Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• ferrocene moieties. It should be noted that the first oxidation potential is almost identical to free ferrocene [6]. Herein we report the crystal structure of triferrocenyl trithiophosphite. For triferrocenyl trithiophosphite a trans-gauche-gauche configuration with torsion angles of −34°, −40°, and 173

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• the HOMO energy of 1,2-diphosphaferrocenes 8. The number of phosphorus atoms in cyclopentadiene had a much greater effect on the shifts of the FeII/FeIII oxidation potential. As shown earlier, an increase in the number of phosphorus atoms led to the irreversible oxidation of phosphaferrocenes

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• . DiKTa possesses an oxidation potential of 1.66 V and an associated HOMO energy level of −5.93 eV. The reduction potentials, Ered, are −1.67 V and −1.61 V, respectively, for DiKTa-OBuIm and DiKTa-DPA-OBuIm. The corresponding LUMO levels are −3.13 eV and −3.18 eV for DiKTa-OBuIm and DiKTa-DPA-OBuIm

Synthesis of protected precursors of chitin oligosaccharides by electrochemical polyglycosylation of thioglycosides

• Md Azadur Rahman,
• Kana Kuroda,
• Hirofumi Endo,
• Norihiko Sasaki,
• Tomoaki Hamada,
• Hiraku Sakai and
• Toshiki Nokami

Beilstein J. Org. Chem. 2022, 18, 1133–1139, doi:10.3762/bjoc.18.117

• electrochemical polyglycosylation is also discussed, based on the oxidation potential of the monomer and oligosaccharides. Keywords: electrochemical glycosylation; glucosamine; oligosaccharide; oxidation potential; polyglycosylation; Introduction Chitin oligosaccharides are partial structures of chitin, which

• . Contrary, thioglycoside 1c (Ar = 4-MeC6H4, Eox = 1.47 V vs SCE), which had the lowest oxidation potential, showed the lowest conversion (51%) and the lowest yield of tetrasaccharide 4c (2%) [8]. This being the case, lower conversion of the building block 1c and lower yield of oligosaccharides 2c–4c

• indicated that thus-generated oligosaccharides 2c–4c, with a lower oxidation potential, also consumed electricity and converted to the corresponding hydroxy-substituted sugars, as observed by MS analysis. Thioglycoside 1d (Ar = 2,4-F2C6H3, Eox = 1.73 V vs SCE), which had the highest oxidation potential

Electrochemical vicinal oxyazidation of α-arylvinyl acetates

• Yi-Lun Li,
• Zhaojiang Shi,
• Tao Shen and
• Ke-Yin Ye

Beilstein J. Org. Chem. 2022, 18, 1026–1031, doi:10.3762/bjoc.18.103

• oxidation of the isopropylbenzene moiety [31][36], which was consistent with its relative low oxidation potential (Eonset = 1.68 V vs Fc+/0). Other electron-donating substituents, such as the OMe (10–12), OPh (13), and OAc (14) were also well tolerated. However, halogenated substrates, including fluoro (15

Electrochemical and spectroscopic properties of twisted dibenzo[g,p]chrysene derivatives

• Tomoya Imai,
• Ryuhei Akasaka,
• Naruhiro Yoshida,
• Toru Amaya and
• Tetsuo Iwasawa

Beilstein J. Org. Chem. 2022, 18, 963–971, doi:10.3762/bjoc.18.96

• DBCs with MeO groups located at X and/or Y (MeO-DBC-1, MeO-DBC-2, and MeO-DBC-3, Figure 1b) [43]. The first oxidation potential (Eox1) of MeO-DBC-1 was reported to be 0.40 V (based on Fc/Fc+), which is 0.48 V lower than that of DBC. In contrast, when a MeO group is introduced at the X position (MeO-DBC

• -2), the Eox1 is lower by only 0.15 V than that of DBC. It has also been reported that the oxidation potential of MeO-DBC-3, in which the MeO groups are attached at both X and Y, is 0.06 V higher than that for MeO-DBC-1. These remarkable substituent effects are an interesting and important finding

• groups are introduced in place of the isopropyl groups, which has a 0.06 V higher oxidation potential than that of MeO-DBC-1. This indicates that alkyl substituents in the X position are effective in stabilizing the radical cation, thus making it more susceptible to oxidation. Unlike DBC-H, an

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• as the electrolyte and Fc/Fc+ as the internal reference, data are reported versus a saturated calomel electrode (SCE). In both DICzTRZ and ICzTRZ [14] we observed a reversible oxidation wave with respective oxidation potential (Eox) at 0.87 V and 0.96 V vs SCE (Figure 4a). Both compounds also present

• a second oxidation wave that is more prominent and cathodically shifted for DICzTRZ at 1.05 V, compared to 1.14 V for ICzTRZ. No reduction wave is observed for DICzTRZ. The HOMO value calculated from the oxidation potential obtained from differential pulse voltammetry (DPV), is −5.21 eV, which is

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• forms of monomer 24, dimer 29, and polyazulene 31 were further red-shifted and their respective energy gaps were also reduced compared to their neutral forms. The oxidation potential for the neutral (−0.23 V) and protonated forms of polyaminoazulene 31 (0.70 V) was significantly different unlike the

• and larger cathodic shift of the oxidation potential in these polymers compared to their metal-free counterparts. In 2012, Hawker and co-workers [22], along with 17–20, also synthesized a polymer 45 which had azulene and thiophene units connected via the 4,7-positions of azulene. The reaction of 4,7

• –144 containing azulene-carbazole-benzothiadiazole, with varying composition of N-alkyl carbazole and benzothiadiazole units by a Suzuki protocol (Scheme 24). These polymers exhibited Mn in the range 4200–7200 Da with PDI 1.14–1.38. The oxidation potential of the benzothiadiazole-containing polymers

Electron-rich triarylphosphines as nucleophilic catalysts for oxa-Michael reactions

• Susanne M. Fischer,
• Simon Renner,
• A. Daniel Boese and
• Christian Slugovc

Beilstein J. Org. Chem. 2021, 17, 1689–1697, doi:10.3762/bjoc.17.117

• formation of the corresponding phosphine oxide derivative as the only decomposition product was observed. The results, shown in Figure 3, reveal that the oxidation stability is decreasing in the order TPP > MMTPP > TMTPP, which is in line with electrochemical studies showing a decrease of the oxidation

• potential from 1.400 V (TPP) to 1.050 V (TMTPP) [35]. Furthermore, the share of phosphine oxide is dependent on the oxygen solubility in the solvent, as indicated by the experiments in chloroform and 1-hexanol exhibiting the higher oxygen solubility [36]. To obtain further insight, the SOMO energies of the

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

• Information File 1. Parent compound 2 and borane complex 6 showed reversible reduction peaks (Ered = −1.25 and −1.26 V, respectively). Due to the increased electron–acceptor character of the phosphorus center, P-modification compounds 4 and 5 show a more positive oxidation potential than parent 2 [26

Synthesis, crystal structures and properties of carbazole-based [6]helicenes fused with an azine ring

• Daria I. Tonkoglazova,
• Anna V. Gulevskaya,
• Konstantin A. Chistyakov and
• Olga I. Askalepova

Beilstein J. Org. Chem. 2021, 17, 11–21, doi:10.3762/bjoc.17.2

• ]helicene 12 was equal to 2.92 eV [42]. The Egopt values for its π-extended analogs were 2.45 eV (10a), 2.76 eV (10b) and 2.85 eV (10c), suggesting a higher HOMO and lower oxidation potential, which are typically desired characteristics when designing organic materials. Unfortunately, for all azine-fused [6

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• replacement of sulfur by nitrogen atoms in the tetra- and hexacyclic systems leads to a red-shift in absorption, a decrease in oxidation potential and energy gap. On the other hand, the replacement of a thiophene ring by benzene leads to the opposite effects. Keywords: Buchwald–Hartwig amination; Cadogan

• TTA, SN4 9, and SN4'' 33 irreversible oxidation waves were obtained due to follow-up reactions of the formed radical cations and peak potentials gradually decrease from 0.81 V for TTA to 0.07 V for SN4'' 33 (Figure 2, right). As expected, the oxidation potential is substantially influenced by the

• increasing number of electron-rich pyrrole rings and drops continuously. As expected, if an electron-rich fused thiophene ring in H-SN4 13 is replaced by a phenyl ring in 19, the oxidation potential is increased by 190 mV. The value for hexacyclic 22 (Epox1 = 0.33 V) is in the same regime than for H-SN4 13

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

• TTFC7, respectively, in a DCE/CH3CN 1:1 solution has no significant effect on E1/2ox1 and E1/2ox2 (see Supporting Information File 1). However, an increase in the oxidation potential (ΔE1/2ox1 = +0.04 V) was observed for the A2·PF6@TTFC7 complex in pure DCE, which can be attributed to the increased

Metal-free synthesis of phosphinoylchroman-4-ones via a radical phosphinoylation–cyclization cascade mediated by K₂S₂O₈

• Qiang Liu,
• Weibang Lu,
• Guanqun Xie and
• Xiaoxia Wang

Beilstein J. Org. Chem. 2020, 16, 1974–1982, doi:10.3762/bjoc.16.164

• obtained. Dimethylphosphine oxide (2k) did not participate in the reaction, likely due to its high oxidation potential and poor ability to undergo tautomerization [36]. To demonstrate the practicability of this methodology, a gram-scale experiment was next performed, employing 1b and 2a as substrates under

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

• . Rotaxane 1a presents a reversible redox transition at E1/2 = 0.51 V (that corresponds to E1/2 = +0.47 V vs SCE), where E1/2 = (Epa + Epc)/2 (Figure 6). As only one oxidation wave was observed, this showed that the two metal centres were electronically decoupled, while the oxidation potential of ferrocene

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• venerable transformations [39][40], allowing the smooth generation of alkyl radicals from carboxylic acid derivatives. One of the main strategies for accessing C(sp3) radicals from carboxylic acids relies on the oxidation of the CO2H group. However, the high oxidation potential of these species makes them

• hydrogen atom source (PhSH). The reaction allows the direct conversion of carboxylic acids, e.g., 3.1 to the corresponding alkanes, e.g., 3.2. The scope includes carboxylic acids that were previously recalcitrant to other oxidative photocatalytic decarboxylations due to their high oxidation potential

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

• to nickel(0) is believed to occur by β-hydride elimination on a sacrificial amount of amine [10]. The strained character of azaspiro[3,3]heptane might prevent this event. On the other hand, pyramidalization at nitrogen is much more important in azetidines [16][17][18]. This might lower the oxidation

• potential of the arylated product and promote oxidative decomposition. Several spirocyclic compounds with larger ring sizes could be coupled to 3-bromopyridine to give products 4c, 4d, 5a and 5b, provided that steric hindrance was not too high (see 5c). Surprisingly, oxetanes appear to be incompatible with

Copper catalysis with redox-active ligands

• Agnideep Das,
• Yufeng Ren,
• Cheriehan Hessin and
• Marine Desage-El Murr

Beilstein J. Org. Chem. 2020, 16, 858–870, doi:10.3762/bjoc.16.77

• interaction greatly affected the chemical properties. They also reported that complexes that had higher oxidation potential and went through irreversible oxidation were not good catalysts for the oxidation of benzyl alcohol to benzaldehyde (0–30% yields, e.g., PhPhCuO.S.2, O.S.x signifies oxidation state and

• incorporating two copper(I) centers. These specific quinidine ligands have the ability to supply electrons to the metal center thanks to their low oxidation potential and can shuttle up to two electrons to the copper centers. The specific geometry of this ligand also has an influence on the rate of electron

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

Visible-light-induced addition of carboxymethanide to styrene from monochloroacetic acid

• Kaj M. van Vliet,
• Nicole S. van Leeuwen,
• Albert M. Brouwer and
• Bas de Bruin

Beilstein J. Org. Chem. 2020, 16, 398–408, doi:10.3762/bjoc.16.38

• voltammetry to determine the oxidation potential (EOx) of monochloroacetic acid in acetonitrile (Figure 2). This way it could be verified, if monochloroacetic acid can quench the excited state of one of the common photoredox catalysts. In Figure 1 the cyclic voltammogram of monochloroacetic acid is shown. One

Synthesis of a dihalogenated pyridinyl silicon rhodamine for mitochondrial imaging by a halogen dance rearrangement

• Jessica Matthias,
• Thines Kanagasundaram,
• Klaus Kopka and
• Carsten S. Kramer

Beilstein J. Org. Chem. 2019, 15, 2333–2343, doi:10.3762/bjoc.15.226

• moiety of silicon rhodamines could tune the HOMO energy level [15]. Depending on the oxidation potential and the HOMO energy level of the benzene moiety, the quantum yield was greatly altered but absorption and emission bands remained unchanged. Thus, the quantum yield shows a direct connection to the

• negative value of the HOMO energy level and/or the oxidation potential [15], but it is also influenced by other factors. Nonradiative quenching (e.g., bond rotation) can effectively contribute to depopulation of the fluorophore’s excited state [28], yielding a lower quantum yield. However, the rational

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

• substituents R at the para-position of the benzene adjacent to the nitrogen centers were synthesized to tune the oxidation potential of the nitrogen centers (Figure 1). According to a previously reported method for the synthesis of ureas [45], symmetric ureas 1 were synthesized from the corresponding amines

• with that for 1b. This substituent effect on the oxidation potential is typical for the reported NAr3 system [53]. Because the electron-donating group of the NAr3 unit destabilizes the MV state, the potential splitting for 1a is 50 mV smaller than that for 1b (Figure 2, top). Similar substituent

Synthesis of acremines A, B and F and studies on the bisacremines

• Nils Winter and
• Dirk Trauner

Beilstein J. Org. Chem. 2019, 15, 2271–2276, doi:10.3762/bjoc.15.219

• undergo Diels–Alder reactions with electron-rich dienophiles [13][14][15][16][17], treatment of 5 with Fukuzumi’s catalyst [18] under illumination with blue light only led to decomposition of the starting material (Table 1, entry 15). Notably, a photoredox catalyst with a lower oxidation potential could

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

• oxidation potential of 0.38 V vs SCE [59]. Together with the reduction potential of Ered = 0.69 V and E00 = 3.25 eV for NDI 1 (vide infra), this electron transfer is clearly exergonic (ΔG = Eox − Ered − E00 = −2.2 eV). NDI 6 shows a strong and broad fluorescence in CH2Cl2 with a maximum at 640 nm and a

Selenophene-containing heterotriacenes by a C–Se coupling/cyclization reaction

• Pierre-Olivier Schwartz,
• Sebastian Förtsch,
• Astrid Vogt,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2019, 15, 1379–1393, doi:10.3762/bjoc.15.138

• ., a lowering of the oxidation potential with increasing number of selenium atoms (vide supra), seems to be blurred for the polymers. Published data for P(DTT) P1 is very similar showing an onset potential of −0.12 V vs Fc/Fc+ (calculated from 0.37 V vs Ag/AgCl) [46][52]. The redox characteristic of P1