CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• reduction potential of Cu(dap)2Cl in the excited state, and its important ability to mediate the transfer of the Cl atom. Consequently, a variety of electron-deficient alkenes, such as N-arylacrylamides, acrylonitrile, acrylate and enone derivatives furnished their chlorotrifluoromethylated analogues in

Sugar-based micro/mesoporous hypercross-linked polymers with in situ embedded silver nanoparticles for catalytic reduction

• Qing Yin,
• Qi Chen,
• Li-Can Lu and
• Bao-Hang Han

Beilstein J. Org. Chem. 2017, 13, 1212–1221, doi:10.3762/bjoc.13.120

• negative reduction potential and higher SSA, which make them more effective in catalytic reactions [22]. However, AgNPs with high surface energy are subject to certain limitations in catalysis due to their extreme tendency to aggregate. In order to solve this problem, an effective method is to encapsulate

High performance p-type molecular electron donors for OPV applications via alkylthiophene catenation chromophore extension

• Paul B. Geraghty,
• Calvin Lee,
• Jegadesan Subbiah,
• Wallace W. H. Wong,
• James L. Banal,
• Mohammed A. Jameel,
• Trevor A. Smith and
• David J. Jones

Beilstein J. Org. Chem. 2016, 12, 2298–2314, doi:10.3762/bjoc.12.223

• the expected gradual increase in HOMO levels as we increase the conjugation length and the expected general downward trend in energy gap from 2.40 eV to 1.77 eV for the BXR series. The first reduction potential could also be measured allowing an estimation of the LUMO levels for the BXR series and

Effect of the π-conjugation length on the properties and photovoltaic performance of A–π–D–π–A type oligothiophenes with a 4,8-bis(thienyl)benzo[1,2-b:4,5-b′]dithiophene core

• Ni Yin,
• Lilei Wang,
• Yi Lin,
• Jinduo Yi,
• Lingpeng Yan,
• Junyan Dou,
• Hai-Bo Yang,
• Xin Zhao and
• Chang-Qi Ma

Beilstein J. Org. Chem. 2016, 12, 1788–1797, doi:10.3762/bjoc.12.169

• reduction potential (E0red) of −1.53 eV, the other three compounds showed almost identical E0red of −1.60 V, indicating that the reduction process is mainly due to the reduction of the terminal COOP group. The onset oxidation potentials (Eoxonset) and onset reduction potentials (Eredonset) determined from

Photoinduced 1,2,3,4-tetrahydropyridine ring conversions

• Baiba Turovska,
• Henning Lund,
• Viesturs Lūsis,
• Anna Lielpētere,
• Edvards Liepiņš,
• Sergejs Beljakovs,
• Inguna Goba and
• Jānis Stradiņš

Beilstein J. Org. Chem. 2015, 11, 2166–2170, doi:10.3762/bjoc.11.234

• difference between the first oxidation potential of the donor and the first reduction potential of the acceptor; In CH2Cl2 the reduction potential of O2 is −1.18 V and E0 of 1 is +1.14 V. The reaction becomes thermodynamically favourable if the organic molecule is excited to a singlet state. The oxidation

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

• reduction potential of F4-TCNQ (Eapp0red1 = + 0.14 V vs Fc+/Fc – Figure 3), it is clear that F4-TCNQ guest presents a high reduction potential, sufficient to allow the oxidation of molecular clip 3. Consequently, the (F4-TCNQ)2@clip 3 complex should result from a redox interaction between the host and the

Diastereoselective and enantioselective conjugate addition reactions utilizing α,β-unsaturated amides and lactams

• Katherine M. Byrd

Beilstein J. Org. Chem. 2015, 11, 530–562, doi:10.3762/bjoc.11.60

• ) iodide was added to retard this reaction by modifying the reduction potential of SmI2 [173][174]. The authors were pleased that the cyclization of Weinreb amides 81 and 83 proceeded in high yields and diasteroselectivities. As the authors used 5 equiv SmI2 in their reaction and it is well documented that

Synthesis and properties of novel star-shaped oligofluorene conjugated systems with BODIPY cores

• Clara Orofino-Pena,
• Diego Cortizo-Lacalle,
• Joseph Cameron,
• Muhammad T. Sajjad,
• Pavlos P. Manousiadis,
• Neil J. Findlay,
• Alexander L. Kanibolotsky,
• Dimali Amarasinghe,
• Peter J. Skabara,
• Tell Tuttle,
• Graham A. Turnbull and
• Ifor D. W. Samuel

Beilstein J. Org. Chem. 2014, 10, 2704–2714, doi:10.3762/bjoc.10.285

• calculations for this structure (vide infra) which show slight expansion of the LUMO from the core to the arm. The increase in reduction potential with increasing length of the arm could be explained by the lower electron density exerted by one fluorene in each arm, as opposed to the oligofluorenes in the

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

• are due to the reduction of the DPP and BODIPY moieties. By analogy, the reduction waves at higher negative potentials can be due to the reduction of the oligothiophene units, with 10 having a lower reduction potential for the reduction of the thiophenes because of the extended conjugated chain. The

• in a greater reduction potential in compound 10. This in turn contributes to the larger HOMO–LUMO gap determined by cyclic voltammetry for compound 10 with respect to compound 9. In addition to the DFT calculations, TDDFT was also carried out in order to investigate the vertical absorption profile of

Visible light photoredox-catalyzed deoxygenation of alcohols

• Daniel Rackl,
• Viktor Kais,
• Peter Kreitmeier and
• Oliver Reiser

Beilstein J. Org. Chem. 2014, 10, 2157–2165, doi:10.3762/bjoc.10.223

• . Therefore different trifluoromethyl-substituted benzoates were prepared and subjected to cyclovoltametric measurements. 3,5-Bis(trifluoromethyl)-substituted benzoate 3 showed the most promising reduction potential of the compounds investigated (Scheme 2) and was therefore expected to be most susceptible for

• reduction potential (E0 = −1.51 V vs E0 = −1.31 V) [11]. Having identified a promising activation group for deoxygenation in combination with an iridium-based photocatalyst, different solvents and reaction temperatures were examined for the conversion of 3 (Table 2). Gratifyingly, toxic DMF could be

Novel indolin-2-one-substituted methanofullerenes bearing long n-alkyl chains: synthesis and application in bulk-heterojunction solar cells

• Irina P. Romanova,
• Andrei V. Bogdanov,
• Inessa A. Izdelieva,
• Vasily A. Trukhanov,
• Gulnara R. Shaikhutdinova,
• Dmitry G. Yakhvarov,
• Shamil K. Latypov,
• Vladimir F. Mironov,
• Vladimir A. Dyakov,
• Ilya V. Golovnin,
• Dmitry Yu. Paraschuk and
• Oleg G. Sinyashin

Beilstein J. Org. Chem. 2014, 10, 1121–1128, doi:10.3762/bjoc.10.111

• nine different n-alkyl substituents. Their optical absorption and the first electrochemical reduction potential are close to those of PCBM. The lengthening of the n-alkyl radical at the nitrogen atom results in a gradual increase in the AIM solubility. The photovoltaic properties of PSCs based on the

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

• ] 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

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

• ]. 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

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

• 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

Tuning the interactions between electron spins in fullerene-based triad systems

• Maria A. Lebedeva,
• Thomas W. Chamberlain,
• E. Stephen Davies,
• Bradley E. Thomas,
• Martin Schröder and
• Andrei N. Khlobystov

Beilstein J. Org. Chem. 2014, 10, 332–343, doi:10.3762/bjoc.10.31

• reduction of the two fullerene cages is observed as two separate one-electron processes with the reduction potential being slightly less cathodic for the C70 cage. EPR spectroscopy measurements of the two electron reduced triads reveal that the nature of the intramolecular electron spin–spin interactions is

Synthesis, characterization and initial evaluation of 5-nitro-1-(trifluoromethyl)-3H-1λ³,2-benziodaoxol-3-one

• Nico Santschi,
• Roman C. Sarott,
• Elisabeth Otth,
• Reinhard Kissner and
• Antonio Togni

Beilstein J. Org. Chem. 2014, 10, 1–6, doi:10.3762/bjoc.10.1

• the initial hypothesis that nitration may lead to a more positive reduction potential, cyclic voltammetry (CV) measurements were carried out. These experiments were conducted under an atmosphere of nitrogen in anhydrous MeCN with Bu4NBF4 (0.1 M) as supporting electrolyte. A platinum working electrode

• studies carried out on bis(acetoxy)iodobenzene [18]. For the first wave Epc1 = −1.17 and Epa1 = −0.97 were determined, indicating a standard reduction potential E01/2 = −1.1 V vs the Ag/Ag+ pair. These values are comparable to the ones reported for reagent 2 (Epc = −1.1 V vs Ag/Ag+, scan rate 0.2 V/s

• , MeCN) [8]. Therefore, nitration did not influence the standard reduction potential significantly and 3 should behave in a comparable manner as 2. These electrochemical findings are in line with the expectations of reactivity based on the X-ray structural considerations. Finally, the decomposition

The chemistry of amine radical cations produced by visible light photoredox catalysis

• Jie Hu,
• Jiang Wang,
• Theresa H. Nguyen and
• Nan Zheng

Beilstein J. Org. Chem. 2013, 9, 1977–2001, doi:10.3762/bjoc.9.234

• approach to exploit synthetic utility of photogenically produced amine radical cations. Reductive quenching of the photoexcited state of a photocatalyst (M) by amine 1 is governed by the reduction potentials of the photoexcited state and the amine (Scheme 1). The amine’s reduction potential, which can be

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

• and TCNQF4. The comparison of the reduction potential of 3 and 5 indicates that the first and the second reduction potentials of 5 apparently decrease compared to those of 3, and the first reduction potential of 5 (0.02 V) just corresponds to the second reduction potential of 3 by chance (Table 1

Electron self-exchange activation parameters of diethyl sulfide and tetrahydrothiophene

• Martin Goez and
• Martin Vogtherr

Beilstein J. Org. Chem. 2013, 9, 1448–1454, doi:10.3762/bjoc.9.164

• spin mixing becomes effective [30]. All these conditions are fulfilled by the 2,4,6-triphenylpyrylium cation TTP+. Compared to typical carbonyl sensitizers such as benzophenone or xanthone, its reduction potential (−0.29 V in acetonitrile versus SCE [31]) is more favorable by more than 2 V, yet its

Development of an additive-controlled, SmI₂-mediated stereoselective sequence: Telescoped spirocyclisation, lactone reduction and Peterson elimination

• Brice Sautier,
• Karl D. Collins and
• David J. Procter

Beilstein J. Org. Chem. 2013, 9, 1443–1447, doi:10.3762/bjoc.9.163

• of reductive electron transfer processes [4][5][6][7][8][9][10][11][12][13]. Cyclisations are one of the most notable classes of transformation induced by SmI2 and have been widely employed in natural-product syntheses [8][9][10]. Importantly, fine tuning of the reagent’s reduction potential through

New core-pyrene π structure organophotocatalysts usable as highly efficient photoinitiators

• Sofia Telitel,
• Frédéric Dumur,
• Thomas Faury,
• Bernadette Graff,
• Mohamad-Ali Tehfe,
• Didier Gigmes,
• Jean-Pierre Fouassier and
• Jacques Lalevée

Beilstein J. Org. Chem. 2013, 9, 877–890, doi:10.3762/bjoc.9.101

• experiments (see below). The rate constants in that case are 1.5 × 1010, 9 × 109, 1 × 1010 and 3.7 × 109 M−1 s−1, respectively. The 1Py_3/PBr, 1Py_3/Iod and 1Py_3/TH interactions are diffusion-controlled in full agreement with the highly favorable ΔGs (Table 1; the reduction potential for TH is −1.3 V [1

• potential of the donor, the reduction potential of the acceptor, the excited state energy and the coulombic term for the initially formed ion pair, respectively. C is neglected as usually done in polar solvents. Fluorescence experiments The fluorescence properties of the different Co_Pys were studied by

Spectroscopic characterization of photoaccumulated radical anions: a litmus test to evaluate the efficiency of photoinduced electron transfer (PET) processes

• Maurizio Fagnoni,
• Stefano Protti,
• Davide Ravelli and
• Angelo Albini

Beilstein J. Org. Chem. 2013, 9, 800–808, doi:10.3762/bjoc.9.91

• reduced and an oxidized product is formed. As an example, the largely positive reduction potential of aromatic nitriles [5][8][9] and cyanophthalimides [10] in the singlet excited state or of aromatic esters in the triplet state [5][11] makes PET a common occurrence upon irradiation of such substrates in

• ][9], DCP [10] and DCP-ME [10] were taken from the literature, whereas the redox potentials of the excited state of 1,3,5-TrCB [21], 1,2,4-TrCB [21], ME [58] and PME [28] were determined by the Rehm–Weller equation [63]. Reduction potential (versus SCE) of the ground and excited state of acceptors and

Electron and hydrogen self-exchange of free radicals of sterically hindered tertiary aliphatic amines investigated by photo-CIDNP

• Martin Goez,
• Isabell Frisch and
• Ingo Sartorius

Beilstein J. Org. Chem. 2013, 9, 437–446, doi:10.3762/bjoc.9.46

• . With Equation 2, the free energy of the relayed deprotonation can be estimated from the reduction potential Φred (DH•+) of the radical cation (see, Table 1, but taken relative to NHE instead of SCE), the pKa of the protonated amine (8.9 [43]), and the calculated heats of formation ∆Hf of D• (+208 kJ

• is between 6.9 and 9.2, depending on the water content [47]. Even with the smaller of these values, using the reduction potential of Table 1 and the calculated heats of formation (∆Hf (D•), −33 kJ/mol; ∆Hf (DH), −111 kJ/mol) we arrive at an exergonicity of at least −50 kJ/mol, which means that a

Reduction of benzylic alcohols and α-hydroxycarbonyl compounds by hydriodic acid in a biphasic reaction medium

• Michael Dobmeier,
• Josef M. Herrmann,
• Dieter Lenoir and
• Burkhard König

Beilstein J. Org. Chem. 2012, 8, 330–336, doi:10.3762/bjoc.8.36

• . Alcohols other than those that were benzylic or α to carbonyl groups were not converted into the corresponding alkanes, and the reaction stopped at the iodoalkanes (Table 3). The reactivity follows the order of primary < secondary < tertiary alcohols, as expected for an SN1 reaction. The reduction

• potential of the nonbenzylic iodoalkanes is not sufficient for reduction by hydriodic acid. The mechanism of reduction by hydriodic acid consists of two steps (Scheme 1): The nucleophilic substitution of the hydroxy group by iodide and the subsequent reduction of the alkyl iodide by hydriodic acid. The

Fluorescent hexaaryl- and hexa-heteroaryl[3]radialenes: Synthesis, structures, and properties

• Antonio Avellaneda,
• Courtney A. Hollis,
• Xin He and
• Christopher J. Sumby

Beilstein J. Org. Chem. 2012, 8, 71–80, doi:10.3762/bjoc.8.7

• electron rich azole rings and methyl substituents make it particularly hard to reduce. Its first reduction potential is −1.21 V and its second was not observed as it occurs outside the solvent window for dichloromethane. Most hexaaryl[3]radialenes are orange or red in colour with UV–visible absorption