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Search for "control" in Full Text gives 1574 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers
Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95
- ]. Widespread use of 3D π-skeletons requires not only efficient construction of the skeletons but also functionalization with precise control of substitution numbers and positions. Along this line, fully π-fused [4.4.4]- and [3.3.3]propellanes [40][41][42][43] were able to be brominated and nitrated at six
- ][59][60]. This scheme also enables control of the number of formyl groups by starting materials and reagents. Brominated [4.3.3]propellane was reacted with n-BuLi or iPrMgCl·LiCl to generate an organometal species, which was quenched with N,N-dimethylformamide (DMF) as an electrophile (Table S201 in
- same protocol was successfully applicable to pristine π-fused [3.3.3]propellane [3.3.3], giving [3.3.3]_CHO selectively in 67% yield (Table 1, entry 3). In electrophilic aromatic substitutions, multifold reactions are possible, and the number of substitution is sometimes difficult to control by tuning
Synthetic approach to borrelidin fragments: focus on key intermediates
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- ]. Their method was based on the concept of “catalytic total synthesis”, wherein all stereocenters were installed under the control of catalysts. Minnaard and Madduri proposed the synthesis of the C1–C11 fragment from unsaturated thioester 92 through iterative, previously developed asymmetric 1,4-addition
Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines
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
Recent advances in controllable/divergent synthesis
Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73
- review systematically examines, how these multidimensional control elements (including ligands, metal catalysts, solvents, time, temperature, acids/bases, and subtle modifications of substrates) synergize to achieve predictable product diversification. In addition, mechanistic insights are discussed
- control The precise regulation of product selectivity represents a fundamental challenge in transition-metal-catalyzed organic transformations, with significant implications for complex molecule synthesis. In this context, ligand-modulated divergent catalysis has emerged as a paradigm-shifting strategy
- , thereby offering unprecedented control over chemo-, regio-, and stereoselectivity parameters in catalytic manifolds. In 2015, the Jiang group developed a palladium-catalyzed regioselective three-component C1 insertion reaction (Scheme 1) [19]. In this reaction, an o-iodoaniline 1, phenylacetylene, and
Cu–Bpin-mediated dimerization of 4,4-dichloro-2-butenoic acid derivatives enables the synthesis of densely functionalized cyclopropanes
Beilstein J. Org. Chem. 2025, 21, 877–883, doi:10.3762/bjoc.21.71
- not result in the formation of the dimerization product and complex mixtures of products were observed in these cases. To gather insight into the reaction mechanism, several control experiments were performed (Scheme 3). We first observed that the reaction does not take place in the absence of B2pin2
- addition to a second molecule of 1. Given the negative results observed for other crotonate derivatives (Scheme 3c), coordination between the Li cation and the two chlorine atoms via proposed transition state D may be crucial not only for diastereoselective control but also for the viability of this step
- functionalized cyclopropane scaffolds depending on the nature of the carboxylic acid derivative. Chemodivergent reactivity observed in copper-catalyzed borylative couplings of allylic gem-dichlorides. Cu-Bpin-mediated dimerization of 4,4-dichoro-2-butenoic acid derivatives. Control experiments. Proposed
Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters
Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69
- , and control reactions support sensitization, enabling an intramolecular [2 + 2] cycloaddition to be realized accessing 3D bicyclic fragments containing a boron handle. Keywords: boron; catalysis; [2 + 2] cycloaddition; energy transfer; photochemistry; Introduction The strategic use of a photon to
- identify a suitable catalyst and boron residue, while control reactions and mechanistic studies support the proposed sensitization. The platform enables direct access to mono- and vicinal cyclobutylboronic esters that could be effectively derivatized to demonstrate their potential in synthesis. Results and
- solvent had a profound effect on reactivity with more Lewis-basic solvents suppressing reactivity (Table 1, entries 4 and 5 vs entries 6 and 7), indicating p-orbital availability plays a prominent role [56][57]. A control reaction (Table 1, entry 8), in combination with UV–vis absorption studies (see
Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation
Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68
- that a tripodal hexaurea receptor L (Figure 1b) could selectively and reversibly extract sulfate and phosphate anions from water into organic phase (under pH control) [30][31][32][33]. Single crystal structures of the receptor–K2SO4 complex in the presence of 18-crown-6 clearly displayed ion-dipole
Chitosan-supported CuI-catalyzed cascade reaction of 2-halobenzoic acids and amidines for the synthesis of quinazolinones
Beilstein J. Org. Chem. 2025, 21, 839–844, doi:10.3762/bjoc.21.67
- 96% isolated yield (Table 1, entry 12). Control experiments indicated poor results when no catalyst was used, with the corresponding product obtained only in 31% yield (Table 1, entry 13). When CuI or chitosan alone was used as a catalyst, the reaction occurred but with less efficiency (Table 1
Substituent effects in N-acetylated phenylazopyrazole photoswitches
Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66
- are molecules reversibly changing their optical and chemical properties upon irradiation. These features offer easy, precise, and reversible control over the system they are embedded in and make them attractive modulators for diverse applications. In the last decades, many classes of photoswitches
- -art technologies ranging from energy-storage materials [6][7] to pharmacology [8][9][10][11], materials chemistry [12][13], control of peptides structure [14][15] or proteins [16], as antibacterial agents [17][18], smart coating [19], or multivalent photoresponsive systems [20][21], to name only a few
4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches
Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65
- ligands (Figure 4 and Figure 5). Additionally, dexamethasone (DEX) was employed as an experimental control for comparative purposes [34][35][36]. The docking scores (DS), reported in Table 5 as binding affinities, reveal that negative DS values correspond to stronger binding affinities between the ligand
- ellipsoids at the 30% probability level. The intramolecular hydrogen bond is shown as red dashed line. The bioavailability radar of studied compounds 5a–e. The interactions of potential drugs 5a–c in the active site of enzyme iNOS. The interactions of potential drugs 5d and 5e and control drug (DEX) in the
Recent advances in the electrochemical synthesis of organophosphorus compounds
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- 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
Development and mechanistic studies of calcium–BINOL phosphate-catalyzed hydrocyanation of hydrazones
Beilstein J. Org. Chem. 2025, 21, 755–765, doi:10.3762/bjoc.21.59
- 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
Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion
Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57
- ]. 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
Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA
Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56
- % 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
Origami with small molecules: exploiting the C–F bond as a conformational tool
Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54
- 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
Recent advances in allylation of chiral secondary alkylcopper species
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
- 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
Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters
Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50
- 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
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- 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
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- 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
Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions
Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47
- , 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
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- 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
Binding of tryptophan and tryptophan-containing peptides in water by a glucose naphtho crown ether
Beilstein J. Org. Chem. 2025, 21, 541–546, doi:10.3762/bjoc.21.42
- 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
Cryptophycin unit B analogues
Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40
- 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
Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
- 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
Synthesis of the aggregation pheromone of Tribolium castaneum
Beilstein J. Org. Chem. 2025, 21, 510–514, doi:10.3762/bjoc.21.38
- 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
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