Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• in the absence of light. Note that recent work from the laboratories of Cahard and Bizet [50] suggests that autoxidation of the ethereal solvent could serve as one possible explanation for initial formation of SF5 radicals in the absence of light to initiate a radical chain reaction. It is also well

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• to absorb significant amounts of visible light photons, which allows them to reach an excited state. The excited porphyrin molecule is likely to undergo energy transfer (ET; photosensitization) or single-electron transfer (SET; photoredox catalysis) to substrate molecules (Figure 13). In

• (1O2) finds many applications in photochemistry and photobiology, e.g., for wastewater treatment, fine chemical synthesis, and photodynamic therapy (PDT) [79][80][81][82][83]. Additionally, after light excitation, porphyrins can also oxidize a substrate by accepting electrons from a substrate molecule

• porphyrin catalyst, amine, aldehyde, EDA, or light source – completely halted the reaction, resulting in no product formation. The further study found that porphyrins with both electron-withdrawing and electron-donating substituents at the meso-positions were catalytically active. Additionally, among

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

• Noble Brako,
• Sreerag Moorkkannur Narayanan,
• Amber Burns,
• Layla Auter,
• Valentino Cesiliano,
• Rajeev Prabhakar and
• Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

• extensively investigated allylation with allyltrichlorosilane [58][59]. In light of the excellent reactivity and promising selectivity displayed by catalyst 8 for the model reaction, we proceeded to evaluate its ability to enantioselectively promote the allenylation of various aldehydes (Scheme 5). The

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• up to 8 h at room temperature. Furthermore, the norbornadienes were transformed quantitatively into their quadricyclane photoproducts by irradiation with green light (520 nm) in the presence of a photosensitizer. Keywords: light energy conversion; photochemistry; photochromism; quadricyclanes

• promising approach towards storage of solar energy is represented by the molecular solar thermal (MOST) energy storage systems, which have the ability to convert and store (sun)light energy in reversible photochemical reactions. Specifically, this approach is based on photoactive compounds that are

• converted into photoisomers with higher energy upon absorption of light. In turn, this reaction is reversible, thus allowing to release the stored chemical energy as heat in a specifically triggered back reaction [7][8][10][11][12][13]. For a practicable MOST system, some key parameters have to be ensured

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• approaches have already facilitated the discovery of numerous new bioactive molecules [29][30][31][32][33][34][35][36] and shed light on the scope of past discovery efforts by uncovering select oversampled/underexplored niches in the natural product chemical spaces [37]. While nonribosomal peptides (NRP

• unacceptably high rediscovery rates, because BGF has nearly exhausted the rather limited chemical space it can access. In light of BGF’s decreasing return-on-investment, scientists have developed new natural product discovery methods to tap into the microbial biosynthetic diversity of the “uncultured majority

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• visible-light irradiation or heating, CD was moved back to the azobenzene moiety, and the entire process was reversible. This system was further developed in 2005 by introducing bipyridinium moieties to implement the selective transfer of the wheel via heating or light irradiation (Figure 5B) [57]. During

• α-CD-based rotaxane comprising a stilbene axle that was synthesized by the Suzuki coupling reaction to light irradiation (Figure 6, right) [58]. In this structure, α-CD was first located on the trans-stilbene moiety, after which it moved to the benzene ring moiety via the cis-isomerization of the

• stilbene framework by 335 nm light irradiation before returning to the stilbene moiety via trans-isomerization induced by the 280 nm light irradiation; this system is also reversible. The change in the local position of CD is significantly reflected in the ICD behavior of this system. Kodaka and co-workers

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• materials [14][20][21][22][23][24][25][26][27][28][29][30][31][32][33]. For example, organic π-systems whose main structural unit is stilbazole are used as active compounds in organic light-emitting diodes (OLEDs) [20], dye-sensitized solar cells (DSSCs) [21], nonlinear optics (NLO) materials [22][23

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• in Kwon’s review [34]. Cu-catalyzed oxygen atom transfer with TBHP were discussed in the review [35]. The review by Xiao considered visible light-driven C–C bond cleavage enabled with organic peroxides [36]. This comprehensive review summarizes all ever published studies on radical peroxidation with

• photocatalytic system under visible light irradiation (443 nm) [56]. Peroxidation of β-ketoesters, cyanoacetic esters, and malonic esters 37 was performed using the TBAI/TBHP system (Scheme 15) [57]. The highest product yields in the TBAI-catalyzed peroxidation were achieved with malonic acid esters, in contrast

• in situ-generated Cu(I) complexes was developed (Scheme 23) [43]. 2-Phenylbutane (64) was converted into peroxide 65 in a 70% yield with 4% ee. A visible light-induced direct decarboxylative peroxidation of carboxylic acids 66 with the formation of peroxides 67 under metal-free conditions using Mes

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• chemistry [1][2][3]. In particular, cholesteric, i.e., chiral nematic, liquid crystals (LCs) are attractive for many display applications due to their chiroptical characteristics as well as the selective reflection of light giving rise to Bragg interference colors [4]. Cholesteric LCs can be obtained either

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• field-effect transistor; organic semiconductor; violanthrone; Introduction Recently, organic semiconductors have received considerable attention due to their potential technological applications in semiconductor devices, such as organic field-effect transistors (OFETs) [1][2], organic light-emitting

• violanthrone 2b to act as an electron acceptor in OPVs when blended with PDI as a co-acceptor, which showed an enhanced light harvesting and photocurrent generation compared to the device without violanthrone being incorporated (Figure 2) [31]. Liu et al. [32] reported a novel violanthrone derivative 3b via

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• position of quinoline N-oxides and pyridine N-oxides, utilizing hypervalent iodine salts as the arylation reagents. The reaction was facilitated by visible light in conjunction with a photocatalyst. The absence of either the photocatalyst or light resulted in only trace amounts of the product, underscoring

• mechanism by adding 2 equivalents of TEMPO to the reaction mixture. The absence of the desired product indicated the involvement of a radical pathway in the process. The proposed reaction mechanism begins with the activation of eosin Y by visible light from 5 W blue LEDs, transitioning it to its excited

• photosensitizer and DIPEA was effective as a base (Scheme 12). The reaction yielded the E-isomers in a solvent mixture of methanol/water 5:1 under blue LED light (467 nm) irradiation in good yields. Various DAIRs substituted at different positions were found to be suitable for the reaction giving the respective

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• organic azide that is very sensitive to external factors such as light, heat, friction, and pressure and should be stored in amber plastic containers without light and at a temperature below zero degree Celsius. Exposure to azide occurs through skin absorption, inhalation, or ingestion through the

• , volatile, and explosive, the reaction containers must be completely dry and clean. When consuming TMSN3, it should be done cold (below zero degree Celsius) in a container insulated from light. The reaction must be completely closed under the hood and the lid of the reaction container, and the product

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• ][9][10]. In this context, the best CDK2 inhibitory activities were observed for indirubin-derived oximes [11]. Yellow colored isoindigo received a lot of attention as constituent of polymers applied as semi-conducting materials, organic light emitting materials (OLED), and for related applications

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• literature. In light of the promise of appropriately designed nonplanar porphyrins as receptors and catalysts we report here on our efforts to use the Suzuki–Miyaura reaction for the modification of the o,m,p-phenyl positions in 5,10,15,20-tetraryl-2,3,7,8,12,13,17,18-octaethylporphyrins. Results and

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• Instutite for Liberal Arts and Sciences (ILAS), Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan 10.3762/bjoc.20.231 Abstract We have reported that upon visible light irradiation, ferrocene-porphyrin-[60]fullerene triad molecules yield long-lived charge-separated states, enabling the control of the plasma

• light irradiation [7], with the C60 species becoming negatively charged while the ferrocene moiety became positively charged (Figure 1a). This charge-separated state can be used to initiate nanoscale electric fields, e.g., Vm. The design of the triad molecules may also help to keep their orientation

• Sciences AG (Farmingdale, NY, USA). FeSO4, DETAPAC and NADH was bought from Sigma-Aldrich (St. Louis, Missouri, USA). DMPO was bought from TCI (Tokyo Chemical Industry Co. Ltd., Tokyo, Japan). Irradiation was performed by blue LED light (464–477 nm, 23 lm·W–1) from Lumiflex300 Pro RGB LED Stripes

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• indole alkaloids. Here, we develop a novel approach for the one-pot multistep synthesis of different spiro[indole-isoquinolines]. The protocol proposed involves the visible light mediated oxidation of N-aryl tertiary amines using bromochloroform with the generation of a reactive iminium species, which

• reacts with an isocyanide and an electron-rich aniline in a three-component Ugi-type reaction to give an α-aminoamidine. This compound might undergo an additional visible light-mediated oxidation to furnish a second iminium intermediate, which acts as electrophile in an intramolecular electrophilic

• : isocyanide; multicomponent reactions; one-pot reaction; oxidation; spiroindolenine; Ugi reaction; visible light; Introduction Diversity-oriented synthesis (DOS) is a successful approach to biologically active scaffolds directed to create an enormous exploratory space in pharmaceutical hit discovery [1][2

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• properties All synthesized compounds exhibit photoluminescence by excitation with UV light. Hence, we studied the photophysical properties of all obtained derivatives 5 by steady-state absorption and fluorescence spectroscopy. The influence of the substitution pattern on the photophysical properties is

Photoluminescence color-tuning with polymer-dispersed fluorescent films containing two fluorinated diphenylacetylene-type fluorophores

• Kazuki Kobayashi,
• Shigeyuki Yamada,
• Motohiro Yasui and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2682–2690, doi:10.3762/bjoc.20.225

• Kazuki Kobayashi Shigeyuki Yamada Motohiro Yasui Tsutomu Konno Faculty of Molecular Chemistry and Engineering, Kyoto Institute of Technology, Matsugasaki, Sakyo-ku, Kyoto 606-8585, Japan 10.3762/bjoc.20.225 Abstract The development of organic light-emitting devices has driven demand for new

• white-light-emitting materials. Keywords: energy transfer; fluorinated diphenylacetylenes; photoluminescence; polymer-dispersed films; white luminescence; Introduction Luminescent materials in lighting and display devices have become indispensable in daily life [1][2][3]. In recent years, organic

• electroluminescent devices have attracted significant attention as lightweight and energy-saving optical devices, and there has been a strong demand for the development of luminescent materials. Until now, the design of solid-state light-emitting materials has not been established, and therefore, their development

Transition-metal-free decarbonylation–oxidation of 3-arylbenzofuran-2(3H)-ones: access to 2-hydroxybenzophenones

• Bhaskar B. Dhotare,
• Seema V. Kanojia,
• Chahna K. Sakhiya,
• Amey Wadawale and
• Dibakar Goswami

Beilstein J. Org. Chem. 2024, 20, 2655–2667, doi:10.3762/bjoc.20.223

• -absorbing as well as photo-antioxidant properties via an intramolecular hydrogen transfer [5]. The structure–activity relationship between the substituents of 2-hydroxybenzophenones and their UV-absorption properties has been reported previously [6]. It was concluded that the ability to absorb UV light and

• two molecules 2-hydroxytetrahydrofuran to give the target product 4. One of the commercially important 2-hydroxybenzophenones, oxybenzone, is widely used as an ingredient in sunscreen lotions, due to its ability to absorb UV light, both in the UV-A and UV-B region [28][29]. However, oxybenzone, having

Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study

• Stiliyana Pereva,
• Stefan Dobrev,
• Tsveta Sarafska,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221

• light on the mechanism of the γ-CD hydration and to address some unanswered questions: (i) what are the preferable locations for water molecules in the macrocyclic cavity (“hot spots”); (ii) what are the major factors contributing to the stability of the water cluster in the CD interior; (iii) what type

• studies to elucidate the mechanism of the γ-CD hydration. Herewith, by employing a combination of experimental (differential scanning calorimetry/thermogravimetry) and theoretical approaches (density functional theory calculations) we endeavor to shed additional light on the mechanism of the γ-CD

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

• structures. Some of the key features and capabilities of these techniques are summarised in Table 1. CLSM is a fluorescence microscopy technique capable of acquiring high-resolution optical images at selected depths of the sample. This is achieved by exciting compounds with laser light and, by using a

• systems are indeed representative. CLSM also often has poor resolution due to the use of light used for imaging. Other fluorescent imaging techniques such as super resolution fluorescence microscopy (for example, stimulated emission depletion (STED) microscopy or point accumulation for imaging in

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• TLC (eluent ethanol/ammonia aqueous 4:1), cooled to room temperature, alkalinized with NaHCO3 solution to pH 7–8, extracted with chloroform (3 × 10 mL), and the organic layer was dried with MgSO4. After removal of the solvent 1.17 g (95%) of pyridin-2(1H)-one (9) was obtained as a thick mass of light

• brown color. After recrystallization from ethanol, 1.11 g (90%) of pyridine 9 were obtained as a light yellow powder. Mp 108–110 °С; 1H NMR (CDCl3) δ 6.16 (dd, 1H, С5H), 6.38 (d, 1H, С3H), 7.38 (d, 1H, С6H), 7.40 (dd, 1H, С4H), 11.5 (s, 1H, C1-OH); 13С NMR (CDCl3) δ 104.8 (С4), 119.7 (С3), 135.2 (С6

• with hot ethanol. 0.9 g (50%) to obtain a reddish brown glassy solid. After recrystallization in ethanol, light beige crystals of 2,5-dihydroxypyridine (11) were obtained. Mp 107–109 °С; 1H NMR (CDCl3) δ 6.96 (1H, С3H), 7.16 (1H, С6H), 7.60 (1H, С4H), 9.76 (C5-OH), 10.78 (C2-OH); 13С NMR (CDCl3) δ106.2

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• traces of residual moisture. Reactions were monitored by thin-layer chromatography (TLC) using E. Merck silica gel plates and components were visualized by illumination with short wavelength UV light and/or staining (ninhydrin or basic KMnO4). All aldehydes were distilled right before use. All aryl

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• of photocatalysts or UV light irradiation without metal catalysts [45][46][47][48]. Similar homolysis by electrolysis has also been reported [49]. These two activation methods required special equipment (i.e., light sources or electronic devices). To achieve thermal homolysis of the Ar–Bi bonds, the

• reaction conditions were harsh, requiring heating at 260 °C for several days [50]. Thus, only two examples of the use of triarylbismuthines as aryl radical sources have been reported for the synthesis of arylboronates, which proceeds under light irradiation conditions (Scheme 1a) [47][48]. Our group has

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• +) cations, used as visible light fluorescent dyes, have been synthesized via a nucleophilic aromatic substitution (SNAr) reaction with primary alkylamines (e.g., 1a+; Figure 1) [15][16]. The highly planar geometry of the TATA+ core unit induces π–π stacking structures in single-crystal and film states, as