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

• previously reported by Zysman-Colman and co-workers [19]. Compound 5d showed the best performance with a 27% calculated NMR yield (20%, isolated yield) (Table 3, entry 3), while the azepine derivatives 5a and 5b led the transformation at 13 and 8%, respectively (Table 3, entries 1 and 2). However, these

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• .) of 24 led only to epimerization at C10 or slow decomposition of the starting material (see Supporting Information File 1, Table S1). Pleasingly, treating 24 with HMDS and TMSI regioselectively generated the expected TMS enol ether [46], which underwent a Li/Si exchange in the presence of MeLi

• stage was set for the construction of the target skeleton through a 1,2-addition (Scheme 4). Preliminary trials to generate organometallic species via Li/I exchange under various conditions (n-BuLi, t-BuLi, or t-BuLi in combination with CeCl3 or MgBr2) led to rapid decomposition, likely due to inherent

• Nazarov cyclization under a variety of conditions (Table 1). Initial trials under acid-mediated Nazarov conditions (AlCl3, BF3·Et2O and Me2AlCl) led to complete decomposition, while the exposure to AcOH resulted in recovery of the starting material (Table 1, entries 1–4). Recognizing the limitations of

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

• reduction with LiAlH₄, which led to a further decrease in the degree of unsaturation of the pyrazolodiazepine core, while the more sterically hindered exocyclic amide moiety remained intact. However, both reactions were accompanied by partial epimerization, and careful kinetic control was therefore required

Cu–Bpin-mediated dimerization of 4,4-dichloro-2-butenoic acid derivatives enables the synthesis of densely functionalized cyclopropanes

• Patricia Gómez-Roibás,
• Andrea Chaves-Pouso and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2025, 21, 877–883, doi:10.3762/bjoc.21.71

• bearing aromatic and aliphatic substituents efficiently provided the allylboration product (Scheme 1a), the use of ester derivative 1 under same reaction conditions led to the formation of an unexpected product arising from the coupling of two dichloride molecules with no alkyne incorporation (Scheme 1b

• , entry 2), although the use of sub-stoichiometric amounts led to a significant decrease in reaction yield (Table 1, entry 3). We also tried to reduce the amount of base, but this caused a drop in the reaction efficiency (Table 1, entry 4). Evaluation of different bases demonstrated the important role of

• the base metal cation. Gratifyingly, we observed that the use of LiOt-Bu led to the formation of product 2 as a single diastereomer (Table 1, entry 5). A slightly lower diastereoselectivity was observed when KOt-Bu was used, which also gave rise to 2 in diminished yield (Table 1, entry 6). The nature

Data accessibility in the chemical sciences: an analysis of recent practice in organic chemistry journals

• Sally Bloodworth,
• Cerys Willoughby and
• Simon J. Coles

Beilstein J. Org. Chem. 2025, 21, 864–876, doi:10.3762/bjoc.21.70

• exist in several disciplines. For example: the ‘Bermuda Principles’ in genomics [4][5], the Omics Discovery Index in biomedical science [6], access to sky survey data in astronomy [7], and commitments to data sharing in Earth and environmental sciences [8]. Sharing has led to the development of tools

• primary data were not deposited in a public repository (Figure 5a). Except for one example from Synthesis, data of any type had only been shared to a public repository when published in one of the four ACS journals. 95% of these used Figshare [40], (Figure 5b), and this is entirely publisher-led behavior

• article cited or linked?’ assesses if it is possible to trace data back to the original publication where the methods used to generate those data are described. 76% of primary data had a citation, however, publisher-led copying of SI files to Figshare positively distorts this proportion, as the repository

Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

• Lewis McGhie,
• Hannah M. Kortman,
• Jenna Rumpf,
• Peter H. Seeberger and
• John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

• state catalyst are not operational (see Supporting Information File 1 for full details), providing support for an EnT mechanism, while exposing the Z-isomer (Z)-1a to the model reaction conditions, led to the generation of a similar photostationary state equilibrium of isomers, characteristic of an EnT

Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation

• Zhihua Liu,
• Ya-Zhi Chen,
• Ji Wang,
• Qingling Nie,
• Wei Zhao and
• Biao Wu

Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68

• cations within a single molecule, have facilitated advancements in ion-pair recognition. This progress has led to the development of ion separation utilizing ion-pair receptors [16][17][18][19][20], which eliminate the need for auxiliary reagents to balance overall charges compared to the use of

• ]. According to our previous results, the binding affinity of L with chloride, sulfate and phosphate is determined to be 2.2 × 102 M−1, 9.9 × 104 M−1, and 3.8 × 106 M−1, respectively (in DMSO) [31]. Such strong anion binding affinity has led to selective extraction of sulfate and phosphate from basic aqueous

Chitosan-supported CuI-catalyzed cascade reaction of 2-halobenzoic acids and amidines for the synthesis of quinazolinones

• Xuhong Zhao,
• Weishuang Li,
• Mengli Yang,
• Bojie Li,
• Yaoyao Zhang,
• Lizhen Huang and
• Lei Zhu

Beilstein J. Org. Chem. 2025, 21, 839–844, doi:10.3762/bjoc.21.67

• nonprotonated solvents such as THF and toluene were used, the yields were relatively low (Table 1, entries 1 and 2, 39 and 27% yields), indicating poor catalytic activity in these solvents. In contrast, using proton solvents (MeOH, iPrOH and H2O) led to improved yields (Table 1, entries 3−5, 51−60% yields

Substituent effects in N-acetylated phenylazopyrazole photoswitches

• Radek Tovtik,
• Dennis Marzin,
• Pia Weigel,
• Stefano Crespi and
• Nadja A. Simeth

Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66

• * transition, while the weaker n→π* band shows absorption maxima in the range of 410–451 nm in CH3CN. The introduction of methyl and acyl groups on one nitrogen of the pyrazole ring led to a hyperchromic effect and a minor bathochromic shift. Also, the introduction of an EDG or EWG on the R position led to

• hyperchromic effects compared for NH- and NMe-PAP-H. Photochemical isomerization Upon irradiation with a 365 nm LED (exemplarily displayed for NMe-PAP-CN in Figure 2), we observed a decrease of the π→π* band for the E isomers. Simultaneously the π→π* bands around 253–369 nm and the n→π* bands around 426–457

• , while for NMe-PAP-CN 146 nm and for NH-PAP-CN 102 nm are found. Subsequent illumination with a 445 nm LED led to the formation of the E isomer, which is accompanied by an increase of its π→π* band until reaching the PSS445. However, judging from the intensity of the E isomers’ π→π* band, the

Synthesis and photoinduced switching properties of C₇-heteroatom containing push–pull norbornadiene derivatives

• Daniel Krappmann and
• Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

• ) derivatives. Push–pull substitution on the 2 and 3 position as well as introduction of oxygen or nitrogen at position 7 of the NBD scaffold have led to the development of a new family of photoswitches. We studied the potential conversion of norbornadiene to quadricyclane (QC) isomers. As main investigation

• explored. For instance, incorporation of a C2H4 moiety into the bridge led to the formation of [2.2.2]-bicyclooctadiene derivatives with increased storage capacities but significantly reduced half-lifes compared to analogues NBD derivatives [23][24]. Additionally, introduction of one or more heteroatoms at

• observed π–π* absorption from λπ–π* = 294 nm to 298 nm was found. Prolonged irradiation up to 660 s led to a complete change in the overall absorption properties with maxima at λ = 348 nm and 297 nm and an absorption shoulder at λ = 228 nm suggesting photodecomposition. Next, NMR monitoring of the

Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers

• Seeun Lim,
• Teresa Kim and
• Yunmi Lee

Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63

• , achieving yields of 93% and 87%, respectively. When the catalyst loading was reduced to 3 mol % for the reaction of allene 4b, the hydroalumination did not reach full conversion even with an extended reaction time (6 h vs 3 h). As a result, the incomplete hydroalumination led to a side reaction between the

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• of organic compounds. In recent years, many advances have been made in this field of research, and researchers have been able to synthesize many compounds and confirm various uses for chemical compounds in this field. The significant progress in this field of research led to the name of this field as

• shape and contact area of the electrodes led to different reaction outcomes. Spirocyclic indolines have broad applications in medicine. The phosphorylated structures of indolines have also played a significant role in synthesis and industry. In 2023, Mo et al. [48] reported the electrochemical synthesis

• reaction yield slightly decreased, and the formation of the Boc-deprotected product increased. When the reaction was performed in acetonitrile without THF, a greater quantity of the Boc-deprotected product was produced, which led to its degradation. This can be attributed to the Boc-deprotected compound

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

• the computational investigation, could not be isolated either – probably due to its high sensitivity to hydrolysis. However, a 2D 1H-15N NMR correlation spectrum showed no interactions of hydrogen nuclei in silicon-bound methyl groups and any of the nitrogens in the product. This led us to conclude

• hydrocyanation reaction of hydrazones, towards precursors of α-hydrazino acids. Model achiral catalyst 4, pre-formed by reaction of Ca(OiPr)2 and biphenyl phosphate 3, led to racemic product 2 in nearly full conversion in different reaction times, depending on the amount of catalyst used. Biphenyl phosphate 3

Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• demonstrated excellent compatibility with the protocol, affording the desired products 3ba–ea in good yields. However, the introduction of strong electron-withdrawing groups, such as trifluoromethoxy, ester, and acetyl, at the para-position of the benzene ring (1f–h) led to a noticeable decrease in the yields

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• glycophotoswitches in their different isomeric states led to new insights into the role of ligand orientation in carbohydrate recognition. The experimental results were underpinned by molecular modeling. Keywords: azobenzene glycoconjugates; carbohydrate recognition; docking; FimH; orthogonal photoswitching

• (Scheme 2B). Photochromic properties Irradiation of the glycoazobenzene-functionalized mannosides 6αMan 3, 6βGlc 4, and 3αMan 5 with light of 365, 435, and 520 nm, respectively, led to three photostationary states (PSS) in each case of which the E/Z ratios were determined by integration of the anomeric

• the closed gate conformation of FimH led to binding energies of −70.01 kcal mol−1 for E-4 and −71.08 kcal mol−1 for E-5 versus −60.96 kcal mol−1 for Z-4 and −59.43 kcal mol−1 for Z-5. These calculation results correspond to the experimentally determined inhibitory potencies which are significantly

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

• , however, there was no complementary RNA-based tool with comparable live-cell-imaging properties. Based on the autocatalytically generated fluorophore 4-(p-hydroxybenzylidene)imidazolidin-5-one (HBI) in GFP, in vitro selection on derivatives of HBI led to the discovery of the first fluorogen-activating

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• identified as optimal delivering a yield of alkylated complex of 60% (Table 1, entry 4). With DBU as base different solvents differing in polarity have been tested. At room temperature, acetonitrile proved best and increased the yield to 88% (Table 1, entry 11). Lowering the temperature to 0 °C led to a

• h), and the subsequent fluorenylmethoxycarbonyl (Fmoc) protection with FmocOsu led to the formation of the desired fluorinated amino acids. Here, Fmoc-[2.3.5.6F]TfMePhe (2) was isolated in a yield of 67% and a good enantiomeric purity of 90% ee. Fmoc-bisTfMePhe (3) was obtained even in a

• and 97% de. Both alkylated Ni(II) complexes were then hydrolyzed under standard conditions (HCl/DME 60 °C, 2 h), and the subsequent fluorenylmethoxycarbonyl (Fmoc) protection with FmocOsu led to the formation of the desired fluorinated amino acids. However, only one isomer could be isolated, requiring

Recent advances in allylation of chiral secondary alkylcopper species

• Minjae Kim,
• Gwanggyun Kim,
• Doyoon Kim,
• Jun Hee Lee and
• Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

• eponymous Tsuji–Trost reaction, they faced a significant limitation: poor regioselectivity with non-symmetrical allylic substrates 2. This constraint led to the predominant development of Pd-catalyzed methods using symmetric 1,3-disubstituted allylic substrates 1 that contain a leaving group in the allylic

• temperature led to a significant decrease in dr values, suggesting partial racemization. This observation highlights the importance of careful experimental handling of [RCu·ZnX2·L] species {X = Br, Cl; L = P(OEt)3}, where both temperature control and reaction time must be precisely managed to maintain

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

• Olesja Koleda,
• Janis Sadauskis,
• Darja Antonenko,
• Edvards Janis Treijs,
• Raivis Davis Steberis and
• Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

• observed (see Supporting Information File 1, page S3). Decrease in supporting electrolyte concentration led to a drop in yields (Table 1, entry 9 vs entry 8), whereas current density deviations from 12 mA/cm2 did not affect the outcome of 6a (see Supporting Information File 1, page S4). Interestingly

• F led to a drop in the pyrrolidine 6a yield due to the formation of a new side-product. We hypothesized that the side-product formation at increased amounts (>2.5 F) of passed charge results from undesired Shono oxidation of pyrrolidine 6a [10][11]. Indeed, CV studies of 6a revealed an irreversible

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• exhibit significant antimicrobial or cytotoxic activities upon testing [16]. This led us to hypothesize that possible chemical modification might enhance its biological activity. Therefore, the present research work aimed to investigate whether structural modifications could improve the biological

• , 4.4 Hz) and H-4 (δH 4.38, dd, J = 4.3, 0.9 Hz, H-4), the trans-2-methyl-2-butenoyl moiety was placed at C-7. The above spectroscopic data combined to the analysis of 2D experiments led to the elucidation of the structure of compound 6 as massarilactone D 7-O-trans-2-methyl-2-butenoyl. The reaction of

• , as indicated by structure–activity relationship analysis. Conclusion In the present study, the use of various acylating reagents to modify massarilactone D introduces distinct functional groups, each with unique chemical properties. This approach led to the synthesis of seven previously undescribed

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

• that, the use of 3-fold excess of amine 2a led to the same results. Apparently, the stability of salt 3a is connected with high acidity of the starting furanone 1a and its recovery is only possible under the action of strong acids (HCl, H2SO4). Further, we investigated the chemical behavior of

• isolation of intermediate salt 3a. Indeed, the reflux of starting compound 1a with amine 2a in AcOH for 24 h led to formation of product 4a with 62% yield. Using various furanones 1 and amines we attempted to synthesize analogues of compound 4a based on the above procedure. It was found that the presence of

• . So, reflux of the mixture of starting materials in AcOH for 24 h led to pyrazolone 8a in 37% yield (Table 1, entry 1). Note that increasing the process time didn’t affect on the observed result (Table 1, entry 2). Next, we tested the studied reaction applying various solvents and in all cases the

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

• organic base such as tetramethylethylenediamine (TMEDA) or 1,8-diazabicyclo(5.4.0)undec-7-ene (DBU) [28]. Our initial attempt to apply this method was as follows: A reaction mixture of 9,10-ANTH(Br)2, 10 equiv BnFI, and 10 equiv DBU dissolved in acetone was illuminated with a blue LED for 20 h (see

• ) were used as received. Instrumentation 19F (376 MHz) and 1H (400 MHz) NMR spectra were recorded using a Varian INOVA 400 instrument with a trace amount of C8H4F6 (δ(19F) = −66.35 ppm) added as the internal standard. UV–vis spectra were recorded using a Cary 500 UV–VIS–NIR. Emission spectra of the LED

• Schlenk flask was then placed in a metal container equipped with a blue LED strip (1.2 W, Tenmiro) at room temperature for 20 h. Afterwards, the reaction mixture was washed with a 10% solution of Na2S2O3 (2 × 10 mL), H2O (3 × 10 mL), and brine (1 × 10 mL) before being dried over MgSO4. All solvents were

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• shielding from light, and unavoidable light exposure during crystal selection, and the X-ray measurement itself. As an additional test, the compounds were prepared as NMR samples in DMSO-d6 and irradiated with 405 nm LED. Irradiation in the solution phase did not result in any dimerization; the respective

• crystals were then irradiated for variable periods of time using 405 nm LED (75 mW cm−2) in an Elegoo Mercury Plus Wash and Cure (turntable chamber). Samples were placed approximately 8 cm far from the light source. The average light power measured at this distance was 5 mW cm−2. During the irradiation

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• racemization when treated with inorganic bases [25], which had led us to check the equilibrium between Michael and the retro-Michael reaction (Scheme 1). These observations have prompted us to conduct further research into this reaction for potential applications in the kinetic resolution of these adducts. In

• additive (entries 10–13, Table 2), but none of the tests performed led to an improvement in enantioselectivity. We also studied the influence of the reaction temperature by performing two tests at 0 °C (entries 15 and 16, Table 2). We observed that the reaction occurs more slowly, and the enantiomeric

• excess reached is lower than at room temperature. Additionally, when the reaction mixture was stirred at −18 °C, no change was observed after 100 hours (entry 14, Table 2). These results led us to raise the reaction temperature to 31 °C (entries 17–20, Table 2). We observed that the retro-Michael

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

• for its high-energy input, automated operation, and reproducibility, making it ideal for larger-scale and more force-intensive reactions. Both LED strips and LED lamps are used as light sources in combination with transparent jars in PMMA, glass, or epoxy resins. It can achieve consistent results but

• automated and continuous mixing during irradiation, thus increasing the reproducibility and convenience of the process [67]. In particular, the authors found that the simultaneous irradiation using a low-pressure Hg lamp and grinding led to 97% 1H NMR yield of 2.3 in 24 h starting from 2.1 and 2.2, which

• oxidation of 1,2-diphenylethyne to benzil [71]. Thus, when a 1:2 mixture of 7.1 and 4-chlorothiophenol (7.2) was ground in the presence of eosin Y as the photocatalyst and anhydrous Na2SO4 as a bulking agent, benzil (7.3) was obtained in 43% GC yield under blue light irradiation (LED, 14.5 W). Isolation led