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

• 4.95 ppm with a J value of 3.6 Hz in the 1H NMR spectrum proving the anomeric α-configuration. The presence of Troc-rotamers was also apparent, with a ratio of 19:6 being observed by 1H NMR in CDCl3 at 25 °C. Catalytic amounts of NaOMe (0.005 M) in MeOH were used to remove the acetate from compound 4

• in formation of a homogenous solution, but still no conversion to the sulfated product, even when the temperature was raised to 80 °C [28][29]. Switching the sulfating reagent to SO3·Py or performing the reaction at 150 °C in a microwave did not improve the outcome [30][31]. Since there was no

• -exchange resin, with no apparent presence of tin impurities by NMR when the sequence was executed in this order and sulfated target 2 was obtained in a 66% yield on a one-gram scale. Comparing the 1H,13C HSQC spectra of compounds 1 and 2, there is a clear downfield shift of the H-3’/C-3’ signal from 1 to

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

• C–C bond adjacent to the hydroperoxide group (Scheme 1a). The best-known application of this reaction is the cumene process, which allows the production of millions of tons of phenol each year [2]. The reaction has also been used in an industrial synthesis of artemisinin [3]. Allylic hydroperoxides

• ), successively involving a Schenck-ene photooxygenation of an alkene A, an acid-catalyzed Hock cleavage of hydroperoxide B generating an aldehyde derivative C, and an acid-catalyzed Friedel–Crafts reaction in the presence of an aromatic nucleophile leading to D [17]. In principle, a second Friedel–Crafts

• structure shows one disordered ethyl ester group (backward). Examples of cyclolignan natural products [25][26][27]. The Hock rearrangement: (a) General mechanism (substituents are omitted); (b) Example of previous tandem process; (c) Objective of this work. One-pot conversion of substrate 1 into

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• , employing activated and unactivated alkyl bromides as the halogenation reagents without additional external oxidants. This method features outstanding site selectivity, broad substrate scope, and excellent yields. Keywords: aminoquinolines; C–H bromination; copper catalysis; regioselectivity; Introduction

• important auxiliary group for the proximal C–H activation with the efforts of Daugulis [5] and others [6]. Results from medical research indicated that the introduction of halogen atoms into quinoline motifs has positive effects on their bioactivities, such as antimalarial, antitumor, and so on [7

• reaction parameters (Table 1). The treatment of 1a with 2a (4.0 equiv) in the presence of FeCl3 (20 mol %) and K3PO4 (1.0 equiv) in DMSO at 100 °C for 12 h gave the brominated product 3aa in 65% yield (Table 1, entry 1). The bromination was found to selectively take place at the C5-position of the

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

• the DCF molecule [83][84], as shown in Scheme 3. In the reaction between 4-ethynyl-N,N-dimethylaniline (1) and triisopropylsilylethynyl-substituted DCF 2a, heating at 80 °C in acetonitrile selectively yields the corresponding adduct 3a with 64% yield. In 3a, the anilino group forms a covalent linkage

• variation in the products arises from the difference in the initial reaction step, in particular, whether the nucleophilic attack of the alkyne carbon in 1 occurs at C(6) or C(1) of the DCF framework. This differentiation can be attributed to the efficient electron conjugation between the alkyne and

• fashion. For instance, the reaction of one equivalent of TCNE with two equivalents of 1 in chloroform at 50 °C for 36 h yields the corresponding TCHT 5 with 80% yield [101]. In this reaction, the nucleophilic attack of the alkyne carbon of 1 occurs at the C(2) carbon of 4. Moreover, when TCBD 6

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

• Academy of Sciences, Vavilova str. 28, 119991 Moscow, Russia 10.3762/bjoc.20.11 Abstract The photoreactions of selected styrylpyridine derivatives to the corresponding benzo[c]quinolizinium ions are described. It is shown that these reactions are more efficient in aqueous solution (97–44%) than in

• irradiation of the styrylpyridines and formation of the intercalator directly in the presence of DNA. In addition to the DNA-binding properties, the tested benzo[c]quinolizinium derivatives also operate as photosensitizers, which induce DNA damage at relative low concentrations and short irradiation times

• , even under anaerobic conditions. Investigations of the mechanism of the DNA damage revealed the involvement of intermediate hydroxyl radicals and C-centered radicals. Under aerobic conditions, singlet oxygen only contributes to marginal extent to the DNA damage. Keywords: DNA intercalators

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

• Laura Abella Gerard Novell-Leruth Josep M. Ricart Josep M. Poblet Antonio Rodriguez-Fortea Departament de Química Física i Inorgànica, Universitat Rovira i Virgili, C/Marcel·lí Domingo 1, 43007 Tarragona, Spain Hydrogen and Power-to-X Department, Iberian Center for Research in Energy Storage

• with irreversible C–C fusions [7]. In phase 1, a [2 + 2] cycloadduct C120 dimer is formed, which was initially proposed to be with Cs symmetry, in contrast to the X-ray structure for the C120 dimer that shows D2h symmetry [3][9]. In phase 2, irreversible structural rearrangements occur leading to a

• 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

• coefficient, c is the concentration of a light-absorbing solute, and d is the optical path length. Figure 8 shows the measured absorbance as function of the photocatalyst loadings in the methanol/water solution using different optical path lengths. The absorbance depends linearly on the photocatalyst

• Equation 2 and Equation 3: where PR represents the predicted maximum photocatalytic hydrogen generation rate (µmol h−1), q is the photon flux (µmol s−1), c is the photocatalyst loading (g L−1), v is the stirring speed (rpm), and is the inert gas flow rate (mL min−1). The response surfaces for the modified

• conventional experimental approach, the photocatalyst loading and the stirrer speed were investigated as well. Photon flux: The effect of the photon flux on the temporal evolution of the hydrogen generation rate was investigated individually for a constant set of operating parameters (c = 0.22 g L−1, v = 560

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• lengths of the bonds (b–f) within the five-membered rings of the cores as well as the exocyclic C=C double bond (a) that is present in compounds 25 and 26 (for bond labels, see Figure 11). A small difference in the exocyclic C=C bond length is observed between 25 and 26, with the bond in 26 being slightly

• longer. Bonds b and f are affected by the moiety X, with the less π-delocalized structure 29 having the longest bonds of 1.51 Å, while only minor differences are observed for bonds c, d, and e. Conclusion In summary, various redox-active chromophores based on the indenofluorene scaffold were synthesized

• Cary 50 UV–vis spectrophotometer scanning between 800 and 200 nm. All spectra were recorded with baseline correction in CH2Cl2 or toluene (HPLC grades) at 25 °C in a quartz cuvette with a 10 mm path length. Electrochemistry Cyclic voltammograms (CV) and differential pulse voltammograms (DPV) were

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

• effect [15][33][34]. As a result, the volume fraction of DWCNTs at the edge increased. Notably, the widths of bundled DWCNTs at the edge were larger than in the inner region (Figure 5b,c). The direction of the bundled DWCNTs near the film surface were parallel to the shear direction in both regions. Due

• acetone using a bath-type sonicator and were put onto a copper grid with carbon mesh. To perform thermogravimetric analysis (TGA), a TG/DTA7300 instrument from SII Nano Technology Inc. was utilized. The DWCNT powder was preheated at 180 °C for ten minutes under vacuum and subsequently measured under

• flowing air (200 mL/min) at a ramping rate of 1 °C/min. The Raman and absorption spectra were obtained from DWCNT thin film on a silicon substrate. The DWCNT thin film was prepared using vacuum filtration. Raman measurements were conducted using a HORIBA T64000 532 nm laser, while far-infrared (FIR

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

• phosphorus signal for 2d). Stability tests were also performed in two different deuterated solvents, CDCl3 and DMSO-d6. No air or moisture exclusion was applied. The tests were performed at room temperature and at 60 °C. 1H and 31P NMR spectra of the solutions were taken after 24, 48 and 72 h. At room

• detected in the 31P NMR, giving rise to peaks at 32.0 and 17.8 ppm. The overall decomposition at room temperature in both solvents after 72 h is less than 2%. At 60 °C, the decomposition is somewhat faster. After 72 h, the overall decomposition is less than 5% in both solvents according to 31P NMR spectra

• primary adduct A (see Scheme 2) is too short-lived that an intramolecular hydrogen transfer toward 2a (C, in Scheme 2) is occurring [48]. Instead, in case of acrylonitrile another hydrogen bond donor, which is the solvent methanol [49], is necessary to trap intermediate A forming the ion pair D. Finally

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• -solubilization and modification of nanocarbons (NCs). b) Bent aromatic amphiphiles AA and PA-R (R = CH3 and CH2CH2(OCH2CH2)2–Y (Y = OCH3, OH, and imidazole)). c) Nonionic surface modification of NCs via noncovalent encircling with PA-Rs. a) Synthetic route toward prePA and PA-CH3, including the optimized

• structure (DFT) of PA-CH3. b) Structures of PA-OCH3, PA-OH, and PA-Im. 1H NMR spectra (500 MHz, rt, 0.5 mM and 1.0 mM based on PA-CH3 and PA-OCH3, respectively, TMS in CDCl3 as external standard) of a) PA-CH3 in CD3OD, b) (PA-CH3)n in D2O, c) PA-OCH3 in CD3OD, and d) (PA-OCH3)n in D2O. DLS charts (rt, H2O

• , (PA-OH)n·(C60)m, and (PA-Im)n·(C60)m. c) Relative uptake efficiencies (λdet = 525 nm) of C60 by PA-R and AA. d) DLS charts (rt, H2O, 1.0 mM based on PA-Im) of (PA-Im)n·(C60)m and (PA-Im)n. e) Optimized structure (MM) of (PA-Im)5·C60. UV–visible spectra (H2O, rt, 1.0 mM based on PA-OCH3) of f) (PA-OCH3

NMRium: Teaching nuclear magnetic resonance spectra interpretation in an online platform

• Luc Patiny,
• Hamed Musallam,
• Alejandro Bolaños,
• Michaël Zasso,
• Julien Wist,
• Metin Karayilan,
• Eva Ziegler,
• Johannes C. Liermann and
• Nils E. Schlörer

Beilstein J. Org. Chem. 2024, 20, 25–31, doi:10.3762/bjoc.20.4

• Luc Patiny Hamed Musallam Alejandro Bolanos Michael Zasso Julien Wist Metin Karayilan Eva Ziegler Johannes C. Liermann Nils E. Schlorer Zakodium Sàrl, Route d'Echandens 6b, 1027 Lonay, Switzerland Faculty of Chemistry and Earth Sciences, Friedrich Schiller University, 07743 Jena, Germany Chemistry

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• opening of triazole 6 to form diazo compound anti-7, followed by rotation around the C‒C bond of the amidine group to furnish rotamer syn-7 which then undergoes 1,5-dipolar cyclization to products 3. The second path involves a Dimroth-type cyclization to form products 3′, which however, were not

• ethyl 2-cyanoacetimidate and corresponding amines according to the literature procedure [17] and compounds 1a,c–e,h–j are commercially available. Azides 2a–d,f,g were synthesized according to the literature procedures [18][19][20][21][22][23], and azide 2e is commercially available. Preparation of

• hydroxide, freshly prepared from sodium hydroxide (20 mg, 0.5 mmol) and ethanol (2 mL), and the resulting mixture was stirred at room temperature for 5–10 min. Then, the mixture was cooled to 0 °C, the corresponding azide 2 (0.5 mmol) was added and the resulting mixture were stirred for 30 min, after which

Synthesis of N-acyl carbazoles, phenoxazines and acridines from cyclic diaryliodonium salts

• Nils Clamor,
• Mattis Damrath,
• Thomas J. Kuczmera,
• Daniel Duvinage and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 12–16, doi:10.3762/bjoc.20.2

• , this new method creates two C–N bonds simultaneously based on a mono-halogenated starting material, thus allowing heterocycle formation with diminished halogen waste. Keywords: carbazoles; heteroaromatics; iodanes; metal-catalyzed; one-pot reaction; Introduction N-Acyl carbazoles are effective

• method to produce this versatile N-acyl carbazole motif involves combining 9H-carbazoles with acyl chlorides or similar activated acyl derivatives in the presence of a base (Scheme 1a) [13][14]. As an alternative, acyl carbazoles can be synthesized through step-wise metal-catalysed C–X-amidations

• [33][34]. Results and Discussion Initially, we investigated the synthesis of N-acyl carbazole by treatment of diaryliodonium salt 1a with valeramide using Cu(I) catalysts [18]. The results are shown in Table 1. In the first experiments in p-xylene at 120 °C with DMEDA as N,N-ligand, only modest

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

• in Supporting Information File 1). In addition, S. albus-cma produced compound 6, which showed [M + H]+ ion at m/z = 222, as well as other putative 3,4-AHBA derivatives, among which compound 9 was indicated to be N-acetyl-3,4-AHBA (9) by its mass and UV spectra (Figure 2B and Figure S3B,C,E,F in

• inoculated into 10 mL of Tryptone Soya Broth (TSB) medium with kanamycin (50 mg/L) and incubated with shaking (300 rpm) at 30 °C for 2 days. One milliliter of this preculture medium was inoculated into 100 mL of Waksman medium (5 g/L BactoTM peptone, 5 g/L BactoTM yeast extract, 20 g/L glucose, 5 g/L meat

• extract, 5 g/L NaCl, and 3 g/L CaCO3) with kanamycin (50 mg/L), and incubated with shaking (120 rpm) at 30 °C for 2 days. Thiostrepton (15 mg/L) was then added to the culture, and the culture was continued for another 1 day. After incubation, brine (0.5 mL) was added to 5 mL of the culture, and the

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

• Marta David Elisa Galli Richard C. D. Brown Marta Feroci Fabrizio Vetica Martina Bortolami Department of Basic and Applied Sciences for Engineering (SBAI), Sapienza University of Rome, via Castro Laurenziano, 7, 00161 Rome, Italy School of Chemistry, University of Southampton, Southampton SO17 1BJ

• examples of the hydration reaction of alkynes carried out in ILs. In one case, a dicationic IL, containing sulfuric acid as catalyst, was used as reaction medium to carry out the hydration of different alkynes under mild conditions (40–60 °C, 0.5–1 h) [84]. In a second case, different Brønsted acid ionic

• liquids (BAILs) have been used both as medium and as catalysts for the hydration of various alkynes (60 °C, 10–24 h) [85][86]. In these works, the ILs were efficiently reused for subsequent reaction cycles. Another research group reported the use of commercially available 1-butyl-3-methylimidazolium

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• full-length 800 bp GFP gene construct was transformed into NEB® 5-alpha chemically competent cells (step 7', Figure 1). The transformed cells were plated on kanamycin plates and grown at 37 °C overnight. Colony PCR was carried out over selected colonies, and the PCR products were analyzed with agarose

• expression by requiring rhamnose induction, were used for the transformation (step 8, Figure 1). The cells were plated on an agar plate containing kanamycin and incubated at 37 °C overnight. Cells from a single colony on the plate were incubated in LB containing kanamycin. A portion of the culture was plated

• sequencing. (c) Sequence analysis via transforming NEB® 5-alpha cells, colony PCR, gel electrophoresis (Figure 2C), and Sanger sequencing. CBP, catching-by-polymerization. GFP, green fluorescent protein. nt, nucleotide. PCR, polymerase chain reaction. Gel electrophoresis images of 399 bp (A), 401 bp (B), and

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• just three decades (Figure 1) [2]. In particular, cyclic diaminocarbenes based on the imidazoline, benzimidazole, or imidazole ring system (A–C) have led to a myriad of applications in organometallic chemistry, homogeneous catalysis, and materials science, to name just a few [3][4][5]. Due to their

• applications [24][25][26][27][28]. N-Heterocyclic carbenes and their enetetramine dimers readily add to the central carbon atom of allenes and heteroallenes X=C=Y (X, Y = CR2, NR, O, S) to afford zwitterionic adducts [29]. In particular, their reaction with carbon disulfide affords stable azolium-2

• (−)-menthone was obtained in a separate step by deprotonating the corresponding aldiminium triflate with lithium diisopropylamide (LDA) at −78 °C [8]. Herein, we disclose the synthesis of three CAAC·CS2 and six MIC·CS2 inner salts from the corresponding aldiminium or 1,2,3-triazolium salts and carbon disulfide

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• spirooxindoles [36][37][38][39][40][41][42][43]. In the presence of Lewis bases, isatin-derived MBH carbonates usually undergo [3 + 2] and [3 + 3] cycloaddition reactions with a broad range of active C–C and C–N double bonds and 1,3-dipolarpohiles to give various five- or six-membered cyclic spirooxindoles [44

• shortened to 12 h or prolonged to 36 h (Table 1, entries 8 and 9). Also, neither decreasing or increasing the reaction temperature did improve the yield of product 3a which was obtained in 26% yield at 0 °C and 52% yield in refluxing DCM, respectively (Table 1, entries 10 and 11). In the presence of

• methods. Because there are one C=C bond and one C=N bond in the molecules 3a–m, no diastereoisomers are obtained. Therefore, the 1H NMR spectra gave simple absorptions for the characteristic groups in the molecules. For further developing the scope of the [4 + 3] cycloaddition reaction, MBH esters of

Beyond n-dopants for organic semiconductors: use of bibenzo[d]imidazoles in UV-promoted dehalogenation reactions of organic halides

• Kan Tang,
• Megan R. Brown,
• Chad Risko,
• Melissa K. Gish,
• Garry Rumbles,
• Phuc H. Pham,
• Oana R. Luca,
• Stephen Barlow and
• Seth R. Marder

Beilstein J. Org. Chem. 2023, 19, 1912–1922, doi:10.3762/bjoc.19.142

• achieved using highly reducing metals, molecular reductants can potentially enable more selectivity, as required for the use of such reactions in the synthesis of molecules bearing various functional groups. In particular, Wanzlick dimers (C=C-bonded dimers of N-heterocyclic carbenes, Figure 1a, i) have

• to any detectable BnSiMe3, thus supporting a radical dimerization pathway (see Supporting Information File 1, Table S3). As in the case of sp2 R–X systems, only small extents of dehalogenation for R = aryl are observed in the absence of reductants. For the more easily reduced aryl halides (3a–c

• . Specifically, we examined 2-iodobenzyl chloride, in which the C–I and C–Cl bond strengths are expected to be fairly similar (C–X bond dissociation enthalpies of 280 and 310 kJ mol−1 have been reported for BnCl and PhI, respectively [38]), but the aryl–I bond is likely to be better coupled to the reduction

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• (19) in the presence of activated zinc dust in THF (Scheme 4) [35]. By making minor adjustments to the reaction conditions, such as employing DMF as the solvent and raising the temperature to 100 °C, along with utilizing compound 20 as the starting material, Barton and his team achieved the synthesis

• researchers efficiently conducted palladium-catalyzed C–H activated annulation reactions, involving oxanorbornadiene derivative 26 and aryl bromides including dibromoanthracene 27 [38]. Subsequent aromatization reactions were then carried out, resulting in the successful synthesis of the target POAs with high

• reactions involving 1,4-dibromo-2,5-dichlorobenzene (31) and substituted oxanorbornenes (26 and 30b,c), products 32a–c, with R groups representing (a) H, (b) F, and (c) –OCH2O–, were successfully synthesized, albeit with moderate yields (Scheme 7). Following that, compounds 32a–c underwent derivatization

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

• macrodipoles. (C–E) Anion–π catalysis on (C) C60 fullerenes 1, (D) SWCNTs 2 and (E) MWCNTs 3. Part E of Figure 1 was adapted from [44] (© 2023 M. A. Gutiérrez López et al., published by the American Association for the Advancement of Science, distributed under the terms of the Creative Commons Attribution 4.0

• , catalyst inactivation with 70 in formal complex 71 and product 69 in formal complex 72 supports anion-π catalysis but not autocatalysis. (B) Electric-field-induced anion–π catalysis on MWCNTs 3 in electrochemical microfluidic reactors, with reactor design (C) and notional transition states for ether

• cyclization of 68 at positive (XVIII), zero (XVII) and negative voltage (XIX). Parts B and C of Figure 9 were adapted from [44] (© 2023 M. A. Gutiérrez López et al., published by the American Association for the Advancement of Science, distributed under the terms of the Creative Commons Attribution 4.0

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

• of 2 to the corresponding 2,6-dibromo-4-(4-bromophenyl)pyridine-3,5-carbonitrile (3) was carried out by melting of compound 2 with phosphorous oxybromide without any solvent at 170 °C for 1 h in good yield. According to the previously reported procedure [4][5], 2,6-bis(3,6-di-tert-butylcarbazol-9-yl

• copper(I) iodide in DMF/DIPEA solution at 55 °C with subsequent desilylation with potassium carbonate. Finally, butadiyne 6 was prepared by a homocoupling reaction of 5 with 80% yield. Derivatives containing two dicyanopyridyl moieties, 7 and 8, were prepared starting with a Sonogashira coupling of

• observed during the 1st and 2nd DSC heating and cooling scans. However, glass transitions were detected for all the studied compounds. The glass transition temperatures (Tg) fall in the range between 63 and 93 °C (Figure 5b). A correlation between the glass transition temperature and the molecular weight

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• , such as alkyl halides. In this study, the thermal reaction of the La@C2v-C82 anion with benzyl bromide derivatives 1 at 110 °C afforded single-bonded adducts 2–5 with high regioselectivity. The products were characterized by matrix-assisted laser desorption/ionization time-of-flight mass spectrometry

• °C for 2 h (Scheme 1). Figure 1 depicts the changes in the visible–near infrared (vis–NIR) absorption spectra during the reaction, showing gradual changes with isosbestic points. Since the electrolyte interferes with the high-performance liquid chromatography (HPLC) separation and anionic species may

• ][25]. Regardless of the substituents (a–c) of benzyl bromide, 2, 3, 4, and 5 exhibited similar characteristic absorption features, respectively, supporting that the addition site of each isomer (e.g., 2a–c) are the same. We determined the addition sites of the single-bonded La@C2v-C82 derivatives, La

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• )-catalyzed N–H insertion reactions involving NH-heterocycles. The proposed method enables the synthesis of multigram quantities of diazo compound 5 rapidly. Furthermore, it can be stored up to several weeks in the refrigerator (5 °C) without any observable alterations. A diverse array of NH-heterocycles with

• (OTf)2 and Cu(acac)2 in DCE at 80 °C) in reaction with ethyl isonipecotate (see Supporting Information File 1 for details). While in the case of Cu(OTf)2 (5 mol %), the reaction mixture did not contain the desired product 6r, using Cu(acac)2 (10 mol %) resulted in 25% NMR yield of the insertion product

• , C–H insertion products 9 were also observed. Thus, when reacting with indole, the product of carbenoid attack at position 3 (9a) was isolated along with target compound 6a. Introduction of a carbomethoxy group into this position of indole leads to the exceptional formation of the N–H insertion