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Search for "selectivity" in Full Text gives 1285 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper
Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108
- demonstrated good product conversion and selectivity without the need to perform the reaction under oxygen, while Cu(OAc)2 was slightly less efficient. When the catalyst loading was reduced to 15 mol %, the reaction yield decreased to approximately 75% for both copper salts. However, reducing the reaction time
- to 6 hours, with a catalyst loading of 20 mol %, resulted in complete conversion and high selectivity, comparable to the results obtained from an overnight reaction. Notably, decreasing the reaction temperature to 60 °C still yielded excellent results with both catalysts after an overnight reaction
- reported in numerous green protocols, offer significant advantages over the use of conventional heating. The goal was to utilise selective, volumetric dielectric heating to save time and energy, enable selective catalysis and generally achieve higher selectivity and yields [53][55][56]. Building on the
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- infants and it has successfully completed a phase III clinical trial [17][18]. Finally, sulphonamide 4 is a lead compound for the treatment of osteoarthritis via MMP-13 (matrix metalloproteinase 13) inhibition which exhibited an excellent selectivity profile and complete inhibition of collagenolysis in
Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer
Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100
- transfer (HAT) in photocatalytic reactions. These radicals display exceptional selectivity and efficiency in abstracting hydrogen atoms from C–H, Si–H, B–H, and Ge–H, positioning them as invaluable tools in synthetic chemistry. This review summarizes the latest advancements in the photocatalyzed generation
- /mol (Figure 2a) [28][29][30]. Almost 5 kcal/mol difference between two species could spontaneously undergo a HAT process. That also justifies the selectivity and efficiency of amidyl radical serving as HAT reagent. 2) Recent research indicated a critical correlation between electronic effects and
- a central role in this photocatalytic system. This strategy demonstrated good chemical selectivity for the functionalization of pyridine and alkanes, resulting in 55% to 86% yields of products 38, 39, 40, and 41, respectively. Amidyl radical from N–O bond cleavage In 2022, Alexanian’s group
Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes
Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99
- oxidation: The Scholl-type oxidation has also been employed also for azulene-embedded PAHs. where it was used to fuse substituents around the already existing azulene moiety in the direct precursor. However, such reactions often lead to suboptimal results in terms of yield and selectivity. Positions 1 and 3
Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents
Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98
- ) [6]. This methodology enabled the selective functionalization of one or two C(sp3)–H bonds adjacent to the nitrile group, leading to the formation of diverse polycycles with high selectivity. Various reaction parameters were systematically examined, including Lewis acids, oxidants, bases, reaction
- selectivity, and high functional group compatibility (65a–f). In 2024, Huang, Liu, and Li’s group introduced a novel approach for the photochemical radical cascade 6-endo cyclization of dienes using α-carbonyl bromides, as illustrated in Scheme 32 [20]. This method is characterized by a visible-light-induced
Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers
Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95
- well with the observed reactivities and selectivity. Attempted macrocyclization leading to linear polymers Formyl groups have diverse reactivities and enable facile condensation, dynamic covalent chemistry, and so on. In this work, we tried the synthesis of cyclic oligomers composed of naphthalene
- N2 adsorption and desorption. Molecular design for uniform microporosity and efficient polymerization is a next challenge. Conclusion In this work, we developed formylation on a naphthalene ring in [3.3.3]- and [4.3.3]-type fully π-fused propellanes. High selectivity was achieved for monoformylation
Synthetic approach to borrelidin fragments: focus on key intermediates
Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91
- the Z-product during the cross-metathesis reactions. Therefore, the synthetic study was initiated by performing cross-metathesis reactions between both (E,E)- and (Z,E)-134 with various alkenes to investigate the Z- or E-selectivity of the reaction. Fortunately, Iqbal observed that all cross
- -metathesis reactions in the study exhibited high E-selectivity. As a result, the reaction of (Z,E)-134 with olefin 135 provided the desired product 136 in 56% yield, with a (Z,E)/(Z,Z) ratio of 4:1 (Scheme 21). Compound 136 was subsequently protected as a TBS ether, 137 [35]. The aldehyde counterpart 147 for
Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold
Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90
- compound selectivity was made using the human embryonic kidney cell line HEK293, according to previously reported protocols [16][17]. The results are shown in Table 1, including IC50 values for the reference compounds puromycin, chloroquine, pyrimethamine, and dihydroartemisinin. Compounds 2–9 and 15 did
- limited activity against Pf 3D7 resulted in low selectivity indices, as indicated in Table 1. Compounds 3 and 13–15 demonstrated some inhibition of HEK293 at the highest concentrated tested, but did not display sigmoidal dose-dependent kinetics, thus accurate IC50 values were unable to be determined
- . Meaningful selectivity indices for these compounds could, therefore, likewise not be calculated. Hence, the mean % growth inhibition (duplicate, n = 1) at the top concentration is indicated in Table 1. Conclusion A modified approach for amine substitution of 5-chloro-3-(4-chlorophenyl)-[1,2,4]triazolo[4,3-a
Gold extraction at the molecular level using α- and β-cyclodextrins
Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89
- high selectivity. The present review is centered on the use of cyclodextrins, natural and biocompatible oligosaccharides that form upon microbial fermentation of starch. The method is environmentally safe because it resorts to natural compounds, posing as a promising alternative to the use of cyanides
- such as sodium sulfite. As a disadvantage, the step of gold reduction causes co-precipitation of all other metals that are present in solution, which has raised the need for the use of selective precipitation methods. One of the strategies to address this selectivity precipitation issue is the use of β
A versatile route towards 6-arylpipecolic acids
Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88
- kinetically controlled diastereofacial selectivity. The resulting diastereomers are separable by chromatography. 1H NMR was used to assign the configuration of the 2 diastereomers [53][54][55]. Carbon C2 is R-configured, as ᴅ-2-aminoadipic acid (1) was employed as the starting material. The minor diastereomer
Recent advances in synthetic approaches for bioactive cinnamic acid derivatives
Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85
- -branched (L/B) selectivity of >20:1. The reaction involves the formation of palladium hydride (Pd–H) 270 as the key species followed by alkyne and CO insertion reactions via 271 and 272 (Scheme 68A) [116]. On the one hand, Jia and co-workers (2021) utilized environmentally benign water as the hydrogen
- -Markovnikov selectivity catalyzed by Au(III) in the presence of dimethylaminopyridine N-oxide (DMAPO) as oxidant. The reaction proceeds via Au–allenylidene species 307 (Scheme 73) [124]. Various cinnamic esters and amides with natural product-based alkoxy groups 301–304 and sulfoximines 305 and 306, a
- cinnamamides 13, 77, 99, and 371 in good yields via the active palladium–hydride species 372 (Scheme 81A) [137]. The Z-to-E-selectivity could be effectively tuned by changing the solvent and temperature from CH3CN to DMF and rt to 80 °C, respectively. Similarly, Wang and co-workers (2023) employed Pd to
Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes
Beilstein J. Org. Chem. 2025, 21, 947–954, doi:10.3762/bjoc.21.78
- , which attacks the pendant olefin to form an aziridinium cation (Scheme 2). A sulfonate counter-anion then opens this aziridinium ring in an exo-selective, SN2 reaction. We were successful in scaling the reaction from 0.3 mmol to 11.5 mmol (38-fold increase) without any erosion in yield or selectivity
Recent advances in controllable/divergent synthesis
Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73
- literatures focusing on key regulatory factors for product divergent formation, in which controlling chemical selectivity primarily relies on ligands, metal catalysts, solvents, time, temperature, acids/bases, and subtle modifications of substrates. To gain a deeper understanding of the mechanisms underlying
- reaction activity and selectivity differentiation, the review provides a systematic analysis of the mechanisms of critical steps through specific case studies. It is hoped that the controllable/divergent synthesis concept will spark the interest of practitioners and aficionados to delve deeper into the
- 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
Dicarboxylate recognition based on ultracycle hosts through cooperative hydrogen bonding and anion–π interactions
Beilstein J. Org. Chem. 2025, 21, 884–889, doi:10.3762/bjoc.21.72
- selectivity for heptanedioate (C72−) was attributed to cooperative hydrogen bonding, anion–π interactions, and a size-matching effect, as supported by DFT optimizations. Keywords: anion–π interactions; anion recognition; hydrogen bonding; dicarboxylates; ultracycles; Introduction Macrocycles containing more
- anticipated to exhibit high association efficiency and selectivity for large guests, driven by cooperative effects of their convergent macrocyclic elements. Dicarboxylates are crucial species in biological system and chemistry [20]. Examples such as malonate, succinate, and glutarate play key roles in
- interactions, the host undergoes conformational adjustments: the distance between the two submacrocycles increases, and the glycol chains adopt extended conformations compared to the structure shown in Figure 1. These results suggest that the experimentally observed strong binding capability and selectivity of
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
- and making new receptors, thereby saving considerable time. However, the selectivity of ion separation achieved through the dual-host strategy may not match that of ion-pair receptors, possibly due to less defined interactions between the receptor-complexed anions and cations. Early studies employing
- , the extraction efficiency follows the order of PO43− > CO32− > SO42− > NO3−, consistent with the order of negative charges as well as the anions’ hydration energies (Table 1) [49][50]. This anti-Hofmeister selectivity of phosphate over other studied oxyanions is normally seen in liquid–liquid and
Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers
Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63
- by the regio- and stereoselective allylation with p-toluenesulfonyl cyanide. The proposed methodology is efficient for accessing acyclic β,γ-unsaturated nitriles with α-all-carbon quaternary centers and achieves yields up to 99% and excellent regio- and E-selectivity. The reaction proceeds under mild
- , we synthesized new and versatile functionalized acyclic nitriles that include all-carbon quaternary centers with high selectivity (Scheme 1c). Compared to previous methodologies, our approach enables the efficient generation of tertiary nitrile products with a broader substrate scope, highlighting
- efficiently constructed α-all-carbon quaternary centers on β,γ-unsaturated nitriles with excellent >98% regioselectivity and >98% (E)-selectivity. 1,1-Disubstituted allenes bearing silyl ether- and benzyl ether-tethered propyl groups were successfully converted into the desired nitriles 3a–c in yields ranging
Recent advances in the electrochemical synthesis of organophosphorus compounds
Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61
- that controls reaction selectivity by adjusting voltage or current [13]. Simple synthetic systems in electrochemical methods are limited to electrodes, cells, electrolytes, and power supplies. Today, in addition to the above, light, metallic, and organic catalysts are also used to increase the
- resistance, and maintain ion balance (e.g., LiClO4, n-Bu4NBF4), and active electrolytes, which participate directly in redox reactions, acting as oxidizing or reducing agents (e.g., H2SO4, Et4NOH). Choosing the proper electrolyte affects reaction efficiency, selectivity, and overall performance. Electrodes
- -phosphorylated indole was obtained with high selectivity when n-Bu4NClO4 was used as the electrolyte. Additionally, under certain conditions that reduced the reaction yield, the C3-phosphorylated product was also observed. Similar to previous heteroaromatic coupling reactions with phosphine oxides [53][54], this
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
- used, although often with limited success. We believe that the electrophilic warheads presented here offer an excellent balance between reactivity and selectivity for labeling of nucleic acids, and therefore, may also stimulate new designs for RNA targeting and RNA drugging. Experimental General
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
- target binding will incur little entropic cost) and high selectivity (since off-target interactions will be minimised) [1]. There are several methods by which the conformations of small molecules can be controlled, but in this review we will focus upon one particular method, which is the installation of
- motif has been exploited in the design of bioactive molecules [22][23] such as the histone deacetylase (HDAC) inhibitors 6 and 7 (Figure 2). The presence of the 1,2-difluoro moiety in 6 leads to greater potency and selectivity for certain HDAC isoforms, attributable to the higher polarity of the
- including protein kinase A (PKA). Fluorination was investigated as a strategy for altering the conformation of the central seven-membered nitrogen heterocycle, and hence possibly improving the selectivity for PKCε. A variety of fluorination patterns were investigated (100–103, Figure 11), which were found
Recent advances in allylation of chiral secondary alkylcopper species
Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51
- their exploration of phosphoramidite ligands with various organometallic nucleophiles [24][25]. The field was further advanced by the research group of Hoveyda, who made substantial contributions by introducing bidentate N-heterocyclic carbene (NHC)-based chiral ligands, achieving high selectivity with
- into a powerful and versatile tool in asymmetric synthesis, capable of employing a wide array of organometallic reagents that furnish the desired compounds with high efficiency and selectivity. The regioselective asymmetric construction of stereogenic carbon centers from prochiral allylic substrates
- regioselectivity (SN2/SN2' = >99:1). The reaction with 3-methylbut-2-en-1-yl bromide (15) was particularly noteworthy, as it exhibited superior selectivity compared to the corresponding phosphates. The high efficiency of this protocol was demonstrated through the synthesis of various functionalized alkenes with
Photocatalyzed elaboration of antibody-based bioconjugates
Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49
- conjugation methods often face challenges related to site-selectivity and heterogeneous product mixtures, highlighting the need to develop new, innovative chemical strategies. Photoredox chemistry emerges as a powerful tool in this context, enabling precise, mild, and selective modifications of peptides and
- ], therapeutic index, selectivity, and overall success of the ADC. The linker will ideally be stable in plasma for an extended period before the intended target can be reached, and after internalization, linkers play a key role in the drug-releasing event. Importantly, some exceptions exist. For example, in
- functionalized nature of polypeptides/proteins demands exquisite selectivity to target specific sites on the macromolecule of interest. In addition to the requisite features of the chemical methods outlined above, there are key requirements for synthetic methods used in ADCs, which include high site-selectivity
Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities
Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48
- preserved, with chemical modifications focusing on massarilactone H rather than massarilactone D. These modifications should target other regions of the molecule, such as the number and position of acyl substituents. Future research should investigate the stability and selectivity of these compounds, as
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- (75 °C) are needed. The selectivity of the reaction shown in Scheme 27 could be explained according to the proposed mechanism (Scheme 28a). The first step is the generation of the trialkyl(chloromethyl)ammonium chloride species 36 from the amine compound and CH2Cl2. Then, 36 decomposes by a cleavage
- product 35b was obtained, confirming that the dihaloalkane compound is the source of the methylene unit (Scheme 28c). Depending on the stability of the leaving carbocation, the selectivity of the R–N cleavage follows the decreasing order for the R groups: H, t-Bu, allyl, benzyl > methyl > primary
- amine with two methyl groups and a benzyl or allyl group, the cleavage of the N–CH2Ph and N–allyl bond takes place more selective (by 85% and 67%, respectively), instead of the cleavage of an N–Me bond. This explains the high selectivity observed for some examples in Scheme 27. Finally, this methodology
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
- chain is the second highest among the tested amino acids and approximately 30% lower than towards Trp (entry 5, Table 1). Thus, the glucose-derived naphtho crown ether 1 displays selectivity towards the binding of tryptophan over other amino acids in water. Additionally, 1 displays a slight preference
Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene
Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39
- higher selectivity with milder reaction temperatures. The weaker C(sp2)–Br bond is easier to cleave than a C(sp2)–H bond, resulting in a higher likelihood of radical substitution at those positions. To the best of our knowledge, there are no previous examples of perfluorobenzyl substitution of any PAH(Br
- , and poor selectivity. The latter approach was shown to be more promising due to a faster rate, use of an inexpensive, low-boiling solvent, and easier work-up. This method will continue to be investigated in our laboratory. The emission spectrum of 9,10-ANTH(BnF)2 revealed its deeper blue fluorescence
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