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Search for "substituents" in Full Text gives 1761 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones
Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113
- situ-generated 1 towards enolizable 5-mercapto-1H-tetrazoles 4 bearing various aliphatic and aromatic substituents at the N(1) atom. Competition between the expected S–H and N–H insertion processes was of primary interest. In extension of the synthetically oriented study, bioactivity of selected
Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides
Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110
- reaction yields allowed us to establish the dependency from the electronic effects of substituents in the diaryliodonium salts. Diaryliodonium salts containing electron-deficient aryls afforded products 2 in higher yields compared to those bearing electron-donating groups (EDG). Specifically, the reaction
- (4-NO2C6H4) compared to (4-OMeC6H4) [45]. Therefore, despite the fact that literature data mostly suggest similar reactivity for aryl radicals with different substituents in the phenyl ring, the formation itself is more favorable for EWG-substituted radicals. To gain a deeper understanding of the
Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications
Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106
- the optical, chiroptical, and stimuli-responsive behavior of azahelicenes, providing strategic design avenues for next-generation chiral optoelectronic materials. In 2023, Langer’s group synthesized a series of double aza[4,6]helicenes 18a–l featuring diverse peripheral substituents through a one-pot
- [33] and Ishigaki’s [34] groups independently reported a class of highly twisted nitrogen-doped heptalene derivatives (e.g., compound 20a), which exhibit consistent absorption at 315 nm and blue fluorescence centered near 450 nm, regardless of the substituents. These compounds display redox and
- -workers introduced various boryl substituents at both termini of a series of nitrogen-doped [5]helicenes, yielding helicenoids 42a–h [57] (Table 14). The Bpin-substituted derivatives 42a–e exhibited broad emission across the 400–800 nm range, whereas their analogues 42f and 42g showed negligible emission
Tautomerism and switching in 7-hydroxy-8-(azophenyl)quinoline and similar compounds
Beilstein J. Org. Chem. 2025, 21, 1404–1421, doi:10.3762/bjoc.21.105
- , printing, and coloring agents for various materials, due to their excellent color fastness, high stability, and ease of synthesis. The azo functionality allows for a wide range of colors to be achieved by altering the substituents on the azo group, improving the color intensity, lightfastness, and wash
- CH3 group) and 3 leads to destabilization of K, while placing a substituent in positions 5 (weakly) and 6 stabilizes it. The effect on position 4 is mixed – electron donors stabilize the K form, while acceptors rise its energy. All substituents in position 8 stabilize K, but the effect of the
- ) (Figure 8b) the needed reduction is observed in position 2 for CH3 group (weakly), substantially for NR2 in position 4 and strongly for all substituents in position 6. The value of ΔE(KE-E) (Figure 8c) has to be larger than 2, but it cannot be achieved. Almost all functional groups on position 2 and all
Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles
Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104
- compounds is provided by the variation of substituents in positions 2–5 of the 1,2-thiazole ring. Thus, arylsulfonyl groups containing a methyl, fluorine, chlorine, or nitro group at the aryl moiety, or a mesyl substituent were introduced into position 2 of the thiazole ring and various aryls, quinolinyl
- , pyridinyl, furyl, isopropyl, and cyclohexyl substituents were introduced into position 3; cyano and various carbonyl groups were added to position 4 and cyclic amine residues were added to position 5 which increase the solubility of the synthesized compounds 3 (Scheme 2). An analysis of the yields of
- , the atom N(2) deviates from the RMS plane S(1)C(3)C(4)C(5) by 0.461 Å. The atom of the N(1) morpholine fragment has a planar configuration with significant asymmetry in the lengths of C–N bonds. Due to the electron-acceptor effects of substituents, the C(3)‒H bond exhibits significant polarity and is
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- heteroarenes. This practical synthesis of 3-aryloxetan-3-carboxylic acids potentially opened the door to installation of a wide range of substituents into the 3-position through a decarboxylative radical coupling, which was eventually exploited by Duarte and Bull et al. in 2023 (Scheme 38) [89]. The
- 178 from 3-aryloxetan-3-ols through a tandem Friedel–Crafts alkylation/intramolecular ring opening (Scheme 45) [87]. The reaction was mostly high yielding and best results were obtained for electron-rich para-substituted phenols, while substituents in the ortho/meta-positions diverted the
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
- and co-workers [55]. A palladium-catalysed variation of [3 + 2] annulation, accompanied by ring expansion [56], was used for the intermolecular reaction between acenes bearing alkyne substituents 55a–d and di-n-butylacetylene (56). The reaction gave a series of azulene-embedded isomers of linear
- to the dication induced an aromaticity switch, resulting in the pentagon–heptagon pair adopting an aromatic character. The group later extended this strategy to scaffold 91 decorated with two imide substituents, which was isolated in 4% yield [66]. Annulation of substituted azulenes Scholl-type
- 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
- and alcohols. Substrates with different substituents, including both electron-donating and electron-withdrawing groups, provided satisfactory yields (7a–f). However, steric hindrance significantly influenced the outcome, as ortho-substituted substrates yielded lower amounts (7c). The study also
- , diverse β,γ-unsaturated ketoximes and N-arylacrylamides were compatible with the transformation. Various substituents on the phenyl ring of ketoximes, including both electron-donating and electron-withdrawing groups, were well tolerated, affording the desired products in satisfactory to high yields
- . Additionally, thiophene-substituted ketoxime and aliphatic ketoxime also participated effectively in the reaction to afford products 9f and 9e. Notably, N-arylacrylamides bearing different substituents, particularly at the para- and ortho-positions of the phenyl ring, were well tolerated, although ortho
Optimized synthesis of aroyl-S,N-ketene acetals by omission of solubilizing alcohol cosolvents
Beilstein J. Org. Chem. 2025, 21, 1201–1206, doi:10.3762/bjoc.21.97
- ) and electron-donating (-OMe) substituents were used. Additionally, a heterocycle could be incorporated. Different benzyl substituents were employed, and substitution at the benzothiazole core was also tolerated (Table 1). As an alternative to 1,4-dioxane, 2-methyltetrahydrofuran was tested the solvent
Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers
Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95
- go beyond common organic functional materials composed of rigid π-conjugated planes and flexible peripheral substituents. Because larger π-conjugated planes mostly display low solubility and dense packing due to the π–π stacking and CH–π interactions, surrounding alkyl and other flexible moieties are
A versatile route towards 6-arylpipecolic acids
Beilstein J. Org. Chem. 2025, 21, 1104–1115, doi:10.3762/bjoc.21.88
- a key intermediate product. This late-stage approach was previously described by us while utilising Suzuki–Miyaura or Sonogashira–Hagihara cross-coupling reactions to generate pipecolic acid derivatives with alkynyl substituents in the C6 position [35]. Here, we present a robust synthetic route to
Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes
Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86
- electron-withdrawing para-substituents generally gave the desired products 3ae and 3af in higher yields and enantioselectivities than aldehydes with electron-donating substituents (2b–d). Sterically congested 3-chlorobenzaldehyde (2g) and 2,6-dichlorobenzaldehyde (2h) produced the desired products 3ag and
Pd-Catalyzed asymmetric allylic amination with isatin using a P,olefin-type chiral ligand with C–N bond axial chirality
Beilstein J. Org. Chem. 2025, 21, 1018–1023, doi:10.3762/bjoc.21.83
- did not proceed, and (S)-13e was not produced. Likewise, no reaction occurred with a trifluoromethoxy-substituted derivative, resulting in no formation of (S)-13f. Reactions using isatin derivatives bearing halogen substituents at the 6-position proceeded efficiently, affording (S)-13g–i in good
Synthesis of pyrrolo[3,2-d]pyrimidine-2,4(3H)-diones by domino C–N coupling/hydroamination reactions
Beilstein J. Org. Chem. 2025, 21, 1010–1017, doi:10.3762/bjoc.21.82
- groups attached to the aniline, such as OMe, F, CF3, Me, and Br, were tolerated and did not greatly differ in terms of yield. With respect to substituents located at the alkynyl moiety, diminished yields were obtained for N,N-dimethylaminophenyl-substituted derivatives 4k and 4l and for m-tolyl
- -substituted compound 4h. No conversion was observed for starting materials 3g,h containing electron-withdrawing substituents located at the phenylacetylene moiety (products 4n,p). In addition, no conversion was observed for 3-methylaniline (product 4o). The photophysical properties of selected pyrrolo[3,2-d
- . Electron-donating N,N-dimethylaminophenyl substituents led to bathochromically shifted absorption and emission spectra accompanied by strongly elevated fluorescence quantum yields (up to 83%). Further studies will be devoted to the synthesis of novel polycyclic uracil derivatives with potential biological
Recent total synthesis of natural products leveraging a strategy of enamide cyclization
Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81
- cyclization to form products in high yields and excellent enantioselectivities. Notably, only a single diastereomer was produced in each case. The single-crystal X-ray crystallography revealed a cis-configuration for both the alkene and ketone substituents on the enamide, indicating that the intramolecular
On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals
Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80
- triphenylmethyl radical [38][39]. In contrast to the Gomberg radical, the perchlorination prevents dimerization through the para-position. Moreover, the chlorine substituents in the ortho-positions twist the phenyl rings into a propeller conformation and out of the sp2-hybridization plane of the central methine
- radical unit. Now, the chlorine substituents screen the hemispheres above and below this plane, protecting the unpaired electron in the p-orbital from oxidation or other detrimental degradation. The weak emission of PTM with ϕ of 0.7% peaks at 609 nm (in tetrachloromethane (CCl4)) [40]. The racemic
- low ϕ (see Figure 2a) [50][51]. Perfluorinated triphenylmethyl radicals have been reported as well; however, neither UV–vis nor photoluminescence data are available [54]. Mixed perhalogenated triphenylmethyl radicals with fluorine, chlorine, and bromine substituents have been synthesized in an attempt
Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline
Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79
- , Semmelweis University, Üllői út 26, H-1085 Budapest, Hungary 10.3762/bjoc.21.79 Abstract A new total synthesis of the β-carboline alkaloid brevicarine is disclosed. The synthesis was carried out starting from an aromatic triflate key intermediate, allowing the introduction of various substituents into
- , versatile key triflate intermediate 3, which allowed the introduction of substituents attached by a C–C bond to position 4 of the β-carboline scaffold by cross-coupling reactions. Sonogashira reaction of compound 3 with N-(3-butynyl)phthalimide (4) led to coupled compound 5. Cleavage of the phthalimide
Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes
Beilstein J. Org. Chem. 2025, 21, 947–954, doi:10.3762/bjoc.21.78
- compatible with our optimized conditions (Table 2, poor performers). In many cases, complex mixtures of recovered starting material and multiple products were observed. Carbamate tethers with N-alkoxy substituents were essential for clean reactions; indeed, extensive decomposition was observed with N-ethyl
Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines
Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74
- , propiolic acids 8a–d, and isocyanides 4a–e. By conducting the reactions in methanol at 70 °C, we obtained the desired Ugi adducts 15a–x in fair to good yields of 26–72% allowing for the variation of substituents across all components of the U4CR (Scheme 2). Notably, the Ugi reaction toward substrate 15a
- substrates 15e–l was tested. The process proceeded efficiently in all cases, yielding pyrazolodiazepines 16e–l and demonstrating tolerance for various substituents on the aniline-derived aromatic fragment, including alkyl, halogens, electron-donating alkoxy groups, as well as electron-withdrawing
Recent advances in controllable/divergent synthesis
Beilstein J. Org. Chem. 2025, 21, 890–914, doi:10.3762/bjoc.21.73
- different substituents and polysubstituted annular boronic acids 98, a Suzuki coupling was employed to synthesize advanced isoquinoline intermediates 100. Following this, a 6π electrocyclization reaction and nucleophilic reaction were developed to achieve C–C and C–N bond constructions, respectively
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
- introduction of lower-rim hydroxy substituents effectively enhances the dicarboxylate binding through cooperative hydrogen bonding and anion–π interactions. The selective recognition of long and flexible dicarboxylates holds exciting promise for the use of dicarboxylate sensors in medicine and industry. (a, b
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
- bearing aromatic and aliphatic substituents efficiently provided the allylboration product (Scheme 1a), the use of ester derivative 1 under same reaction conditions led to the formation of an unexpected product arising from the coupling of two dichloride molecules with no alkyne incorporation (Scheme 1b
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
- demonstrated the efficient sensitization of an alkene-containing four boron substituents using Ir(ppy)3 as a suitable sensitizer in the presence of styrene, indicating a prominent role of the adjacent p-orbital [51]. While simple alkenylboronic esters have been employed as triplet diradical quenchers to
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
- group, we investigated the reactions with various substituted 2-halobenzoic acids. The reactivity of 2-iodobenzoic acid derivatives (3a–d, 90−96% yields) was higher than that of 2-bromobenzoic acid derivatives (3a–d, 57−73% yields), the electronic properties of the substituents on the benzene ring had
- little effect on the reactivity. When the amidine substituent (R2) was changed to a cyclopropyl group, the yields of all reaction decreased, especially when substituents were present on the benzene ring (3e–h, 55−94% yields for 2-iodobenzoic acid, 43–76% yields for 2-bromobenzoic acid). We then
- reaction activity observed when substituents were presented on the benzene ring. Finally, we examined reactions with 2-halobenzoic acid derivatives where the R2 substituent was a phenyl group. In this case, the reactivity of 2-iodobenzoic acid derivatives (3m–p, 61–99% yields) was again superior to that of
Substituent effects in N-acetylated phenylazopyrazole photoswitches
Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66
- relative position of the absorption bands in the azobenzene derivatives depends on the substitution pattern on the aromatic rings, which can act as a handle to affect the absorption properties of the compound class [3]. For instance, push–pull systems or the introduction of tetra-ortho substituents were
- studies on azobenzene [32][40]. Another interesting aspect, that could point to a more complex picture in the excited state landscape of these switches, is that the QYs of NAc-PAPs with R = NO2 and R = H are lower for the π→π* than for the n→π* transition, while for the other substituents the opposite was
- found. We thus suspect that the substituents play a crucial role in in the population of the respective exited state and we can at this state not rule out a contribution also from the triplet state. Moreover, we could not find a quantitative correlation between the R-substituents and ΦE→Z, however, some
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