Small anion-assisted electrochemical potential splitting in a new series of bistriarylamine derivatives: organic mixed valency across a urea bridge and zwitterionization

• Keishiro Tahara,
• Tetsufumi Nakakita,
• Alyona A. Starikova,
• Takashi Ikeda,
• Masaaki Abe and
• Jun-ichi Kikuchi

Beilstein J. Org. Chem. 2019, 15, 2277–2286, doi:10.3762/bjoc.15.220

• the degree of delocalization [1][2][3][4][5]. Changing the redox-active components from ferrocene to NAr3 led to a 4.3-fold increase in the α value. The degree of delocalization in the MV species can be understood in terms of the properties of the redox-active components; the positive charge of the

• ), and a Ag/AgCl (3.0 M NaCl) reference electrode in CH2Cl2 solutions (1.0 mM) of the target compound containing 0.1 M n-Bu4NPF6. Additional experiments were carried out in the presence of decamethylferrocene (Fc*). The potentials versus the Fc+/Fc couple (where Fc = ferrocene) are also included in Table

1,2,3-Triazolium macrocycles in supramolecular chemistry

• Mastaneh Safarnejad Shad,
• Pulikkal Veettil Santhini and
• Wim Dehaen

Beilstein J. Org. Chem. 2019, 15, 2142–2155, doi:10.3762/bjoc.15.211

• -triazolium receptors A ferrocene-containing dicationic bis-triazolium macrocycle 4 (see Figure 4) has been designed and synthesized by utilising the intramolecular Eglinton cyclisation of an acyclic bis(triazolylalkyne)ferrocene precursor followed by alkylation. The anion sensing ability was investigated by

• charge-assisted C–H···anion interactions. According to the cyclic voltammetry analysis, the redox-active macrocycle was able to recognize chloride, causing a cathodic shift of the Epa wave of the ferrocene/ferrocenium redox couple. However, a quick disappearance of the redox signal was observed when the

Morphology-tunable and pH-responsive supramolecular self-assemblies based on AB₂-type host–guest-conjugated amphiphilic molecules for controlled drug delivery

• Yang Bai,
• Cai-ping Liu,
• Di Chen,
• Long-hai Zhuo,
• Huai-tian Bu and
• Wei Tian

Beilstein J. Org. Chem. 2019, 15, 1925–1932, doi:10.3762/bjoc.15.188

• utilized as host units to construct these stimuli-responsive supramolecular self-assemblies [21][22][23][24][25][26][27]. For example, β-CD can form inclusion complexes with guests such as azobenzene [28][29], ferrocene [30][31] and benzimidazole [32][33][34] to construct light-, redox-, and pH-responsive

Functional panchromatic BODIPY dyes with near-infrared absorption: design, synthesis, characterization and use in dye-sensitized solar cells

• Quentin Huaulmé,
• Cyril Aumaitre,
• Outi Vilhelmiina Kontkanen,
• David Beljonne,
• Alexandra Sutter,
• Gilles Ulrich,
• Renaud Demadrille and
• Nicolas Leclerc

Beilstein J. Org. Chem. 2019, 15, 1758–1768, doi:10.3762/bjoc.15.169

• well as to determine the energy levels of their highest occupied molecular orbital (HOMO) and lower unoccupied molecular orbital (LUMO). All the redox potentials were calibrated with respect to Ferrocene (Fc), assuming that E(Fc/Fc+) = 0.40 V with respect to SCE (see experimental details). The low

Synthesis, photophysical and electrochemical properties of pyridine, pyrazine and triazine-based (D–π–)₂A fluorescent dyes

• Keiichi Imato,
• Toshiaki Enoki,
• Koji Uenaka and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2019, 15, 1712–1721, doi:10.3762/bjoc.15.167

• tetrabutylammonium perchlorate (Bu4NClO4). The cyclic voltammograms of the three dyes are shown in Figure 5. The reversible oxidation waves (Epaox) for the three dyes were observed at 0.42 V for OUY-2 and OUK-2 and 0.45 V for OUJ-2, vs ferrocene/ferrocenium (Fc/Fc+) (Table 2). The corresponding reduction waves

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• ferrocene/ferricenium couple (Fc/Fc+). For the measurements, concentrations of 10−3 M of the electroactive species were used in freshly distilled and deaerated dichloromethane (Lichrosolv, Merck) purified with a Braun MB-SPS-800 and 0.1 M (n-Bu)4NPF6 (Fluka; recrystallized twice from ethanol

• 1,1’-bis(diphenylphosphino)ferrocene (dppf) from Frontier Scientific. Absolute tetrahydrofuran, dichloromethane, and toluene were provided from Sigma-Aldrich and purified using a Büchi MB SPS-800. Dimethyl sulfoxide, acetonitrile, and acetone were purchased from Merck and Sigma-Aldrich, purified, and

N-Arylphenothiazines as strong donors for photoredox catalysis – pushing the frontiers of nucleophilic addition of alcohols to alkenes

• Fabienne Speck,
• David Rombach and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 52–59, doi:10.3762/bjoc.15.5

• transfer, BET = back-electron transfer). Reduction potentials Ered(X+·/X) of N-phenylphenothiazines 1–11 (determined by cyclic voltammetry using ferrocene as standard). Screening of reaction conditions for the methanol addition to α-methylstyrene (13a).a Supporting Information Supporting Information File

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

• treatment. In the reaction mixture, olefin isomers were also generated in 20% yield. The ligands were found to have a strong influence in yields and selectivity. Thus, the use of DPEphos (2,2′-bis(diphenylphosphino)diphenyl ether), dppf (1,1′-bis(diphenylphosphino)ferrocene), dppp (1,3-bis(diphenylphosphino

Applications of organocatalysed visible-light photoredox reactions for medicinal chemistry

• Michael K. Bogdos,
• Emmanuel Pinard and
• John A. Murphy

Beilstein J. Org. Chem. 2018, 14, 2035–2064, doi:10.3762/bjoc.14.179

• novel difluoromethylating agent which was used to simultaneously install a difluoromethyl and an acetamide group on various styrene-type derivatives, under perylene-catalysed (Eox* (cat+•/cat) = −2.23 V vs ferrocene in acetonitrile) photoredox conditions (Scheme 14) [57]. For the most part, the scope of

Thiocarbonyl-enabled ferrocene C–H nitrogenation by cobalt(III) catalysis: thermal and mechanochemical

• Santhivardhana Reddy Yetra,
• Zhigao Shen,
• Hui Wang and
• Lutz Ackermann

Beilstein J. Org. Chem. 2018, 14, 1546–1553, doi:10.3762/bjoc.14.131

• by weakly-coordinating thiocarbonyl-assisted cobalt catalysis. Thus, carboxylates enabled ferrocene C–H nitrogenations with dioxazolones, featuring ample substrate scope and robust functional group tolerance. Mechanistic studies provided strong support for a facile organometallic C–H activation

• manifold. Keywords: amidation; C–H activation; cobalt; ferrocene; mechanochemistry; Introduction C–H activation has surfaced as a transformative tool in molecular sciences [1][2][3][4][5][6][7][8][9]. While major advances have been accomplished with precious 4d transition metals, recent focus has shifted

• ) cobalt-catalyzed C–H amidations of thiocarbonylferrocenes by weak coordination, (ii) thermal and mechanochemical [98][99][100] cobalt-catalyzed ferrocene C–H nitrogenations, (iii) versatile access to synthetically useful aminoketones, and (iv) key mechanistic insights on facile C–H cobaltation. Results

Recent applications of chiral calixarenes in asymmetric catalysis

• Mustafa Durmaz,
• Erkan Halay and
• Selahattin Bozkurt

Beilstein J. Org. Chem. 2018, 14, 1389–1412, doi:10.3762/bjoc.14.117

• . The low enantioselectivities obtained were mainly attributed to the high flexibility of catalytic amino groups of N,O-type enantiomers. Suzuki–Miyaura cross–coupling and Tsuji–Trost allylic substitution reaction Manoury et al. described the synthesis of ferrocene-bearing enantiomerically pure

Polysubstituted ferrocenes as tunable redox mediators

• Sven D. Waniek,
• Jan Klett,
• Christoph Förster and
• Katja Heinze

Beilstein J. Org. Chem. 2018, 14, 1004–1015, doi:10.3762/bjoc.14.86

• ’-bis(methoxycarbonyl)- (2), 1,1’,3-tris(methoxycarbonyl)- (3) and 1,1’,3,3’-tetrakis(methoxycarbonyl)ferrocene (4), has been studied with respect to their potential use as redox mediators. The impact of the number and position of ester groups present in 1–4 on the electrochemical potential E1/2 is

• of 1–4 and 1+–4+ correlate with the number of ester groups. Paramagnetic 1H NMR redox titration experiments give access to the chemical shifts of 1+–4+ and underline the fast electron self-exchange of the ferrocene/ferrocenium redox couples, required for rapid redox mediation in organic

• electrosynthesis. Keywords: cyclic voltammetry; ferrocene; paramagnetic NMR spectroscopy; redox mediator; spectroelectrochemistry; Introduction Since its discovery, ferrocene (FcH) has been established as versatile redox-active building block [1][2][3]. Ferrocene can be reversibly oxidized to the 17 valence

Two novel blue phosphorescent host materials containing phenothiazine-5,5-dioxide structure derivatives

• Feng-Ming Xie,
• Qingdong Ou,
• Qiang Zhang,
• Jiang-Kun Zhang,
• Guo-Liang Dai,
• Xin Zhao and
• Huai-Xin Wei

Beilstein J. Org. Chem. 2018, 14, 869–874, doi:10.3762/bjoc.14.73

• the supporting electrolyte. The cyclic voltammograms are shown in Figure 3. Cyclic voltammetry was measured with a glassy carbon working electrode, a platinum wire counter electrode, a saturated Ag/AgCl reference electrode, ferrocenium-ferrocene (Fc+/Fc) as the internal standard and tetrabutylammonium

Enhanced quantum yields by sterically demanding aryl-substituted β-diketonate ancillary ligands

• Rebecca Pittkowski and
• Thomas Strassner

Beilstein J. Org. Chem. 2018, 14, 664–671, doi:10.3762/bjoc.14.54

• and 100% amorphous film measurements, see Figures S1, S2 and Tables S2, S3 in Supporting Information File 1), which can be assigned to the steric demand of the aryl-substituted diketonate counter ligand. Cyclic voltammograms of complexes 2 and 3 were measured in DMF with ferrocene as an internal

• V vs ferrocene for both complexes. No reduction was observed for both complexes in the electrochemical window of the solvent. Thus, the electrochemical behavior of the newly synthesized substances is comparable. Discussion Compared to the already published, structurally related 3-methyl-1

Recent applications of click chemistry for the functionalization of gold nanoparticles and their conversion to glyco-gold nanoparticles

• Vivek Poonthiyil,
• Thisbe K. Lindhorst,
• Vladimir B. Golovko and
• Antony J. Fairbanks

Beilstein J. Org. Chem. 2018, 14, 11–24, doi:10.3762/bjoc.14.2

• substitution by reaction with NaN3 then resulted in AuNPs with mixed monolayers containing 52% N3- and 44% CH3-terminated alkanethiol ligands. A series of alkynes were synthesised, including derivatives of nitrobenzene (1), ferrocene (2), anthracene (3), pyrene (4), aniline (5), and polyethylene glycol (6) all

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

• -photon absorbers (2PA). In this respect, the central DPP bicyclic lactam is often decorated with electron donors such as alkoxy- or dialkylamino groups [11][12], triphenylamine [13][14], heterocyclic carbazole [15], thiophene [16][17], furan [18], and organometallic ferrocene [19]. 2PA-active DPPs were

• report herein the systematic modification of the 3,6-dithienyl-2,5-dihydropyrrolo[3,4-c]pyrrole-1,4-dione central acceptor with N,N-dimethylanilino (DMA), methoxyphenyl, thiophene, methoxythiophene, and ferrocene peripheral electron donors (Figure 1). Fundamental properties of D–π–A–π–D chromophores 1–5

• chromatography without a need of further crystallization. Hence, this ferrocene derivative was prepared with the highest yield of 73%. In the solid state, all target chromophores resemble dark metallic solids. Differential scanning calorimetry The thermal behaviour of compounds 1–5b was studied by differential

New electroactive asymmetrical chalcones and therefrom derived 2-amino- / 2-(1H-pyrrol-1-yl)pyrimidines, containing an N-[ω-(4-methoxyphenoxy)alkyl]carbazole fragment: synthesis, optical and electrochemical properties

• Daria G. Selivanova,
• Alexei A. Gorbunov,
• Olga A. Mayorova,
• Alexander N. Vasyanin,
• Igor V. Lunegov,
• Elena V. Shklyaeva and
• Georgii G. Abashev

Beilstein J. Org. Chem. 2017, 13, 1583–1595, doi:10.3762/bjoc.13.158

• -electrode cell (RE – Ag|AgCl; SE – Pt wire; WE – carbon-pyroceramic disk or an ITO-covered glass plate). The redox potentials are referenced to the ferrocene/ferrocenium couple (Fc/Fc+). The data are presented in Figure 7 and Figure 8 and summarized in Table 3. The first cycle of the 9-[ω-(4-methoxyphenoxy

Molecular-level architectural design using benzothiadiazole-based polymers for photovoltaic applications

• Vinila N. Viswanathan,
• Arun D. Rao,
• Upendra K. Pandey,
• Arul Varman Kesavan and
• Praveen C. Ramamurthy

Beilstein J. Org. Chem. 2017, 13, 863–873, doi:10.3762/bjoc.13.87

• Ag/AgCl as the reference electrode in acetonitrile with 0.1 M tetrabutylammonium hexafluorophosphate as electrolyte at a scan rate of 100 mV/s. The instrument was calibrated with ferrocene/ferrocenium and was found to be ≈0.11 V. The HOMO–LUMO energy levels were calculated using the following

A versatile route to polythiophenes with functional pendant groups using alkyne chemistry

• Xiao Huang,
• Li Yang,
• Rikard Emanuelsson,
• Jonas Bergquist,
• Maria Strømme,
• Martin Sjödin and
• Adolf Gogoll

Beilstein J. Org. Chem. 2016, 12, 2682–2688, doi:10.3762/bjoc.12.265

• from −1.2 to 0.6 V vs ferrocene/ferrocenium (Fc+/Fc0) during polymerization cycling. Apparently, the presence of an ethynyl group on pyEDOT did not disturb the polymerization of the EDOT backbone. The CVs of pyEDOT indicated an irreversible reduction reaction at a potential lower than −2.4 V vs Fc+/Fc0

Synthesis and characterization of fluorinated azadipyrromethene complexes as acceptors for organic photovoltaics

• Forrest S. Etheridge,
• Roshan J. Fernando,
• Sandra Pejić,
• Matthias Zeller and
• Geneviève Sauvé

Beilstein J. Org. Chem. 2016, 12, 1925–1938, doi:10.3762/bjoc.12.182

• are observed at 669 and 800 nm, respectively. Compared to λmax of BF2(WS3), BF2(L4) exhibits a large hypsochromic shift of 33 nm. Electrochemistry Cyclic voltammetry of the zinc(II) and BF2+ chelates was studied in dichloromethane solutions using ferrocene/ferricinium (Fc/Fc+) as an internal reference

• tetra-n-butylammonium hexafluorophosphate (TBAPF6) in DCM. Ferrocene/ferrocenium was used as an internal standard and was purified prior to use by sublimation. A typical three-electrode configuration was used, with a glassy carbon electrode as the working electrode and two platinum wires used as the

Experimental and theoretical investigations on the high-electron donor character of pyrido-annelated N-heterocyclic carbenes

• Michael Nonnenmacher,
• Dominik M. Buck and
• Doris Kunz

Beilstein J. Org. Chem. 2016, 12, 1884–1896, doi:10.3762/bjoc.12.178

• most common types of NHC ligands L. A graphical illustration of these values is depicted in Figure 3. It shows that the dipyrido-annelated carbenes have an overall donor capacity that lies in between that of acyclic (Ia) or ferrocene bridged (Ib) diaminocarbenes and saturated imidazolidin-2-ylidenes

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

• the CV results are also listed in Table 1. The frontier molecular orbital energy levels (HOMO/LUMO) and also the energy band gaps of these compounds were calculated according to the method reported in our previous paper [20], where the ferrocene/ferrocenium couple (Fc+/Fc) was used as the standard

Synthesis and characterization of benzodithiophene and benzotriazole-based polymers for photovoltaic applications

• Desta Gedefaw,
• Marta Tessarolo,
• Margherita Bolognesi,
• Mario Prosa,
• Renee Kroon,
• Wenliu Zhuang,
• Patrik Henriksson,
• Kim Bini,
• Ergang Wang,
• Michele Muccini,
• Mirko Seri and
• Mats R. Andersson

Beilstein J. Org. Chem. 2016, 12, 1629–1637, doi:10.3762/bjoc.12.160

• was calibrated by measuring the ferrocene/ferrocenium (Fc/Fc+) redox peak. The HOMO and LUMO energy levels of the polymers and electron acceptors were calculated from the peak values of the third scans by setting the oxidative peak potential of Fc/Fc+ vs the normal-hydrogen electrode (NHE) to 0.630 V

Synthesis of ferrocenyl-substituted 1,3-dithiolanes via [3 + 2]-cycloadditions of ferrocenyl hetaryl thioketones with thiocarbonyl S-methanides

• Grzegorz Mlostoń,
• Róża Hamera-Fałdyga,
• Anthony Linden and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2016, 12, 1421–1427, doi:10.3762/bjoc.12.136

• ; ferrocene; thiocarbonyl S-methanides; thioketones; Introduction In a recent publication, a straightforward method for the synthesis of hitherto little known ferrocenyl aryl/hetaryl thioketones of type 1 via a standard procedure by treatment of the corresponding ferrocenyl ketones with Lawesson reagent was

• described [1]. The latter substrates were prepared efficiently via acylation of ferrocene with in situ generated mixed anhydrides containing a trifluoroacetyl unit or, alternatively, by ferrocenylation of furan, thiophene or selenophene with mixed trifluoroacetyl anhydride. The obtained ferrocenyl