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

• quinolines, at the benzene ring, and the resulting nitro compounds could potentially be subjected to further transformations, including nucleophilic substitution of nitro groups. Indeed, under the action of a small excess of the nitrating mixture, dipyridoacenaphthene 5 undergoes double nitration at

• decided to carry out its oxidation to 12 by the traditional method – the action of chloranil in boiling benzene or chloroform (in the latter, the solubility of the components is somewhat better, although the temperature of the process decreases). At the end of the synthesis, the reaction mass was treated

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

• and C=O bonds of the indoxyl groups are somewhat longer than typical double bonds of these types (Figure 3). On the contrary, the C–N bonds in indigo are much shorter than the single C–N bond in pyrrolidine, while the lengths of the C–C bonds in the fused benzene rings are approximately the same as in

• benzene (Figure 3). This indicates that in addition to structure I, which is traditionally used to depict indigo, intraionic resonance structures II and III with single C–O bonds and double C=N bonds make a pronounced contribution in the ground state of indigo (Figure 3) [13][14]. In the excited state

• , the resonance structures II and III with separated charges become predominant, while both benzene rings remain fully aromatic. The indigo dye contains two heterocyclic indole ring systems, which are connected through a double bond and have 22 π-electrons [16][17]. However, only 10 π-electrons are

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• –Lam/carbonylative cyclization After disclosing the optimal conditions for the Chan–Lam coupling, we screened different varieties of o-phenylenediamine derivatives. Overall, the o-phenylenene substrates bearing electron-donating substituents on the benzene ring proceeded smoothly under these conditions

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• dried at 80 °C in vacuo (0.1 Torr, 1 h)) was added. The mixture was stirred at room temperature (≈20 °C) until complete consumption of the starting material (TLC monitoring, Rf = 0.10 (7), Rf = 0.57 (2), benzene/EtOAc 9:1). The reaction mixture was concentrated under reduced pressure, the residue was

• triturated with anhydrous benzene (5 mL), and the extract was filtered through a PTFE microfilter (0.45 μm, 13 mm diameter, Iso-Disk, Supelco). The filtrate was concentrated under reduced pressure and the residue was dried in vacuo to give 2 as a colorless solid (118.8 mg, 73%). [α]D19 −87.4 (c 4.3, CHCl3

• ); Rf 0.57 (benzene/EtOAc 9:1); 1H NMR (300 MHz, CDCl3, δ, ppm, J, Hz) 2.25 (dd, J3a,3e = 13.9, J3a,4 = 11.7, 1H, H-3a), 2.82 (dd, J3e,3a = 13.9, J3e,4 = 4.8, 1H, H-3e), 3.71 (s, 3H, OMe), 3.96 (ABq, ΔδAB = 0.03, JAB = 15.0, 2H, CH2Cl), 4.09 (ABq, ΔδAB = 0.02, JAB = 15.4, 2H, CH2Cl), 4.12 (dd, J9a,9b

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

• glycosylation reactions. The 3’-sulfate was finally introduced through tin activation in benzene/DMF followed by treatment with a sulfur trioxide–trimethylamine complex in a 66% yield. Keywords: regioselective sulfation; thioglycoside donors; Thomsen–Friedenreich antigen; Introduction In a collaboration

• observable sulfation taking place, the tin-activation step was suspected to be the root of the problem. To rectify this, similar to Malleron et al., 1 was refluxed, in a Dean–Stark set-up, with Bu2SnO in benzene/DMF (5:1, v/v) [32]. The solvent in the receiver was drained after 24 hours and the benzene was

• -galactopyranoside sodium salt (2): Compound 1 (1.24 g, 2.29 mmol) and Bu2SnO (645 mg, 2.75 mmol) were placed under N2 together. Dry benzene/DMF (380 mL, 5:1, v/v) was added and the reaction was refluxed at 125 °C using a Dean–Stark apparatus. After 24 hours, the solvent in the receiver was drained, and the benzene

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

• CH2Cl2 (CD2Cl2, 1H = 5.32 ppm, 13C = 54.00 ppm), deuterated DMSO ((CD3)2SO, 1H = 2.50 ppm, 13C = 39.53 ppm), deuterated acetone ((CD3)2CO, 1H = 2.05 ppm, 13C = 29.84 ppm), or deuterated benzene (C6D6, 1H = 7.16 ppm, 13C = 128.39 ppm) were used as solvents and internal references. Chemical shift values

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

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

• ; biphenylene; [N]phenylenes; polycyclic aromatic compounds; Introduction Acenes represent an important category of carbon-rich polycyclic aromatic hydrocarbons (PAHs) characterized by the presence of linearly fused benzene rings [1][2]. Investigating the electronic properties of acenes is essential for

• benzene rings connected with a four-membered ring, is a highly intriguing compound in terms of its structure. It possesses a planar configuration and consists of 4n π-electrons, rendering it antiaromatic. However, despite being antiaromatic, biphenylene is more stable than other known antiaromatic

• 12 topologies (Figure 2) [26][27][28][29][30]. In [N]phenylene structures, the presence of a formally antiaromatic four-membered ring leads to the localization of π-electrons on the benzene rings [31]. Despite this phenomenon, the oligomer series demonstrates a decreasing band gap, indicating the

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

• small singlet–triplet splitting and a fair photoluminescence quantum yield (PLQY). The optimized organic light-emitting diode (OLED) based on 13 wt % CPC doped in 1,3-bis(9H-carbazol-9-yl)benzene (mCP) as host exhibited maximum current efficiency, power efficiency, and external quantum efficiency (EQE

• . Similarly, the strongest TADF intensity was obtained for the neat films of compound 9 and of compound 9 molecularly dispersed in the host 1,3-bis(N-carbazolyl)benzene (mCP; Figure 3c,d and Figure S3a in Supporting Information File 1). Low-energy absorption bands of molecular mixtures of compounds 6–9 and

• , 116.60, 114.11, 112.38, 99.13, 92.84, 86.01, 34.93, 31.83, 31.65, 30.67, 29.07, 28.89, 22.60, 14.12; Anal. calcd for C130H132N10S2: C, 82.24; H, 7.01; N, 7.38; found: C, 81.59; H, 7.13; N, 6.95. 4,4’,4’’-((Benzene-1,3,5-triyltris(ethyne-2,1-diyl)tris(benzene-4,1-diyl))tris(2,6-bis(3,6-di-tert-butyl-9H

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

• catalyst for obtaining the product of insertion into the NH bond of the heterocycle. An effort to obtain the N–H insertion product with dibenzoazepine proved fruitless. Instead, the product of insertion into the C–H bond of the activated benzene ring (9z) was isolated in moderate yield. The chemo- and

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

• . In 1-iso, only the two hexagonal imide groups affect the HOMO/LUMO localization, whereas the pentagonal central imide group is little affected. In 2-iso, both pentagonal are relevant to the HOMO/LUMO localization, whereas the two terminal benzene rings are little affected. The cartesian coordinates

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• and therefore more conformationally rigid compounds. Previously, the unintentional preparation of two polyunsaturated 1,2,4,8,9,11-hexaazamacrocycles fused with two benzene or two pyrazole rings has been reported [39][40]. In particular, Dolzhenko et al. attempted to reproduce the synthesis of 4-imino

• the starting material. This compound was prepared according to the described regioselective method [42] based on the reaction of malononitrile with triethyl orthoformate followed by subsequent treatment of the obtained dinitrile 2 with benzaldehyde methyl hydrazone in benzene, conc. aqueous HCl in

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

• -withdrawing terminal acceptor units, and careful selection of solvents and annealing processes have also been demonstrated as potential solutions to improve charge transport and refine the device fabrication processes. You et al. found that the position of alkoxy side chains on the pendant benzene rings

• significantly influenced the performance of Qx2 acceptors. Three variants of Qx2, i.e., Qx7 and Qx8 were synthesized with alkoxy side chains located at the meta and para positions of the pendant benzene rings. Qx7 exhibited efficient exciton dissociation, good electron-transporting ability, and a PCE of 5.07

• 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

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• ) (30 nm)/tris(4-carbazoyl-9-ylphenyl)amine (TCTA) (10 nm)/TPECNZ (60 nm)/1,3,5-tris(1-phenyl-1H-benzimidazol-2-yl)benzene (TPBi) (40 nm)/LiF (1 nm)/Al (100 nm), in which ITO and Al served as anode and cathode, respectively (Figure 7a). Herein, HAT-CN and LiF were used as the hole- and electron

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• and 28.8. Hence, these key correlations permitted to assign the attachment of the hemiketal carbon (δC 106.1) to the ketone group and the benzene ring. Based on the above evidence, the structure of 1 was assigned with a trivial name of 5,7-dimethylpseudopithonone (Figure 1). Pseudopithonone was

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• nucleophilic attack of TMSN3 to deliver product 11 (Scheme 7). Tian and Chang et al. could synthesize 3‑sulfenylated coumarin compounds 13 by using N-sulfanylsuccinimides 1 under a Lewis acid catalysis system (Scheme 8) [48]. Additionally, oxidation of 3-sulfenylated coumarins utilizing (diacetoxyiodo)benzene

One-pot nucleophilic substitution–double click reactions of biazides leading to functionalized bis(1,2,3-triazole) derivatives

• Hans-Ulrich Reissig and
• Fei Yu

Beilstein J. Org. Chem. 2023, 19, 1399–1407, doi:10.3762/bjoc.19.101

• (bromomethyl)benzene furnished geometrically differing bis(1,2,3-triazole) derivatives. The use of tris[(1-benzyl-1H-1,2,3-triazol-4-yl)methyl]amine (TBTA) as ligand for the click step turned out to be very advantageous. The compounds with 1,2-oxazinyl end groups can potentially serve as precursors of divalent

• . In this study we investigated the compatibility of the nucleophilic substitution of 1,2-, 1,3- or 1,4-bis(bromomethyl)benzene H with sodium azide and the copper-catalyzed alkyne–azide cycloadditions with compounds of type G to provide divalent compounds I (Scheme 1). These may serve as precursors of

• substituent undergo a one-pot reaction with reasonable efficiency and furnished the expected 1,2,3-triazole derivative 7 in 61% yield under the approved conditions. Next, we turned our attention to the generation of divalent systems, starting with the reactions of 1,3- (8) and 1,2-bis(bromomethyl)benzene (11

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• from racemic solketal which is deprotonated with potassium [74], NaH [75], NaNH2 [76] or KH and by using different solvents including benzene [74], toluene [76][77], THF [78], or DMF [75][79] and then alkylated with bromoalkyl [75][76] or mesylate lipid alcohol [74]. The same protocols (NaH, toluene or

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• the plane of the central benzene ring. In both molecules in the asymmetric unit, the benzoguanidine moiety bound to the benzene carbon neighboring two nitrile groups, is orientated in the opposing projection about the plane of the benzene ring to the remaining benzoguanidine moieties (Figure 2b

• the benzoguanidine moieties around the central benzene ring. Representative example for the torsion angle α is shown in red; (c) Crystal structure for compound 4BGIPN in triclinic form; (d) packing diagram with key geometrical parameters and intermolecular contacts shown as a cyan dashed line; (e

Enabling artificial photosynthesis systems with molecular recycling: A review of photo- and electrochemical methods for regenerating organic sacrificial electron donors

• Grace A. Lowe

Beilstein J. Org. Chem. 2023, 19, 1198–1215, doi:10.3762/bjoc.19.88

• . Carpenter and co-workers also proposed, but did not test, recycling their amine with electrochemistry and light [32]. They cited a work by Itoh et al. who modified a proton exchange membrane electrolyzer with a Rh–Pt catalyst to generate hydrogen from water to hydrogenate benzene to cyclohexane in one

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• -substituted substrate was exclusively employed to make the aromatic ring sufficiently electron rich. The substrate scope was mainly attributed to alterations of the substituents on the benzene ring of imines 12 (Scheme 4b) [28]. In 2018, Morimoto, Ohshima and co-workers reported an aza-Friedel–Crafts process

• presence of an electron-donating functional group is crucial in the ring to activate it for aromatic electrophilic substitution processes. In 2019, Zhang and co-workers succeeded in the C6-selective aminoalkylation of 2,3-disubstituted indoles 4 without the presence of a directing group in the benzene ring

• desired products as well but an elevated temperature was required for these reactions. Further expansion of the substrate scope was achieved by altering functionalities with contrasting electronic and steric nature in the benzene ring of substrate 49. Generally high enantioselectivities were obtained with

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• -dicarbonyl compounds are treated with (diacetoxyiodo)benzene and tetrabutylammonium iodide, iodination occurs at the α-position of the nitro group, and the subsequent O-attack of the enol moiety leads to 2,3-dihydrofuran. Cyclopropane was successfully synthesized through C-attack as the acyl group became

• ), was subjected to cyclopropanation according to a method described in the literature [13]. To a solution of adduct 4b in toluene, (diacetoxyiodo)benzene and tetrabutylammonium iodide were added, and the resulting mixture was stirred at room temperature for 14 h. Unexpectedly, from the reaction mixture

• , compound 8b was isolated after column chromatography with 21% yield instead of the desired cyclopropane 1b (Scheme 4). The NMR data for the ring protons of product 8b and compound 1b’ are listed in Table 2. Although the benzene ring in compound 8b is methyl-substituted, a 1H NMR spectrum similar to those

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• additional methyl group on the benzene ring. The HMBC correlations (Figure 2 and Figure S5 in Supporting Information File 1) of H3-10/C-4 (δC 72.9, weak), C-4a (δC 136.1), C-5 (δC 124.5), C-6 (δC 148.5) disclosed that C-10 is connected to C-5 in compound 1. The coupling constant was used to determine the

• indicated that the compound possesses the same two pentasubstituted benzene rings, suggesting an axially symmetric structure. The methoxy group is situated at C-3, as determined by the HMBC correlation (Figure 2 and Figure S12 in Supporting Information File 1) of H3-11/C-3 (δC 154.1). The hydroxy group and

• that the second benzene ring shares the same structure. By comparing the 1H and 13C chemical shifts with similar compounds [19][20][21][22], the NMR data implied the presence of C-8a–C-9–C-9a and C-4a–O–C-10a bonds in the structure of 2. Consequently, the structure of compound 2 was identified and

Synthesis of substituted 8H-benzo[h]pyrano[2,3-f]quinazolin-8-ones via photochemical 6π-electrocyclization of pyrimidines containing an allomaltol fragment

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky,
• Mikhail E. Minyaev and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2023, 19, 778–788, doi:10.3762/bjoc.19.58

• -electrocyclization under UV irradiation resulting in the formation of unstable intermediate A, starting from which two directions of further transformation are possible. The most obvious pathway is a simple elimination of a methanol molecule with aromatization of the central benzene ring leading to polycyclic

• product 12. In addition to the considered variant thermal suprafacial [1,9]-H sigmatropic shift resulting in compound 11 is implemented in this case. This transformation is energetically favorable due to the restoration of aromaticity of the benzene and pyrimidine rings. At the same time, the elimination

Construction of hexabenzocoronene-based chiral nanographenes

• Ranran Li,
• Di Wang,
• Shengtao Li and
• Peng An

Beilstein J. Org. Chem. 2023, 19, 736–751, doi:10.3762/bjoc.19.54

• pursuit of HBC-tetramer-based supertwistacene (compound 115 in Scheme 12), Wang and co-workers synthesized a chiral HBC-dimer 46 [46], in which two HBC units structurally shared one benzene ring (Scheme 6). 1,4-Bis((4-(tert-butyl)phenyl)ethynyl)benzene reacted with tetracyclone 2 through a two-fold Diels

• –Alder cycloaddition to afford compound 45 in a 79% yield. Due to the steric hindrance from two bulky tert-butyl groups on the benzene rings in the adjacent hexaphenylbenzene monomers in precursor 45, two [5]helicenes were formed in the oxidative cyclodehydrognation reaction, which gave compound 46 as

• )benzene through Co-catalyzed cyclotrimerization in a 45% yield. Then monoiodide NG 49 was obtained through oxidative cyclodehydronation in a high yield. From the heptagon-containing NG 49, Sonogashira coupling with p-tert-butylphenylacetylene (50) afforded 51 in a quantitative yield. Subsequent Diels