Search results

Search for "control" in Full Text gives 1514 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.

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

Graphical Abstract
  • examined in the presence of TEMPO as a radical scavenger, and the results revealed that the reaction proceeded through a radical pathway. The results of control experiments suggested that the phosphorylation might proceed through ferrocenium. It should also be noted that ferrocene and ruthenocene compounds
  • reaction was carried out in an undivided cell using platinum electrodes as the anode and cathode. In this method, S8 was used as a sulfur source and ammonium iodide as a mediator, which has a key role. Based on the control experiments, a nucleophilic substitution is the main pathway for the reaction. The
PDF
Album
Review
Published 16 Apr 2025

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

Graphical Abstract
  • kcal·mol−1 higher in energy, resulting in a theoretical ee value of 74% (at 263 K), if pure Z-hydrazone would be used and under the assumption of kinetic reaction control. In contrast, the E-hydrazone gives preferably the "R" product (with a theoretical ee value of 64%). The transition state which gives
  • -hydrazones, respectively. A thermodynamic control of the reaction outcome (i.e., especially enantioselectivity) would require the possibility to approach an equilibrium between 9 and 10 (seeing the reversibility of step 9 → 10), in which case the relative energies of stereoisomeric forms of 10 determine the
  • of the relative stabilities of different forms of this complex. Consequently, under kinetic reaction control, enantioselectivity would decrease over time as the reaction progresses. This occurs because slower-reacting complexes would accumulate, leading to a gradual equilibration of reaction rates
PDF
Album
Supp Info
Full Research Paper
Published 14 Apr 2025

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

Graphical Abstract
  • ]. Specifically, the reversible E/Z isomerization of the azo group in azobenzene glycosides is suited to control the spatial presentation of glycoligands and, for example, switch carbohydrate-specific bacterial adhesion on and off [20][21][22][23]. Indeed, glycoazobenzene derivatives are excellent tools to
  • like glycoclusters 1 and 2 are capable of many conformational alternatives and therefore, the control of molecular shape by photoisomerization of azobenzene linkers has its limitations. In addition, water solubility requires improvement. Furthermore, our study, combining synthesis, analysis of
PDF
Album
Supp Info
Full Research Paper
Published 08 Apr 2025

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

Graphical Abstract
  • % dichloromethane. General procedure D. In a manner similar to [11], the product obtained in general procedure B, methanesulfonyl chloride, and triethylamine were dissolved in dichloromethane and stirred overnight at room temperature. After reaction control and 100% consumption of the starting material, the entire
PDF
Album
Supp Info
Full Research Paper
Published 04 Apr 2025

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

Graphical Abstract
  • stereoelectronic effects such as hyperconjugation and electrostatic attraction/repulsion. These fluorine-derived conformational effects have been exploited to control the shapes, and thereby enhance the properties, of a wide variety of functional molecules including pharmaceutical agents, liquid crystals
  • involve conformational control it is outside the scope of this review. Another way to fluorinate the end of an alkyl chain is with a 1,2-difluoro pattern. The vicinal difluoro motif is able to sample different rotamers (e.g., with the C–F bonds aligned either gauche or anti). Crucially however, such
  • emerges. The 1,3-C–F bonds tend to avoid a parallel alignment, due to dipolar repulsion (III, Figure 3) [30][31][32]. This phenomenon can be harnessed to control molecular conformations in a predictable way, and once again the stereochemistry is important. For example, compare the natural product
PDF
Album
Review
Published 02 Apr 2025

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

Graphical Abstract
  • transmetalation of organolithium and organoboron compounds, copper hydride catalysis, and enantiotopic-group-selective transformations of 1,1-diborylalkanes. Detailed mechanistic insights into stereochemical control and current challenges in this field are also discussed. Keywords: allylic substitution; chiral
  • catalysts generally produce straight-chain products lacking chirality when reacting with monosubstituted allylic substrates, whereas iridium catalysts selectively generate branched products with high optical purity and precise control over the reaction site. Furthermore, the development of chiral
  • 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
PDF
Album
Review
Published 20 Mar 2025

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

Graphical Abstract
  • monohydrolysis under basic conditions. The electrolysis proceeds in an undivided cell under galvanostatic control using low-cost graphite or stainless-steel electrodes, and the protocol was easily upscaled. Notably, an excellent diastereoselectivity (97:3 dr) could be achieved in the cyclization of a tethered
  • relatively narrow potential window of 0.22 V between the desired decarboxylation of 9a (Ep = 1.56 V vs Ag/Ag+) and the undesired Shono-type oxidation of the formed 6a required careful control of the amount of passed charge to afford high yields of 6a. Next, the formation of decarboxylation product 11a was
PDF
Album
Supp Info
Full Research Paper
Published 19 Mar 2025

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

Graphical Abstract
  • thus to have a better control of the selectivity and the DAR, leading to more homogeneous ADCs. In this specific context, photocatalysis (Figure 2) enables site-specific bioconjugation by generating reactive intermediates (such as radicals or electron-deficient species) that can selectively react under
  • the agency of low-energy visible light with specific functional groups on biomolecules. This allows precise control over the conjugation process, enabling targeted modifications without affecting non-reactive sites. Although previous reviews have discussed the more traditional synthetic methods
  • facilitate various modifications, including labeling, crosslinking, and the creation of protein–drug conjugates. The incorporation of photoredox strategies has facilitated the synthesis of complex protein architectures, enabling precise control over conjugation sites and degrees of modification. The number
PDF
Album
Perspective
Published 18 Mar 2025

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

Graphical Abstract
  • challenge in clinical practice. This resistance often leads to treatment failure and poor survival outcomes for patients [1]. Another ongoing problem is the excessive use of chemical pesticides such as methyl bromide, carbamates, and organophosphates to control plant-parasitic nematodes that has shown a
  • added to 120 µL aliquots of a cell suspension (5 × 104 cells/mL) in 96-well microplates. After 5 days incubation, an MTT assay was performed, and the absorbance measured at 590 nm using an ELISA plate reader (Victor). The concentration at which the growth of cells was inhibited to 50% of the control
  • (IC50) was obtained from the dose–response curves. Epothilone B was used as the positive control. Nematicidal activity Nematicidal activity was performed using Caenorhabditis elegans in a microtiter plate assay as described by Rupcic et al. (2018) [30]. The assay was performed in four concentrations
PDF
Album
Supp Info
Full Research Paper
Published 17 Mar 2025

Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions

  • Xiao-Yang Bi,
  • Xiao-Shuai Yang,
  • Shan-Shan Chen,
  • Jia-Jun Sui,
  • Zhao-Nan Cai,
  • Yong-Ming Chuan and
  • Hong-Bo Qin

Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47

Graphical Abstract
  • , successfully forming the aryl-containing quaternary center. However, in this step, the reaction was too rapid to control. After optimizing the reaction time and temperature, the reaction was carried out at −30 °C for 15 minutes and product 14 was isolated in a yield as high as 58% [14]. Iodination of compound
PDF
Album
Supp Info
Full Research Paper
Published 17 Mar 2025

Formaldehyde surrogates in multicomponent reactions

  • Cecilia I. Attorresi,
  • Javier A. Ramírez and
  • Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

Graphical Abstract
  • concerns and improved reaction control can be addressed, paving the way for more efficient and sustainable synthetic methodologies. Keywords: cascade reactions; formaldehyde surrogates; green chemistry; heterocycles; multicomponent reactions; Introduction Organic chemistry is a mature discipline that has
PDF
Album
Review
Published 13 Mar 2025

Binding of tryptophan and tryptophan-containing peptides in water by a glucose naphtho crown ether

  • Gianpaolo Gallo and
  • Bartosz Lewandowski

Beilstein J. Org. Chem. 2025, 21, 541–546, doi:10.3762/bjoc.21.42

Graphical Abstract
  • peptides for binding we prepared the derivatives of peptides 2–4 bearing an acetyl-capped N-terminus (compounds 5–7). As a control we also studied tripeptide 8 containing exclusively alanine residues. The binding of tripeptides was again studied by ITC and fluorescence spectroscopy and the results are
PDF
Album
Supp Info
Letter
Published 10 Mar 2025

Cryptophycin unit B analogues

  • Thomas Schachtsiek,
  • Jona Voss,
  • Maren Hamsen,
  • Beate Neumann,
  • Hans-Georg Stammler and
  • Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

Graphical Abstract
  • control of equivalents and pH, or Leuckart–Wallach-like reaction with ammonium formate and Pd/C [25] provided monomethylaniline 7 in 37% and 35% yield, respectively. The absolute structure of monomethylaniline 7 was confirmed by single-crystal X-ray diffraction measurements (Figure 2). Compound 7
PDF
Album
Supp Info
Full Research Paper
Published 07 Mar 2025

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

Graphical Abstract
  • were collected at 100(2) K using a diamond (111) crystal monochromator, a wavelength of 0.41328 Å, and a Bruker CCD detector. The structure was solved using direct methods and refined (on F2, using all data) by a full-matrix, weighted least squares process. Standard Bruker control and integration
PDF
Album
Supp Info
Full Research Paper
Published 07 Mar 2025

Synthesis of the aggregation pheromone of Tribolium castaneum

  • Biyu An,
  • Xueyang Wang,
  • Ao Jiao,
  • Qinghua Bian and
  • Jiangchun Zhong

Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38

Graphical Abstract
  • harmful to human health and this became a significant challenge to food security [6]. Long-term synthetic pesticide applications to control the red flour beetle has resulted in the development of resistance to organophosphates, pyrethroids, methyl carbamates, and neonicotinoids [7][8]. It became critical
  • for devising a more effective and environmentally friendly strategy to control this pest [9]. Pheromone-based pest management is one of most environment benign, effective, and promising solutions [10][11]. The aggregation pheromone of T. castaneum was first reported by Ryan in 1976, secreted by the
  • tosylate and a chiral Grignard reagent. The synthetic pheromone could be valuable for the control of the red flour beetle. The aggregation pheromone of Tribolium castaneum. Retrosynthetic analysis of the aggregation pheromone (4R,8R)-1. Synthesis of chiral tosylate (S)-10. Synthesis of chiral tosylate (R
PDF
Album
Supp Info
Letter
Published 06 Mar 2025

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

  • Thomas Brandt,
  • Pascal Lentes,
  • Jeremy Rudtke,
  • Michael Hösgen,
  • Christian Näther and
  • Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

Graphical Abstract
  • accumulation in the environment after excretion [1][6][7]. These superior properties of diazocines have been exploited in several applications such as the control of protein folding by implementation as cross-linkers between protein side chains [8] or in peptide backbones [9], as photoswitchable
  • efficiency. In any case the light-induced geometry change via isomerization should selectively control the interaction between the inhibitor and the receptor [21]. Currently there is only one example reported in the literature for the incorporation of N-acetyl diazocines into biologically active molecules
PDF
Album
Supp Info
Full Research Paper
Published 04 Mar 2025

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

Graphical Abstract
  • the surface area of the solids and, therefore, irradiation efficiency. UV lamps (e.g., medium-pressure Hg lamps) are typically used for irradiation, thus requiring specialized safety equipment. While it offers some control over pressure and duration, manual grinding suffers from inconsistencies due to
  • , since in a control experiment without RFTA the mixture was found to liquefy. This was due to the heat generated by LEDs and not by the grinding action. Thus, light irradiation fulfils a double function: the excitation of the photocatalyst and melting of the substrate, inducing mobility of the molecules
  • mechanochemistry as well, leading to the introduction of ball milling, which enables precise control over energy input, operating temperatures, and offers the potential for automated, reproducible processes. As an added benefit, the use of closed reactors ensures maximum operational safety, preventing direct
PDF
Album
Perspective
Published 03 Mar 2025

Electrochemical synthesis of cyclic biaryl λ3-bromanes from 2,2’-dibromobiphenyls

  • Andrejs Savkins and
  • Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

Graphical Abstract
  • substrates that do not form the desired electrochemical oxidation product see Supporting Information File 1, Scheme S1). A series of control experiments was performed to rationalize the observed reactivity trends (Scheme 2). The measured redox potentials EP/2 for 2,2'-dibromo-1,1'-biphenyls 4a–g (from 1.77 V
  • the overall oxidation of 4a to 1a likely is a two-electron process, suggesting that the second oxidation step may involve disproportionation of putative Br(II) species (see Scheme 3D). Based on the control experiments described above we propose a plausible mechanism as shown in Scheme 3D. The reaction
PDF
Album
Supp Info
Letter
Published 27 Feb 2025

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

Graphical Abstract
  • polarization (enthalpic) (Figure 1). Organization, the control of the position(s) and orientation(s) of reacting molecules, has been achieved historically in supramolecular chemistry using “pre-organized” catalyst designs (vide infra). More recently, organization has been mooted by List as a unifying concept
  • a size-selective space [105][126][129][130][132][134]. A key advantage is that these capsules have been made on multi-hundred-gram scales and can be recycled [132]. Additionally, control of structural or bound water by the capsule [105] and properties such as a lowered pKa inside [125] demonstrate a
  • instance, the window[1]resorcin[3]arene capsule type [135] demonstrates that the symmetry and properties of traditional symmetric capsules can be modulated, although precise control over the assembly remains difficult. Finally, we must mention the recently reported cavitand capsules of Gibb, who has
PDF
Album
Supp Info
Perspective
Published 24 Feb 2025

Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

  • Bingnan Wang,
  • Yong Lu and
  • Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

Graphical Abstract
  • by which glutarimide displacement affects quality control analysis, we tested a series of amines and compared the retention times of 8 and 9 (Table 1). Rather surprisingly, the length of amino-PEG-OH had no effect on the relative retention time of 8 and 9. The byproduct co-eluted with the desired
PDF
Album
Supp Info
Letter
Published 18 Feb 2025

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

Graphical Abstract
  • (NGP) to control the 1,2-trans selectivity of the glycoside product. Torikai et al. developed a wide range of alkoxymethyl derivatives for directing the stereochemical outcome of the glycosylation reactions. The most significant of the protections include methoxymethyl (MOM) [140], benzyloxymethyl (BOM
PDF
Album
Review
Published 17 Feb 2025

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

  • Yurii A. Sayapin,
  • Eugeny A. Gusakov,
  • Inna O. Tupaeva,
  • Alexander D. Dubonosov,
  • Igor V. Dorogan,
  • Valery V. Tkachev,
  • Anna S. Goncharova,
  • Gennady V. Shilov,
  • Natalia S. Kuznetsova,
  • Svetlana Y. Filippova,
  • Tatyana A. Krasnikova,
  • Yanis A. Boumber,
  • Alexey Y. Maksimov,
  • Sergey M. Aldoshin and
  • Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

Graphical Abstract
  • experimental samples compared to control samples [39]. A431 and H1299 cells were seeded into 96-well plates at 15000/well in DMEM medium supplemented with 10% EFV and cultured under standard conditions at 5.0% CO2 and 37 °C. The next day, the medium was replaced and test compound 7a was added in a series of
  • two-fold dilutions from 0.12 μM to 120 μM. In the control wells, the medium was replaced without adding the compound 7a. The cells were then incubated under the same standard conditions for 24 h, after which the medium was replaced and 10% MTT solution in DMEM medium supplemented with 10% EFV was
  • cytotoxic activity was determined by the change in optical density at 540 nm in wells treated with the compound 7a or cisplatin compared to control wells. The experiment was carried out in three biological replicates with 6 technical replicates in each. Results were analyzed using one-way ANOVA followed by
PDF
Album
Supp Info
Full Research Paper
Published 17 Feb 2025

Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

  • Ayesha Saeed,
  • Shahana Ehsan,
  • Muhammad Zia-ur-Rehman,
  • Erin M. Marshall,
  • Sandra Loesgen,
  • Abdus Saleem,
  • Simone Giovannuzzi and
  • Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

Graphical Abstract
  • prepared in DMSO and cancer cells were treated with 10 μM doses of compounds using the apoptosis inducing standard mensacarcin (10 μM) as a positive control [56]. Only compound 7l decreased cell viability to 63%, while the rest of the compounds showed very low to no significant decrease in cell viability
  • microbroth single-dose assays. Dimethyl sulfoxide was used at a final concentration of 0.1% as negative control. Microbroth dilution assays [52] for the most potent bioactive compounds 7b and 7h were performed using nine serial dilutions of the tested compounds with final concentrations of 256, 128, 64, 32
  • cells were treated with 10 μM doses of each compound and mensacarcin (10 μM) as a positive control [56]. MTT in 1X PBS was added for a final concentration of 0.5 mg/mL 48 hours post compound addition to each well. Post incubation at 37 °C was carried out for 2 h. After the removal of the growth media
PDF
Album
Supp Info
Full Research Paper
Published 12 Feb 2025

Antibiofilm and cytotoxic metabolites from the entomopathogenic fungus Samsoniella aurantia

  • Rita Toshe,
  • Syeda J. Khalid,
  • Blondelle Matio Kemkuignou,
  • Esteban Charria-Girón,
  • Paul Eckhardt,
  • Birthe Sandargo,
  • Kunlapat Nuchthien,
  • J. Jennifer Luangsa-ard,
  • Till Opatz,
  • Hedda Schrey,
  • Sherif S. Ebada and
  • Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 327–339, doi:10.3762/bjoc.21.23

Graphical Abstract
  • responses [1]. Biofilm-forming microbes were found to be up to 1,000 times more resistant to antibiotics than their planktonic forms [2]. According to the fact sheets of the National Institute of Health (NIH) and the Center for Disease Control and Prevention (CDC), 65 and 80% of all microbial and chronic
  • (SKOV-3), epidermoid carcinoma (A431) and lung cancer (A-549) cell lines. Epothilone B served as the positive control. Following a 5 day incubation period, the minimum concentration required to achieve 50% growth inhibition (IC50 values) was determined. Biofilm inhibition sssay Biofilm inhibition
  • (TPP Tissue Culture ref no. 92196) for 24 hours. Biofilm inhibition was measured using crystal violet (CV) staining, with methanol as the control and microporenic acid A as the positive control [21]. Error bars indicate SD with duplicates in two biological repeats (n = 4). Biofilm dispersal assay
PDF
Album
Supp Info
Full Research Paper
Published 11 Feb 2025

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

Graphical Abstract
  • -red region, providing excellent control over molecular weight and polydispersity in the polymerization of various monomers, including methyl acrylate. The authors highlight that under red-light irradiation, the bacteriochlorin catalyst has achieved 89% monomer conversion in just 12 hours, with
PDF
Album
Review
Published 07 Feb 2025
Other Beilstein-Institut Open Science Activities