Oxidation of [3]naphthylenes to cations and dications converts local paratropicity into global diatropicity

• Abel Cárdenas,
• Zexin Jin,
• Yong Ni,
• Jishan Wu,
• Yan Xia,
• Francisco Javier Ramírez and
• Juan Casado

Beilstein J. Org. Chem. 2025, 21, 277–285, doi:10.3762/bjoc.21.20

• Electrochemistry Cyclic voltammetry experiments were conducted with a three-electrode geometry operating with a glassy carbon as the working electrode. A Pt-coil counter electrode. and an Ag wire, as the pseudo-reference, were used. Potential values are given with respect to the ferrocene/ferrocenium (Fc/Fc

Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• enantioselective C–H alkynylation of ferrocene carboxamides with terminal alkynes by using Cu/BINOL and an electrocatalytic system (Figure 5) [49]. 8-Aminoquinoline-assisted C–H functionalization provided planar chiral ferrocenes with high yield and enantioselectivity. This reaction can be applied to a wide range

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• one reversible oxidation wave and one quasi-reversible oxidation wave with half-wave potentials of 0.40 V and 0.88 V, respectively, versus ferrocenium/ferrocene (Fc+/Fc). The HOMO energy level is estimated from the first oxidation peak to be −5.5 eV [28], which is consistent with the DFT-calculated

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• )porphyrin, H2FAP), and 18 (5,10,15,20-meso-tetraphenylporphyrin, H2TPP) can catalyze oxygen reduction to H2O2 using ferrocene-based electron donors [ferrocene (Fc) and decamethylferrocene (DMFc)] at acidified water/1,2-dichloroethane (DCE) interface [115][117]. This two-phasic oxygen reduction undergoes via

• binding of O2 to diprotonated forms of porphyrins, 1092+ (H4FAP2+) and 182+ (H4TPP2+), which are then reduced in the organic phase by ferrocene-based reductants, resulting in H2O2, Fc+/DMFc+, and the respective metal-free porphyrin macrocycle (Figure 20a and b). The conditions of homogeneous O2 reduction

• the UV–vis spectrum revealed a red shift, indicating the presence of diprotonated H4TPP2+ macrocycle (Figure 21a). Fc addition into an air-saturated DCE solution containing 18 (H2TPP) and HTB led to oxidation of Fc to Fc+ and initiated the ORR process (Figure 20b). The rate of ferrocene oxidation (Fc

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• Instutite for Liberal Arts and Sciences (ILAS), Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan 10.3762/bjoc.20.231 Abstract We have reported that upon visible light irradiation, ferrocene-porphyrin-[60]fullerene triad molecules yield long-lived charge-separated states, enabling the control of the plasma

• an acceptor in photoinduced charge-separation systems, we have previously employed ferrocene-porphyrin-C60 triad molecules (Figure 1a) in a biological system to control the plasma membrane potential (Vm) of living mammalian neuronal cells under photoirradiation [4][5][6]. Generally, Vm originates

• from a difference in electric charge on the two sides of the plasma membrane (approximately 5 nm thickness), with a slight excess of the positive ions inside relative to the negative ions outside. Our ferrocene-porphyrin-C60 triad molecule exhibited long-lived charge-separated states under visible

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• mechanism starts with the formation of a nickel-chelated enolate intermediate, followed by the anodic oxidation to form the nickel-coordinated carbon-centered radical intermediate. Another mechanism is proposed for alkyl-substituted acylimidazoles. In this case, the additive ferrocene (Cp2Fe) serves as

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• employed ferrocene as electrocatalyst instead of iodide salts. Additionally, Tang et al. demonstrated that amidines could react with preformed aldehydes-derived hydrazones to produce similar 1,3,5-trisubstituted 1,2,4-triazoles [54]. The last example of electrochemical synthesis of trisubstituted 1,2,4

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• hexafluorophosphate ([NBu4] [PF6]) solution in acetonitrile. The solvent was dried and degassed using N2 prior to each experiment. All experiments were conducted at room temperature. All redox potentials were calibrated against ferrocene/ferrocenium (Fc/Fc+) redox couple. Cyclic voltammograms of PAPs first scan at

Electrophotochemical metal-catalyzed synthesis of alkylnitriles from simple aliphatic carboxylic acids

• Yukang Wang,
• Yan Yao and
• Niankai Fu

Beilstein J. Org. Chem. 2024, 20, 1497–1503, doi:10.3762/bjoc.20.133

• plate as the cathode, was electrolyzed with a cell potential of 2.3 V (corresponding to an initial anodic potential of 0.10 V versus the ferrocenium ion/ferrocene redox couple) under the irradiation of 400 nm light-emitting diodes (LEDs). Through systematic optimization, we found that the use of readily

Two-fold addition reaction of silylene to C₆₀: structural and electronic properties of a bis-adduct

• Masahiro Kako,
• Masato Kai,
• Masanori Yasui,
• Michio Yamada,
• Yutaka Maeda and
• Takeshi Akasaka

Beilstein J. Org. Chem. 2024, 20, 1179–1188, doi:10.3762/bjoc.20.100

• on a BAS CV50W electrochemical analyzer (BAS Inc.). The reference electrode was a saturated calomel reference electrode (SCE). The glassy carbon electrode was used as the working electrode, and a platinum wire was used as the counter electrode. All potentials are referenced to the ferrocene

• ) level. Hydrogen atoms are omitted for clarity. Cyclic voltammograms (CV) and differential pulse voltammograms (DPV) of 3 in o-dichlorobenzene containing 0.1 M (n-Bu)4NPF6. In DPVs, peaks of the adducts are denoted by circles. Potentials are shown in volts relative to the ferrocene/ferrocenium couple

Spin and charge interactions between nanographene host and ferrocene

• Akira Suzuki,
• Yuya Miyake,
• Ryoga Shibata and
• Kazuyuki Takai

Beilstein J. Org. Chem. 2024, 20, 1011–1019, doi:10.3762/bjoc.20.89

• Akira Suzuki Yuya Miyake Ryoga Shibata Kazuyuki Takai Graduated School of Science and Engineering, Hosei University, Tokyo 184-8584, Japan Department of Chemical Science and Technology, Hosei University, Tokyo 184-8584, Japan 10.3762/bjoc.20.89 Abstract Ferrocene (FeCp2) was introduced as a non

• interactions between the nanographene host and the guest molecules will be a promising strategy for developing a new class of molecular magnets. Keywords: charge transfer; ferrocene; graphene; host–guest; spin interaction; Introduction Nanocarbon host material, which is based on elements free from resource

• . Ferrocene (FeCp2) is a “sandwich” compound where the two cyclopentadienyl (Cp or C5H5-) rings sit above and below the Fe2+ ion [16]. The electronic structure of FeCp2 satisfies the 18-electron rule, so this compound is stable due to a closed L-shell structure in view of the atomic orbitals of Fe and it is a

Enhanced reactivity of Li⁺@C₆₀ toward thermal [2 + 2] cycloaddition by encapsulated Li⁺ Lewis acid

• Hiroshi Ueno,
• Yu Yamazaki,
• Hiroshi Okada,
• Fuminori Misaizu,
• Ken Kokubo and
• Hidehiro Sakurai

Beilstein J. Org. Chem. 2024, 20, 653–660, doi:10.3762/bjoc.20.58

• photoirradiation at room temperature. 1H-1H 2D-NOESY NMR spectrum (600 MHz, CD2Cl2) of 5a (a) and NOE correlations between two protons. The spectrum (700 MHz, CD2Cl2) of 5b is shown in (b). Cyclic voltammograms of 5a, 5b, and Li+@C60 TFSI− with the potentials relative to the ferrocene/ferrocenium (Fc/Fc

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• (diphenylphosphino)ferrocene, SPhos = 2-dicyclohexylphosphino-2',6'-dimethoxybiphenyl, APDTC = ammonium pyrrolidinedithiocarbamate. Evaluation of potential side reactions in the borane-mediated preparation of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridine 13c. Preparation of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 7a–c

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• a 1,2-dichloroethane solution of a sample containing 0.10 mol L−1 Bu4N+ B(C6F5)4−. The cyclic voltammogram of the complex showed one reversible oxidation wave of [10]CPP at 0.92 V versus (vs) ferrocene/ferrocenium couple (Fc/Fc+) (Figure 3a), which was positively shifted by 0.13 V from that of

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• exemplified by the emergence of a maximum absorption peak at 1,024 nm, indicating the one-electron reduced form of C60. Although the observation of the oxidation process of the ferrocene unit was obstructed by the more substantial absorption changes associated with fullerene reduction, the lifetimes of the

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• in Figure 6, and potentials against ferrocene (Fc/Fc+) (obtained from differential pulse voltammetry, see Supporting Information File 1) are summarized in Table 2. Compounds 11 and 15 showed two irreversible first oxidations at +0.34 V and +0.38 V vs Fc/Fc+, showing that replacing the ketone with the

• platinum disk (diameter = 1.6 mm) or a glassy carbon disk (3 mm) was used as the working electrode. The reference electrode was separated from the solution containing the substrate by a ceramic frit. Measured potentials were referenced to ferrocene/ferrocenium (Fc/Fc+) redox couple, measured before and

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• strong reductants with effective potentials of ca. −2 V vs ferrocenium/ferrocene, yet are relatively stable to air due to the coupling of redox and bond-breaking processes. Here, we examine their use in accomplishing electron transfer-induced bond-cleavage reactions, specifically dehalogenations. The

• dimers reduce halides that have reduction potentials less cathodic than ca. −2 V vs ferrocenium/ferrocene, especially under UV photoexcitation (using a 365 nm LED). In the case of benzyl halides, the products are bibenzyl derivatives, whereas aryl halides are reduced to the corresponding arenes. The

• to initiate the coupling of aryl halides and arenes [5]. However, even relatively easily reduced organic halides have sufficiently cathodic reduction potentials (e.g., ca. −1.6 V and −1.8 vs ferrocenium/ferrocene (FeCp2+/0) for diethyl bromomalonate [6] and 4-iodotoluene, see Table 2, respectively

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• using ferrocene (Fc) as inner standard. The CV curves are shown in Figure 6 and the data are collected in Table 1. The reduction onset potentials (Ered,onset) of compounds 6–9 fall in the range from −1.63 to −1.47 V, while the onset values of the first oxidation wave range from 1.02 to 1.09 V. The

• as a quasireference electrode, while a platinum wire served as a counter electrode to facilitate the redox reactions. For calibration purposes, the potentials were standardized using the standard ferrocene/ferrocenium (Fc/Fc+) redox system, a well-known and widely used reference for establishing

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• profile of redox processes (Figure 4a, black lines). In particular, two irreversible reductions occur at the cathodic potentials −1.53 V and −1.9 V versus ferrocene. These electrochemical processes may correspond to the first and second reduction of the metal core Co(II)/Co(I) and Co(I)/Co(0

• ) ferrocene and (b) decamethylferrocene. Scan rate was 100 mV s−1. Time evolution of CO (blue squares) and H2 (red triangles) with the power functional fitting (blue and red curve, respectively). Data were collected for photocatalytic tests in 5 mL DMA/TEA 7:1, [PS] = 0.5 mM; [1] = 0.025 mM; [BIH] = 10 mM

Benzoimidazolium-derived dimeric and hydride n-dopants for organic electron-transport materials: impact of substitution on structures, electrochemistry, and reactivity

• Swagat K. Mohapatra,
• Khaled Al Kurdi,
• Samik Jhulki,
• Georgii Bogdanov,
• John Bacsa,
• Maxwell Conte,
• Tatiana V. Timofeeva,
• Seth R. Marder and
• Stephen Barlow

Beilstein J. Org. Chem. 2023, 19, 1651–1663, doi:10.3762/bjoc.19.121

• , 0.1 M Bu4NPF6) of 1g+PF6–, 1gH, and 1g2, in each case containing ferrocene as an internal reference. Black arrows indicate the starting point and scan initial direction for each voltammograms. Note that the oxidation peak of 1g2 is seen in the voltammogram of 1g+PF6– following scanning of the

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• GCE was left to air dry and residual traces of water were removed under vacuum. The Ag wire pseudoreference electrodes were calibrated to the ferrocene/ferrocenium couple in THF at the end of each run to allow for any drift in potential, following IUPAC recommendations [16]. All electrochemical

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• who used a similar photocatalyst to systematically study ferrocene derivatives as sacrificial donors [31]. The ferrocene derivatives reductively quenched the photosensitizer but could not accumulate as effectively as the BIH derivatives used by Gimeno et al. [29][31]. In contrast, Z-schemes that

• recyclable amine species for comparison [32]. The ferrocene, TEMPO, and viologen derivatives shown in Figure 4 are used in aqueous organic redox flow batteries [59][63]. The batteries store charge in concentrated aqueous solutions of small organic redox mediators that can be oxidized and re-reduced (or

• . TEMPO and ferrocene derivatives are used to store positive charge in RFB catholytes [59][63]. Both parent compounds undergo reversible one-electron oxidation and re-reduction but had to be modified to improve their solubility. TEMPTMA and both ferrocene derivatives have one or more ammonium groups added

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• -purged saturated solutions containing 0.10 M Bu4NPF6 as a supporting electrolyte, a platinum electrode as counter electrode, a glassy carbon electrode as working electrode, and the Ag/AgNO3 (0.1 M in ACN) couple as the reference electrode. Ferrocenium/ferrocene (Fc+/Fc) redox couple was used as an

• ; NI-PTZ-C5-O in deaerated ACN. Ferrocene (Fc) was used as internal reference (set as 0 V in the cyclic voltammograms), 0.10 M Bu4NPF6 as supporting electrolyte, scan rates: 100 mV/s, c = 1.0 × 10−3 M, 20 °C. Thermogravimetric analysis curves of NI-PTZ-F, NI-PTZ-Ph, NI-PTZ-CH3, NI-PTZ-OCH3, NI-PTZ-F-O

Light-responsive rotaxane-based materials: inducing motion in the solid state

• Adrian Saura-Sanmartin

Beilstein J. Org. Chem. 2023, 19, 873–880, doi:10.3762/bjoc.19.64

• of rotaxanes in crystalline molecular solids has been studied [38][39]. Rotaxane crystals bearing ferrocene motifs experienced elongation and contraction along the axes in a rapid and reversible manner by simply turning on and off a laser light irradiation, thus providing enough free space in order

• azobenzene and ferrocene motifs (Figure 1a). The azobenzene scaffolds play a dual role, both as the engine transforming photoenergy into mechanical motion via trans/cis photoisomerization upon UV light input and as a modulator of the crystalline packing by varying the para-substituent R1, which leads to