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Search for "heterocycle" in Full Text gives 351 result(s) in Beilstein Journal of Organic Chemistry. Showing first 200.
Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles
Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194
- compounds. The utility of click chemistry [11][12] for achieving chemoselective conjugation in a diversity of chemical environments has established the 1,2,3-triazole ring as a ubiquitous heterocycle in many research areas such as therapeutics [13][14][15][16], chemosensors [17][18][19], bioconjugation [20
- isoquinoline subunits. Heterocycle subunit identity and triazole C/N connectivity influenced the annulation reaction efficiency. Aromatic π-system expansion resulting from annulation was characterized by NMR, absorption and emission spectroscopy. Five benzotriazolophenanthroline regioisomers sharing structural
- reactivity of this family of pentacyclic aromatic heterocycles towards N-benzylation and the antimicrobial properties of such resulting quaternary ammonium compounds are ongoing. Examples of polycyclic aromatic heterocycle structures: phenanthridine (left), 1,5-naphthyridine (center), and 1,9-phenanthroline
Isoorotamide-based peptide nucleic acid nucleobases with extended linkers aimed at distal base recognition of adenosine in double helical RNA
Beilstein J. Org. Chem. 2025, 21, 2513–2523, doi:10.3762/bjoc.21.193
- , heterocycle of Db2 is rotated, placing its polar face towards solute and non-polar methyl group towards RNA. This results in the whole Db2 base being tilted, which breaks the intended stabilizing H-bond between the Db2 linker and the adjacent M. Db3 resulted in the best interaction in silico despite the low
Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings
Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166
- electrochemical [4 + 1] annulation of alkynoate with arylbenzimidazole [108], and the electrochemical ortho-annulation of 2-alkynylbenzenesulfonamide gave the corresponding five-membered heterocycle [106]. In recent years, a few reviews about the electrochemical cyclization of alkynes and electrochemical
Multicomponent reactions IV
Beilstein J. Org. Chem. 2025, 21, 2082–2084, doi:10.3762/bjoc.21.163
- a strong emphasis on heterocycle synthesis. Beyond traditional condensation-based approaches, mechanistically innovative crossovers – linking metal catalysis with radical chemistry and, more recently, with photo(redox) catalysis – are opening entirely new avenues for MCR development. Finally, seven
α-Ketoglutaric acid in Ugi reactions and Ugi/aza-Wittig tandem reactions
Beilstein J. Org. Chem. 2025, 21, 2021–2029, doi:10.3762/bjoc.21.157
- ], antibacterial [8][14][15], and anticancer [16][17] activities. The use of the Ugi reaction followed by post-cyclization is an effective strategy that yields diverse heterocycle-containing peptidomimetics and requires a minimal number of steps [18]. For example, Mazur et al. [19] developed an efficient method
Aryl iodane-induced cascade arylation–1,2-silyl shift–heterocyclization of propargylsilanes under copper catalysis
Beilstein J. Org. Chem. 2025, 21, 1984–1994, doi:10.3762/bjoc.21.154
- linker provides entry to 1,2,3,6-tetrahydropyridines. Additionally, in the absence of internal nucleophiles, this methodology yields aryl-substituted 1,3-dienes. This work introduces a palladium-free, single-step alternative to multistep heterocycle construction from propargylsilanes and highlights the
Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis
Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151
- JohnPhos (6) induced cyclization, yielding bicyclic compound 7 with a 7-membered heterocycle. Final deprotection of the methoxymethyl (MOM) group in 7 afforded (+)-heliannuol D (8). Having successfully applied PPL-catalyzed acetylation to the synthesis of (+)-heliannuol D, the Shishido group subsequently
Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules
Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145
- the efficient asymmetric synthesis of inherently chiral eight-membered N-heterocycle 6,7-diphenyldibenzo[e,g][1,4]diazocines (DDDs), which displayed a rigid saddle-shaped configuration [16]. Starting from readily available [1,1'-biphenyl]-2,2'-diamines 62 and benzyl compounds 63, the asymmetric
- CPA-catalyzed cyclization of INT-E through the dual hydrogen bonding activation transition state TS-1 afforded the eight-membered heterocycle INT-F with a stereogenic center. Through the elimination of aniline 73, the saddle-shaped dibenzo[1,5]diazocine 72 was produced via a central-to-inherent
Photoswitches beyond azobenzene: a beginner’s guide
Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143
- nitrogen in “ortho” position (according to the nomenclature in the original paper) [14] also gives slightly twisted Z-isomers 10a and 10b. Moreover, a rough approximation of the thermal lifetime could be made considering the nature and connectivity of the heterocycle as either “complete” or “partial
- lifetimes with great accuracy [7]. In summary, the more extended the conjugation of the heterocycle with the N=N bond, the more feasible the inversion mechanism (which does not involve the rupture of the double N=N bond). The less conjugated switches, however, would undergo rotation around the (instant
[3 + 2] Cycloaddition of thioformylium methylide with various arylidene-azolones in the synthesis of 7-thia-3-azaspiro[4.4]nonan-4-ones
Beilstein J. Org. Chem. 2025, 21, 1791–1798, doi:10.3762/bjoc.21.141
- single either cis or trans stereoisomers, dependent on the heterocycle core used. Keywords: arylidene-azolones; cycloaddition; nitrogen heterocycles; sulfur heterocycles; thioformylium methylide; Introduction Spirocyclic derivatives of heterocycles occupy an important place in modern organic and
- a single diastereomer with traces or no of the other one (dr >19:1). For the derivative 5e with an oxygen-containing heterocycle, we failed to obtain the corresponding products under any of the proposed conditions. In all cases, we observed only very complex mixtures with traces of the target
- reaction is shown to proceed with exclusive formation of a single diastereomer of the spirocyclic product, the exact configuration of which is dependent on the nature of heterocycle employed. Key stereo- and electronic factors for successful realization of the cycliaddition reaction were discovered, which
Catalytic asymmetric reactions of isocyanides for constructing non-central chirality
Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129
- nucleophiles in the DKR of various bridged biaryls bearing different linkages to give diverse nitrogen heterocycle-substituted atropoisomeric biaryls. In 2021, our group achieved the catalytic enantioselective DKR of biaryl lactones 46 with α-acidic isocyanides (Scheme 8a) [48]. By using Ag2CO3 and cinchonine
Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins
Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118
- therapeutic efficacy (lower IC50 values) [18] but greater toxicity to healthy cells in comparison with spiro compounds [19]. Such hybrid-designed molecules may contain a third heterocycle as a linker, spiro-joined with one of the pharmacophore moieties. In this case, another pharmacophore fragment is included
Highly distinguishable isomeric states of a tripodal arylazopyrazole derivative on graphite through electron/hole-induced switching at ambient conditions
Beilstein J. Org. Chem. 2025, 21, 1496–1507, doi:10.3762/bjoc.21.112
- derivatives play a crucial role in realizing efficient bidirectional photoswitches with longer half-lives [18][19]. In particular, replacing one of the phenyl units in AB with a five-membered heterocycle and the resulting Z isomer of phenylazoheteroarenes has extended half-life ranging up to 1000 days and
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
- , and 60c – featuring 2,1,3-thiadiazole termini [75] (Table 20). Among them, compound 60c exhibited pronounced CPL activity in toluene (|glum| = 0.04, ΦF = 3%), demonstrating the efficacy of terminal heterocycle incorporation for boosting chiroptical performance. In 2024, Babu and co-workers developed
Oxetanes: formation, reactivity and total syntheses of natural products
Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101
- oxidation state ruthenium, allowing for a facile purification (simple acidic/basic workup) and is very mild, scalable and high-yielding. However, the yield tends to get rather low (below 25%), if the oxetane bears a heterocycle (e.g., indole or thiophene), most likely due to competing oxidations of the
- oxygen and a subsequent proton transfer affords the aromatic heterocycle. The authors also devised a modification to this procedure for olefin precursors which were difficult to prepare: this alternative uses cross-aldol adducts 180 between 3-oxetanone and a ketone, and the ring opening and dehydration
- -catalysed heterocycle synthesis, specifically a [3 + 2] annulation of 3-(4-hydroxyphenyl)oxetan-3-ol (211) with β-naphthylamines or phenols 210 to give benzoindolines and 2,3-dihydrobenzofurans 212, respectively (Scheme 50) [104]. The reaction gave moderate to high yields and control experiments indicated
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 demonstrated that also BN heterocycles can be obtained using similar types of precursors (Scheme 23) [107]. Compound 179 was reacted with PhBCl2 to yield BN heterocycle 180 in 78% yield. Compound 180 exhibits high sensitivity for the visual detection of fluoride ions and undergoes an
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
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
Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates
Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96
- various synthetically useful transformations, including alkene synthesis via Horner–Wadsworth–Emmons reaction [14][15], heterocycle construction [16][17], and the synthesis of chiral β-amino and β-hydroxy phosphonic acids [18][19]. Furthermore, they exhibit metal-complexing abilities [20], and anti
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
- tertiary enamides as cyclization precursors (Scheme 6). The analogous polycyclization generated a tetracyclic N-heterocycle with three continuous stereogenic centers, one of them being an aza-quaternary carbon [31]. The resulting fused ring-system structurally resembles the nucleus of erysotramidine
- notable example is (−)-cephalocyclidin A, a cytotoxic pentacyclic cephalotaxus alkaloid [33][34]. Although the molecular structure contains a benzo-bridge ring system, disconnection of this bridge reveals a critical tricyclic N-heterocycle. To efficiently synthesize this tricycle, polycyclization of
Substituent effects in N-acetylated phenylazopyrazole photoswitches
Beilstein J. Org. Chem. 2025, 21, 830–838, doi:10.3762/bjoc.21.66
- often show higher quantum yields and increased thermal half-life of the metastable state. For the half-life, the choice of the heterocycle is crucial, as revealed through density functional theory (DFT) calculations, which showed that a 5-membered ring promotes the stability of the Z isomer [30]. Within
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
- 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
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
- , replacement of graphite with stainless steel (SS) [9] as the cathode material afforded similar yields of the desired heterocycle 6a (72% and 70%, respectively; Table 1, entries 8 and 10), so both graphite and SS were subsequently used in the scope studies (vide infra). Other cathode materials such as Pt or
Formaldehyde surrogates in multicomponent reactions
Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45
- (as exemplified in Scheme 10 above) and its use in heterocycle multicomponent synthesis is not limited to quinolines, as the reaction to diarylpyridines [42][43], quinazolinones [44], and pyrazoles [45] is also described by this approach (Scheme 11). These examples deserve further discussion
- reaction works very well for a wide variety of functional groups and substitution patterns in the aryl methyl ketone substrate, affording the desired heterocycle with good yields. Even heteroaryl methyl ketone and 1,3-dicarbonyl compounds work very well under these reaction conditions, leading to more
- complex heterocycle products of general structure 9 and 11. Interestingly, Wu et al. demonstrated that the reaction did not proceed when paraformaldehyde is used as the C1 synthon, indicating that formaldehyde is not involved in the reaction [43]. Furthermore, in isotope labelling studies using DMSO-d6
Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates
Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41
- compounds that generally enhance the bioactivity of agrochemical and pharmaceutical substrates. On the other hand, 5-aminopyrazole [11][12] is a nitrogen heterocycle that has attracted significant interest to pharmaceutical and medicinal chemists due to the presence of this nitrogen heterocycle in various
- on the regioselective electrophilic functionalization of this nitrogen heterocycle [15][16][17][18][19][20][21][22][23][24][25]. However, the vinylogous functionalization of 5-aminopyrazoles has not been described to the best of our knowledge (Figure 2). As a part of our ongoing interest in the
- ] as electrophiles. It is noteworthy that the development of such vinylogous functionalizations of this nitrogen heterocycle with a fluorine-containing electrophile may be of interest to pharmaceutical and medicinal chemists. Results and Discussion 4-(Alkenyl)-5-aminopyrazoles 3 were selected as
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