1,2,3,4-Tetrahydro-1,4,5,8-tetraazaanthracene revisited: properties and structural evidence of aromaticity loss

• Arnault Heynderickx,
• Sébastien Nénon,
• Olivier Siri,
• Vladimir Lokshin and
• Vladimir Khodorkovsky

Beilstein J. Org. Chem. 2019, 15, 2059–2068, doi:10.3762/bjoc.15.203

• led to variation of its electron donor/acceptor capability that allowed fine-tuning the absorption properties. The propensity of these compounds and a number of its derivatives to form infinite chains involving >N–H···N= and >N–H···Hal−···N+ atoms is demonstrated by X-ray structure analysis. The DFT

Conformational signature of Ishikawa´s reagent using NMR information from diastereotopic fluorines

• Laize A. F. Andrade,
• Lucas A. Zeoly,
• Rodrigo A. Cormanich and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2019, 15, 506–512, doi:10.3762/bjoc.15.44

• interaction nX → σ*C–H/F (X = electron donor atom, usually oxygen) seems to contribute to the magnitude of 1JC–H/F, since the resonance structure originated from this interaction exhibits a longer and weaker C–Hax/Fax bond relative to C–Heq/Feq, thus reducing 1JC–Hax/Fax relative to 1JC–Heq/Feq. In turn, the

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

• ]. Many of these complexes contain rhodium or iridium coordinated with fully (methyl)substituted cyclopentadienyl ligands and bis-coordinating diamino ligands as shown in Figure 7. The reducing agent may be a formate anion as a source of hydride, triethanolamine as an electron donor in the case of

Silanediol versus chlorosilanol: hydrolyses and hydrogen-bonding catalyses with fenchole-based silanes

• Falco Fox,
• Jörg M. Neudörfl and
• Bernd Goldfuss

Beilstein J. Org. Chem. 2019, 15, 167–186, doi:10.3762/bjoc.15.17

• interactions (3502 cm−1 to 22.16 kcal mol−1 vs 3830 cm−1 to 3.06 kcal mol−1, Table 4, entries 5 and 7). With a stronger electron donor, as the chloride ion, the lone pair···σ* orbital interactions rises (36.87 kcal mol−1 vs 50.97 kcal mol−1, Table 4, entries 11 and 12). In here, the BIFOXSi(OH)2 (9) binds the

Organometallic vs organic photoredox catalysts for photocuring reactions in the visible region

• Aude-Héloise Bonardi,
• Frédéric Dumur,
• Guillaume Noirbent,
• Jacques Lalevée and
• Didier Gigmes

Beilstein J. Org. Chem. 2018, 14, 3025–3046, doi:10.3762/bjoc.14.282

• created as illustrated in Figure 1 to regenerate the PC. As illustrated, for an oxidative cycle, the excited photocatalyst (PC*) reacts first with an electron acceptor (also named oxidation agent, OA1 in Figure 1) which leads to PC●+ and OA1●− . Then, PC can be regenerated with an electron donor (also

• mechanisms. From a single or triplet state of the photoredox catalyst, an electron is transferred. According to Rehm–Weller, an electron can be transferred from the electron donor to the electron acceptor in the excited state if the free energy change ∆Get is negative. ∆Get can be calculated from the

• equation: where Eox is the oxidation potential of the electron donor, Ered the reduction potential of the electron acceptor, E* the excited state energy level and C the coulombic term for the initially formed ion pair (if there are ions in solution). For polar solvent, C is neglected. (TMS)3SiH is not

Cobalt- and rhodium-catalyzed carboxylation using carbon dioxide as the C1 source

• Tetsuaki Fujihara and
• Yasushi Tsuji

Beilstein J. Org. Chem. 2018, 14, 2435–2460, doi:10.3762/bjoc.14.221

• et al. reported the Rh-catalyzed hydrocarboxylation of alkenes driven by visible-light irradiation conditions in the presence of a photoredox catalyst (Scheme 37) [75]. A model reaction using 4-cyanostyrene (40a) was carried out using iPrNEt2 as a sacrificial electron donor in the presence of [Ru(bpy

Revisiting ring-degenerate rearrangements of 1-substituted-4-imino-1,2,3-triazoles

• James T. Fletcher,
• Matthew D. Hanson,
• Joseph A. Christensen and
• Eric M. Villa

Beilstein J. Org. Chem. 2018, 14, 2098–2105, doi:10.3762/bjoc.14.184

• rearrange by a ring-degenerate process promoted by an increasing electron-donor strength of the imine functionality. It was further demonstrated that this rearrangement could be utilized as a reliable synthetic tool, with 1-phenyl-1H-1,2,3-triazole-4-carbaldehyde being used to prepare 1-substituted-4-formyl

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• nanoparticles, were capable of reducing CO2 into formate under visible light (λ > 400 nm) in the presence of triethanolamine as an electron donor, with the aid of a molecular Ru(II) cocatalyst (RuP). The CO2 reduction activity was improved by increasing the synthesis temperature of g-C3N4, with the maximum

• evolution Using the as-prepared g-C3N4, CO2 reduction was conducted with the aid of RuP cocatalyst and Ag promoter in a N,N-dimethylacetamide (DMA)/TEOA mixed solution under visible light (λ > 400 nm). Here TEOA works as an effective electron donor that scavenges holes generated in the valence band of g

• activity for CO2 reduction was much lower than that for H2 evolution, even though the same electron donor, TEOA, was employed. This in turn implies that there still remains much room for the improvement of CO2 reduction activity, for example, if a proper modification method, which allows for more efficient

Recent advances in phosphorescent platinum complexes for organic light-emitting diodes

• Cristina Cebrián and
• Matteo Mauro

Beilstein J. Org. Chem. 2018, 14, 1459–1481, doi:10.3762/bjoc.14.124

• same group reported very recently another family of platinum(II) complexes containing both electron-donor and electron-acceptor moieties embedded within the dopant structure (Figure 13) [63]. This bipolar character was intended to reduce the TTA phenomena commonly experienced at high current density

Rapid transformation of sulfinate salts into sulfonates promoted by a hypervalent iodine(III) reagent

• Elsa Deruer,
• Vincent Hamel,
• Samuel Blais and
• Sylvain Canesi

Beilstein J. Org. Chem. 2018, 14, 1203–1207, doi:10.3762/bjoc.14.101

• investigations to extend this approach to other carbon-based nucleophiles must be developed. Presumably, the presence of an electron-donor group such as methoxy on the aromatic moiety would stabilize the sulfonium species and increase the yield obtained in these transformations (Scheme 3). This process may also

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

• selectively bind mixed G·C and A·T sequences of DNA. They hypothesized that thiophene (positive electrostatic potential) and the electron-donor nitrogen of N-MeBI should pre-organize the conformation for accepting hydrogen bond from G-NH2, which was validated by replacing the thiophene moiety with other

Diels–Alder cycloadditions of N-arylpyrroles via aryne intermediates using diaryliodonium salts

• Huangguan Chen,
• Jianwei Han and
• Limin Wang

Beilstein J. Org. Chem. 2018, 14, 354–363, doi:10.3762/bjoc.14.23

• synthesized in 75% yield (Scheme 2b), whose structure was determined by 2D-NMR analyses (see Supporting Information File 1). Furthermore, as a unique electron donor, the novel compound 5 may have potential applications in photosensitive dyes and OLEDs [28][29]. Interestingly, the bridged-ring compound 6 could

Recent advances on organic blue thermally activated delayed fluorescence (TADF) emitters for organic light-emitting diodes (OLEDs)

• Thanh-Tuân Bui,
• Fabrice Goubard,
• Malika Ibrahim-Ouali,
• Didier Gigmes and
• Frédéric Dumur

Beilstein J. Org. Chem. 2018, 14, 282–308, doi:10.3762/bjoc.14.18

• silicon atom, two phenyl rings can be introduced on the silicon-bridged structure providing bulkiness and rigidity to the donor. Intermolecular interactions are thus efficiently prevented and the conformation disorder drastically reduced. When used as electron donor in T1, a ΔEST of 0.14 eV was determined

• ). Azasiline is a promising electron donor but examples of blue TADF emitters are still scarce. The opposite situation is found for carbazole, which has long been considered as an excellent donor and a large variety of blue TADF emitters have been designed on the basis of this scaffold. At least 19 examples of

• to combine the electron-donating 9,9-dimethyl-10-phenylacridan with the electron-accepting 2,4,6-triphenyl-1,3,5-triazine was reported under the form of random copolymers derived from a polystyrene (T31–T34, see Figure 9) [60]. Contrarily to the classical TADF materials in which the electron donor is

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• base and DMSO as solvent they observed a colouring of the reaction mixture, whereas the reagents are colourless themselves. They suggest that the thiol becomes deprotonated to the respective thiolate anion and subsequently an electron donor–acceptor complex with the aryl halide is formed. Irradiation

Structure–property relationships and third-order nonlinearities in diketopyrrolopyrrole based D–π–A–π–D molecules

• Jan Podlesný,
• Lenka Dokládalová,
• Oldřich Pytela,
• Adam Urbanec,
• Milan Klikar,
• Numan Almonasy,
• Tomáš Mikysek,
• Jaroslav Jedryka,
• Iwan V. Kityk and
• Filip Bureš

Beilstein J. Org. Chem. 2017, 13, 2374–2384, doi:10.3762/bjoc.13.235

• be the strongest electron donor within the studied series of compounds. This is in accordance with our previous observations [9][35]. Except for chromophores 3a,b, insertion of an additional acetylene linker rather extended the electrochemical HOMO–LUMO gap (series a vs b). Linear optical properties

Synthesis and application of trifluoroethoxy-substituted phthalocyanines and subphthalocyanines

• Satoru Mori and
• Norio Shibata

Beilstein J. Org. Chem. 2017, 13, 2273–2296, doi:10.3762/bjoc.13.224

• phthalocyanine, which originally acts as an electron donor, will exhibit an electron acceptor property. Thus, it is expected that TFEO-Pcs can be developed as unique functional molecules [41]. This review summarizes the synthesis of various TFEO-Pc derivatives and the effect of fluorine on their properties

Conformational impact of structural modifications in 2-fluorocyclohexanone

• Francisco A. Martins,
• Josué M. Silla and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2017, 13, 1781–1787, doi:10.3762/bjoc.13.172

• of the studied compounds, according to the NBO analysis and in spite of some stabilizing electronic delocalization interactions from electron-donor orbitals to antiperiplanar antibonding orbitals. The electronic interactions mentioned above appeared to be sensitive to the solvent effect, since the

Chemical systems, chemical contiguity and the emergence of life

• Terrence P. Kee and
• Pierre-Alain Monnard

Beilstein J. Org. Chem. 2017, 13, 1551–1563, doi:10.3762/bjoc.13.155

• , and a nucleobase, 8-oxoguanine, serving as recyclable electron donor to trigger the redox cleavage of the precursor molecule, [71] was also found to be enhanced by the presence of pre-formed fatty acid vesicles. In aqueous media, both parts of the photochemical catalyst needed to be covalently linked

Transition-metal-free one-pot synthesis of alkynyl selenides from terminal alkynes under aerobic and sustainable conditions

• Adrián A. Heredia and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2017, 13, 910–918, doi:10.3762/bjoc.13.92

• to the acetylenic group were also studied (Table 4). Thus, the p-methyl-substituted derivative 6b afforded the selenide 5i in comparable yields as with the unsubstituted alkyne 6a (Table 4, entries 1 and 2). The presence of a strong electron donor such as a methoxy group (compound 6c), decreased the

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

• )propanenitriles 193 has been described by Pletnev and Larock [84]. This reaction was compatible with a wide variety of electron-donor and electron-acceptor functional groups. The authors have also found that the formation of 1-indanones 194 is accompanied by the reduction of the carbon–iodine bond in 3-(2

The reductive decyanation reaction: an overview and recent developments

• Jean-Marc R. Mattalia

Beilstein J. Org. Chem. 2017, 13, 267–284, doi:10.3762/bjoc.13.30

• advantages of the nitrile functional group before its removal. Mechanistic details and applications to organic synthesis are provided. Keywords: α-aminonitrile; decyanation; electron donor; hydride; malononitrile; transition metal catalysis; Introduction Many strategies in organic synthesis involve the

• ) iodide/THF/HMPA at respectively 0 °C and room temperature [123]. Metallic samarium can also promote the decyanation [124]. Doni and Murphy have reported the reductive decyanation of malononitriles and α-cyanoesters by using the neutral organic electron donor 78 (Scheme 25) under photoactivation (method A

• highly efficient neutral organic electron donor (Scheme 25) [127]. This compound is able to reduce aryl halides and appears as the only reductant able to reduce dialkylarenesulfonamides as well as malononitriles without photoexcitation. Electron donor 80 can be isolated but is more conveniently generated

Direct arylation catalysis with chloro[8-(dimesitylboryl)quinoline-κN]copper(I)

• Sem Raj Tamang and
• James D. Hoefelmeyer

Beilstein J. Org. Chem. 2016, 12, 2757–2762, doi:10.3762/bjoc.12.272

• ) to form benzyne or that organic electron donors form in situ with suitable additives under the basic conditions of the reaction [58][59][60]. For example, observation of faster direct arylation in the presence of DMF led to proposals of deprotonated DMF as one electron donor [61] or forming a dibasic

• -enediol in situ as an electron donor [62]. While the SET mechanism has drawn much interest, our observation of large rate enhancement upon addition of the preformed catalyst 2 may be better described with a metalation–deprotonation step followed by oxidative addition/reductive elimination (Scheme 2) [63

Effects of solvent additive on “s-shaped” curves in solution-processed small molecule solar cells

• John A. Love,
• Shu-Hua Chou,
• Ye Huang,
• Guilllermo C. Bazan and
• Thuc-Quyen Nguyen

Beilstein J. Org. Chem. 2016, 12, 2543–2555, doi:10.3762/bjoc.12.249

• , National Taiwan University, Taipei, 10617, Taiwan 10.3762/bjoc.12.249 Abstract A novel molecular chromophore, p-SIDT(FBTThCA8)2, is introduced as an electron-donor material for bulk heterojunction (BHJ) solar cells with broad absorption and near ideal energy levels for the use in combination with common

• counterparts [5][6]. Also of import stands the fact that easily modified, modular structures lead to finely-tunable energy levels and optical properties through molecular design [7][8]. Most high-performing small molecule electron-donor materials are configured such that the conjugated backbone consists of

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

• -donor– π-bridge-acceptor (A–π-D–π-A) electron donor molecules. Based on the known benzodithiophene-terthiophene-rhodanine (BTR) material, the BXR series of materials, BMR (X = M, monothiophene), BBR (X = B, bithiophene), known BTR (X = T, terthiophene), BQR (X = Q, quaterthiophene), and BPR (X = P(penta

• to the SVA devices indicates that further optimization may be required. It is evident that modification of the chromophore length has a large impact on the device stability and performance. BQR as a molecular electron donor is the stand-out performer with the best initial results under all device

• devices optimization is still required. The performance of BQR as a molecular electron donor and the stability of BQR containing BHJ devices encouraged the examination of BQR in ternary BHJ devices. It has been reported that addition of a small percentage of a molecular electron donor to polymer:fullerene

Comparing blends and blocks: Synthesis of partially fluorinated diblock polythiophene copolymers to investigate the thermal stability of optical and morphological properties

• Pierre Boufflet,
• Sebastian Wood,
• Jessica Wade,
• Zhuping Fei,
• Ji-Seon Kim and
• Martin Heeney

Beilstein J. Org. Chem. 2016, 12, 2150–2163, doi:10.3762/bjoc.12.205

• -scale is of particular interest in the field of organic photovoltaics (OPV), where separation of the electron donor and acceptor domains on the order of the exciton diffusion length (5–10 nm) is required [1][6][7][8][9]. Many approaches have been reported to tether two or more light-absorbing polymers