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Search for "oxidation potential" in Full Text gives 114 result(s) in Beilstein Journal of Organic Chemistry.

Cathodic hydrodimerization of nitroolefins

  • Michael Weßling and
  • Hans J. Schäfer

Beilstein J. Org. Chem. 2015, 11, 1163–1174, doi:10.3762/bjoc.11.131

Graphical Abstract
  • expected to have a higher oxidation potential than DMF due to the nitro group the advantageous use of an undivided cell appears to be possible. Taking the optimal conditions of electrolysis Nr. 5 in Table 1 the influence of the parameters mentioned above was investigated (Table 2). The influence of the
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Published 14 Jul 2015

Advances in the synthesis of functionalised pyrrolotetrathiafulvalenes

  • Luke J. O’Driscoll,
  • Sissel S. Andersen,
  • Marta V. Solano,
  • Dan Bendixen,
  • Morten Jensen,
  • Troels Duedal,
  • Jess Lycoops,
  • Cornelia van der Pol,
  • Rebecca E. Sørensen,
  • Karina R. Larsen,
  • Kenneth Myntman,
  • Christian Henriksen,
  • Stinne W. Hansen and
  • Jan O. Jeppesen

Beilstein J. Org. Chem. 2015, 11, 1112–1122, doi:10.3762/bjoc.11.125

Graphical Abstract
  • thermodynamically stable. These properties are responsible for the strong electron-donor character of TTF and its derivatives. Furthermore, the precise oxidation potential of a TTF derivative can be changed by the addition of electron-donating or electron-withdrawing substituents [4]. Usually, each of the three
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Published 03 Jul 2015

Regioselective synthesis of chiral dimethyl-bis(ethylenedithio)tetrathiafulvalene sulfones

  • Flavia Pop and
  • Narcis Avarvari

Beilstein J. Org. Chem. 2015, 11, 1105–1111, doi:10.3762/bjoc.11.124

Graphical Abstract
  • to transform into BEDT-TTF. Moreover, since the inner sulfur atoms present large orbital coefficients in the HOMO, the introduction of the electron-withdrawing oxygen atom induces a massive increase of the oxidation potential from the neutral to the radical cation states. We have then hypothesized
  • that the oxidation of the outer sulfur atoms into sulfoxide or sulfone should only moderately influence the oxidation potential and thus provide more stable radical cation species. In order to access chiral precursors with controlled stereochemistry we decided to investigate the sulfoxidation of the DM
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Published 02 Jul 2015

Single-molecule conductance of a chemically modified, π-extended tetrathiafulvalene and its charge-transfer complex with F4TCNQ

  • Raúl García,
  • M. Ángeles Herranz,
  • Edmund Leary,
  • M. Teresa González,
  • Gabino Rubio Bollinger,
  • Marius Bürkle,
  • Linda A. Zotti,
  • Yoshihiro Asai,
  • Fabian Pauly,
  • Juan Carlos Cuevas,
  • Nicolás Agraït and
  • Nazario Martín

Beilstein J. Org. Chem. 2015, 11, 1068–1078, doi:10.3762/bjoc.11.120

Graphical Abstract
  • argon atmosphere and at a scan rate of 0.1 Vs−1. The electrochemical cell consisted of a glassy carbon working electrode, Ag/AgNO3 reference electrode and a Pt wire counter electrode. It is worth mentioning that ferrocene was not employed as the inner reference since its oxidation potential overlaps
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Published 24 Jun 2015

Glycoluril–tetrathiafulvalene molecular clips: on the influence of electronic and spatial properties for binding neutral accepting guests

  • Yoann Cotelle,
  • Marie Hardouin-Lerouge,
  • Stéphanie Legoupy,
  • Olivier Alévêque,
  • Eric Levillain and
  • Piétrick Hudhomme

Beilstein J. Org. Chem. 2015, 11, 1023–1036, doi:10.3762/bjoc.11.115

Graphical Abstract
  • clip 4 is an efficient receptor for F4-TCNQ guest electron acceptor. This difference in binding interaction between host molecular clips 3 and 4 towards the F4-TCNQ guest could be explained by their electrochemical properties. By comparing the first oxidation potential of clips 3 and 4 with the first
  • guest. On the other hand, the oxidation potential of molecular clip 4 is increased due to the introduction of the naphthoquinone spacer. Consequently, the corresponding 1:1 stoichiometry should reasonably correspond to the binding of F4-TCNQ inside the cavity of clip 4 (Figure 11). This binding of F4
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Published 17 Jun 2015

Tuning of tetrathiafulvalene properties: versatile synthesis of N-arylated monopyrrolotetrathiafulvalenes via Ullmann-type coupling reactions

  • Vladimir A. Azov,
  • Diana Janott,
  • Dirk Schlüter and
  • Matthias Zeller

Beilstein J. Org. Chem. 2015, 11, 860–868, doi:10.3762/bjoc.11.96

Graphical Abstract
  • processes in molecular and supramolecular systems [3][4]. Availability of selective synthetic methods [5][6] gave access to differently substituted tetrathiafulvalene (TTF) moieties which allowed tuning of oxidation potential, donating ability, as well as other physical and chemical properties. The
  • the second to the dication. Non-substituted derivative 4c shows a lower first oxidation potential than its alkylS-substituted counterpart 4a,b, as expected due to the electron-withdrawing effect of the two thioalkyl groups [28][29]. The strong electron-withdrawing effect of the 4-nitrophenyl group in
  • 4d manifests itself in an increased oxidation potential with a shift of ca. 0.08 V for both oxidation waves. Aromatic electron-donating groups as in 4e and 4f do barely influence the potential of the two oxidation waves. Instead, they induce an additional oxidation wave at higher potentials of 1.06 V
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Published 21 May 2015

Trifluoromethyl-substituted tetrathiafulvalenes

  • Olivier Jeannin,
  • Frédéric Barrière and
  • Marc Fourmigué

Beilstein J. Org. Chem. 2015, 11, 647–658, doi:10.3762/bjoc.11.73

Graphical Abstract
  • . Electrochemical data confirm the good correlations between the first oxidation potential of the TTF derivatives and the σmeta Hammet parameter, thus in the order CO2Me < CF3 < CN, indicating that, in any case, the mesomeric effect of the substituents is limited. Besides, crystal structure determinations show that
  • tetrathiafulvalenes functionalized by electron-withdrawing groups (EWG) are less documented, essentially because the presence of such substituents as halogen, acyl, ester, amide or nitrile on the TTF redox core dramatically increases its oxidation potential and destabilizes the radical cation form. This strong anodic
  • moieties and formation of fluorine bilayers [32][33], attributed to the amphiphilic character of those TTF derivatives upon CF3-functionalization. A strong anodic shift of the first oxidation potential was also noted for 1c and 2cc, when compared with the unsubstituted EDT-TTF molecule. This work has been
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Published 06 May 2015

Photocatalytic nucleophilic addition of alcohols to styrenes in Markovnikov and anti-Markovnikov orientation

  • Martin Weiser,
  • Sergej Hermann,
  • Alexander Penner and
  • Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2015, 11, 568–575, doi:10.3762/bjoc.11.62

Graphical Abstract
  • oxidation potential of 2.07 V. In combination with the oxidation potential of 1.81 V (vs SCE) [22] for substrate 1 the driving force ΔG of initial oxidation was estimated by Rehm–Weller to be around 250 meV. In general, irradiations were carried out in quartz glass cuvettes at a constant temperature of 30
  • of phenol, weakened the nucleophilicity for this type of reaction. Styrene (6) has an oxidation potential of 1.94 V (vs SCE) [22] and, hence, could also be oxidized by the chosen photocatalyst PDI. The corresponding photocatalytic nucleophilic additions to 6 (Table 1) yielded less of each product
  • , which was in agreement with the higher oxidation potential (compared to 1). Here again, the addition of phenol showed no significant amounts of product formation. We representatively demonstrated the dependency of the performance of photocatalysis with substrate 1 on different PDI concentrations (Figure
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Published 27 Apr 2015

Bis(vinylenedithio)tetrathiafulvalene analogues of BEDT-TTF

  • Erdal Ertas,
  • İlknur Demirtas and
  • Turan Ozturk

Beilstein J. Org. Chem. 2015, 11, 403–415, doi:10.3762/bjoc.11.46

Graphical Abstract
  • coupling methods [45][46]. Depending on the presence of electron-withdrawing groups on the TTF, they exhibit various oxidation potential ranges [15][26]. Recently, TTF and analogues have received widespread attention involving the development of new materials by using various anions to form different
  • were performed under a nitrogen atmosphere at room temperature using Pt as working and counter electrodes and Ag/AgCl reference electrode. The oxidation potentials of the coupled products were compared with ET 3. The measurements indicated that as the first oxidation potential of ET was higher than the
  • first oxidation potential of 29a, 29c and 29d, the oxidation potential of 29b was equal to that of ET 3 and the second oxidation potentials of 29a–d were found to be lower than for ET. On the other hand, the first and second oxidation potentials of the donors 33a–c were slightly higher than the
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Published 27 Mar 2015

Electrochemical oxidation of cholesterol

  • Jacek W. Morzycki and
  • Andrzej Sobkowiak

Beilstein J. Org. Chem. 2015, 11, 392–402, doi:10.3762/bjoc.11.45

Graphical Abstract
  • cholesterol oxidation products are rather low, often less than 30%. This may be caused by the high oxidation potential of cholesterol and the necessity to operate at a relatively high positive potential. Moreover, due to the hydrophobic properties of cholesterol it is necessary to use non-polar solvents, e.g
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Published 25 Mar 2015

Photovoltaic-driven organic electrosynthesis and efforts toward more sustainable oxidation reactions

  • Bichlien H. Nguyen,
  • Robert J. Perkins,
  • Jake A. Smith and
  • Kevin D. Moeller

Beilstein J. Org. Chem. 2015, 11, 280–287, doi:10.3762/bjoc.11.32

Graphical Abstract
  • (galvanostatic) electrolysis [4]. When a constant current is passed through an electrolysis cell, the potential at the anode increases until it reaches that of the substrate in solution with the lowest oxidation potential. It then remains constant at that potential until the effective concentration of the
  • oxidants [5]. In such experiments, the potential at the anode increases to a point where it matches the oxidation potential of the reduced chemical oxidant (Scheme 1). The reduced chemical oxidant is then oxidized in order to generate the active chemical oxidant. The chemical oxidant then performs the
  • photovoltaic cell exposed to the light until the current passing through the reaction was the same as that used with the traditional setup. The two cases in Scheme 2 were selected because the oxidation potential of the substrates differed by more than 0.5 V. However, that difference in potential had little
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Published 23 Feb 2015

3α,5α-Cyclocholestan-6β-yl ethers as donors of the cholesterol moiety for the electrochemical synthesis of cholesterol glycoconjugates

  • Aneta M. Tomkiel,
  • Adam Biedrzycki,
  • Jolanta Płoszyńska,
  • Dorota Naróg,
  • Andrzej Sobkowiak and
  • Jacek W. Morzycki

Beilstein J. Org. Chem. 2015, 11, 162–168, doi:10.3762/bjoc.11.16

Graphical Abstract
  • phenoxy radical formed can be further oxidized to the phenoxenium ion, which reacts with nucleophiles. However, since the phenolic OH group is not sterically shielded here, competitive oligo- and polymerization reactions may also occur. Therefore, despite the low oxidation potential of 6g, the side
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Published 26 Jan 2015
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  • higher oxidation potential of 2h compared to that of the starting substrate 1h. In support of this, we have already shown that introduction of one fluorine atom to the α-position of α-(phenylthio)acetonitrile increased the oxidation potential by 0.36 V [22]. A plausible mechanism for the anodic
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Published 19 Jan 2015

Redox active dendronized polystyrenes equipped with peripheral triarylamines

  • Toshiki Nokami,
  • Naoki Musya,
  • Tatsuya Morofuji,
  • Keiji Takeda,
  • Masahiro Takumi,
  • Akihiro Shimizu and
  • Jun-ichi Yoshida

Beilstein J. Org. Chem. 2014, 10, 3097–3103, doi:10.3762/bjoc.10.326

Graphical Abstract
  •  2. Di(p-bromophenyl)carbinol (1) was treated with SOCl2 to obtain di(p-bromophenyl)methyl chloride (2) in quantitative yield. A Friedel–Crafts-type alkylation [29] of diphenylsilane 3 with 2 in the presence of boron trifluoride etherate as a Lewis acid gave 4 in 86% yield. The oxidation potential of
  • than the oxidation potential of dendrimer 4, indicating that the triarylamine moiety is oxidized before the benzylsilane moiety. Using the “graft to” approach to synthesize peripherally functionalized dendronized polystyrene (Figure 1b) employing 5 as a precursor of the dendritic carbocation was
  • . A saturated calomel electrode (SCE) (RE-2B, ALS Co. Ltd.) was used as the reference electrode. The oxidation potential (Eox) of dendrimer 4 was measured using linear sweep voltammetry employing a gassy carbon (GC) rotating disk electrode (diameter = 3.0 mm, ALS Co. Ltd.) and a Pt wire counter
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Published 22 Dec 2014

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

  • Alan M. Jones and
  • Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

Graphical Abstract
  • conditions [32][33]. Although the introduction of an electroauxiliary requires an additional synthetic step to prepare, the resulting carbon–tin, carbon–silicon or carbon–sulfur bond has a less positive oxidation potential than an unfunctionalised carbamate. Therefore, exquisite control can be exerted on the
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Published 18 Dec 2014

Recent advances in the electrochemical construction of heterocycles

  • Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

Graphical Abstract
  • groups are therefore not compatible with direct oxidation [48]. A milder and more selective approach is represented by the installation of an electroauxiliary (EA), a functional group which lowers the oxidation potential of the compound, in α-position to the oxygen/nitrogen [30][49]. In this context, the
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Published 03 Dec 2014

Solution processable diketopyrrolopyrrole (DPP) cored small molecules with BODIPY end groups as novel donors for organic solar cells

  • Diego Cortizo-Lacalle,
  • Calvyn T. Howells,
  • Upendra K. Pandey,
  • Joseph Cameron,
  • Neil J. Findlay,
  • Anto Regis Inigo,
  • Tell Tuttle,
  • Peter J. Skabara and
  • Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2683–2695, doi:10.3762/bjoc.10.283

Graphical Abstract
  • +0.73 V. In both cases, the first oxidation wave is assigned to the formation of the radical cation on one of the bi/terthiophene segments of the molecule. The lower oxidation potential for 10 compared to 9 is consistent with the tendency to decrease the oxidation potential when the oligothiophene chain
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Published 18 Nov 2014

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

  • Roman Matthessen,
  • Jan Fransaer,
  • Koen Binnemans and
  • Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

Graphical Abstract
  • focused on the fixation of CO2 using sacrificial anodes [38][39][40] (Scheme 6a). The higher oxidation potential of sacrificial anodes compared to that of the other reaction species makes this setup readily compatible with a simple undivided electrolysis cell, without a membrane separating the catholyte
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Published 27 Oct 2014

The Ugi four-component reaction as a concise modular synthetic tool for photo-induced electron transfer donor-anthraquinone dyads

  • Sarah Bay,
  • Gamall Makhloufi,
  • Christoph Janiak and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 1006–1016, doi:10.3762/bjoc.10.100

Graphical Abstract
  • have become attractive electrophores due to their reversible and tunable oxidation potential. Interestingly quenching of the phenothiazine inherent fluorescence offers a facile evidence for the occurrence of intramolecular PET in phenothiazine-containing Do–Acc dyads [41][42]. As suitable acceptor
  • ] Where is the difference of the first oxidation potential of the donor and first reduction potential of the acceptor, respectively, E00 expresses the energy of the photonic excitation, RDo–Acc delineates the distance between the centers of the donor and acceptor moieties, εs and εref are the dielectric
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Published 05 May 2014

Tailoring of organic dyes with oxidoreductive compounds to obtain photocyclic radical generator systems exhibiting photocatalytic behavior

  • Christian Ley,
  • Julien Christmann,
  • Ahmad Ibrahim,
  • Luciano H. Di Stefano and
  • Xavier Allonas

Beilstein J. Org. Chem. 2014, 10, 936–947, doi:10.3762/bjoc.10.92

Graphical Abstract
  • ]. The last important step is the dye regeneration. In order for the cycle and for the catalytic behavior to occur, the corresponding Gibbs free energy change should be negative. If one assumes that the reduction potential of PS•+ is given by the oxidation potential of PS, then . Thus, in order to
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Published 25 Apr 2014

Metal and metal-free photocatalysts: mechanistic approach and application as photoinitiators of photopolymerization

  • Jacques Lalevée,
  • Sofia Telitel,
  • Pu Xiao,
  • Marc Lepeltier,
  • Frédéric Dumur,
  • Fabrice Morlet-Savary,
  • Didier Gigmes and
  • Jean-Pierre Fouassier

Beilstein J. Org. Chem. 2014, 10, 863–876, doi:10.3762/bjoc.10.83

Graphical Abstract
  • ]. Such long lifetimes for triplet states are important in photoredox catalysis to ensure an efficient quenching by the oxidation agents. Ir(piq)2(tmd) is characterized by an oxidation potential of 0.67 V vs SCE (Figure 7A); its triplet-state energy level (ET ~ 2.07 eV) was determined from absorption
  • and C are the oxidation potential of Ir(piq)2(tmd), the reduction potential of Ph2I+, the excited triplet state energy of Ir(piq)2(tmd), and the electrostatic interaction energy for the initially formed ion pair, generally considered as negligible in polar solvents) [69]. This favorable 3PIC/Ph2I
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Published 15 Apr 2014

Rapid pseudo five-component synthesis of intensively blue luminescent 2,5-di(hetero)arylfurans via a Sonogashira–Glaser cyclization sequence

  • Fabian Klukas,
  • Alexander Grunwald,
  • Franziska Menschel and
  • Thomas J. J. Müller

Beilstein J. Org. Chem. 2014, 10, 672–679, doi:10.3762/bjoc.10.60

Graphical Abstract
  • oxidation potential E1/20/+1. This gap was estimated by the cross-section of the absorption and emission spectra. For the missing oxidation potentials of 2f, 2g, 2m, and 2l the HOMO and LUMO energies were determined by DFT calculations [48]. For validation of the experimental and computational data the
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Published 18 Mar 2014

Gold(I)-catalyzed enantioselective cycloaddition reactions

  • Fernando López and
  • José L. Mascareñas

Beilstein J. Org. Chem. 2013, 9, 2250–2264, doi:10.3762/bjoc.9.264

Graphical Abstract
  • carbophilicity, low oxophilicity and high oxidation potential between gold(I) and gold(III) have shown a unique potential to unveil novel types of chemoselective and stereoselective cycloadditions involving alkynes, allenes or alkenes [24][25][26]. A lot of interest has been directed to the development of these
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Published 30 Oct 2013

Anodic coupling of carboxylic acids to electron-rich double bonds: A surprising non-Kolbe pathway to lactones

  • Robert J. Perkins,
  • Hai-Chao Xu,
  • John M. Campbell and
  • Kevin D. Moeller

Beilstein J. Org. Chem. 2013, 9, 1630–1636, doi:10.3762/bjoc.9.186

Graphical Abstract
  • afforded the five-membered ring product using either lithium methoxide or 2,6-lutidine as a base. Clearly, decarboxylation of the carboxylate anion was not a problem. In fact, cyclic voltammetry data suggest that the reaction originated from an oxidation of the ketene dithioacetal. The oxidation potential
  • (Ep/2) for 14a was measured to be +0.68 V versus Ag/AgCl. For comparison, the oxidation potential measured for 10-undecenoic acid was +1.91 V versus Ag/AgCl in DMF solvent and +1.85 V versus Ag/AgCl in acetonitrile. When 0.5 equivalents of benzyltrimethylammonium hydroxide was added to the cyclic
  • voltammetry solutions in order to generate the carboxylate and mimic the preparative oxidation conditions used for the reaction originating from 14a, the oxidation potential of the 10-undecenoic acid fell to 1.36–1.40 V versus Ag/AgCl for the DMF solution and 1.38 V versus Ag/AgCl for the acetonitrile
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Published 09 Aug 2013

Structures of the reaction products of the AZADO radical with TCNQF4 or thiourea

  • Hideto Suzuki,
  • Yuta Kawahara,
  • Hiroki Akutsu,
  • Jun-ichi Yamada and
  • Shin’ichi Nakatsuji

Beilstein J. Org. Chem. 2013, 9, 1487–1491, doi:10.3762/bjoc.9.169

Graphical Abstract
  • -configuration. The cyclic voltammetry (CV) data of TEMPO (1), AZADO (2), TCNQF4 (3) and the adduct 5 are summarized in Table 1. The lower first oxidation potential (E1OX) of AZADO than that of TEMPO suggests that the reaction between AZADO and TCNQF4 can take place slightly more easily than that between TEMPO
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Published 25 Jul 2013
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