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

• base complexes; stereoselective electrosynthesis; voltammetric testing; Introduction Electrochemistry provides a direct access to highly reactive species by means of harnessing electrons or electron holes as reagents [1][2]. This capacity can be efficiently exploited in organic synthesis for rational

Electro-conversion of cumene into acetophenone using boron-doped diamond electrodes

• Mana Kitano,
• Tsuyoshi Saitoh,
• Shigeru Nishiyama,
• Yasuaki Einaga and
• Takashi Yamamoto

Beilstein J. Org. Chem. 2022, 18, 1154–1158, doi:10.3762/bjoc.18.119

• , first reported in 1944 [3], a wide variety of catalytic systems are still being reported [4][5][6][7][8][9][10][11][12]. Electro-organic synthesis refers to an organic synthetic method combined with electrochemistry [13][14]. A striking feature in electro-organic synthesis is the use of electricity as a

Radical cation Diels–Alder reactions of arylidene cycloalkanes

• Kaii Nakayama,
• Hidehiro Kamiya and
• Yohei Okada

Beilstein J. Org. Chem. 2022, 18, 1100–1106, doi:10.3762/bjoc.18.112

• electrochemistry in most cases, probably because both single-electron oxidation and reduction are made possible at the same surface [45]. This is especially true for the radical cation Diels–Alder reaction, since non-substituted β-methylstyrene, which was previously reported as an unsuccessful dienophile, was

• electrochemistry in many cases for these dienophiles, which accords well with our previous reports. The ring size effect of cycloalkanes was also clearly observed and cyclobutane was much more effective than the others. A similar trend was observed using some heterocycles, which also accorded well with the

Synthesis, optical and electrochemical properties of (D–π)₂-type and (D–π)₂Ph-type fluorescent dyes

• Kosuke Takemura,
• Kazuki Ohira,
• Taiki Higashino,
• Keiichi Imato and
• Yousuke Ooyama

Beilstein J. Org. Chem. 2022, 18, 1047–1054, doi:10.3762/bjoc.18.106

• practical concern with the objective of not only fundamental studies [1][2][3][4][5][6][7][8][9][10][11][12][13] in synthetic chemistry, electrochemistry and photochemistry, but also their potential applications to emitters for optoelectronic devices, such as organic light-emitting diodes (OLEDs) [14][15

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

• used as organocatalyst in two classical umpolung reactions of cinnamaldehyde: its cyclodimerization and its oxidative esterification. Keywords: Breslow intermediate; cathodic reduction; flow electrochemistry; N-heterocyclic carbene; oxidative esterification; Introduction Ionic liquids (ILs) are well

• reactions and usually the product separation is easy [4][5]. Among ILs, imidazolium derivatives are the most studied, in part due to their ease of synthesis, low cost and diverse applications from solvents and reagents in synthesis, to supporting electrolytes in electrochemistry [6]. The imidazolium cation

• as slow rates of conversion, low selectivity and reproducibility [26]. As a matter of fact, these problems can be addressed by using flow electrochemistry, usually achieving higher rates of conversion of reagents to products [27]. Moreover, electrochemical flow cells can have a very small gap between

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• its phase below its melting point. The limits of thermal stability were recorded by a 5% mass loss at elevated temperatures, as determined by thermal gravimetric analysis (TGA), and found to be 406 °C, indicating a high thermal stability (Figure S18 in Supporting Information File 1). Electrochemistry

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• was assumed to be the reason for the decrease of the band gap. Meanwhile, the LUMO levels estimated from electrochemistry experiments (see Figure 11c and 11d) were also depressed from −3.60 eV (compound 19) to −3.96 eV (compound 19/B(C6F5)3) and from −3.59 eV (compound 20) to −4.12 eV (compound 20/B

Synthesis of α-(perfluoroalkylsulfonyl)propiophenones: a new set of reagents for the light-mediated perfluoroalkylation of aromatics

• Durbis J. Castillo-Pazos,
• Juan D. Lasso and
• Chao-Jun Li

Beilstein J. Org. Chem. 2022, 18, 788–795, doi:10.3762/bjoc.18.79

• perfluorinated chains into aromatic rings have been developed since the first reports of such transformation by George Tiers in 1960, and McLoughlin and Thrower in 1969 [2][3]. Most approaches have made extensive use of organometallic chemistry, radical initiators, photocatalysis, electrochemistry, and more

Complementarity of solution and solid state mechanochemical reaction conditions demonstrated by 1,2-debromination of tricyclic imides

• Petar Štrbac and
• Davor Margetić

Beilstein J. Org. Chem. 2022, 18, 746–753, doi:10.3762/bjoc.18.75

• , irradiation and electrochemistry as methods of chemical activation [8]. Based upon our experience in applications of this method to organic synthesis [9][10][11][12], we recognized its potential for the adjustment of conditions in zinc-mediated debromination reactions. Highly reactive dienophiles such as

Electrocatalytic C(sp³)–H/C(sp)–H cross-coupling in continuous flow through TEMPO/copper relay catalysis

• Bin Guo and
• Hai-Chao Xu

Beilstein J. Org. Chem. 2021, 17, 2650–2656, doi:10.3762/bjoc.17.178

• and sustainable access to 2-functionalized tetrahydroisoquinolines. Keywords: continuous flow; copper; catalysis; dehydrogenative cross-coupling; electrochemistry; Introduction The dehydrogenative cross-coupling of two C–H bonds represents an ideal strategy for the construction of C–C bonds [1][2

• electrochemistry is an ideal tool for promoting dehydrogenative cross-coupling reactions as no external chemical oxidants are needed [11][12][13][14][15][16][17][18][19]. In this context, Mei and co-workers have reported an elegant TEMPO/[L*Cu] co-catalyzed asymmetric electrochemical dehydrogenative cross-coupling

Sustainable manganese catalysis for late-stage C–H functionalization of bioactive structural motifs

• Jongwoo Son

Beilstein J. Org. Chem. 2021, 17, 1733–1751, doi:10.3762/bjoc.17.122

• excluded. This late-stage process by Mn catalysis, electrochemistry, and visible-light catalysis exhibits high value as a sustainable tool to investigate problematic synthetic transformations. Recently, the Ackermann group disclosed a convenient manganese-catalyzed late-stage C–H azidation of bioactive

Synthesis, structural characterization, and optical properties of benzo[f]naphtho[2,3-b]phosphoindoles

• Mio Matsumura,
• Takahiro Teramoto,
• Masato Kawakubo,
• Masatoshi Kawahata,
• Yuki Murata,
• Kentaro Yamaguchi,
• Masanobu Uchiyama and
• Shuji Yasuike

Beilstein J. Org. Chem. 2021, 17, 671–677, doi:10.3762/bjoc.17.56

• ]. Unfortunately, the electrochemistry of some compounds could not be determined under the conditions available to us. Therefore, computational investigations are particularly useful for understanding the trends of the electrochemical and photophysical properties of molecular materials. Density functional theory

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• the metal ions localized at different sites of the molecule. Electrochemistry studies Cyclic voltammograms for new o-quinones have been recorded in CH3CN solution containing 0.10 M (n-Bu4N)ClO4 as supporting electrolyte at a glassy carbon working electrode and a Ag/AgCl/KCl reference electrode. Table

•  1 summarizes the results of the electrochemical studies. Usually, the electrochemistry of sterically hindered o-quinones is relatively simple, it includes two one-electron steps with separation of potentials. Cyclic voltammetry studies reveal that the reduction of 3a, 6a and 7 takes place in two

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

• 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

• hexafluoride dissolved in various organic solvents. After combining an analytical approach of electrochemistry and 19F NMR spectroscopy, we have succeeded in the total consumption of SF6 in an electrochemical cell. Results and Discussion The first step of this work began with the measurement of the solubility

• electrochemistry. Having a dielectric constant relatively high (ε = 38), acetonitrile allows a good dissociation of several salts providing the conductivity of the medium. The concentration of SF6 in the following studies was then around 1.7 × 10−2 M. We then turned our attention to the determination of the

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

• entropy. However, to further elucidate the role of WCAs in crown/ammonium complexes, more detailed studies are certainly indicated. Electrochemistry The electrochemical properties of the TTF and NDI-bearing macrocycles and pseudorotaxanes are summarized in Table 2. To get some insight into the solvent

Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

• Natalie Lagesse,
• Luca Pisciottani,
• Maxime Douarre,
• Pascale Godard,
• Brice Kauffmann,
• Vicente Martí-Centelles and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

•  5). Additional proof of the mechanical bond was provided by 1H DOSY NMR showing the same diffusion for thread and macrocycle signals with a diffusion coefficient of −9.33 m2/s and a hydrodynamic radius of 8.7 Å (see Figure S4 in Supporting Information File 1). Electrochemistry The ferrocene

• voltage was maintained at 3200 V and the capillary temperature set to 320 °C. Samples were introduced by injection through a 20 µL loop into a 300 µL/min flow of methanol from the LC pump. Electrochemistry: Cyclic voltammetry was carried out in a Metrohm Autolab PGSTAT302N potentiostat using a three

Synthesis of novel multifunctional carbazole-based molecules and their thermal, electrochemical and optical properties

• Nuray Altinolcek,
• Ahmet Battal,
• Mustafa Tavasli,
• William J. Peveler,
• Holly A. Yu and
• Peter J. Skabara

Beilstein J. Org. Chem. 2020, 16, 1066–1074, doi:10.3762/bjoc.16.93

• , respectively. Keywords: carbazole; electrochemistry; fluorescence; formyl group; solvatochromism; Introduction Carbazole derivatives have found many different applications in a variety of technologically important areas, such as organic light emitting diodes (OLEDs), organic photovoltaics (OPVs), dye

Accelerating fragment-based library generation by coupling high-performance photoreactors with benchtop analysis

• Quentin Lefebvre,
• Christophe Salomé and
• Thomas C. Fessard

Beilstein J. Org. Chem. 2020, 16, 982–988, doi:10.3762/bjoc.16.87

• -catalyzed cross-coupling reactions [9]. Recently, milder cross-coupling methods using more abundant and affordable metals such as nickel, in combination with photochemistry or electrochemistry, significantly improved accessibility to N-arylated complex amines [10][11][12]. Results and Discussion As we

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

• chemistry. In this review, we aim to focus on methods for achieving stereocontrol in synthetic organic electrochemistry via a systematic description of the reported literature on chiral inductors, followed by their applications in the synthesis of natural products and bioactive compounds including late

• explored as chiral mediators in electrochemistry. Notably, the distinction between mediators and catalysts can be difficult, but we have grouped them in terms of their role as per our classification. In 1999, Kashiwagi and his group explored the applicability of chiral azaspiro-N-oxyl radical SPIROXYL (61

• variants of these synthetic operations remains challenging, making the use of electrochemistry to achieve stereoselective transformations an often unsolved problem. Modern synthetic laboratories have, however, made advances in this regard due to arduous studies resulting in a number of landmark

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

• photochemistry of two closely related and more reducible quinazolinespirohexadienones (QSHDs), wherein the naphthalene of the PSHD is replaced with a quinoline. In the present work, we report our investigation of the electrochemistry of these asymmetric QSHDs. In addition to the short wavelength and photochromic

• small molecule organic electrochromism [6][7][9]. One example that combines photochromic and electrochromic behavior (the latter of an unusual sort) is the class of perimidinespirohexadienones 1 (PSHDs) whose synthesis, electrochemistry and UV–vis spectroscopy were reported by Minkin and co-workers [10

• quinazolinespirohexadienone (QSHD) photochromes 3a,b (Scheme 2) and their photochemical properties as well as a proof of structure for the photochemically generated long-wavelength isomer (pLW) 4a,b (not 5a,b) [21]. Herein, we report the electrochemistry of these QSHDs. Results and Discussion Electrochemical analysis When we

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

• intervalence charge transfer characteristics of the zwitterionic MV state. Keywords: anion binding; electrochemistry; hydrogen bonding; triarylamine; urea; zwitterionic mixed valency; Introduction Mixed-valence (MV) compounds have received increasing attention from the viewpoint of fundamental research on

Naphthalene diimides with improved solubility for visible light photoredox catalysis

• Barbara Reiß and
• Hans-Achim Wagenknecht

Beilstein J. Org. Chem. 2019, 15, 2043–2051, doi:10.3762/bjoc.15.201

• light photoredox catalysts and characterized by methods of optical spectroscopy and electrochemistry in comparison with one unsubstituted naphthalene diimide as reference. The core-substituted naphthalene diimides differ by the alkyl groups at the imide nitrogens and at the nitrogens of the two

• light range between 520 nm and 640 nm. The irradiation by visible light together with the use of an organic dye instead of a transition metal complex as photoredox catalyst improve the sustainability and make photoredox catalysis “greener”. Keywords: chromophore; dyes; electrochemistry; photochemistry

• characterized in DMF and CH2Cl2 by means of optical spectroscopy and electrochemistry. The UV–vis absorbance of the core-unsubstituted NDI 1 in CH2Cl2 show characteristic bands in the range between 300 nm and 400 nm with the maximum at 380 nm (Figure 1). The absorbance of NDI 1 in DMF is very similar to that in

A diastereoselective approach to axially chiral biaryls via electrochemically enabled cyclization cascade

• Hong Yan,
• Zhong-Yi Mao,
• Zhong-Wei Hou,
• Jinshuai Song and
• Hai-Chao Xu

Beilstein J. Org. Chem. 2019, 15, 795–800, doi:10.3762/bjoc.15.76

• the biaryls with good to excellent central-to-axial chirality transfer. Keywords: axial chirality; biaryl; electrochemistry; oxidation; radical; Introduction Axially chiral biaryls are prevalent in natural products, bioactive molecules and organocatalysts [1][2]. Among the many methods that have

• electrochemistry is a powerful tool for adding or taking electrons from organic molecules to promote redox reactions because of its reagent-free feature and the tunability of electric current and potential [20][21][22][23][24][25][26][27][28][29][30]. We [31][32][33][34] and others [35][36][37][38][39][40][41

Oxidative and reductive cyclization in stiff dithienylethenes

• Michael Kleinwächter,
• Ellen Teichmann,
• Lutz Grubert,
• Martin Herder and
• Stefan Hecht

Beilstein J. Org. Chem. 2018, 14, 2812–2821, doi:10.3762/bjoc.14.259

• dithienylethenes bearing benzonitrile substituents an additional and rare reductive electrocyclization was observed. The mechanism underlying both observed electrocyclization pathways has been elucidated. Keywords: diarylethenes; electrochromism; molecular switches; (spectro)electrochemistry; Introduction

• cyclovoltammetry (CV) and spectro-electrochemistry (SEC) [33]. Our present study is aiming to: 1) elucidate the influence of possible double bond isomerization on the electrochromism of sDTEs; 2) explore the structural effect of varying ring size as well as electronic modification; and 3) contribute to the

• benzonitrile substituents (DTE-PhCN) to these conditions. The electrochemistry of this compound [8] and its hexafluorocyclopentene derivative [43] have already been investigated, but its behavior under reductive conditions has not been discussed. Indeed, an irreversible reduction wave at Epc = −2.436 V was

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

• Mn4CaO5 cubane of oxygen-evolving complex in photosystem II, there is an emerging number of molecular cubanes with metallic and heterobimetallic cores that are designed and synthesized for photosynthesis and electrochemistry. Cobalt-based molecular catalysts [44], in particular the ones containing a