Photochemical and electrochemical behavior of thiophene-S-oxides

Thiemann, Thies; Ohira, Daisuke; Arima, Kazuya; Sawada, Tsuyoshi; Mataka, Shuntarō; Marken, Frank; Compton, Richard G.; Bull, Steven D.; Davies, Stephen G.

doi:10.1002/1099-1395(200010)13:10<648::aid-poc290>3.0.co;2-t

Cited by 33 publications

(43 citation statements)

References 21 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Such 1,2-shifts have been demonstrated repeatedly for nitrogenous carbene precursors that are subject to 1,2 hydrogen shifts or carbon shifts to relieve ring strain. [4][5][6][7][8][9][10] We 11-13 and others [14][15][16][17][18] have shown in previous work that photolysis of dibenzothiophene-S-oxide and its derivatives leads to chemistry that appears to derive from S-O cleavage and formation of atomic oxygen. Although direct evidence for this mechanism in the form of spectroscopic detection of O( 3 P) is lacking, we have recently shown through time-resolved IR experiments that benzoyl nitrene is formed on photolysis of N-benzoyl dibenzothiophene sulfilimine.…”

mentioning

confidence: 99%

S,C-Sulfonium Ylides from Thiophenes: Potential Carbene Precursors

2007

View full text Add to dashboard Cite

Carbenes remain important and intriguing reactive intermediates in organic chemistry despite years of study for many reasons, among them the access they provide to unusual product compounds, their differing chemistry depending on spin state, and their mechanistic complexity. Photochemical precursors to carbenes, such as diazo compounds and diazirines, are often favored, because they can yield carbenes by photolysis at low temperatures and can be used for laser flash photolysis experiments. However, because these nitrogenous precursors have been shown to undergo reactions in their excited states that mimic chemistry expected from the carbene itself, there is demand for alternative practical precursors. In this Communication, we report the use of S,C-sulfonium ylides 1-4 as photochemical carbene precursors, as illustrated in Scheme 1 for compound 4.The choice of compounds 1-4 as potential precursors to dicarbomethoxycarbene for this study was driven by two considerations. First S,C-ylides of malonates are known to be stable and easy to prepare, at least in part because of the electron withdrawing groups that delocalize the formal negative charge. Second, by generating dicarbomethoxycarbene 1-3 for the proof-of-concept work of showing carbene generation, we believed we could distinguish between reactions of the carbene and a potential excited state Wolfflike rearrangement that might yield a ketene derivative. Such 1,2shifts have been demonstrated repeatedly for nitrogenous carbene precursors that are subject to 1,2 hydrogen shifts or carbon shifts to relieve ring strain. [4][5][6][7][8][9][10]

show abstract

mentioning

confidence: 99%

S,C-Sulfonium Ylides from Thiophenes: Potential Carbene Precursors

2007

View full text Add to dashboard Cite

show abstract

“…Again, this reaction may proceed via isomerisation of one of the double bonds of the thiophene-S -oxide into one of the methyl groups, this time under strongly basic conditions, to form a vinyl sulfoxide with the vinyl group being exocyclic. The reason that the 3,4-dibenzyl-2,5-dimethylthiophene-S -oxide shows different behaviour in ethanol'/water than in acetonitrile under more acidic conditions, where in the presence of benzoic acid the molecule can be reduced cleanly to the corresponding thiophene at lower reduction potential [2], is thought to stem from the effective competition of both ethanol and water for protons, which under the conditions used here may almost completely suppress protonation of the thiophene-S -oxide, necessary for the second mechanism of reduction at lower potential.…”

Section: Reductionmentioning

confidence: 99%

“…In the absence of proton donors, the reduction potential of the compounds is dependent on the substituents of the molecules. In the presence of proton donors, the substituents play a less significant role and a number of thiophene-S -oxides were reduced electrochemically to the corresponding thiophene in the presence of a tenfold excess of benzoic acid in acetonitrile solution [2]. Another electrochemical study with similar compounds [3] also using a non-aqueous solvent, acetonitrile, and very negative reduction potentials, not possible to reach in aqueous solutions, was carried out.…”

Section: Introductionmentioning

confidence: 95%

Detection of the damage caused to DNA by a thiophene-S-oxide using an electrochemical DNA-biosensor

Oliveira-Brett

Silva

Fujii

et al. 2003

Journal of Electroanalytical Chemistry

Self Cite

View full text Add to dashboard Cite

The electrochemistry of 3,4-dibenzyl-2,5-dimethylthiophene-S -oxide was investigated as well as its interaction with dsDNA. The electrochemical study of the thiophene-S -oxide was performed at different pH values, in a mixed solvent and by solid state voltammetry, and showed that the molecule is reduced at a very negative potential, and the reduction is pH dependent. A glassy carbon electrode modified with a thick thiophene-S -oxide'/dsDNA mixture was used to study the interaction of thiophene-S -oxide in situ with dsDNA at a charged interface. The experimental results give strong evidence that the reduced thiophene-S -oxide interacts with dsDNA causing damage with possible strand break and that the thiophene-S -oxide adduct formed with dsDNA can still undergo reduction. #

show abstract

“…[1][2][3][4][5][6][7][8][9] However, the synthesis, reactivity as dienes in Diels-Alder reactions, and photochemical and electrochemical behavior of other thiophene-related molecules such as thiophene S,S-dioxide, and thiophene S-oxide have also been investigated. [10][11][12][13][14][15][16][17][18][19][20] The orbital energies and electrochemical properties of thiophene S-oxide monomers have been studied theoretically using MP2/6-31G*. 21 The bridging of thiophene derivatives to modulate the electronic band gaps has attracted interest of researchers at both experimental and theoretical levels.…”

Section: Introductionmentioning

confidence: 99%

DFT STUDY ON LOW MOLECULAR WEIGHT α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b'] DITHIOPHENE AND α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b']DITHIOPHENE S-OXIDE BRIDGED DERIVATIVES

Semire¹,

Odunola²

2014

Química Nova

View full text Add to dashboard Cite

The equilibrium geometries of α,α-ditert-butyl-4H-cyclopenta [2,1-b,3;4-b']dithiophene (DBDT) and α,α-ditert-butyl-4H-cyclopenta[2,1-b,3;4-b']dithiophene S-oxide (DBDTO) were studied at the DFT level of theory with a standard 6-311G* basis set. The molecular structures of the DBDT series were more planar than the corresponding DBDTO series, as revealed by dihedral angles. The UV-visible absorption calculated at TD-DFT/6-311G* showed two absorption peaks for all the molecules except C=S and C=O bridged molecules. In DBDTOs, C=S and C=O bridged molecules showed three and four absorption peaks, respectively. The DBDTOs had lower band gaps and longer wavelengths compared to the corresponding DBDTs.

show abstract

Photochemical and electrochemical behavior of thiophene-S-oxides

Cited by 33 publications

References 21 publications

S,C-Sulfonium Ylides from Thiophenes: Potential Carbene Precursors

S,C-Sulfonium Ylides from Thiophenes: Potential Carbene Precursors

Detection of the damage caused to DNA by a thiophene-S-oxide using an electrochemical DNA-biosensor

DFT STUDY ON LOW MOLECULAR WEIGHT α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b'] DITHIOPHENE AND α,α-DITERT-BUTYL-4H-CYCLOPENTA[2,1-b,3;4-b']DITHIOPHENE S-OXIDE BRIDGED DERIVATIVES

Contact Info

Product

Resources

About