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

• 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

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

• in the previous paper) [25]. In order to ascertain the role of the solvent in this electrosynthesis, we carried out an electrolysis in DMF instead of ACN on a Pt cathode at the controlled potential of −2.00 V vs SCE, corresponding to the first reduction wave of 1a (Table 1, entry 2). The current flow

• influence the outcome of an electrosynthesis, so we carried out electrolyses of 1a using a glassy carbon cathode (Table 1, entry 8) and a silver cathode (Table 1, entry 9). In both cases the working potential was that of the first reduction wave. In the case of glassy carbon, the electrolysis could not be

• electrode material. This voltammetric analysis shows that the cathodic reduction of both 1a and 3a could lead to the formation of the desired alkyne 2a. To ascertain this hypothesis and to get information on the nature of the intermediates of the electrochemical process, we carried out the electrosynthesis

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

• -(pent-1-enyl)-α-pyrone and trans-6-(pent-1,4-dienyl)-α-pyrone, which are naturally occurring metabolites isolated from Trichoderma viride and Penicillium, in high chemical yield and with excellent stereo selectivity. Keywords: Corey–Winter reaction; electrosynthesis; 6-pentyl-2H-pyran-2-ones; reduction

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

• ohmic drop at the whole process. In the case of organic electrosynthesis, electrocatalytic hydrogenation of aromatic ketones, specifically acetophenone, has been recently carried out [22][23] achieving a high selectivity using the above-mentioned technology. In this work, we have chosen benzophenone, as

• factor was defined as the Pd electrochemically active surface divided by the geometric total area, expressed in (cm2 Pd) cm−2 (vide supra). Electrosynthesis reactions were performed using a 25 cm2 PEM single cell fuel cell (EFC-25-01 model from ElectroChem Inc.) acting as polymer electrolyte membrane

• cathode. Fractional conversion of benzophenone as a function of coulombic passed charge using the PEMER; 0.5 M benzophenone as starting solution in ethanol/H2O (90:10 v/v) + 0.1 M H2SO4. Pd0.02/C/T electrode. Plot of cell voltage versus time obtained from a preparative electrosynthesis performed at 10 mA

The selective electrochemical fluorination of S-alkyl benzothioate and its derivatives

• Shunsuke Kuribayashi,
• Tomoyuki Kurioka,
• Shinsuke Inagi,
• Ho-Jung Lu,
• Biing-Jiun Uang and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2018, 14, 389–396, doi:10.3762/bjoc.14.27

• ; electrosynthesis; fluorobenzothiophenone; selective fluorination; Introduction Due to the interesting properties of fluorine atoms and carbon–fluorine bonds, organofluorine compounds are widely used in various fields like pharmaceutical chemistry, agrochemistry, and materials sciences [1][2]. Therefore, the

Cathodic hydrodimerization of nitroolefins

• Michael Weßling and
• Hans J. Schäfer

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

• formation; 1,4-dinitrocompounds; electrosynthesis; nitroalkene; Introduction Olefins being activated by an electron withdrawing group can be hydrodimerized by cathodic reduction [1][2]. Thereby, the cathode serves as cheap, versatile, immobilized and mostly non-polluting reagent providing economical and

Electrosynthesis and electrochemistry

• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 949–950, doi:10.3762/bjoc.11.105

• Siegfried R. Waldvogel Institute for Organic Chemistry, Johannes Gutenberg University Mainz, Duesbergweg 10–14, 55128 Mainz, Germany 10.3762/bjoc.11.105 Keywords: chemical method; electrochemistry; electrosynthesis; sustainability; Since the pioneering work of Kolbe, electrochemistry and

• current unsteady supply does not match the demand. Thus, the use of abundant electric power in electrosynthetic processes seems to be rational because high valorisation can be expected. Therefore, electrosynthesis fulfils all requirements for “green chemistry” [4]. When changing feed stocks and natural

• molecules. Such electro-oxidative treatment generates potential metabolites that can be then biologically studied [10]. The combination of electrosynthesis with other powerful techniques, such as ultrasonic treatment and flow microcells, will push the electrosynthetic applications beyond current limits [11

IR and electrochemical synthesis and characterization of thin films of PEDOT grown on platinum single crystal electrodes in [EMMIM]Tf₂N ionic liquid

• Andrea P. Sandoval,
• Marco F. Suárez-Herrera and
• Juan M. Feliu

Beilstein J. Org. Chem. 2015, 11, 348–357, doi:10.3762/bjoc.11.40

• ) has shown an enhancement in stability, organization and electroactivity [12][13][14]. These characteristics are obtained mainly because of the dry medium, their wide electrochemical window, and their low nucleophilicity. Therefore, during the electrosynthesis of conducting polymers the overoxidation

• begins at 0.9 V in Pt(111) and Pt(110) while in Pt(100) it starts at 1.0 V. The loop observed during the first scans (Figure 1a – insert) is typical of the electrosynthesis of conducting polymers both in organic media [17] and in ILs [2][18][19]. This characteristic has been well described by Heinze et

Stereoselective cathodic synthesis of 8-substituted (1R,3R,4S)-menthylamines

• Carolin Edinger,
• Jörn Kulisch and
• Siegfried R. Waldvogel

Beilstein J. Org. Chem. 2015, 11, 294–301, doi:10.3762/bjoc.11.34

• additional substituent in position 8 is described. Due to 1,3-diaxial interactions a pronounced diastereoselectivity for the menthylamines is found. Keywords: cathodic reduction; chiral amines; electrosynthesis; menthylamines; oximes; Introduction Optically active amines serve as powerful and versatile

Photovoltaic-driven organic electrosynthesis and efforts toward more sustainable oxidation reactions

• Bichlien H. Nguyen,
• Robert J. Perkins,
• Jake A. Smith and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2015, 11, 280–287, doi:10.3762/bjoc.11.32

Switching the reaction pathways of electrochemically generated β-haloalkoxysulfonium ions – synthesis of halohydrins and epoxides

• Akihiro Shimizu,
• Ryutaro Hayashi,
• Yosuke Ashikari,
• Toshiki Nokami and
• Jun-ichi Yoshida

Beilstein J. Org. Chem. 2015, 11, 242–248, doi:10.3762/bjoc.11.27

• . Keywords: DMSO; electrosynthesis; epoxides; halohydrins; halogen cations; Introduction Alkene difunctionalization through three-membered ring halonium ion intermediates [1] is an important transformation in organic synthesis. Usually the halonium ions such as bromonium or iodonium ions are generated by

Cathodic reductive coupling of methyl cinnamate on boron-doped diamond electrodes and synthesis of new neolignan-type products

• Taiki Kojima,
• Rika Obata,
• Tsuyoshi Saito,
• Yasuaki Einaga and
• Shigeru Nishiyama

Beilstein J. Org. Chem. 2015, 11, 200–203, doi:10.3762/bjoc.11.21

• -type products were synthesized from the hydrodimer. Keywords: boron-doped diamond (BDD) electrode; cathodic reduction; electrochemistry; electrosynthesis; neolignan; Introduction Numerous lignans and neolignans were found as secondary plant metabolites, and many of them are known to exhibit

Highly selective electrochemical fluorination of dithioacetal derivatives bearing electron-withdrawing substituents at the position α to the sulfur atom using poly(HF) salts

• Bin Yin,
• Shinsuke Inagi and
• Toshio Fuchigami

Beilstein J. Org. Chem. 2015, 11, 85–91, doi:10.3762/bjoc.11.12

• having a strongly electron-withdrawing nitrile group gave the α-fluorination product predominantly regardless of the poly(HF) salts used. Keywords: anodic fluorination; anodic fluorodesulfurization; electrosynthesis; fluorination product selectivity; poly(HF) salt; Introduction The introduction of

The Shono-type electroorganic oxidation of unfunctionalised amides. Carbon–carbon bond formation via electrogenerated N-acyliminium ions

• Alan M. Jones and
• Craig E. Banks

Beilstein J. Org. Chem. 2014, 10, 3056–3072, doi:10.3762/bjoc.10.323

• also highlight new technologies and techniques applied to this area of electrosynthesis. We conclude with the use of this electrosynthetic approach to challenging syntheses of natural products and other complex structures for biological evaluation discussing recent technological developments in

• electroorganic techniques and future directions. Keywords: anodic oxidation; electrochemistry; electroorganic, electrosynthesis, N-acyliminium ions; natural products; non-Kolbe oxidation; peptidomimetics; Shono oxidation; synthesis; Review N-Acyliminium ions are synthetically versatile N-Acyliminium ions [1][2

• and comprehensive reviews on the art of electroorganic synthesis and the reader is directed to these articles for a thorough background and insight into the many facets of electrosynthesis [5][6][7][8][9][10]. In this review, we focus upon the development and application of the Shono-type

Recent advances in the electrochemical construction of heterocycles

• Robert Francke

Beilstein J. Org. Chem. 2014, 10, 2858–2873, doi:10.3762/bjoc.10.303

• construction of heterocyclic cores still involve the use of strong acids or bases, the operation at elevated temperatures and/or the use of expensive catalysts and reagents. In this regard, electrosynthesis can provide a milder and more environmentally benign alternative. In fact, numerous examples for the

• reactions is presented and discussed in this review. Keywords: anodic cyclization; electrosynthesis; heterocycle; olefin coupling; organic electrochemistry; radical cyclization; Introduction The construction of heterocyclic cores undoubtedly represents a highly important discipline of organic synthesis

• interesting and practical alternative to conventional methods for heterocycle synthesis [19][20]. Since toxic and hazardous redox reagents are either replaced by electric current (direct electrolysis) or generated in situ from stable and non-hazardous precursors (indirect electrolysis), electrosynthesis is

Electrocarboxylation: towards sustainable and efficient synthesis of valuable carboxylic acids

• Roman Matthessen,
• Jan Fransaer,
• Koen Binnemans and
• Dirk E. De Vos

Beilstein J. Org. Chem. 2014, 10, 2484–2500, doi:10.3762/bjoc.10.260

• electrons is determined by the applied voltage [25]. Since the electroreduction takes place on a cathode surface, the need for complex homogeneous organometallic catalysts is minimized. Furthermore, electricity will be increasingly of renewable origin in the future, making organic electrosynthesis a

• electrons per CO2 molecule, as shown in Scheme 3 for olefins, with the C–C bond formation highlighted in bold. Industrial organic electrosynthesis The chemical industry is devoting increasing research efforts to the field of organic electrosynthesis [31]. An extended series of electro-organic processes have

• from dimethyl phthalate and tert-butyltoluene, respectively (Scheme 5). After separation, by distillation and precipitation, both products can be used in the production of pesticides [34]. This is an example of a paired electrosynthesis, in which the anodic and cathodic reactions simultaneously form

A practical synthesis of long-chain iso-fatty acids (iso-C₁₂–C₁₉) and related natural products

• Mark B. Richardson and
• Spencer J. Williams

Beilstein J. Org. Chem. 2013, 9, 1807–1812, doi:10.3762/bjoc.9.210

• approaches have been used: (1) two-component cross-couplings that include α-ketoester alkylation/decarboxylation [32][33], aldehyde–olefin photoaddition [34], acetylide alkylation (sp3–sp) [35][36], Wittig coupling [3][21][37][38][39], Kolbe electrosynthesis [35][40][41][42], organocadmium (sp2–sp3) [43][44

A practical microreactor for electrochemistry in flow

• Kevin Watts,
• William Gattrell and
• Thomas Wirth

Beilstein J. Org. Chem. 2011, 7, 1108–1114, doi:10.3762/bjoc.7.127

• -supported, paired electrosynthesis of 2,5-dimethoxy-2,5-dihydrofuran from furan with excellent yields and flow rates of up to 0.5 mL·min−1. A microflow system where the current flow and liquid flow are parallel was reported by Yoshida et al. [7]. Two carbon fibre electrodes were separated by a hydrophobic