toxicity is not fully understood. A potential mechanism for superoxide-mediated injury involves addition to tyrosyl radicals, to give peptide or protein hydroperoxides. The rate constant for the reaction of tyrosyl radicals with superoxide is higher than for dimerization, but the efficiency of superoxide addition to peptides depends on the position of the Tyr residue. We have examined the requirements for superoxide addition and structurally characterized the products for a range of tyrosyl peptides exposed to a peroxidase/O(2)(.) system. These included enkephalins as examples of the numerous proteins and physiological peptides with N-terminal tyrosines. The importance of amino groups in promoting hydroperoxide formation and effect of methionine residues on the reaction were investigated. When tyrosine was N-terminal, the major products were hydroperoxides that had undergone cyclization through conjugate addition of the terminal amine. With non-N-terminal tyrosine, electron transfer from O(2)(.) to the peptide radical prevailed. Peptides containing methionine revealed a novel and efficient intramolecular oxygen transfer mechanism from an initial tyrosine hydroperoxide to give a dioxygenated derivative with one oxygen on the tyrosine and the other forming methionine sulfoxide. Exogenous amines promoted hydroperoxide formation on tyrosyl peptides lacking a terminal amine, without forming an adduct. These findings, plus the high hydroperoxide yields with N-terminal tyrosine, can be explained by a mechanism in which hydrogen bonding of O(2)(.) to the amine increases is oxidizing potential and alters its reactivity. If this amine effect occurred more generally, it could increase the biological reactivity of O(2)(.) and have major implications.

| S-EPMC2685654 | biostudies-literature

Effect of sequence and metal ions on UVB-induced anti cyclobutane pyrimidine dimer formation in human telomeric DNA sequences.

Project description:Irradiation of G-quadruplex forming human telomeric DNA with ultraviolet B (UVB) light results in the formation of anti cyclobutane pyrimidine dimers (CPDs) between loop 1 and loop 3 in the presence of potassium ions but not sodium ions. This was unexpected because the sequences involved favor the nonphotoreactive hybrid conformations in K(+) solution, whereas a potentially photoreactive basket conformation is favored in Na(+) solution. To account for these contradictory results, it was proposed that the loops are too far apart in the basket conformation in Na(+) solution but close enough in a two G-tetrad basket-like form 3 conformation that can form in K(+) solution. In the current study, Na(+) was still found to inhibit anti CPD formation in sequences designed to stabilize the form 3 conformation. Furthermore, anti CPD formation in K(+) solution was slower for the sequence previously shown to exist primarily in the proposed photoreactive form 3 conformation than the sequence shown to exist primarily in a nonphotoreactive hybrid conformation. These results suggest that the form 3 conformation is not the principal photoreactive conformation, and that G-quadruplexes in K(+) solution are dynamic and able to access photoreactive conformations more easily than in Na(+) solution.

| S-EPMC4005637 | biostudies-literature

Intramolecular hydrogen transfer reactions of thiyl radicals from glutathione: formation of carbon-centered radical at Glu, Cys, and Gly.

Project description:Glutathione thiyl radicals (GS(•)) were generated in H(2)O and D(2)O by either exposure of GSH to AAPH, photoirradiation of GSH in the presence of acetone, or photoirradiation of GSSG. Detailed interpretation of the fragmentation pathways of deuterated GSH and GSH derivatives during mass spectrometry analysis allowed us to demonstrate that reversible intramolecular H-atom transfer reactions between GS(•) and C-H bonds at Cys[(α)C], Cys[(β)C], and Gly[(α)C] are possible.

| S-EPMC3736831 | biostudies-literature

Formation of an unexpected 3,3-diphenyl-3<i>H</i>-indazole through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate.

Project description:The one-pot reaction of 2,6-bis(diphenylmethyl)-4-methoxyaniline with tert-butylnitrite, BTEAC and DABSO in the presence of CuCl2 provided an unexpected 3H-indazole product 8. The structure of the compound was determined by HRMS, IR, NMR and further confirmed by single crystal X-ray crystallography. The compound crystallises in the triclinic P-1 space group, with unit cell parameters a = 9.2107 (4), b = 10.0413 (5), c = 14.4363 (6) Å, α = 78.183 (2), β = 87.625 (2), γ = 71.975 (2)°. The formation of 8 proceeded through a facile intramolecular [2 + 3] cycloaddition of the diazo intermediate 9. The molecules of 8 are organised by edge-face Ar-H···π, face-face π···π, and bifurcated OCH2-H···N interactions. In addition to these, there are Ar-H···H-Ar close contacts, (edge-edge and surrounding inversion centres) arranged as infinite tapes along the a direction.

| S-EPMC6604747 | biostudies-literature

Crystal structures of the sulfones of 2,3-diphenyl-2,3-dihydro-4H-1,3-benzothiazin-4-one and 2,3-diphenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazin-4-one

Project description:The title sulfones crystallize in space group P21/n with two molecules in each of the asymmetric units and have almost identical unit cells and extended structures. In both structures, the thiazine rings exhibit a screw-boat pucker. The title sulfones, 2,3-diphenyl-2,3-dihydro-4H-1,3-benzothiazine-1,1,4-trione, C20H15NO3S, and 2,3-diphenyl-2,3-dihydro-4H-pyrido[3,2-e][1,3]thiazine-1,1,4-trione, C19H14N2O3S, crystallize in space group P21/n with two molecules in each of the asymmetric units and have almost identical unit cells and extended structures. In both structures, the thiazine rings exhibit a screw-boat pucker. The intermolecular interactions observed are C—H⋯O-type hydrogen bonds and parallel partial π–π stacking between the fused aromatic rings (benzo- or pyrido-) of the core of the molecules within each asymmetric unit, and also connecting to molecules with translational periodicity in the a-axis direction in what can be described as columns (two per asymmetric unit) of stacked molecules with alternating chirality. The pendant phenyl groups of both molecules do not participate in aromatic ring interactions.

| S-EPMC9993925 | biostudies-literature

Arene Activation through Iminium Ions: Product Diversity from Intramolecular Photocycloaddition Reactions.

Project description:While 2-alk-ω-enyloxy-sustituted benzaldehydes do not display any photochemical reactivity at the arene core, the respective iminium perchlorates were found to undergo efficient reactions either upon direct irradiation (λ=366 nm) or under sensitizing conditions (λ=420 nm, 2.5 mol% thioxanthen-9-one). Three pathways were found: (a) Most commonly, the reaction led to benzoxacyclic products in which the olefin in the tether underwent a formal, yet unprecedented carboformylation (13 examples, 44-99 % yield). The cascade process occurred with high diastereoselectivity and was found to be stereoconvergent. (b) If a substituent resides in the 3-position of the benzene ring, a meta photocycloaddition was observed which produced tetracyclic skeletons with five stereogenic centers in excellent regio- and diastereoselectivity (2 examples, 58-79 % yield). (c) If the tether was internally substituted at the alkene, an arene photocycloaddition was avoided and an azetidine was formed in an aza Paternò-Büchi reaction (2 examples, 95-98 % yield).

| S-EPMC9826208 | biostudies-literature

OmicsDI is part of the ELIXIR infrastructure

OmicsDI is an Elixir interoperability service. Learn more ›

Tweets

OmicsDI Databases

PRIDE
PeptideAtlas
MassIVE
JPOST Repository
Physiome Model Repository

EGA
EVA
ENA
LINCS
PAXDB
Cell Collective

MetaboLights
Metabolomics Workbench
MetabolomeExpress
GNPS
BioModels
FAIRDOMHub

ArrayExpress
dbGaP
ExpressionAtlas
GEO
NODE

Information

Databases
Help
API
Contact us
Code on GitHub
Terms of use
Submit Data