Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

•  4). The suggested method allows one to utilize arylhydrazines both with donor and acceptor substituents in the aromatic ring. Besides that, heterocyclic hydrazines also can be used in the considered transformation. In addition, we have tried to carry out the process under investigation with

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• of its unique interaction in organic synthesis. Chiral halonium salts have been found to have strong halogen-bonding-donor abilities and work as powerful asymmetric catalysts. Recently, we have developed binaphthyl-based chiral halonium salts and applied them in several enantioselective reactions

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• used to achieve higher yields [27]. Even in the absence of a transition-metal-based photosensitizer, a recent study showed that perfluoroalkylation using perfluoroalkyl iodides (RFI) could be carried out by activation of the RF–I bonds by formation of electron donor–electron acceptor complexes with an

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• observed in dilute solutions because of the formation of aggregates perturbing electronic transitions [51][52][53]. Moreover, at high concentrations, the formation of electron donor–acceptor (EDA) complexes [54] or exciplexes is expected to be favored, and the effect of mechanical forces on these is worth

Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• constriction (ground-state destabilization) are also possible [140][168][169][170]. The metals can sometimes participate in redox catalysis [171], and may be stabilized by the cage structure [160][172][173][174]. The organic part of the MOC has also been levied as a hydrogen-bond donor to activate an

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• glycosylation. Conventional glycosylation involves the ‘nucleophilic substitution’ of the leaving group at the sp3 anomeric centre of the donor moiety with a suitable carbohydrate or non-carbohydrate-based aglycon with the help of an electrophilic promoter to form the equatorial glycoside 7 or the axial

• group participation (NGP)’ [70], while involvement of protecting groups in the far, distal or remote position in the glycosyl donor is often termed as ‘remote group participation’ or ‘long distance participation’ [71]. While neighbouring group participation is a much established reaction pathway, there

• as the participating group facilitating the formation of a 1,2-trans glycoside (Scheme 2). In general, the cleavage of the activated anomeric leaving group of the glycosyl donor 9 leads to the formation of an electron-deficient oxocarbenium ion 10. The participating vicinal acyl group interacts with

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• of the DCA, photodegraded species issued from DCA or DCA•−/substract donor–acceptor complex is debated (Scheme 4b). Nevertheless, the authors underline that the key feature of these transformations is going through the consecutive absorption of two red-light photons which enhances the photoredox

• case a palladium porphyrin complex is used as photocatalyst and a coumarin derivative is used as NO donor when the irradiation is carried out at λ = 630 nm. NO is released in a photoredox catalytic process and both reaction partners are covalently bound in a block copolymer which forms micelles. This

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• three base pairs, predominantly 5’-GGC-3’ and 5’-GGG-3’ [12][13]. Notably, a bis-phenol type unnatural analog 3, composed of the C5 deoxy A-ring bearing a phenolic hydroxy group at C8, presumably as a HB donor upon interaction with nucleic acids, exhibits superior DNA alkylation capability compared to

Quantifying the ability of the CF₂H group as a hydrogen bond donor

• Matthew E. Paolella,
• Daniel S. Honeycutt,
• Bradley M. Lipka,
• Jacob M. Goldberg and
• Fang Wang

Beilstein J. Org. Chem. 2025, 21, 189–199, doi:10.3762/bjoc.21.11

• group can act as a hydrogen bond donor, serving as a potential surrogate for OH or SH groups but with a weaker hydrogen bond donation ability. Here, we describe a series of CF2H group-containing moieties that facilitate hydrogen bond interactions. We survey hydrogen bond donation ability using several

• (CF2H); fluorine; hydrogen bond donors; hydrogen bond strength; Introduction Hydrogen bonding interactions are ubiquitous non-covalent forces in chemistry and biology [1][2][3][4]. In canonical hydrogen bond (HB) donor–acceptor pairs, the donor typically comprises an electronegative heteroatom, such as

• by hydrogen bond acidity [47][48] which is derived from the 1H NMR chemical shift difference of a given proton in DMSO-d6 and CDCl3, the CF2H group is generally a stronger donor than the methyl group but substantially weaker than the OH or amide NH groups [19][20]. These results collectively indicate

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• heteroannulation [50]. The SPINOL-derived chiral phosphoric acid C26 catalyzed the formation of axially chiral products 81 from diarylketones 79a–f and ketoesters 80a–c (Scheme 26). The substrate scope contained a broad range of substituents, including electron-donor groups and whole benzene rings. The authors

• significantly high yields. The CPA organocatalyst activates quinones with an acceptor hydrogen bond while indole acts as hydrogen-bond donor. On the other hand, a hydroxy group of hydroxyindole becomes a hydrogen donor and the iminoquinone nitrogen represents an acceptor to the hydrogen from the CPA, resulting

• cases. High yields and remarkable enantiomeric purities were achieved with all prepared products (119, 121, and 124). The proposed reaction pathway indicates the asymmetric conjugated addition from 2-naphthylamine, stabilized by a donor hydrogen bond to the organocatalyst, towards the o-naphthoquinone

Synthesis, characterization, and photophysical properties of novel 9‑phenyl-9-phosphafluorene oxide derivatives

• Shuxian Qiu,
• Duan Dong,
• Jiahui Li,
• Huiting Wen,
• Jinpeng Li,
• Yu Yang,
• Shengxian Zhai and
• Xingyuan Gao

Beilstein J. Org. Chem. 2024, 20, 3299–3305, doi:10.3762/bjoc.20.274

• studies, revealing that their photophysical behavior can be affected by the different substituents in the donor carbazole group. Keywords: carbazole; D−A−D type; noble-metal-free system; 9‑phenyl-9-phosphafluorene oxide; photophysical properties; Introduction π-Conjugated molecular materials containing

• recent years, and they are mostly based on purely organic electron donor−electron acceptor (D−A) or D−A−D systems with significant intramolecular charge transfer interactions for frontier molecular orbital separation [28][29][30]. Due to the electron-accepting properties, PhFlOP can clearly act as an

• access to PhFlOP-based TADF emitters. Additionally, the design of TADF emitters with the PhFlOP acceptor moiety and the carbazole donor moiety is lacking structural diversity. Herein, we present a 5-step synthesis of several novel D−A−D-type PhFlOP derivatives with substituted carbazole groups as donors

Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki–Miyaura/C–H arylation cascade

• Merve Yence,
• Dilgam Ahmadli,
• Damla Surmeli,
• Umut Mert Karacaoğlu,
• Sujit Pal and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2024, 20, 3290–3298, doi:10.3762/bjoc.20.273

• -catalyzed annulation reaction between bromo-chloronaphthalene dicarboximides 6 and heteroarylboronic esters that enabled the syntheses of acenaphthylene-fused thiophene and indole derivatives 7 having donor-acceptor units (Scheme 1a) [40]. In 2021, Jin and co-workers developed an elegant Pd-catalyzed

Giese-type alkylation of dehydroalanine derivatives via silane-mediated alkyl bromide activation

• Perry van der Heide,
• Michele Retini,
• Fabiola Fanini,
• Giovanni Piersanti,
• Francesco Secci,
• Daniele Mazzarella,
• Timothy Noël and
• Alberto Luridiana

Beilstein J. Org. Chem. 2024, 20, 3274–3280, doi:10.3762/bjoc.20.271

• photochemistry has introduced new ways of generating radicals like photoredox catalysis and via electron donor–acceptor (EDA) complexes [10][11][12][13]. These advances, coupled with modern electrochemical methods, chemical reactor engineering and light emitting diodes (LED), have eliminated the need for thermal

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• has become an essential structural motif in medicinal chemistry due to its hydrogen-bond donor capacity, its lipophilic character, and as a bioisostere for alcohol, thiol, or amine groups [16][17][18][19]. Thus, the contribution of fluorinated compounds to pharmaceuticals has been crucial for more

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

• porphyrin macrocycle contains two Ns and two NHs (from two pyrrolenine and two pyrrole units), both of which can act as supramolecular H-bond donor and acceptors and can promote metal-free catalysis. Additionally, due to their synthetic versatility, these macrocycles can be further functionalized to add

• concluded that both the presence of hydrogen-bond donor moieties (pyrrolic –NH groups) and a basic β-substituent are necessary to make the compound catalytically active. Further, authors have performed 1H NMR binding and kinetic studies and suggested that the reaction mechanism involves a simultaneous

• -free meso-tetra(pentafluorophenyl)porphyrin (67) as a HER electrocatalyst using TsOH (p-toluenesulfonic acid) as a proton donor in THF [111]. Macrocycle 67 undergoes two reversible one-electron reductions at E1/2 = −1.14 V and −1.54 V yielding radical anion [67]˙− and a dianion species [67]2−. Upon

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

• sunlight. Furthermore, the photoisomerization quantum yield is very low and therefore not suitable for an application [7][8][14]. One promising way to overcome these disadvantages is the introduction of a donor–acceptor system at the norbornadiene double bonds, which has resulted in the development of new

• generations of modified norbornadiene derivatives with diverse variations of donor and acceptor substituents [25][26][27][28][29][30][31][32]. However, such a modification often leads to higher molar masses and thus to lower energy densities [7][25][33]. Consequently, further fine tuning of the substituents

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

• pyrindane – (E)-7-arylmethylene-2-chloro-6,7-dihydro-5H-cyclopenta[b]pyridine-3,4-dicarbonitriles – was developed. Tunable full-color emission was achieved for the synthesized push–pull molecules, solely by changing donor groups while keeping both the conjugated system and acceptor part of the molecule

• solid state). Emission maxima ranged from 469 to 721 nm in solution depending on the solvent and type of donor substituent, and from 493 to 767 nm in the solid state. For the arylidene derivative of pyrindane with a dimethylamino group, it was shown that fluorescence can be changed by the action of an

• (pyridostilbenes, azastilbenes, styrylpyridines or azinylarylethenes) are an important class. Uniquely, stilbazole provides a universal framework (exclusive matrix) for the design of donor–π–acceptor (D–π–A) molecules [14][15]. It has a branched π-conjugated system, in which the aromatic ring acts as a donor and

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

• exchange, acts as a donor of the tert-butylperoxy radical D. The target peroxide 30 is formed by recombination of the C-centered radical B and tert-butylperoxy radical D. Peroxidation of barbituric acid derivatives 31 by TBHP were further studied in detail [53]. It was demonstrated that the effective

gem-Difluorovinyl and trifluorovinyl Michael acceptors in the synthesis of α,β-unsaturated fluorinated and nonfluorinated amides

• Monika Bilska-Markowska,
• Marcin Kaźmierczak,
• Wojciech Jankowski and
• Marcin Hoffmann

Beilstein J. Org. Chem. 2024, 20, 2946–2953, doi:10.3762/bjoc.20.247

• group, proving that both gem-difluoroalkenes and the double bond of product Z-9a were excellent Michael acceptors. This confirmed that electrophiles were not involved in the reaction. We therefore focused only on using n-BuLi, which, as it turned out, acted as both the base and Michael's donor (Table 1

Structure and thermal stability of phosphorus-iodonium ylids

• Andrew Greener,
• Stephen P. Argent,
• Coby J. Clarke and
• Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

• stability than the other acyclic phosphorus-iodonium ylids, while nitrate 1d was highly thermally labile [36]. However, we were unable to rationalise or predict the anion effect with parameters such as the anion’s donor ability σm, which has previously been used as a measure of its trans effect (Supporting

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

• leads to the formation of large crystalline domains which influence charge transport. However, the microscale domains reduce the donor–acceptor interface which ultimately impacts on efficient exciton dissociation in OPV devices [12]. Therefore, it is important to further investigate other fused π

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

• assist in the deprotonation of intermediate II to produce final products 27, while K2S2O8 aids in the oxidation of the photocatalyst in the case of pyridine N-oxide. In another photoinduced reaction procedure, Murarka et al. reported the formation of aryl radicals from a tetrameric electron donor

• aryl donor (Scheme 24) [75]. The reaction worked very well at room temperature under base-free conditions. In this one-pot synthesis of double arylation of naphthols 58, a novel radical precursor, [1,1´-oxybis(2,2,6,6-tetramethylpiperidine)] (59), was employed. This precursor undergoes spontaneous

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

• represents a π-donor. Although nitrogen, as present in indirubins 17, is an even better donor than oxygen, the stability of the intramolecular hydrogen bond overrules this effect. Sulfur and selenium are very weak π-donors. It was not studied so far whether the E/Z ratio of indirubin derivatives can be

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

• the 1O2 adduct of 4-oxo-TEMP (4-oxo-TEMPO) were observed in the dispersion of catC60-lip ([catC60] = 5 µM) in PBS(–) showing an evidence of energy transfer reaction by the photoexcited catC60 (Figure 5a(ii)). In the presence of electron donor (NADH) under photoirradiation, •OH generation was observed

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

• optimized conditions. Based on the literature [28], the formation of an electron donor–acceptor complex between bromochloroform and N-Ar-THIQ seems essential for the reaction to occur. Since we did not observe the formation of any color during the irradiation of the solution of BrCCl3 and this specific THIQ

• Scheme 6. Based on the results reported by Zeitler [28], several mechanisms are involved in the oxidation of N-Ph-THIQ. The most probable involves the photoexcitation of the EDA (Electron Donor-Acceptor) complex promoting an electron transfer from N-Ph-THIQ to BrCCl3 to afford the amine radical cation