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Search for "selectivity" in Full Text gives 1346 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Kinetic resolution of racemic planar-chiral vinylcymantrenes by molybdenum-catalyzed asymmetric metathesis dimerization
Beilstein J. Org. Chem. 2026, 22, 568–574, doi:10.3762/bjoc.22.42
- chiral-2a/meso-2a = 96:4 molar ratio, and the selectivity factor (krel) was calculated to be 754 based on a second-order equation. In all the three substrates examined, the dimerized products, chiral-2, were obtained in >98% ee thanks to the outstanding enantioselectivity. Keywords: cymantrene; kinetic
- appropriate chiral Mo-alkylidene precatalyst, the highly diastereo- and enantioselective kinetic resolution (KR) of the racemic substrates was attained with the krel values ([reaction rate of the fast-reacting enantiomer]/[reaction rate of the slow-reacting enantiomer]; selectivity factor) of up to 96 for the
Molecular tweezer–peptide conjugates disrupt the protein–protein interaction between survivin and histone H3 essential in mitosis
Beilstein J. Org. Chem. 2026, 22, 557–567, doi:10.3762/bjoc.22.41
- attached phosph(on)ate anions as powerful new hosts for the amino acids lysine and arginine. In the recent past, we demonstrated that the affinity and selectivity of our lysine-selective molecular tweezers could be improved by attaching natural peptide recognition elements. This could be documented in
- and precisely the natural binding site in the wide 14-3-3-cleft [10]. These examples for designed protein–protein interaction (PPI) inhibitors demonstrated that short but highly flexible linkers are imperative to increase selectivity and minimize entropical penalty. The design was strongly supported
Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor
Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36
- [4]resorcinarene hydroxamic acid has also shown a pronounced binding tendency and selectivity for uranyl and proved to be applicable for the determination of uranium in standard and environmental samples [34]. Importantly, more recent studies have demonstrated that pre-organized or cyclic hydroxamate
Recent advances in the stereoselective synthesis of distal biaxially chiral molecules
Beilstein J. Org. Chem. 2026, 22, 461–479, doi:10.3762/bjoc.22.34
- atropisomeric (hetero)biaryls (Scheme 17) [56]. This highly enantioselective C–H arylation of heteroarenes employs a Pd(0) complex with H8-BINAPO L8 as the chiral ligand, enabling the arylation of 1,2,3-triazoles and pyrazoles in excellent yields with great selectivity. This method also facilitates
Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities
Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28
- carbamoylmethylphosphine oxides along with enrichment of the extraction selectivity [36][37][38][39][40][41][42][43][44][45]. Even more impressive is the effect from grafting of four urea groups at the wide rims of calix[4]arene macrocycles achieved by reacting p-aminocalix[4]arenes with aryl- or arylsulfonyl isocyanates
- their structures, in which the nitrated aromatic units experience an additional shielding. This may be also responsible for the selectivity of the two-fold nitration of compounds 8 and 9 leading to calixarenes 12 and 13 rather than to their isomers containing nitro groups in the propargylated aromatic
- calixarene core. This correlates well with the above selectivity of nitration observed for calixarenes 8 and 9 and may be tentatively explained by an electron-withdrawing effect of the propargyl groups. However, in the molecular structures of calixarenes 15 and 16, another feature was observed: in both cases
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
- carcinoma cells), and T98G (Human glioblastoma multiforme cells). Cytotoxicity was determined by measurement of 50% inhibition of cell growth by the MTT (3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide) assay. The selectivity index (SI) was calculated for the investigated compounds. The
- cytotoxicity results (CC50, µM) for the investigated compounds and the calculated selectivity index values are presented in Table 1. The compounds 2, 6, and 8 were found to be non-toxic towards all the cancer and non-cancer cell lines investigated (CC50 > 1000 µM). In general, cancer cells form the following
- rows in the order of decreasing sensitivity to the active compounds: HeLa: 1 > 3 > 9 > 5 > 7 > 4 A549: 1 > 3 > 4 > 5 > 7 = 9 HepG2: 3 > 1 > 4 T98G: 3 > 1 It was observed that compounds 1 and 3 showed the highest cytotoxicity against all cancer cells. Compound 1 exhibited the highest selectivity towards
Electrosynthetic access to unsymmetrical oxaza[8]helicenes with high chiral stability and strong circularly polarized luminescence (CPL)
Beilstein J. Org. Chem. 2026, 22, 372–382, doi:10.3762/bjoc.22.25
- ]helicenes. Inspired by the superior selectivity and sustainability of organic electrosynthesis as an eco-friendly alternative to conventional oxidative methods [43][44][45][46][47], we leveraged our electrochemical approaches [48][49][50][51][52], and redesigned the synthons to access a new unsymmetrical
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
Arene activation via π-bond localization: concepts and opportunities
Beilstein J. Org. Chem. 2026, 22, 257–273, doi:10.3762/bjoc.22.19
- introduced by Cheong and Altman in 2020 (Figure 10A) [83]. In this study, the authors explored an intramolecular, decarboxylative C–H functionalization of benzylic electrophiles, uncovering a decisive role of the base in governing site selectivity. Computational and mechanistic analyses revealed that only
- [80]. Computational investigations of this latter transformation identified an η3-allylnaphthalene–η1-allenyl palladium complex as the key to achieving ortho-selectivity (Figure 10B) [85][86]. Building on these insights, the Bao group employed malonates as alkylating agents in reactions with
- of this protocol, in which sterically demanding ligands promoted para-selectivity, while less encumbered systems channeled the reaction toward ortho-functionalization [88]. Following a conceptually related strategy, Yamaguchi and co-workers leveraged a three-component strategy that accesses the key
A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives
Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18
- rapid access to these previously unreported compounds, offering a versatile platform for systematic structure–activity relationship exploration and paving the way for the development of next-generation antibacterial agents with optimized potency and selectivity. Results and Discussion Chemistry For
- (transesterification/alcoholysis) under the influence of alcohol, ultimately yielding the open-chain ester (Scheme 6). This mechanistic rationale explains both the observed selectivity and the intrinsic limitations of the reaction scope imposed by the dual role of the alcohol as nucleophile and solvent. Interestingly
- , replacing alcohols with secondary amines (e.g., pyrrolidine) as the reaction medium did not lead to the desired amides. Experimental trials resulted in the formation of complex mixtures (as confirmed by 1H NMR), suggesting that the high reactivity of amines interferes with the selectivity of the cascade
Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF
Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16
- , the triplet exciton management and channel selectivity in different phases of PI-Cz 1 were systematically studied, validating the feasibility of “configuration-packing synergy” for controllable RTP–TADF switching within the same molecule. Results and Discussion Single crystals of 1 were successfully
Screwing the helical chirality through terminal peri-functionalization
Beilstein J. Org. Chem. 2026, 22, 205–212, doi:10.3762/bjoc.22.14
- -induced spin selectivity. These functionalities have great potential to transform in key areas such as drug discovery and modern diagnostic tools, as well as in distinct emerging fields like spintronics and optoelectronics [14]. Helicenes have found applications in chiral optoelectronics, i.e., as
Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH
Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11
- efficacy [2]. Activation of the 5-HT2AR is thought to induce altered states of consciousness and suppress the default-mode network, a process hypothesized to underlie their clinical benefits [3]. However, classic psychedelics lack receptor selectivity, prompting efforts to develop more selective 5-HT2AR
Asymmetric Mannich reaction of aromatic imines with malonates in the presence of multifunctional catalysts
Beilstein J. Org. Chem. 2026, 22, 151–157, doi:10.3762/bjoc.22.8
- adduct in 83% ee (Table 1, entry 9). Replacing the five-membered pyrrolidine ring in the catalyst structure with the more flexible six-membered piperidine ring (catalyst H, Table 1, entry 13) reduced its selectivity slightly (78% ee). However, the catalyst derived from phenylglycine (catalyst F) or
- product in a slightly less enantioselective way (71% ee). When comparing the halogen bond donor properties of tetrafluoroiodophenyl and iodophenyl moieties, the latter is weaker as it is less electron-withdrawing. However, there is a very small difference between reactivity and selectivity for catalysts E
- the halogen bond is not essential for the stereoselectivity of the reaction, but the halogen atom has a beneficial effect on both reactivity and stereoselectivity. A comparative experiment using an imine with a para-toluenesulfonyl protecting group afforded the product in lower selectivity (Table 1
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
- theory (DFT) methods. The dyes also exhibit chemosensor properties, showing selectivity for cyanide via a Michael addition mechanism that causes the disappearance of the ICT band, and a significant color change was observed in both organic and aqueous media. In addition, the interaction mechanism between
- photophysical properties of the dyes. The sensitivity/selectivity properties of the dyes to anions were investigated in DMSO and aqueous media, revealing that the dyes were selectively responsive only to cyanide anions. Changes after interactions were determined through absorption spectra and color changes
- also showed significant color changes with increasing polarity. Color changes of 2a; from purple to blue, 2b; blue to green, and 2c; pale orange to pale pink (Figure 2d). Dyes do not show any significant emission. Chemosensor properties Cyanide selectivity study The dyes 2a–c could have the ability to
Total synthesis of natural products based on hydrogenation of aromatic rings
Beilstein J. Org. Chem. 2026, 22, 88–122, doi:10.3762/bjoc.22.4
- ]. Although oxidative dearomatization has been a widely studied and powerful approach in synthetic chemistry [21][26][27][28], researchers have gradually recognized its inherent limitations, including narrow substrate scope, poor selectivity, and low functional group compatibility. Under the circumstance of
- hydrogenation of aromatic rings The catalytic hydrogenation of arenes offers a powerful route to disrupt aromaticity and access synthetically valuable intermediates. However, its implementation in strategic synthesis has been hindered by the persistent challenge of controlling selectivity across diverse
- -art systems depend on expensive transition metals such as platinum, ruthenium, or palladium, inflating the cost of large-scale applications. In addition, precious-metal catalysts often display poor selectivity, while heteroatoms in heteroarenes – acting as Lewis bases – tend to coordinate to the metal
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
- benzylic position, giving the hydrogenated products with high site selectivity. Zr-catalyzed radical reaction in the total synthesis of complex natural products This section presents examples of zirconium-mediated reactions applied to the synthesis of complex molecules. For application in total synthesis
Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene
Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2
- reactions mainly involve the initial electrophilic attack onto the α-position relative to the hydrogen atom. The selectivity is either due to the high stability of the α-nucleophilic conformer or due to the promotion by the adjacent ester group. Cascade reactions upon the target connection, if installed
- unavailability of other stable cycloheptatrienyl anions until recently, its derivatives were not expected to show high selectivity in reactions. Herein, we present the first examples of selective reactions of low-symmetry hexa(methoxycarbonyl)cycloheptatrienyl anion 2 [20] towards electrophiles. Additionally
- principle [38]. At least, the reaction times and conditions required for the alkylation reactions investigated, which proceed through an α-attack, indicate relatively high barriers. This in turn indicates that the selectivity observed in alkylation reactions (α-attack) is due to some stabilization of the
Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review
Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1
- demonstrated that aromatic alkynes can undergo hydrochlorination with good selectivity for the mono-addition when a nitromethane/acetic acid solvent mixture is employed (Scheme 27) [96]. In contrast, selective monohydrochlorination is commonly observed for alkynes bearing coordinating substituents such as
- , aligned with the axis of the vacant orbital. In the case depicted in Scheme 40B, the face syn to the hydrogen is significantly more accessible than the face syn to the bulky tert-butyl group, accounting for the high E-selectivity observed. In contrast, alkyl groups with reduced steric demand led to
- of the reaction in which TiCl4 was employed in place of BCl3 (Scheme 43) [147]. Interestingly, this modification led to an improved E/Z ratio compared to the values reported by Melloni (compare selectivity for compound 219 in Scheme 38 and Scheme 41). The enhanced selectivity is likely attributable
Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides
Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211
- , electroorganic synthesis has become a powerful and reliable strategy for the functionalization of organic compounds under green and mild reaction conditions [36][37][38][39]. The control of selectivity through the variation of parameters such as current, voltage, electrolyte, electrodes, and the type of
- scalable and can be performed in an undivided cell under high current densities without a loss of selectivity. The use of ammonium dinitramide as a source of the [=N–NO2] group and an electrolyte eliminates the need for hazardous nitronium salts and allows the synthesis of nitro-NNO-azoxy compounds in a
Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones
Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209
- triethylamine in 1,4-dioxane (Table 1, entry 9) did not affect the reaction course significantly. The use of conditions with catalysis by a combination of Bronsted acid and base (acetic acid, Et3N) contributed to a shift in the reaction selectivity towards octahydropyridopyrimidinones 4 (overall yield 71
- 5ctt (δF 79.74 ppm). All products were individually isolated by column chromatography. Carrying out these syntheses in 1,4-dioxane in the presence of acetic acid and triethylamine increased the selectivity for the formation of octahydropyrido[1,2-a]pyrimidinones 4 in the reactions with alkyl methyl
- influenza A/Puerto Rico/8/34 (H1N1) virus on the MDCK cell line using ribavirin as a reference (Table 5). Of all the tested compounds, octahydropyridopyrimidinone 4att (IC50 86 μM, SI = 13) showed moderate antiviral activity. However, the value of selectivity index (SI) did not exceed that of reference
Recent advancements in the synthesis of Veratrum alkaloids
Beilstein J. Org. Chem. 2025, 21, 2657–2693, doi:10.3762/bjoc.21.206
- afford cyclization of the E-ring. The obtained pyridinium species was directly reduced to reveal the piperidine moiety. The observed selectivity for hydrogenation from the α-side was attributed to the steric hindrance of the C20 axial tertiary TMS ether. The survival of the olefin in the D-ring was
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
- leading not only to improved extraction effectivity but also to enhanced selectivity [2]. Anion extractants based on functionalized polystyrene or silica gel typically incorporate calixarenes [6] and their analogues, calixpyrroles [7][8], azacalixarene derivatives [9], or expanded porphyrin-like sapphyrin
- affected by its long aliphatic arms terminated with carboxylic groups, whose flexibility can enable intramolecular complexation competing for an anion binding [13]. Bambusurils are known to bind a wide range of anions with varying selectivity. Dicyanoaurate is particularly relevant to the gold mining
- industry, whereas dicyanoargentate is considered a contaminant in this context. To assess selectivity, we measured the sorption of dicyanoaurate from a 1 mM aqueous solution both in the absence and in the presence of an equimolar amount of dicyanoargentate. The measurements revealed that dicyanoaurate
Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds
Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200
- production of ketone scaffolds, including drug moieties. The organocatalyzed acylation proceeds with excellent site selectivity and broad functional group tolerance of alkanes such as F, Cl, Br, I, CN, CF3, Me, and OMe. The reaction was achieved between acyl fluoride 4 and highly substituted alkane 7 in the
- para-selectivity observed in Friedel–Crafts acylation. The authors anticipate expanding this strategy to other reaction processes, allowing the efficient development of transformative synthetic methods, constructing new chemical spaces for drug discovery, and modifying bioactive molecules (Scheme 13
Recent advances in total synthesis of illisimonin A
Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199
- hydroxy group could be responsible for this reversal in selectivity. Dai’s asymmetric synthesis of (−)-illisimonin A In 2025, Dai and co-workers accomplished an asymmetric total synthesis of (−)-illisimonin A in 16 steps from (S)-carvone (67) using a pattern-recognition strategy and five sequential olefin
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