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

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

• Hisanori Senboku and
• Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

• diarylacetic acids from diarylmethanol species and carbon dioxide without transformation of the hydroxy group into appropriate leaving groups, such as halides and esters including carbonates. Keywords: C(sp3)–O bond cleavage; diarylacetic acid; diarylmethanol; electrochemical reduction; fixation of carbon

• dioxide; Introduction Electrochemical reduction of benzyl alcohol derivatives can induce reductive cleavage of a C(sp3)–O bond [1] at the benzylic position to generate the corresponding benzylic anion species. This protocol has been frequently applied to electrochemical carboxylation [2][3][4][5][6][7][8

• ][9][10][11], yielding phenylacetic acids. For example, Troupel et al. successfully performed electrochemical reduction of benzyl ethers and several esters such as acetate, trifluoroacetate, benzoate, and dibenzyl carbonate derived from benzyl alcohols, including 1-phenylethanol compounds, in the

Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor

• Koichi Mitsudo,
• Atsushi Osaki,
• Haruka Inoue,
• Eisuke Sato,
• Naoki Shida,
• Mahito Atobe and
• Seiji Suga

Beilstein J. Org. Chem. 2024, 20, 1560–1571, doi:10.3762/bjoc.20.139

• of 3a. Based on this hypothesis, we examined the reduction of 1a in the presence of several acids (Table 2). First, electrochemical reduction was performed with 0.2 or 1.0 equiv of acetic acid, but the yield of 3a did not decrease, suggesting that 2a could not be trapped by acetic acid (pKa = 4.75

• increase of the electricity to 16.0 F mol−1, 2a was obtained selectively in 88% yield (Table 2, entry 6). Next, we examined the scope of the electrochemical reduction of cyanoarenes under optimal conditions (Scheme 2). The reactions of cyanoarenes bearing electron-donating methyl, hydroxy, and methoxy

• groups proceeded smoothly to afford the corresponding benzylamines 2b–d in moderate-to-good yields. Electron-withdrawing groups, such as esters, can be tolerated under these conditions. Unfortunately, the electrochemical reduction of 1,4-dicyanobenzene (1f) did not give the desired product 2f probably

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

• achieved by chemical (hydroxide/proton) or electrochemical (reduction/oxidation) stimuli allowing the enrichment of perylene from a mixture of polycyclic aromatic hydrocarbons (PAHs) in phase-transfer experiments into a perfluorocarbon phase. Metal cation responsive tweezers In the early 2000s, Lehn and co

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• diazonium salts produces highly reactive aryl radicals (Scheme 18) [153]. The chemical conversion can be initiated by electrochemical reduction [154], a reducing agent [155][156][157], a base [158], heating [159], or photochemically [160]. Aryl radicals may act as a halogen abstractor for alkyl halides and

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

• charge recombination via unproductive back electron transfer (PC•− + D•+ → PC + D), preventing the second excitation. The prevalence of this charge recombination process in conPET effectively regulates a lower steady-state concentration of active photocatalyst compared to PEC where the electrochemical

• reduction to PC•− ensures higher concentrations that are directly user-influenced. Upon activation, PC1 could successfully reduce various aryl halides generating borylated products in modest to excellent (30–99%) yields. Control experiments confirmed that light, catalyst and DBU as a sacrificial electron

Reductive opening of a cyclopropane ring in the Ni(II) coordination environment: a route to functionalized dehydroalanine and cysteine derivatives

• Oleg A. Levitskiy,
• Olga I. Aglamazova,
• Yuri K. Grishin and
• Tatiana V. Magdesieva

Beilstein J. Org. Chem. 2022, 18, 1166–1176, doi:10.3762/bjoc.18.121

• almost independent on the substituent at the α-carbon atom in the amino acid fragment. Electrochemical reduction of complexes containing an unsubstituted cyclopropane ring (1) or bearing Me (2) substituents is similar to that for α-alkyl derivatives: they exhibit reversible one-electron reduction (the

• derivative are dependent on the electrolysis conditions used for the ring opening in complex 4 (8 mM) (GC, DMF, 0.09 M Bu4NBF4 or 0.8 M LiCl). Yield and diastereomeric ratio of the cysteine derivatives obtained in a one-pot electrochemical reduction (method B: −1.5 V (Ag/AgCl, KCl(sat.)), 4 (8 mM), Ph2N2 (8

Electrogenerated base-promoted cyclopropanation using alkyl 2-chloroacetates

• Kouichi Matsumoto,
• Yuta Hayashi,
• Kengo Hamasaki,
• Mizuki Matsuse,
• Hiyono Suzuki,
• Keiji Nishiwaki and
• Norihito Kawashita

Beilstein J. Org. Chem. 2022, 18, 1116–1122, doi:10.3762/bjoc.18.114

• , Kindai University 3-4-1 Kowakae, Higashi-osaka, Osaka 577-8502, Japan Department of Life Science, School of Science and Engineering, Kindai University, 3-4-1 Kowakae, Higashi-osaka, Osaka 577-8502, Japan 10.3762/bjoc.18.114 Abstract The electrochemical reduction conditions of the reaction of alkyl 2

• derivatives could be formed in moderate yields through the electrochemical reduction [13][14][15][16][17][18][19][20][21] of alkyl 2-chloroacetates in a divided cell (Scheme 1, reaction 4). The in Abushanab’s study utilized metal lithium is one of the rarest and most expensive metals. In addition, the

• investigation. Results and Discussion First, we investigated the reaction conditions for the electrochemical reduction to optimize the reaction outcome. The typical procedure is as follows: the electrochemical reduction was carried out in an H-type divided cell. Both electrodes were made from Pt plates. In the

Electrochemical hydrogenation of enones using a proton-exchange membrane reactor: selectivity and utility

• Koichi Mitsudo,
• Haruka Inoue,
• Yuta Niki,
• Eisuke Sato and
• Seiji Suga

Beilstein J. Org. Chem. 2022, 18, 1055–1061, doi:10.3762/bjoc.18.107

•  2b). As mentioned above, ketone 2a was obtained selectively with the use of a Pd/C catalyst for the cathode (Table 3, entry 1). To clarify the scope of the reaction, we carried out the electrochemical reduction of several enones 1 using Pd/C cathode catalyst (Scheme 2). After current was passed to

• subjected to electroreduction using the PEM reactor to afford ketones in high yield and selectivity. Electroreduction of enones to saturated alcohols We next examined the electrochemical reduction of several enones 1 to saturated alcohols 3 using an Ir/C catalyst for the cathode (Scheme 3). Full conversion

• system and shall report the results at a later time. Electrochemical setup of the PEM reactor: a) Electrochemical reduction system with the PEM reactor. b) Circulating electrochemical reduction system with the PEM reactor. Reaction profile of the electrochemical hydrogenation of 1a with a PEM reactor

Electrochemical Friedel–Crafts-type amidomethylation of arenes by a novel electrochemical oxidation system using a quasi-divided cell and trialkylammonium tetrafluoroborate

• Hisanori Senboku,
• Mizuki Hayama and
• Hidetoshi Matsuno

Beilstein J. Org. Chem. 2022, 18, 1040–1046, doi:10.3762/bjoc.18.105

• likely nucleophile in this reaction medium was the trifluoroacetate ion, which was produced by electrochemical reduction of TFA at the cathode, although we could not detect the coupling product of trifluoroacetate and the corresponding N-acyliminium ion due to the high solubility in water. In addition to

• proton source (supporting electrolyte), iPr2NHEtBF4, caused competitive electrochemical reduction of a proton and the N-benzyl group of 5b at the cathode. We also carried out electrochemical amidomethylation of indole (4c) and found that a mixture of 3-amidomethylated indole 5c and N,3-diamidomethylated

• amidomethylation is induced by electrolysis using a quasi-divided cell equipped with a Pt plate cathode (2 × 2 cm2) and a Pt wire anode (2 cm × 1 mm Ø) in DMA containing 0.1 M iPr2NHEtBF4. At the cathode, electrochemical reduction of a proton in iPr2NHEt+ takes place to generate hydrogen gas and iPr2NEt. Evolution

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• methanol and the Breslow intermediate. Electrochemical reduction of BMImBF4,a followed by the addition of elemental sulfurb. Flow cell, in recycling mode. Electrochemical synthesis of γ-butyrolactones 2a and 2b by conjugate umpolung reaction.a Electrochemical synthesis of esters 3a–c from cinnamaldehyde

Cathodic generation of reactive (phenylthio)difluoromethyl species and its reactions: mechanistic aspects and synthetic applications

• Sadanobu Iwase,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2022, 18, 872–880, doi:10.3762/bjoc.18.88

• the chemical reduction of compound 1 with SmI2 was quite different from the electrochemical reduction. However, notably, when THF containing MeOH (10 equiv with regard to compound 1) was used, adduct 4 was formed in 14% yield (Table 3, run 4). In this case, product 3 was not formed. In order to

• , the radical intermediate C is further reduced to generate anion D followed by protonation to give products 4 and 6. Conclusion We have successfully carried out catalytic electrochemical reduction of bromodifluoromethyl phenyl sulfide using o-phthalonitrile as mediator to generate (phenythio

Controlled decomposition of SF₆ by electrochemical reduction

• Sébastien Bouvet,
• Bruce Pégot,
• Stéphane Sengmany,
• Erwan Le Gall,
• Eric Léonel,
• Anne-Marie Goncalves and
• Emmanuel Magnier

Beilstein J. Org. Chem. 2020, 16, 2948–2953, doi:10.3762/bjoc.16.244

• +/Fc. The exact number of electrons for the full consumption of sulfur hexafluoride was determined and this gas further quantitatively transformed into environmentally benign fluoride anion and sulfur by electrochemical reduction. Keywords: electroreduction; fluoride anion; redox potential; sulfur

• knowledge, electrochemical reduction of SF6 has not yet been disclosed. The decomposition of sulfur hexafluoride by electrochemistry can nevertheless be a suitable answer and interesting alternative to the previous expensive options. In this article, we describe the electrochemical behavior of sulfur

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• further reduction, a new absorption pattern emerges for NDIC7, in accordance to a second electrochemical reduction (NDI•− → NDI2−) (Figure 4a, blue curve). However, only small shifts and intensity changes are observed for NDIC8 and the rotaxane NDIRot when going to a more negative potential (−1.2 V

A review of asymmetric synthetic organic electrochemistry and electrocatalysis: concepts, applications, recent developments and future directions

• Munmun Ghosh,
• Valmik S. Shinde and
• Magnus Rueping

Beilstein J. Org. Chem. 2019, 15, 2710–2746, doi:10.3762/bjoc.15.264

• by Wattanakit described several approaches for the development of chiral metal electrodes for enantioselective recognition and asymmetric synthesis developed over the past decade [18]. Concurrent with pioneering works in the field of asymmetric induction in electrochemical reduction on chiral mercury

• with thionyl chloride followed by derivatization with (S)-(−)-phenylalanine methyl ester. The applicability of this modified electrode [(S)-CelPheM] was tested by using it as a cathode for the electrochemical reduction of 4-acetylpyridine (1). GC analysis of the product indicated the formation of the

• to the corresponding amino acid via electrochemical reduction of FAD in AOx by electron mediator ADPy. It should be noted that the authors also reported the limitation of this electrochemical method in terms of substrate selectivity of the enzymes used [44]. Electrochemical asymmetric oxidation using

Experimental and computational electrochemistry of quinazolinespirohexadienone molecular switches – differential electrochromic vs photochromic behavior

• Eric W. Webb,
• Jonathan P. Moerdyk,
• Kyndra B. Sluiter,
• Benjamin J. Pollock,
• Amy L. Speelman,
• Eugene J. Lynch,
• William F. Polik and
• Jason G. Gillmore

Beilstein J. Org. Chem. 2019, 15, 2473–2485, doi:10.3762/bjoc.15.240

• (presumably while air oxidation of 2b2− to 2b could keep up with electrochemical reduction). With further electrolysis even these solutions turned to the orange-red color observed for the deaerated solutions. The solutions did become green upon prolonged exposure to air. This behavior seems indicative of

Synthesis of nonracemic hydroxyglutamic acids

• Dorota G. Piotrowska,
• Iwona E. Głowacka,
• Andrzej E. Wróblewski and
• Liwia Lubowiecka

Beilstein J. Org. Chem. 2019, 15, 236–255, doi:10.3762/bjoc.15.22

• , H2O; b) BuLi, THF; then H2C=CHCH2MgBr; c) L-selectride, THF; d) Me2C(OMe)2, PTSA, THF; e) O3, CH2Cl2, ether, then Ph3P; f) KMnO4, acetone, H2O; g) t-BuOH, N,N′-diisopropyl-O-tert-butylisourea, CH2Cl2; h) MeOH, HCl (gas); i) O2, Pt, AcOEt, H2O; j) electrochemical reduction. Synthesis of (2R,3S)-2 from

Learning from B₁₂ enzymes: biomimetic and bioinspired catalysts for eco-friendly organic synthesis

• Keishiro Tahara,
• Ling Pan,
• Toshikazu Ono and
• Yoshio Hisaeda

Beilstein J. Org. Chem. 2018, 14, 2553–2567, doi:10.3762/bjoc.14.232

• reported by many researchers [67][68][69]. 3-1. Methyl transfer to thiols Chemical reductants such as NaBH4 or electrochemical reduction could provide Co(I) species, so that α-methylated and β-methylated B12 could be formed by the oxidative addition reaction with a methyl donor. The supernucleophile Co(I

• electrochemical reduction. In addition, the corrin-ring of the B12 derivatives is tolerant to free radicals, as described above. Thus, alkylated complexes have been used for radical-mediated organic synthesis such as halide coupling, alkene coupling, and addition to double bonds [7][26][27]. In particular, the Co

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO₂ reduction

• Zhishan Luo,
• Yidong Hou,
• Jinshui Zhang,
• Sibo Wang and
• Xinchen Wang

Beilstein J. Org. Chem. 2018, 14, 2331–2339, doi:10.3762/bjoc.14.208

• also studied the electrochemical reduction in a CO2-saturated system (Figure 4b). It displays that 1-OMe affords a current density of 200 μA·cm−2 at −0.88 V, a 5.5-fold enhancement over 1-CN (36 μA·cm−2). This suggests that the substituted ligand with the electron-donating group is suitable for the

• electrochemical reduction. It is important to note that ligands with different electronic structures exhibited starkly different activities for redox reaction. The ligand with an electron-withdrawing property favors water oxidation, and the one with electron-donating property is conducive to CO2 reduction. Such a

Electrochemically modified Corey–Fuchs reaction for the synthesis of arylalkynes. The case of 2-(2,2-dibromovinyl)naphthalene

• Fabiana Pandolfi,
• Isabella Chiarotto and
• Marta Feroci

Beilstein J. Org. Chem. 2018, 14, 891–899, doi:10.3762/bjoc.14.76

• Fabiana Pandolfi Isabella Chiarotto Marta Feroci Deptartment of Fundamental and Applied Sciences for Engineering (SBAI), Sapienza University of Rome, via Castro Laurenziano, 7, 00161, Rome, Italy 10.3762/bjoc.14.76 Abstract The electrochemical reduction of 2-(2,2-dibromovinyl)naphthalene in a DMF

• = 25 °C; solvent left: DMF/Et4NBF4 0.1 mol dm−3; right: ACN/Et4NBF4 0.1 mol dm−3. Variation of the amounts of 1a, 2a, and 3a with the number of Faradays of 1a. The Corey–Fuchs reaction. Electrochemical reduction of a carbon–halogen bond. Electrochemical synthesis of vinyl bromides [25]. Scope of this

Electrochemical Corey–Winter reaction. Reduction of thiocarbonates in aqueous methanol media and application to the synthesis of a naturally occurring α-pyrone

• Ernesto Emmanuel López-López,
• José Alvano Pérez-Bautista,
• Fernando Sartillo-Piscil and
• Bernardo A. Frontana-Uribe

Beilstein J. Org. Chem. 2018, 14, 547–552, doi:10.3762/bjoc.14.41

• convert thiocarbonates derived from 1,2-diols containing the 6-pentyl-2H-pyran-2-one framework to trans-alkenes by means of electrochemical reduction in an H-type separated cell was developed. The thiocarbonate functional group can be reduced using a vitreous carbon electrode in MeOH/H2O 80:20 with AcOH

An alternative to hydrogenation processes. Electrocatalytic hydrogenation of benzophenone

• Cristina Mozo Mulero,
• Alfonso Sáez,
• Jesús Iniesta and
• Vicente Montiel

Beilstein J. Org. Chem. 2018, 14, 537–546, doi:10.3762/bjoc.14.40

• generally over 90% is irrespective of the current density. Electrocatalytic hydrogenation of benzophenone was also performed using Pd0.00/C/T electrodes, i.e., in the absence of the Pd electocatalyst, at 10 mA cm−2 demonstrated neither the electrochemical reduction of benzophenone nor the formation of

An effective Pd nanocatalyst in aqueous media: stilbene synthesis by Mizoroki–Heck coupling reaction under microwave irradiation

• Carolina S. García,
• Paula M. Uberman and
• Sandra E. Martín

Beilstein J. Org. Chem. 2017, 13, 1717–1727, doi:10.3762/bjoc.13.166

• . Synthesis of Pd nanoparticles suspension by electrochemical reduction The electrochemical synthesis of PVP-Pd NPs was carried out as previously reported [46]. The experiments were achieved in a glass electrochemical cell equipped with a Pt disc working electrode (geometric area = 0.0746 cm2), a very large

Biocatalysis for the application of CO₂ as a chemical feedstock

• Apostolos Alissandratos and
• Christopher J. Easton

Beilstein J. Org. Chem. 2015, 11, 2370–2387, doi:10.3762/bjoc.11.259

Cathodic hydrodimerization of nitroolefins

• Michael Weßling and
• Hans J. Schäfer

Beilstein J. Org. Chem. 2015, 11, 1163–1174, doi:10.3762/bjoc.11.131

• ]. Furthermore 3 was found in the reduction of 4 with TiCl3 [13][14]. High dimer yields are reported for the reduction of several nitro olefins with the dianion of cyclooctatetraene [15]. ß-Nitrostyrene (4) has been reductively dimerized with organomanganese reagents to 3 in low yield [16]. The electrochemical

• reduction of 1-nitroalkenes was studied by cyclic voltammetry and controlled potential coulometry. The reduction probably proceeds by initial formation of the radical anion, which subsequently dimerizes [17]. Later conditions were described to achieve selectively either a cathodic ß,ß-coupling (cathodic