Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• ; electrochemistry; hypervalent bromine; Introduction Chemistry of hypervalent bromine(III) species has experienced rapid advancements during the recent years [1][2]. The remarkable nucleofugality of aryl bromides in hypervalent bromine(III) compounds has been exploited in the generation of arynes from cyclic

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

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

• stabilization of such redox states. Results and Discussion Electrochemistry Figure 2 shows the electrochemical cyclic voltammograms of 1 and 2, in which two reversible oxidation processes can be observed. By considering the half-wave potential values obtained from the cyclic voltammograms, two one-electron

• 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

• chemistry. Combining electrochemistry with transition-metal catalysis is a promising and rapidly growing methodology for effectively forming challenging C–C and C–heteroatom bonds in complex molecules in a sustainable manner. In this review, we summarize the recent advances in the combination of

• electrochemistry and copper catalysis for various organic transformations. Keywords: copper; electrochemistry; radical chemistry; single-electron transfer; sustainable catalysis; Introduction Transition-metal-catalyzed cross-coupling has emerged as an effective method for forming carbon–carbon (C–C) and carbon

• ’ and Fu’s asymmetric C–N bond cross-coupling reactions by merging photoredox catalysis with copper catalysis [29][30]. Building on the success of photoredox catalysis, electrochemistry has emerged as a complementary and attractive strategy for promoting sustainability of organic synthesis. By offering

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• , cells that allow for the coupling of SAS with non-X-ray techniques continue to be developed; these include spectroscopy, rheology, and electrochemistry [62][63][64]. Ascribing changes in properties of interest directly to changes in the structure further elucidates the interesting properties of self

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

• representative examples to illustrate the potential of electrochemistry or photoelectrochemistry for the LSF of valuable molecular scaffolds. Keywords: electrochemistry; late-stage functionalization; paired electrolysis; pharmaceutical drugs; photoelectrochemistry; Introduction Organic electrochemistry is

• [3]. Transition-metal-catalyzed LSF strategies have been well-established over the past decades. More recently, with the vigorous development of photochemistry and electrochemistry, numerous innovative reports on LSF using photo-, electro-, and photoelectrochemistry have emerged. These areas have

• , which reported the merger of electrochemistry and bioconjugation in 2018 (Scheme 4b) [11]. In 2020, Zheng and coworkers developed an interesting iodoamination of indoles using unactivated amines and benzotriazoles [12]. This difunctionalization reaction was carried out in an undivided cell with an RVC

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• the potential for chemical non-innocence of fluorinated alcohol solvents in NGT catalysis. Keywords: aziridination; electrochemistry; H-bond activation; hypervalent iodine; nitrene transfer; Introduction Hypervalent iodine reagents find widespread application in selective oxidation chemistry due to

gem-Difluorination of carbon–carbon triple bonds using Brønsted acid/Bu₄NBF₄ or electrogenerated acid

• Mizuki Yamaguchi,
• Hiroki Shimao,
• Kengo Hamasaki,
• Keiji Nishiwaki,
• Shigenori Kashimura and
• Kouichi Matsumoto

Beilstein J. Org. Chem. 2024, 20, 2261–2269, doi:10.3762/bjoc.20.194

• containing alkyne substrates could also give the corresponding gem-difluorinated compounds (in-cell method). The ex-cell electrolysis method was also applicable for gem-difluorination of alkynes. Keywords: carbon–carbon triple bonds; chemical method; electrochemistry; gem-difluorination; Introduction

• solution of Bu4NBF4/CH2Cl2 containing substrates might also promote the same reactions (Figure 1, reaction 6, electrochemical method). Currently, electrochemistry can be regarded as a promising technique in organic synthesis, because heavy-metal reagents can be avoided for the oxidation or reduction of

Electrochemical allylations in a deep eutectic solvent

• Sophia Taylor and
• Scott T. Handy

Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189

• time, electrosynthesis requires a solvent and a supporting electrolyte in order for current to pass through the reaction. These are effectively consumable reagents unless a convenient means of recycling can be developed. As part of our interest in unusual solvents and electrochemistry, we explored the

• used, offering an interesting new option for electrochemical allylations. Keywords: allylation; electrosynthesis; eutectic solvent; recycling; tin; Introduction The last several years have witnessed a tremendous resurgence of interest in electrochemistry in the area of organic synthesis [1]. While

• , however, RTILs are expensive compared to conventional solvents. Most of them are also quite viscous, which severely limits their use in synthetic electrochemistry [16]. These same expense and viscosity issues plague the application of RTILs in any area. Driven by this limitation, deep eutectic solvents

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• their place among the efficient and robust catalysts on numerous occasions since the two seminal works [1][2] published in 2000. Since then, organocatalysis has been combined with many other areas of research, such as photocatalysis, electrochemistry and mechanochemistry [3][4][5], while List and

Electrochemical radical cation aza-Wacker cyclizations

• Sota Adachi and
• Yohei Okada

Beilstein J. Org. Chem. 2024, 20, 1900–1905, doi:10.3762/bjoc.20.165

• aza-Wacker cyclizations under acidic conditions, which are expected to proceed via radical cations generated by single-electron oxidation of alkenes. Keywords: alkene; aza-Wacker cyclization; electrochemistry; radical cation; sulfonamide; Introduction Activating bench-stable substrates is the first

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

• estitmation of the HOMO/LUMO energies to shed more light on this transformation. The easy separation of the supporting electrolyte from the product will allow recycling and makes this a green transformation. Keywords: acetal formation; cyclic voltammetry; flow electrochemistry; green oxidation; polycyclic

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• mechanistic strategies, namely, electrophilic, radical and nucleophilic approaches, and highlighted when emerging technologies, such as photo- and electrochemistry effect the desired transformation [22][27]. Review Electrophilic benzylic C(sp3)–H fluorination Base mediated Electrophilic fluorinating reagents

• and oxidation potentials. Electrochemical methods Synthetic electrochemistry is a powerful tool offering excellent control over reaction kinetics and selectivity [86]. Electrochemical oxidation has been demonstrated as an efficient means for generating benzylic cations, allowing for the introduction

• under the cell potentials required to initiate the first single-electron transfer, resulting in benzylic cation IV [89][90]. This species can then be captured by fluoride to give benzylic fluoride product V. HF·amine ionic liquids are a popular choice of fluoride source in organic electrochemistry as

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

• method, we conducted the reaction with ibuprofen on a 3.0 mmol scale and obtained product 3 in 78% isolated yield. More importantly, the extremely mild reaction conditions imparted by the combination of electrochemistry and photochemistry made accessible a broad range of products with functionalities

Transition-metal-catalyst-free electroreductive alkene hydroarylation with aryl halides under visible-light irradiation

• Kosuke Yamamoto,
• Kazuhisa Arita,
• Masami Kuriyama and
• Osamu Onomura

Beilstein J. Org. Chem. 2024, 20, 1327–1333, doi:10.3762/bjoc.20.116

• -light-mediated alkene hydroarylation commonly requires external reductants and/or hydrogen atom sources to complete the catalytic cycle [21][22][23][24][25]. Over the past few decades, electrochemistry has proven to be an environmentally benign and convenient approach for accessing open-shell

• . Recently, the groups of Lin and Lambert [48] and Wickens [49] independently demonstrated that aryl chlorides with highly negative reduction potentials engaged in C–X (X = P, Sn, B) and C–C bond formation reactions involving aryl radical species by integrating photochemistry and electrochemistry [50][51][52

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• years and in the past, they were perceived as fleeting reaction intermediates. Recent progress in photoredox catalysis [6][7][8], electrochemistry [9][10], and the use of transition-metal (TM) catalysts in radical cross-coupling reactions [11] have dramatically expanded the use of radicals in synthesis

• reductant (typically Zn0 or Mn0) to both activate the NHPI ester and turn-over the catalytic cycle. However, the merger of Ni-catalysis and electrochemistry allows for the implementation of more convenient conditions in which these two crucial reductive steps can be mediated by the cathode (Scheme 34). In

• advancements in photochemistry, TM catalysis, NHC catalysis, and electrochemistry to show the generality of these RAEs in diverse mechanistic paradigms. Their application as radical progenitors continues to broaden the scope of radical-mediated reactions, especially in complex molecular settings, where issues

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• Pengcheng Li Daniel Kowalczyk Johannes Liessem Mohamed M. Elnagar Dariusz Mitoraj Radim Beranek Dirk Ziegenbalg Institute of Chemical Engineering, Ulm University, Albert-Einstein-Allee 11, 89081 Ulm, Germany Institute of Electrochemistry, Ulm University, Albert-Einstein-Allee 47, 89081 Ulm

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

• (without an acetylenic moiety as in 20) are themselves poor photosensitizers for singlet oxygen. Electrochemistry Cyclic voltammograms of compounds 11, 13, 15, 16, and 17 (in MeCN for compounds 11 and 15 and in CH2Cl2 for compounds 13, 16, and 17, all with 0.1 M Bu4NPF6 as supporting electrolyte) are shown

• Cary 50 UV–vis spectrophotometer scanning between 800 and 200 nm. All spectra were recorded with baseline correction in CH2Cl2 or toluene (HPLC grades) at 25 °C in a quartz cuvette with a 10 mm path length. Electrochemistry Cyclic voltammograms (CV) and differential pulse voltammograms (DPV) were

Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts

• Nils Clamor,
• Mattis Damrath,
• Thomas J. Kuczmera,
• Daniel Duvinage and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2

• fluorophors, previously shown to exhibit strong organic phosphorescence when mixed with specific additives [1][2][3][4][5]. Carbazole units are also found in drugs and natural products. They are also used in electrochemistry and as reagents in transamidation reactions [6][7][8][9][10][11][12]. The traditional

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• complex organic compounds, widely used both in organic chemistry and in electrochemistry as raw materials for the preparation of different molecules of pharmaceutical and industrial interest [1][2][3][4][5][6][7][8][9]. Among the different organic transformations involving alkynes, their hydration is a

• [90][91]. Due to their wide electrochemical window, imidazolium ILs are commonly used in organic electrochemistry, simultaneously as solvents and supporting electrolytes [92][93][94]. In addition, the cathodic reduction (both in batch [95] and in flow [96]) can be exploited for the generation of N

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

• . Their electrochemistry and reactivity were compared to those derived from 2-(4-(dimethylamino)phenyl)- (1b+) and 2-cyclohexylbenzo[d]imidazolium (1e+) salts. E(1+/1•) values for 2-aryl species are less reducing than for 2-alkyl analogues, i.e., the radicals are stabilized more by aryl groups than the

• donors (1gH, 1hH, 1iH). We also report crystal structures of several of these compounds and of several salts of the corresponding 1+ cations, and compare the electrochemistry and reactivity of these species. Results and Discussion Synthesis Although an unsymmetrical 12-like molecule, 2-diethoxyphosphoryl

• crystallographically characterized. Electrochemistry The 1+, 1H, and 12 species were investigated using cyclic voltammetry in THF/0.1 M Bu4NPF6 at a scan rate of 50 mV s−1. The voltammograms (shown for one series of compounds in Figure 6) were qualitatively similar to those reported and shown elsewhere for other

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

• commercialized. Specifically, the company Twelve are making large advances in the electrolysis of carbon dioxide to carbon monoxide. Their contracts started with materials and have now expanded to fuels [10]. However, industrial electrochemistry either requires a dedicated power source, or plugging into a

• . Carpenter and co-workers also proposed, but did not test, recycling their amine with electrochemistry and light [32]. They cited a work by Itoh et al. who modified a proton exchange membrane electrolyzer with a Rh–Pt catalyst to generate hydrogen from water to hydrogenate benzene to cyclohexane in one

Selective and scalable oxygenation of heteroatoms using the elements of nature: air, water, and light

• Damiano Diprima,
• Hannes Gemoets,
• Stefano Bonciolini and
• Koen Van Aken

Beilstein J. Org. Chem. 2023, 19, 1146–1154, doi:10.3762/bjoc.19.82

• [23][24] and methods for oxidation such as photochemistry, or electrochemistry have been developed [2][25]. However, low selectivity and the need for appropriate catalysts that are stable, cost-effective, and easy to remove remain problematic. Recently, catalyst-free procedures using O2 or air have

• separate” additives, a significant rate enhancement could be obtained with a positive impact on productivity rates. Results and Discussion There are a lot of similarities between electrochemistry and photoredox chemistry [33] as both rely on single-electron transfer processes to initiate reactions. In

• electrochemistry, the electron transfer occurs locally at the surface of the physical electrodes (typically located at a distance in the range of 200 μm to 2 cm) on which a potential is induced by an external potentiostat (Scheme 2). While for photoredox chemistry, the light-activated semiconductor catalyst