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Search for "mechanisms" in Full Text gives 689 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Site-specific labelling of native peptides and proteins: chemical and enzymatic strategies
Beilstein J. Org. Chem. 2026, 22, 857–881, doi:10.3762/bjoc.22.67
- difference is often not sufficient for site-specific modifications. Consequently, recent effort has shifted towards targeting alternative less-frequent amino acid residues [82], as well as novel mechanisms such as linchpin-directed modifications summarized below. Various chemoselective methods for
- modifications remains limited. The following examples illustrate recent advances in recruiting enzymes for native-sequence labelling, all of which rely on reaction mechanisms that activate carbonyl groups (Scheme 13). One of the most studied protein-modifying enzymes is sortase A. Recognising the LPXTG motif
- ), glycosyltransferases (β4GalT1 Y289L) or glycosynthases to install reactive handles on native glycans, enabling precise conjugation for applications such as antibody–drug conjugates (ADCs). Generic reaction mechanisms recruited by various native-sequence modifying enzymes. a,b) Engineered biocatalysts including sortase
The trans-influence in gold chemistry from a catalytic perspective
Beilstein J. Org. Chem. 2026, 22, 838–856, doi:10.3762/bjoc.22.66
- -mediated reaction mechanisms. Following a brief discussion of general considerations, this Perspective examines how ligand structure and the resulting trans-influence determine reactivity and stability of gold(III) complexes supported by tridentate (pincer) ligands and in bidentate chelates, including
- (C^C^N)Au–C(R)=C(R)H (Z-configuration), most probably via (C^C^N)AuH as intermediate [54]. Allenes are more reactive, and both (C^N^C)AuH 8a and [(P^N^C)AuH]+ 11 give allene-insertion products, by unspecified mechanisms [31][52]. This picture changed however when it was realised that (C^N^C)AuH
- ]. However, there is apparently yet more versatility in the mechanisms of alkyne hydroauration and may operate for the [(P^N^C)AuH]+ cation 11. Nevado et al. found recently that 11 inserts both DMAD as well as terminal alkynes, to give Au(III) Z-vinyl complexes. Control experiments ruled out the involvement
Knoevenagel condensation of 4,5- and 1,8-diazafluorenes
Beilstein J. Org. Chem. 2026, 22, 803–812, doi:10.3762/bjoc.22.62
- -diazafluorenes with aromatic aldehydes and evaluated the influence of the diazafluorene nature and solvent on the reaction mechanisms and reactivity. The reactivity of diazafluorenes under basic conditions was demonstrated to be improved in protic solvents due to solvation of ion pairs by these solvents. We
Synthesis and biological evaluation of new brassinosteroid analogs with C-22 benzoate function
Beilstein J. Org. Chem. 2026, 22, 753–762, doi:10.3762/bjoc.22.57
- , conjugation and oxidation via dynamic interaction with different phytohormones and on homeostasis mechanisms [52]. Consequently, exogenous application of a growth regulator initiates not only the process leading to a phenotypic response but also all those associated to its own regulation. Thus, only a
Hydrogen production from formic acid catalyzed by NHC–Cu complexes
Beilstein J. Org. Chem. 2026, 22, 620–627, doi:10.3762/bjoc.22.48
- equivalent of hydrogen was due to concurrent mechanisms at play. A proposed catalytic cycle is depicted in Scheme 3. The first step involves the reaction of [Cu(OH)(IPr)] with phenylsilane affording silanol and a highly reactive Cu–H species [53][54][55][56][57][58]. The latter reacts with FA in an acid–base
- simultaneous occurrence of two dehydrogenative mechanisms can explain the results of the isotopic labeling experiments. Indeed, while HD arises from the coupling of HCO2D with phenylsilane, the formation of H2 takes place by dehydrogenative coupling of the hydrosilanes present in the reaction mixture. To
Towards the targeted protein degradation of CK2: design and synthesis of CAM4066-based PROTACs
Beilstein J. Org. Chem. 2026, 22, 611–619, doi:10.3762/bjoc.22.47
- . Despite successes with ATP-competitive inhibitors, small-molecule kinase inhibitors can be limited by reversible target engagement, off-target effects, and susceptibility to resistance mechanisms [7]. These challenges have motivated the exploration of alternative therapeutic modalities that move beyond
Design and synthesis of an erdafitinib-based selective FGFR2 degrader
Beilstein J. Org. Chem. 2026, 22, 583–591, doi:10.3762/bjoc.22.44
- proper ligand binding, thus promoting uncontrolled cell proliferation [11][14]. Mutations in FGFR2 may alter its structure, enabling it to bypass normal regulatory mechanisms and activate downstream oncogenic pathways independently of external stimuli, which also contributes to tumor development. Gene
- FGFR2-selective inhibitor, is the first highly selective FGFR2 inhibitor. Although substantial advancements have been made in developing FGFR2-targeted therapeutics, the sustained clinical efficacy of these inhibitors in oncology remains constrained by the emergence of acquired resistance mechanisms
- cell surface FGFR2 expression, supporting its role as a membrane-specific degrader. Conclusion Over the past decade, with the identification of FGFR2 as a key oncogenic driver in multiple malignancies [34], significant progress has been made in elucidating the molecular mechanisms underlying the FGFR2
Experimental and DFT studies on the regioselective methanolysis of 5-azido-9-oxabicyclo[6.1.0]nonan-4-yl 4-nitrobenzoate isomers
Beilstein J. Org. Chem. 2026, 22, 547–556, doi:10.3762/bjoc.22.40
- formation mechanisms of the products yielded from the methanolysis of isomeric epoxides 9, we performed a series of density functional theory (DFT) computations using the software Gaussian 16 [26]. For this, geometry optimizations and harmonic vibrational frequency computations for the structures considered
Modern synthetic pathways towards eribulin and its subunits
Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37
- enhances its therapeutic efficacy but also helps in overcoming resistance mechanisms that limit the effectiveness of other microtubule-targeting agents. Research continues to explore additional applications of 1 in various cancer types, including non-small cell lung cancer, ovarian cancer, and other soft
Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes
Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35
- of non-histone proteins [1], and the hydrolysis of other acyl functional groups [2]. The human genome encodes 18 histone deacetylases (HDACs), which are divided into two main groups based on their catalytic mechanisms [3]. Eleven HDACs are zinc-dependent enzymes, while the remaining seven, known as
Design, synthesis and biological evaluation of 2,5-diaryloxazolo[4,5-d]pyrimidin-7-ylamines as selective cytotoxic agents against HeLa cells
Beilstein J. Org. Chem. 2026, 22, 390–398, doi:10.3762/bjoc.22.27
- mechanisms of action have utilitarian value, as they do not account for the probability of including targets not inherent to existing drugs in their molecular mechanisms of anticancer action. The physicochemical properties of such compounds may not fit the parameters developed from databases of approved
Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis
Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21
- terpenoids and highlight the utility of strategically including such a step in a natural product synthesis. To start, an overview of the different classes of enzymes, and thus common mechanisms, of ring-size-altering reactions for terpenes will be presented. In Scheme 1 the four most important manifolds for
- pyrophosphate (GPP, 6). As the goal of this review is to cover mainly skeletal modifications arising from follow up biosynthetic reactions after cyclisation, only selected examples of ring-size altering fundamental steps in polyene cyclisation mechanisms will be presented now. One such example is the formation
Synthesis of diaryl phosphates using phytic acid as a phosphorus source
Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15
- different mechanisms. In addition, the DPpyP 31P NMR peak increases and decreases in conjunction with the decrease of the MPP peak and increase of the DPP peak, suggesting that DPpyP acts as an intermediate in the DPP formation process. When alcohol 1c was used (Figure 3), the reaction stopped mainly at the
Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679
Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12
- Pathogens List (BPPL) in 2024, reaffirming VRE as a “High Priority Pathogen” for which research on and the development of new antimicrobial agents are urgently needed [4]. This emphasizes the continuing demand for antibiotics with novel chemical scaffolds and mechanisms of action. In our ongoing search for
Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection
Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6
- under ambient light. In addition, interaction mechanisms of dyes with cyanide were studied using the 1H NMR titration method, and it was determined that they interacted through an addition mechanism. Photophysical properties and interaction mechanisms of the compounds were also supported through density
Advances in Zr-mediated radical transformations and applications to total synthesis
Beilstein J. Org. Chem. 2026, 22, 71–87, doi:10.3762/bjoc.22.3
- years, however, single-electron transformations mediated by zirconium complexes have begun to emerge. This review systematically highlights the groundbreaking radical mechanisms involving zirconium complexes that have been reported. Zirconium exhibits unique characteristics – such as a strong affinity
Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids
Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203
- Figure 7d and Figure S251d in Supporting Information File 1 provide data on the stabilization mechanism in the excited state in relation to the ICT process and the polarity of the solvent [90][91]. The graphs were generally linear, demonstrating that ICT-type mechanisms were favored for these compounds
Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water
Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201
- ; gold mining; macrocycles; Introduction Inorganic anions play essential roles in a variety of biological and biochemical mechanisms and are also involved in many industrial and manufacturing processes. Due to their significant environmental impact, it is important to monitor their presence and control
Total syntheses of highly oxidative Ryania diterpenoids facilitated by innovations in synthetic strategies
Beilstein J. Org. Chem. 2025, 21, 2553–2570, doi:10.3762/bjoc.21.198
- . This field serves not only as a vital tool for molecular structure validation and the discovery of new reaction mechanisms but also as a fundamental driving force behind advances in related disciplines such as pharmaceutical science. Throughout this endeavor, innovations in methods and strategies
- channels has been extensively studied, the mechanisms of action of other ryanoid diterpenoid natural products remain poorly understood. Elucidating the structure–activity relationships (SAR) of these compounds is essential for identifying the functional groups critical for their biological activity
Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity
Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195
- mechanisms including elevation of reactive oxygen species (ROS) or interference with redox homeostasis, and inhibition of kinase or topoisomerase activities essential for cancer cell proliferation. The selective activity of thiouronium salts against cancer cells compared to non-malignant cells can be related
Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions
Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192
- azobenzene photoswitching, which is supported by MD simulations [15]. Therefore, rotaxane 1 and axle 3 permeabilize membranes through distinct mechanisms. Effect of macrocycle localization The macrocycle with the azobenzene photoswitches in rotaxane 1 can translate and be localized in either of the ammonium
- photochemical process in axle 3, and the diminished effect in rotaxane 2, indicate that release in these systems occurs through different mechanisms. Moreover, our data indicate that the localization of the macrocycle along the axle can lead to variations in release. For rotaxane 4, where the macrocycle is
Catalytic enantioselective synthesis of selenium-containing atropisomers via C–Se bond formations
Beilstein J. Org. Chem. 2025, 21, 2447–2455, doi:10.3762/bjoc.21.186
- phenyl-substituted benzoisoquinoline derivatives. Two plausible reaction mechanisms were proposed in the study: one involving oxidative addition of Int 4, a five-membered rhodium cyclic intermediate, followed by reductive elimination and the other proceeding via a bimolecular nucleophilic substitution
Conformational effects on iodide binding: a comparative study of flexible and rigid carbazole macrocyclic analogs
Beilstein J. Org. Chem. 2025, 21, 2369–2375, doi:10.3762/bjoc.21.181
- ]. Notably, the anion-binding performance of these macrocycles is inherently governed by their conformational dynamics [9][10]. Flexible hosts adaptively adjust their cavities via induced-fit mechanisms to accommodate diverse guests, while rigid hosts rely on preorganized spatial complementarity for
- interplay between conformational selection and induced-fit mechanisms in isomeric systems remains underexplored. Cram’s preorganization theory [13] posits that prestructured hosts with minimized solvation exhibit enhanced binding stability. Recent advances [14][15][16] highlight the pivotal role of
- molecular level of the dynamic regulation mechanisms of conformations [19][20]. Although the influence of conformational dynamics on molecular recognition has been paid attention to, there is still a gap in the comparative study of flexible (PBG) and rigid (WDG) structural analogs of the same framework. In
Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications
Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179
- shuttling dynamics. In this review, we discuss key examples of photoswitchable rotaxanes, organized according to the position of the photoswitch, either embedded in the axle or incorporated into the macrocycle. We examine the major classes of photoswitches used, including their switching mechanisms and the
- , spirobenzopyran, stilbene and stiff-stilbene (Figure 2). Systems whose photoinduced behavior primarily depends on photoredox or energy-transfer mechanisms fall outside the scope of this review. Review Rotaxanes featuring photoswitches on the axle Rotaxanes that incorporate photoswitchable units into the axle are
Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177
- review, drawing on examples from recently reported natural product syntheses, elaborates on reaction mechanisms, factors governing regioselectivity and stereoselectivity, and the impact of substrate structures on reaction pathways. These reactions not only serve as robust tools for the streamlined
- manipulations. Notably, under Mitsunobu conditions, 23 – with its C9 ketal remaining intact – led to 28 and 29 in 40% total yield, with a 1:2.5 ratio favoring the undesired regioisomer 29 (Scheme 5a). These two isomers arise from SN2 and SN2' mechanisms, respectively. Furthermore, when 30 (bearing a saturated
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