TTFs nonsymmetrically fused with alkylthiophenic moieties

• Rafaela A. L. Silva,
• Bruno J. C. Vieira,
• Marta M. Andrade,
• Isabel C. Santos,
• Sandra Rabaça,
• Dulce Belo and
• Manuel Almeida

Beilstein J. Org. Chem. 2015, 11, 628–637, doi:10.3762/bjoc.11.71

• , respectively. These electrochemical studies show that α-tbtdt and α-mtdt are easier to oxidise than the related unsubstituted extended TTFs, with higher electron donor ability compared to related TTF-type donors with the exception of BET-TTF. Crystal structures Ketone I Compound I crystallises in the

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

• Gebze-Kocaeli, Turkey 10.3762/bjoc.11.46 Abstract This review aims to give an overview of the current status of our research on the synthesis of π-electron donor bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF, ET) analogues prepared from 1,8-diketones via a ring forming reaction. The new synthesized π

• molecule [28][40]. The most notable superconductivity was observed with the radical cation salts derived from the electron-donor molecule bis(ethylenedithio)tetrathiafulvalene (BEDT-TTF) as a (BEDT-TTF)2Cu[N(CN)2]Br salt at 12.5 K (resistive onset) [24]. The tetrathiafulvalene (TTF) ring system is one of

Synthesis of dinucleoside acylphosphonites by phosphonodiamidite chemistry and investigation of phosphorus epimerization

• William H. Hersh

Beilstein J. Org. Chem. 2015, 11, 184–191, doi:10.3762/bjoc.11.19

• has not been found [48][49][50]. Once purified, 7 exhibited a strong carbonyl peak in the infrared spectrum at 1654 cm−1, a surprisingly low frequency considering the downfield 13C chemical shift. This inconsistency is perhaps due to an effect caused by the electron-donor diisopropylamide groups. A

Come-back of phenanthridine and phenanthridinium derivatives in the 21st century

• Lidija-Marija Tumir,
• Marijana Radić Stojković and
• Ivo Piantanida

Beilstein J. Org. Chem. 2014, 10, 2930–2954, doi:10.3762/bjoc.10.312

• -phenylphenanthridines. Thus, the electron-donor properties of the exocyclic amines, especially at 8-position have a stronger influence on the electron density of aromatic atoms than the electron withdrawing effects of endocyclic iminium. Fine tuning of electron properties of EB can be easily achieved via chemical

• modulation of its amino groups at 3 and 8 positions of the phenanthridine ring [52][53]. Systematic changing of the ethidium bromide exocyclic amines into guanidine, pyrrole, urea, and various substituted ureas revealed importance of electron-donor properties of substituents at the 3- and 8-position of the

• phenanthridinium relative to the unmodified primary amino groups. Namely, derivatives of EB having substituents with weaker electron-donor properties exhibited a stronger fluorescence emission than EB, while a stronger electron-donating substituent exhibited a much lower fluorescence emission. Such behaviour could

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

• interpenetrating network they form within a bulk heterojunction (BHJ), has led to intense research directed towards the synthesis of conjugated polymers for bulk heterojunction organic photovoltaics (OPVs) [1][2][3]. In these devices, the conjugated polymer acts as an electron donor and a soluble fullerene, most

An integrated photocatalytic/enzymatic system for the reduction of CO₂ to methanol in bioglycerol–water

• Michele Aresta,
• Angela Dibenedetto,
• Tomasz Baran,
• Antonella Angelini,
• Przemysław Łabuz and
• Wojciech Macyk

Beilstein J. Org. Chem. 2014, 10, 2556–2565, doi:10.3762/bjoc.10.267

• was evidenced by measuring the amount of photogenerated 1,4-NADH using water or water/glycerol as electron donor. Figure 3b illustrates the results of the photocatalytic regeneration of NADH in presence of various materials after 6 hours of irradiation. Interestingly, for [CrF5(H2O)]2−@TiO2 the yield

• NADH photoregeneration process when compared to the [CrF5(H2O)]2−@TiO2 photocatalyst. As mentioned above, glycerol was considered as an electron donor in aqueous solution. When only water was used in the photoreduction, the reaction rate was very low due to the weak ability of H2O to transfer electrons

• . Figure 10 shows the influence of the nature of the electron donor and the concentration of the electron mediator, on the reduction rate. The NADH regeneration rate exhibits a strong dependence on the concentration of glycerol, which plays the crucial role of a sacrificial electron donor. Figure 10 also

Microsolvation and sp²-stereoinversion of monomeric α-(2,6-di-tert-butylphenyl)vinyllithium as measured by NMR

• Rudolf Knorr,
• Monika Knittl and
• Eva C. Rossmann

Beilstein J. Org. Chem. 2014, 10, 2521–2530, doi:10.3762/bjoc.10.263

• -type electron pair at C-α (Scheme 1 or Scheme 2) is a somewhat stronger σ-electron donor if coordinated to Li+(THF)3 than if coordinated to Li+(Et2O)2 or to Li+(TMEDA). Of course, the accompanying σ-inductive effect of the α-aryl group contributes likewise to 2JH,H in both 4 and the “parent” olefin 8a

Oxidative phenylamination of 5-substituted 1-hydroxynaphthalenes to N-phenyl-1,4-naphthoquinone monoimines by air and light “on water”

• Julio Benites,
• Juan Meléndez,
• Cynthia Estela,
• David Ríos,
• Luis Espinoza,
• Iván Brito and
• Jaime A. Valderrama

Beilstein J. Org. Chem. 2014, 10, 2448–2452, doi:10.3762/bjoc.10.255

• substitution at the 4-position of compound 1 followed by oxidation of the aminonaphthol intermediate, yield the N-phenyl-1,4-naphthoquinone-4-imines. A mechanism involving radical cation intermediates is supported by the rather high product yields resulting from the reaction of 1,5-DHN (1) with electron-donor

• substituted phenylamines. Given the totally green and high yield access to compound 6 from 1,5-DHN (1) and 4-hydroxyphenylamine, we decided to study the reaction scope to include 5-acetylamino-1-hydroxynaphthalene (5) as a 1-hydroxynaphthalene substrate and phenylamines containing electron-donor and acceptor

• concluded that the oxidative arylamination of 1,5-DHN (1) is favorable with arylamines containing electron-donor substituents. Bearing in mind that the formation of the quinone monoimines 6–10 under the above experimental conditions requires aerial oxidation reactions, most likely mediated by oxygen species

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

• light in the presence of [Ir(ppy)2(dtb-bpy)](PF6) as visible light photocatalyst and Hünig’s base as sacrificial electron donor in an acetonitrile/water mixture generally gave good to excellent yields of the desired defunctionalized compounds. Functional group tolerance is high but the protocol

• byproducts. Related to this work, Stephenson et al. elegantly succeeded in the direct deoxygenation of alcohols by their in situ conversion to iodides using triphenylphospine and iodine followed by visible light-mediated reduction with amines as stoichiometric sacrificial electron donor and fac-Ir(ppy)3 (ppy

• ; dtb-bpy = 4,4′-di-tert-butyl-2,2′-bipyridine] as photocatalysts, Hantzsch ester (diethyl 1,4-dihydro-2,6-dimethyl-3,5-pyridinedicarboxylate) as hydrogen donor, and iPr2NEt as sacrificial electron donor in DMF (Scheme 3). Light generated from a high power LED was channeled into the reaction solution in

The effect of permodified cyclodextrins encapsulation on the photophysical properties of a polyfluorene with randomly distributed electron-donor and rotaxane electron-acceptor units

• Aurica Farcas,
• Ana-Maria Resmerita,
• Pierre-Henri Aubert,
• Flavian Farcas,
• Iuliana Stoica and
• Anton Airinei

Beilstein J. Org. Chem. 2014, 10, 2145–2156, doi:10.3762/bjoc.10.222

Photo, thermal and chemical degradation of riboflavin

• Muhammad Ali Sheraz,
• Sadia Hafeez Kazi,
• Sofia Ahmed,
• Zubair Anwar and
• Iqbal Ahmad

Beilstein J. Org. Chem. 2014, 10, 1999–2012, doi:10.3762/bjoc.10.208

• ]. Anaerobic photobleaching of RF in the absence of an added electron donor has been investigated by Holmström and Oster [81]. The anaerobic irradiation of RF causes intramolecular photoreduction of the isoalloxazine ring which leads to the fading of yellow color. However, if air is introduced into the

Influence of perylenediimide–pyrene supramolecular interactions on the stability of DNA-based hybrids: Importance of electrostatic complementarity

• Christian B. Winiger,
• Simon M. Langenegger,
• Oleg Khorev and
• Robert Häner

Beilstein J. Org. Chem. 2014, 10, 1589–1595, doi:10.3762/bjoc.10.164

• aedamers (aromatic electron donor acceptor oligomers) pioneered by Iverson and coworkers [18][36][37]. They consist of face-to-face stacked electron-rich naphthalene and electron-poor naphthalenediimide (NDI) chromophores and belong to the broader area of foldamers [38]. DNA has been described as a

Organic synthesis using photoredox catalysis

• Axel G. Griesbeck

Beilstein J. Org. Chem. 2014, 10, 1097–1098, doi:10.3762/bjoc.10.107

• catalysis or light-driven charge separation, which leads to an energy harvesting process by taking advantage of the reduction products and filling the holes by a sacrificial electron donor, water. Fortunately, we can use the waste product from this process, oxygen, for breathing. For applications in organic

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

• electronics [2], photonics [3], and bioanalytics [4][5][6]. Therefore, the design of well-defined monomolecular structures with electron-donor (Do) and acceptor (Acc) substitution, so called Do–Acc dyads, is a topical field with a paramount academic and technological interest [7][8]. Tailor-made Do–Acc

Visible light mediated intermolecular [3 + 2] annulation of cyclopropylanilines with alkynes

• Theresa H. Nguyen,
• Soumitra Maity and
• Nan Zheng

Beilstein J. Org. Chem. 2014, 10, 975–980, doi:10.3762/bjoc.10.96

• compounds [21][22][23][24][25][26]. Amines have been used as an electron donor to reduce the excited state of photocatalysts, while they are oxidized to amine radical cations. Our group and others have taken advantage of this facile redox process and developed a number of synthetic methods that harness the

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

• , an electron acceptor and an electron donor leading to energy conversion through electron transfer, was the basis of the so called three-component systems. In this paper, an experimental work combining Rose bengal dye with a triazine derivative as electron acceptor and ethyl 4-(dimethylamino)benzoate

• as electron donor, will underline the benefit of the photocyclic behavior of three-component systems leading to the dye regeneration. A thermodynamic approach of the photocycle is presented, followed by a mechanistic and computational study of ideal photocycles, in order to outline the specific

• on the Rose Bengal as dye, and a triazine derivative (TA) as an acceptor (coinitiator). In addition, an amine (ethyl 4-(dimethylamino)benzoate, EDB) was chosen as redox (electron donor) additive for the PCIS (see Scheme 1). Type II photoinitiating system In Scheme 2, the typical reaction mechanism of

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

• radical Rad-m (from the decomposition of a suitable electron donor as before) is converted into another radical Rad-1 (upon addition of a convenient radical source), this novel radical being able to favorably react with PIC•+. Such a process should be likely more feasible. According to these different

• reduced through a photoinduced electron transfer with an electron donor eD. A suitable B-Y (or B-Y+) compound leads to a regeneration of PIC and the formation of a radical and an anion (or a radical and a neutral product). Therefore, FRP can be achieved. Examples of PICs in the photopolymerization area

• through a subsequent Ph•/R3SiH hydrogen abstraction and R3Si•/PIC•+ interaction, respectively (the eA serves both as an electron donor and a radical mediator source) [45][46][47][48][49][50][51][52]. The Ph2I+/R3Si• interaction increases the yields in both phenyl radicals and silylium species [45][46][47

Domino reactions of 2H-azirines with acylketenes from furan-2,3-diones: Competition between the formation of ortho-fused and bridged heterocyclic systems

• Alexander F. Khlebnikov,
• Mikhail S. Novikov,
• Viktoriia V. Pakalnis,
• Roman O. Iakovenko and
• Dmitry S. Yufit

Beilstein J. Org. Chem. 2014, 10, 784–793, doi:10.3762/bjoc.10.74

• [37][38][39][40][41][42][43][44][45][46][47][48][49] under different conditions is quite common. Moreover, everybody who works with 3-aryl-2H-azirines faces the problem of their storage, because these compounds, both with unsubstituted and an electron-donor substituted benzene ring, fast transform

• proportion of cis-isomer 4 than of trans-isomer 5 is a result of thermodynamic control. We also recommend storing liquid 3-aryl-2H-azirines, both with unsubstituted and an electron-donor substituted benzene ring, over anhydrous K2CO3. Experimental General methods Melting points were determined on a hot stage

Direct and indirect single electron transfer (SET)-photochemical approaches for the preparation of novel phthalimide and naphthalimide-based lariat-type crown ethers

• Dae Won Cho,
• Patrick S. Mariano and
• Ung Chan Yoon

Beilstein J. Org. Chem. 2014, 10, 514–527, doi:10.3762/bjoc.10.47

• understanding of the factors controling the chemical selectivities and efficiencies. For example, we have demonstrated that intramolecular SET-photochemical reactions of linked α-trimethylsilyl n-electron donor-phthalimides/naphthalimides produce functionalized macrocyclic poly-ethers, -thioethers, -amides, and

• chain linking the α-trimethylsilyl n-electron donor centers and the arylimide acceptors play important roles in controlling the rate of formation of the zwitterionic biradicals 21 and 22 and, thus, affecting the yield of the macrocyclic products [31][33][34][65][66][67]. Importantly, these efforts

• electron donor sites in these substances are ideally suited to capture cations in the form of chelate structures [70][71][72][73][74][75][76][77][78][79]. Several practical synthetic protocols have been developed to prepare members of the crown ether familiy. In most cases, the approaches utilize the

Charge-transfer interaction mediated organogels from 18β-glycyrrhetinic acid appended pyrene

• Jun Hu,
• Jindan Wu,
• Qian Wang and
• Yong Ju

Beilstein J. Org. Chem. 2013, 9, 2877–2885, doi:10.3762/bjoc.9.324

• ability of 2,3-dihydroxyiminooleanolic acid, adenineoleanolic acid conjugates as well as the fan-shaped C3 and molecular tweezers based on glycyrrhetinic acid [42][43][44]. In this paper, 18β-glycyrrhetinic acid–pyrene (GA-Pyrene, 3) as the electron donor, and 2,4,7-trinitrofluorenone (TNF, 4) as the

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

• organic molecules such as amines. The photoexcited state is both more oxidizing and more reducing than the ground state. It can be quenched reductively by accepting an electron from an electron donor or oxidatively by donating an electron to an electron acceptor. Amines are often used as an electron donor

• to reductively quench the photoexcited state while they are oxidized to amine radical cations. This single-electron transfer process was investigated intensively in the late 1970s and early 1980s because amines were used as a sacrificial electron donor in water splitting [31][32] and carbon dioxide

• reduction [33][34]. Since 2008, seminal works from MacMillan, Yoon, and Stephenson have reinvigorated the field of visible light photoredox catalysis [35][36][37][38][39][40][41][42]. The use of amines as both the electron donor and the substrate, rather than just the electron donor, has become a major

Computational study of the rate constants and free energies of intramolecular radical addition to substituted anilines

• Andreas Gansäuer,
• Meriam Seddiqzai,
• Tobias Dahmen,
• Rebecca Sure and
• Stefan Grimme

Beilstein J. Org. Chem. 2013, 9, 1620–1629, doi:10.3762/bjoc.9.185

• addition reaction of 9 that has the most electrophilic radical center due to ester substitution. The more nucleophilic radicals 8 and 10 react slower than 1. The –OMe group in 10 is a better electron donor than the –Me group in 8, which should make it more nucleophilic and lead to a slower radical addition

An organocatalytic route to 2-heteroarylmethylene decorated N-arylpyrroles

• Alexandre Jean,
• Jérôme Blanchet,
• Jacques Rouden,
• Jacques Maddaluno and
• Michaël De Paolis

Beilstein J. Org. Chem. 2013, 9, 1480–1486, doi:10.3762/bjoc.9.168

• preparation of N-arylpyrroles is an active field of investigation [5]. Depending on their substituents, N-arylpyrroles could also be electron donor/acceptor molecules with a dual fluorescence ability suggesting attractive optoelectronic applications [6][7]. If the N-arylation of pyrroles is possible by

• ideal for the preparation of electron donor/acceptor N-arylpyrroles as demonstrated in this study. In addition, we documented an efficient C–H oxidation of the bis(heteroaryl)methylene position promoted by CAN. Experimental General: 1H and 13C NMR spectra were recorded in deuterated chloroform on Bruker

True and masked three-coordinate T-shaped platinum(II) intermediates

• Manuel A. Ortuño,
• Salvador Conejero and
• Agustí Lledós

Beilstein J. Org. Chem. 2013, 9, 1352–1382, doi:10.3762/bjoc.9.153

• blocked somehow to prevent undesirable contacts, and in most cases, bulky ligands are required to protect the empty coordination site. Strong electron-donor ligands also help stabilizing the formally 14-electron compounds. It is worthy of note that almost all of them are cationic. The first true T-shaped

Efficient Cu-catalyzed base-free C–S coupling under conventional and microwave heating. A simple access to S-heterocycles and sulfides

• Silvia M. Soria-Castro and
• Alicia B. Peñéñory

Beilstein J. Org. Chem. 2013, 9, 467–475, doi:10.3762/bjoc.9.50

• . Electron-donor and electron-acceptor substituents are tolerated, and polysubstitution can also be successfully accomplished. Experimental Representative experimental procedures for the Cu-catalyzed base-free C–S coupling Method A: The reactions were carried out in a 10 mL two-necked Schlenk tube, equipped