Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• activation energy modulation during transition state formation. Specifically, donor/acceptor electronic configurations in the substrate could either stabilize or destabilize the transient hybrid state, thereby thermodynamically governing the energy barrier for intermolecular HAT progression. When the partial

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

• transformations, (4) electrochemical approaches, and (5) metal-free or electron donor–acceptor (EDA)-driven systems. The substrate scope, limitations, and mechanistic aspects of these radical cascade cyclization strategies are critically examined. Review N-Arylalkenes: alkyl C(sp3)–H radicals Early investigations

• methods utilizing electron donor–acceptor (EDA) complexes and peroxide initiators have recently gained attention due to their operational simplicity and environmental friendliness. In 2024, Song’s group and co-workers presented a novel metal-free, visible-light-promoted method for synthesizing

• difluoroamidated oxindoles via electron donor–acceptor (EDA) complexes (Scheme 37) [23]. The method involved the use of N-phenylacrylamides and bromodifluoroacetamides as starting materials, with N,N,N’,N’-tetramethylethylenediamine (TMEDA) acting as the electron donor. The reaction proceeded efficiently under

Optimized synthesis of aroyl-S,N-ketene acetals by omission of solubilizing alcohol cosolvents

• Julius Krenzer and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2025, 21, 1201–1206, doi:10.3762/bjoc.21.97

• ; condensation; Einhorn-type acylation; 2-methyl N-benzyl benzothiazolium salts; Introduction Aroyl-S,N-ketene acetals, in particular N-benzyl derivatives 1, are very short donor–acceptor chromophores that have recently found a renaissance due to their peculiar intense solid-state emission and significant turn

Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates

• Alexander S. Budnikov,
• Igor B. Krylov,
• Fedor K. Monin,
• Valentina M. Merkulova,
• Alexey I. Ilovaisky,
• Liu Yan,
• Bing Yu and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96

• substitution pattern in the aryl ring does not have a significant effect on the yield of 3 for both acceptor and donor derivatives, which shows the versatility of the developed protocol. However, among halogen-containing derivatives, higher yields were observed for bromine-substituted ones (products 3i and 3l

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• bonding is characterized as those interactions that involve intermolecular hypervalent connections with lengths shorter than the sum of the van der Waals radii between a heavy p-block element and an electron-pair donor (typically O, N, S, or halogen) [15]. Secondary I···O interactions have been found to

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• alcohols and aldehydes [11] and through [2 + 3] cycloaddition of azomethine ylides and carbonyl dipolarophiles [12]. Recently, the [2 + 3] annulation of aldehydes and donor–acceptor dialkyl 2-aryl-1-sulfonylaziridine-2,2-dicarboxylates, which generate azomethine ylides, has been developed for the synthesis

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts

• Valentina Benazzi,
• Arianna Bini,
• Ilaria Bertuol,
• Mariangela Novello,
• Federica Baldi,
• Matteo Hoch,
• Alvise Perosa and
• Stefano Protti

Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84

• photooxidant or photoreductant in the presence of a suitable electron donor or acceptor [18], and these properties have been exploited in procedures for the formation of both C–C and C–heteroatom bonds [18][19]. Our research groups recently focused on the application of CDs in light-mediated organic synthesis

Synthesis of pyrrolo[3,2-d]pyrimidine-2,4(3H)-diones by domino C–N coupling/hydroamination reactions

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

Beilstein J. Org. Chem. 2025, 21, 1010–1017, doi:10.3762/bjoc.21.82

• shift, while the emission band of 4j was slightly red-shifted. The N,N-dimethylaminophenyl-substituted compounds 4k and 4l showed the strongest bathochromic shifts of the emission spectra, which might be due to the occurrence of donor–acceptor interactions between the electron-deficient uracil and the

• amino group. The corresponding fluorescence quantum yields were also strongly affected by the substitution pattern of the pyrrolouracils. Compounds 4k and 4l show very high fluorescence quantum yields of 83% and 71%, respectively, what might be reasoned by the strong donor ability of the NMe2-functional

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• overcoming scalability challenges in quantum technologies. Despite their potential, achieving high luminescence quantum yields has largely been limited to donor-functionalized monoradicals, and a detailed understanding of the luminescent behavior of open-shell organic molecules remains elusive. This review

• radicals has seen new impetus during the last decade, stimulated by the development of highly efficient electroluminescent devices based on donor-functionalized TTM radicals [7][8][9][10][11][12][13]. Today, new derivatives of donor-functionalized triarylmethyl radicals are being synthesized with enhanced

• ][14]. While first examples of radical emitters in light-emitting diodes (LEDs) only delivered around 12% internal quantum efficiency [7], representing no improvement compared to conventional emitters, optimization of the donor-functionalized TTM radical and of the device geometry quickly allowed

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• Katy Medrano-Uribe Jorge Humbrias-Martin Luca Dell'Amico Department of Chemical Sciences, University of Padova, Via Francesco Marzolo 1, 35131, Padova, Italy 10.3762/bjoc.21.76 Abstract Since the discovery of donor–acceptor (D–A) type molecules in the field of materials science, they have found

• demonstrate that these simple D–A structures exhibit promising photocatalytic properties, comparable to those of more complex D–A–D systems. Keywords: donor–acceptor system; photocatalyst design; photoredox catalysis; organic photocatalyst; Introduction In recent years, photocatalysis has emerged as a

• –properties dependence to modulate its optical and photoredox properties [4]. For instance, molecules with donor–acceptor (D–A) structures, classically used as OLED emitters, have gained relevance by finding alternative applications in the field of photocatalysis [5]. In this type of structure, the electron

Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

• attention due to their modular hydrogen bond donor/acceptor profile that can be tuned by varying the nitrogen position and the degree of unsaturation as well as by fusion with other rings [3]. Benzodiazepines, which contain a seven-membered diazepine core fused to a benzene ring, are recognized as

Recent advances in controllable/divergent synthesis

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73

• species Int-44. This reactive intermediate then engages with a Ti(IV)-enolate complex through radical recombination, ultimately delivering 2-aza-bicyclo[3.1.1]heptene (BCHepe) while regenerating the Ti(III) catalyst to complete the catalytic cycle. (2) Scandium-catalyzed pathway: Activation of the donor

Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones

• Carola Tortora,
• Christian A. Fischer,
• Sascha Kohlbauer,
• Alexandru Zamfir,
• Gerd M. Ballmann,
• Jürgen Pahl,
• Sjoerd Harder and
• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59

• studies by the groups of Akiyama and Terada in 2004 [14][15], many excellent results have been achieved by applying BINOL-derived phosphoric acids, which can act as proton donor and acceptor [16][17][18][19], possessing both Brønsted acid and Lewis base character [20]. Substantial effort has been invested

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• )cyanophenylacetonitrile, called HBC [7]. This typical push–pull fluorophore uses a dialkylamino group as the electron donor and a cyano group as the electron acceptor, while the connecting conjugating system has been varied to obtain a series of derivatives covering a broad spectral range (Scheme 1) [7][12]. All of these

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• polar C–F bonds at the end of an alkyl chain, is that the terminal C–H bond also becomes polarised. In the case of the difluoromethyl group, the terminal hydrogen bears a partial positive charge and is able to act as a H-bond donor (II, Figure 2). This can influence the conformation of the molecule if

• there is a H-bond acceptor suitably positioned elsewhere in the molecule (e.g., 4 vs 5, Figure 2) [15][16][17]. The ability of the difluoromethyl group to serve as a H-bond donor has also proven to be useful for optimising drug–target interactions [18][19][20], but since that application does not

• which has potentially useful chameleonic polarity (and also lipophilic H-bond-donor ability). Progressing to the trifluoromethyl system (45, Figure 6): now there is an even stronger tendency for the fluorinated group to be oriented orthogonal to the aryl plane [80]. This can be explained by two factors

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• molecules displayed high hole mobility [20][21][22][23][24][25][26] and imide-fused phenacenes served as n-type organic semiconductors [27]. It was also disclosed that donor–acceptor-type phenacenes provided environment-dependent fluorophores showing solvatochromic fluorescence behavior [28][29]. Because

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• the light, the lamp wattage, and diverse photocatalysts or mechanisms (e.g., energy transfer, photoredox, or electron-donor/electron-acceptor photoinduced electron transfer) might all be brought to bear on controlling the DAR. In addition to the DAR, homogeneity for conjugation at specific sites using

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