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

• ] (Scheme 7A). Cyclic voltammetry measurements of a model NHPI ester showed a shift in its reduction potential from –1.79 V to –1.51 V (vs SCE in MeCN) in the presence of In(OTf)3. As such, it was hypothesized that the Lewis acid lowers the LUMO of the NHPI ester via interaction with the oxygen lone pair in

• oxidative quenching photocatalytic cycle employing Ir-based photoreductants and a Brønsted acid additive. While the interaction between the RAE 32 and diphenyl phosphoric acid involves hydrogen bonding, in analogy to the Glorius proposal, it is thought that the substrate activation occurs through proton

• electron reduction of 58, generating the persistent radical 147 and the transient species 148, which fragments into tert-butyl radical (64). Notably, the reduction of NHPI ester 58 could be facilitated by interaction of a cesium cation with the oxygen lone pair of the phthalimide, in analogy to the

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• electrophilic center C(1) of 1 is much lower. It comes, therefore, with no surprise that the interaction of arylamines and the 5-hydroxy and 5-acetoxy derivatives of 3H-phenoxazin-3-one is directed toward the C(2) reaction center to yield 2-amino-3H-phenoxazin-3-ones as the final products under aerobic

Spatial arrangements of cyclodextrin host–guest complexes in solution studied by ¹³C NMR and molecular modelling

• Konstantin Lebedinskiy,
• Ivan Barvík,
• Zdeněk Tošner,
• Ivana Císařová,
• Jindřich Jindřich and
• Radim Hrdina

Beilstein J. Org. Chem. 2024, 20, 331–335, doi:10.3762/bjoc.20.33

• spectra indicated the interaction of the guest molecule with the host. In cases where the split of prochiral carbons was observed, 13C NMR spectra showed which pair of prochiral carbons in the guest molecule is close to the wall of the host’s chiral cavity, creating an anisotropic environment. For

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• ) spectroscopy to derive binding constants for the interaction between CMA1 and GalNAc. A single cycle kinetics approach was applied, resulting in a measured KD of 1.66 ± 0.08 µM (Figure 3d,e). Inhibiting binding of CMA1 to the GalNAc chip through a dilution series of N-acetyllactosamine (LacNAc) via multicycle

• interaction with the aromatic ring of Tyr26 (Figure 4c). Further, beyond the C2 position of galactose, a cavity filled with coordinated water molecules hinted at the binding mode for C2-substituted galactose. Notably, the seemingly inactive beta site was found to be occupied by a cadmium ion (Figure S4

• (CA18132) and INNOGLY (CA18103) COST actions awarded to J.L. This work was further supported by the Protein-Glycan Interaction Resource of the CFG and the National Center for Functional Glycomics (NCFG) at Beth Israel Deaconess Medical Center, Harvard Medical School (supporting grant R24 GM137763). The

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• , along with the 5-membered 1,8-naphthalene disulfide 49 resulting from the ring contraction of precursor 47. Such SO transfer process, favoured by the peri-interaction existing in the trisulfide-2-oxide substrate, was also successfully promoted by light and the cyclic sulfoxide 50 was obtained under

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process

• Kazuhiro Okamoto,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2024, 20, 264–271, doi:10.3762/bjoc.20.27

• amidyl radical generation through the PCET mechanism. The above studies provided us with valuable insights into the intriguing electrochemical behavior of 1 (Figure 3). Hydrogen bond formation between 1 and the phosphate base yielded small aggregates, the interaction efficiency of which with the

• radical could access MVK because it still had a large surface area for interaction with the solution interface. As mentioned above, the amidyl radical can also be generated through N−Cl species B. However, the large hydrogen-bond complex, which included HFIP, prevented amidyl radical access to MVK. In

• was 0.01 M. A glassy carbon anode (φ 3 mm) and Pt cathode (φ 3 mm) were used. Scan rate = 100 mV/s. Plausible models illustrating the size effect of the hydrogen bond complex on the interaction efficiency with electrode surfaces. Plausible mechanism for the inter-/intramolecular hydroamination of 1

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• unchanged, although quinoline and its derivatives are easily aminated under the same conditions [17]. No interaction occurred under the conditions of the Chichibabin reaction in an attempt to aminate compound 5 with sodium amide in N,N-dimethylaniline at 140–155 °C for an hour. Thus, quinoquinoline 5

• assumed admixture 11. Mononitration of compound 5. Dehydrogenation of compounds 10 and 11. Nucleophilic methoxylation of compounds 10(12). Electrophilic bromination of compound 5. tele-Elimination upon interaction of dibromide 15 with pyrrolidine. Interaction of dibromide 15 with anionic bases. Comparison

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• -aryl-N'-alkylindigo photoswitches 22b, 23c and 23d upon addition of Li+ cations. These studies revealed that the presence of the electron-withdrawing groups on the aryl moiety decreased the charge density on the carbonyl groups and weakened the interaction of the Z-isomers with Li+ that accounted for

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• (β-ᴅ-GalNAc-(1→4)-β-ᴅ-GlcNAc), which have then been used for production of the glycodenrimersomes and interaction studies with various galectins [1][2]. In the continuation of this collaboration, to investigate the binding of siglec-1 and the chimera of 3’-SuTF-binding siglecs and TF-binding galectin

• -3, TEG-N3 glycosides of the TF antigen (β-ᴅ-Gal-(1→3)-α-ᴅ-GalNAc, 1) and its 3’-O-sulfated analogue (2, Figure 1) were required on a gram scale to allow efficient synthesis of the glycodendrisomes. The TF antigen is presented on the surface of most human cancer cell types and its interaction with

• been developed for further interaction studies with lectins (galectins and siglecs). The synthesis of the 3’-Su-TF antigen 2 comprises eight steps from the known N-galactosamine donor 3, where two of the steps, removal of the Troc- and DTBS protecting groups are performed in the same pot and the

Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• oxocarbenium 7 and 7’ which exists as a stabilized form including an intramolecular stabilizing interaction between the carbocation and the ester carbonyl group. However, in close agreement with Hess and Baldwin’s values found for the rearrangement of cis-1,3-pentadiene [24], this transition state was high in

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• ) in Na phosphate buffer, cNa+ = 16 mM. Blue: spectrum of the starting material before irradiation; red: spectrum at the end of the irradiation. Photoinduced formation of benzo[c]quinolizinium and its interaction with DNA upon intercalation. Synthesis of styrylpyridine derivatives 2a–g. Conditions: i

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations

• Laura Abella,
• Gerard Novell-Leruth,
• Josep M. Ricart,
• Josep M. Poblet and
• Antonio Rodríguez-Fortea

Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10

• nanotubular-shaped fullerene inside the peapod. Kinetic analysis with the variable-temperature (VT) SMART-TEM method for the aforementioned C60 dimerization has also been reported by these authors [9]. They concluded that the SWCNT, which accumulates energy by the interaction with the electron beam, activates

• analyzed the interaction between C60 and the nanotube within the peapod. Next, we have found that some dimeric C60–C60 fullerene structures inside the carbon nanotube are thermodynamically favorable. Experiments indicate that, besides C60 sensitization via a singlet excited state, the [2 + 2] cycloaddition

• the subsequent irreversible C–C fusions occurring in phase 2 are proposed with the help of accelerated Car–Parrinello MD simulations. Results and Discussion Nanotube-C60 interaction: stabilization of the peapod First, we estimated the size of the stabilizing interaction that holds the peapod, that is

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

• check if there are any interactions between the studied parameters. After the insignificant parameter interaction terms were removed from the quadratic model, the interaction of photocatalyst loading and stirring speed has a “Prob>F” value of 0.0279, which means this interaction term also significantly

• affects the maximum hydrogen generation rate. The interaction effect was summarized in the modified quadratic model, which has a difference between R2adj and R2pred of 0.0863. Moreover, an ANOVA showed that the p-value of the linear and modified quadratic model is lower than 0.0001, which confirms that

• actual experimental hydrogen generation rate could be achieved. No significant difference between the prediction accuracy of the two models is observable. The only difference between the two models is that the modified model considers the interaction of parameters. Therefore, to validate the model from

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• beneath the thick bundles form mesh-like structures. The shear force exerted by the bar may not sufficiently align the DWCNTs located near the substrate. Thus, optimizing the interaction between the DWCNTs and substrate is necessary to improve the alignment. To further investigate the low alignment, the

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• O1–C15 and O1–C16 distances are in 2a 3.128(3) and 3.162.3(3) Å and in 2f 3.098(4) and 3.019(4) Å, suggesting a weak hydrogen bonding interaction between O1 and the protons of the methylene groups [43]. The P1–O1 distances of 2.750(1) Å in 2a and 2.693(3) Å in 2f suggest an electrostatic interaction

• lines) and in methanol (dotted lines); the inset shows a photograph of a vial containing a solution of 2a in chloroform; right: proposed hydrogen bonding interaction in 2b in CHCl3. Conversion of 1 (initial c = 0.25 mM) toward 2a, 2b, or 2d in the presence of the respective Michael acceptors (initial c

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• CmaA2 and CmaA3 for CmaA1) is a matter of interest. The fact that AvaA1 and CmaA1 recognized CmaA3 and AvaA3, respectively, as partner ACP suggests that there are some important residues conserved between AvaA3 and CmaA3 for the ligase–ACP interaction. Indeed, two amino acid residues (Trp38 and His41 of

• protein–protein interaction between the carrier protein and AMP-dependent ligase and (ii) the chain length control of highly reducing type II PKSs. Experimental Strains, chemicals, and enzymes E. coli JM109 was used for DNA manipulation, and E. coli BL21(DE3) was used for expressing recombinant proteins

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

• ‒ hydrolysis in a 1:1 in volume IL/water solution kept at 45 °C for 24 h) [105]. It should be noted that the same treatment carried out on 1-methyl-3-octylimidazolium tetrafluoroborate (OMIm-BF4) evidenced a much higher extent of BF4‒ hydrolysis. This is probably due to the weaker interaction between cation

• and anion of the IL as the length of the side alkyl chain increases, which makes the BF4‒/water interaction more effective. Although Saihara and co-workers demonstrated that BF4‒ hydrolysis generates HF, which reacts with the surrounding glass container yielding SiF62‒ (signal at −130 ppm in 19F NMR

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• be a potential mechanism of GAG particular sequence recognition by proteins. Keywords: glycosaminoglycan; molecular docking; protein–glycosaminoglycan interaction specificity; RS-REMD; umbrella sampling; Introduction Glycosaminoglycans (GAGs) are long linear periodic anionic polydisperse

• , computational approaches could be efficiently used to gain insight into protein–GAG interactions that take place at single-molecule levels [32]. More than a complementary tool, computational approaches provide a better understanding of the role of individual interaction partners (including GAGs, solvent, and

• simulations were set up. First, hybrid GAGs (Figure 1) were prepared and docked using RS-REMD to find the pose in the binding site with the lowest interaction energy. Then, the GAG was pulled away from the binding site until it was shifted 40 Å from the starting position. Afterwards, the GAG was pulled in

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• activity of fullerene 8 with A/D8/9 = 2.6 (Figure 3) leaves little room to improve, and the interaction between convex aromatic surfaces is not favorable. Taken together, anion–π catalysis on multiwalled carbon nanotubes (53, A/D = 7.3) is better than on single-walled carbon nanotubes (49, A/D = 2.0) and

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• )-4-(4-bromophenyl)pyridine-3,5-carbonitrile (4) was obtained by the interaction of 3,6-di-tert-butyl-9H-carbazole with compound 3 in THF/DMF solution. The ethynylphenyl-substituted pyridine 5 was synthesized by Sonogashira coupling of 4 with ethynyltrimethylsilane in the presence of PdCl2(PPh3)2 and

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• for organic electronic applications [12][35]. Dimesitylboron (DMB), with its unoccupied p-orbital, is an electron-acceptor organoboron compound used in several donor–acceptor systems to provide the system with pull–push interaction [36][37]. In this work, we have designed and synthesized a D–π–A model

• -TPA (8) exhibited a mono-exponential profile having a 3.20 ns fluorescence decay pattern (Figure S1 in Supporting Information File 1), demonstrating a strong pull–push interaction in steady-state time resolved fluorescence performance. OLED application An OLED was fabricated using a standard

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• a wide range of transformations [7][8]. Moreover, they proposed a plausible mechanism for the aforementioned conversions (Scheme 2). Initially, an NaI/PPh3 complex I was formed through a cation–π interaction. Subsequently, the combination of complex I with N-(cyclohexanecarbonyloxy)phthalimide

• radicals for alkenylation, was primarily facilitated by the electrostatic interaction between NaI and Katritzky salts 7. This innovative approach not only expanded the scope of photoredox cross-coupling reactions but also offered valuable insights into the role of NaI in facilitating these transformations

• . An EDA complex was formed through non-covalent interaction between the redox ester 10 and n-Bu4NI (Scheme 7). Subsequently, upon the photoexcitation, radical pairs I were generated via a SET process, accompanied by the liberation of CO2 and the phthalimide anion. The recombination of the alkyl

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• derivatives are among the most investigated due to their easy functionalization, high chemical and thermal stability, strong photoluminescence, and n-type semiconductor character. They tend to adopt columnar organization due to the strong π–π interaction of the rigid cores, providing a path for the efficient

• previously observed for another perylene-based ColLC compound, indicating the strong molecular interaction between neighboring molecules inside the columnar structure [33]. Due to the high temperature of the Iso phase for 2, the PL intensity almost vanished. However, a slight increase could also be observed

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• phenolic hydroxy group and the azomethine nitrogen was identified in the solid state and seems to be maintained in solution. Moreover, the presence of the electron-withdrawing nitro substituent makes this interaction stronger. However, the contact should probably not subsist for the nitro compound under

• ), it becomes possible to calculate the contribution of each type of intermolecular interaction to the whole profile [44]. In our case, results show that the sum of π···π and C–H···π contacts comprises almost 20% of the Hirshfeld surface for both compounds. The curvedness maps were also plotted over the

• Hirshfeld surfaces and evidence the strong flatness of the structures (Figures S2B and S3B in Supporting Information File 1). Important contributions of hydrogen bonds (O···H/H···O) can also be found, especially for hdz-NO2. Besides the interaction maps, crystal structures themselves may be used to

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• , resulting in an efficiency of 18% and marking a significant advancement in OSC research [27]. Zhou and co-workers synthesized Y6-type NFA acceptors, Qx12 and Qx13, by substituting Y6’s benzothiadiazole ring with a Qx moiety. Qx13 exhibited a stronger π–π interaction compared to Qx12, which facilitated

• study raises a concern regarding the performance of dyes with tert-butyl substituted DPQ acceptors, either containing benzene (Qx74) or thiophene (Qx75) as a π-conjugation linker and their benzotriazole analogue. While the incorporation of the Qx enhances the interaction between the donor and acceptor