Harnessing tethered nitreniums for diastereoselective amino-sulfonoxylation of alkenes

• Shyam Sathyamoorthi,
• Appasaheb K. Nirpal,
• Dnyaneshwar A. Gorve and
• Steven P. Kelley

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

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

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

• Jilei Cao,
• Leiyang Bai and
• Xuefeng Jiang

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

• Wen-Hui Mi,
• Teng-Yu Huang,
• Xu-Dong Wang,
• Yu-Fei Ao,
• Qi-Qiang Wang and
• De-Xian Wang

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

• Patricia Gómez-Roibás,
• Andrea Chaves-Pouso and
• Martín Fañanás-Mastral

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

• Lewis McGhie,
• Hannah M. Kortman,
• Jenna Rumpf,
• Peter H. Seeberger and
• John J. Molloy

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

• Xuhong Zhao,
• Weishuang Li,
• Mengli Yang,
• Bojie Li,
• Yaoyao Zhang,
• Lizhen Huang and
• Lei Zhu

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

• Radek Tovtik,
• Dennis Marzin,
• Pia Weigel,
• Stefano Crespi and
• Nadja A. Simeth

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

4-(1-Methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones: synthesis, anti-inflammatory effect and in silico approaches

• Nguyen Tran Nguyen,
• Vo Viet Dai,
• Luc Van Meervelt,
• Do Thi Thao and
• Nguyen Minh Thong

Beilstein J. Org. Chem. 2025, 21, 817–829, doi:10.3762/bjoc.21.65

• ) has occurred at the exocyclic sp2-hybridized carbon atom, leading to the substitution of the 4-methoxybenzylamino group by a methylamino group. Therefore, the presence of substituents (electron-donating or electron-withdrawing groups) on the benzene rings attached to the 1- and 5-positions of the

Regioselective formal hydrocyanation of allenes: synthesis of β,γ-unsaturated nitriles with α-all-carbon quaternary centers

• Seeun Lim,
• Teresa Kim and
• Yunmi Lee

Beilstein J. Org. Chem. 2025, 21, 800–806, doi:10.3762/bjoc.21.63

• from 88% to 99%. Similarly, chloro-substituted allene 1d exhibited good tolerance under these conditions, affording the corresponding nitrile 3d in an 88% yield, whereas phenethyl-substituted allene 1e provided 3e in a 95% yield. Allenes 1f–i featuring phenyl and alkyl substituents, including methyl

• , ethyl, phenethyl, and allyl groups, also underwent smooth cyanation, resulting in α-quaternary nitriles 3f–i in yields of 85–94%. Furthermore, aryl-substituted allenes 1j–o, incorporating electron-donating or electron-withdrawing substituents such as methyl, fluoro, chloro, bromo, trifluoromethyl, or

• . Trisubstituted allenes 1q–s bearing phenyl and dialkyl groups, including a cyclohexyl moiety, underwent selective cyanation to deliver the (E)-isomers of the corresponding nitriles 3q–s in yields of 90–95%. In addition, aryl- and dialkyl-substituted allenes 1t–x containing substituents, such as fluoro, chloro

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• tendency for hydro-dehalogenation. Tetrabutylammonium halide was chosen as the electrolyte due to its lower hygroscopicity and reduced tendency for reductive homocoupling of 4-bromobenzotrifluoride. In the presence of chlorinated substituents, neither the double coupling product nor the hydro

• -dechlorination product was observed. This notable result suggests performing a second coupling using conventional chemical methods, such as the Suzuki–Miyaura reaction. Furthermore, the coupling yield decreased for phenyl bromides bearing bulky ortho-substituents while hydrodehalogenation byproducts formed. The

• presence of air, no product was formed. This finding indicates that iodide salt plays a crucial role in driving the reaction and acts as a catalyst in the reaction process. The electronic properties of the substituents on the compounds influenced the reaction yield. Phenol with the –OMe group produced a

Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• conditions were optimized for the effective formation of tetrahydroquinoline derivatives with varying substituents, showing high yields under mild conditions. Mechanistic studies suggest a catalytic cycle involving nucleophilic attack by the aniline on the cyclobutanone oxime, followed by cyclization to form

• conditions, we proceeded to investigate the generality of this Cu-catalyzed system. Initially, a series of anilines bearing diverse substituents was examined, and the results are summarized in Scheme 2. When copper(II) trifluoroacetate was employed as the catalyst, para-halogen-substituted anilines 1b–e

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• azobenzene derivative 9 [34] to furnish 10. This reaction had to be carried out at −78 °C in order to suppress nucleophilic substitution of the ortho-fluorine substituents in 9 by the thiol 8, a reaction that competes with the desired cross-coupling. For the second Buchwald–Hartwig–Migita cross-coupling, the

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• distance < 5.5 Å is observed. Given the anionic nature of the sulfate substituents, one might expect to observe Me3N+···−O3SO interactions in the crystal. Somewhat surprisingly, only a single short Me3N+···−O3SO contact (4.352 Å) is observed with distance < 4.4 Å. There are, however, numerous longer Me3N

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• is rigidified in a predictable and desired way, by decorating it with an appropriate pattern of fluorine substituents. The purpose of this review is to examine cases where this idea has been put into practice. This topic has previously been reviewed [8], but in the time that has elapsed since that

• dictated by the maximisation of σC–H → σ*C–F hyperconjugative interactions, and this affords different puckers depending on the fluorine stereochemistry [133]. In this sense, the fluorine substituents are performing a similar role to a hydroxy group, so this is a “conformationally conservative” situation

• natural rotameric profile can be restored by replacing the –CH2– moiety of the carbasugar with a –CF2– moiety (e.g., 76, Figure 10), because the electron-withdrawing character of the fluorine substituents enables reasonably effective nO → σ*C1–C(F) hyperconjugation to occur [141]. Another way to influence

Photochemically assisted synthesis of phenacenes fluorinated at the terminal benzene rings and their electronic spectra

• Yuuki Ishii,
• Minoru Yamaji,
• Fumito Tani,
• Kenta Goto,
• Yoshihiro Kubozono and
• Hideki Okamoto

Beilstein J. Org. Chem. 2025, 21, 670–679, doi:10.3762/bjoc.21.53

• [48][49]. Thus, in the solution phase, the introduction of fluorine substituents provided seemingly minimal effects on the electronic spectral features of phenacenes. It has been demonstrated that parent phenacenes phosphoresce in a 500–620 nm wavelength region at 77 K showing the clear vibrational

Recent advances in allylation of chiral secondary alkylcopper species

• Minjae Kim,
• Gwanggyun Kim,
• Doyoon Kim,
• Jun Hee Lee and
• Seung Hwan Cho

Beilstein J. Org. Chem. 2025, 21, 639–658, doi:10.3762/bjoc.21.51

• to the parent allyl group, a variety of 2-substituted electrophiles 31 could be applied. These included those bearing alkyl groups of varying steric demand, halides, and both electron-rich and electron-poor aryl substituents. The olefin coupling partner scope was equally impressive, tolerating

• desired products with up to 99% ee. This methodology worked effectively with both pinacol boronic esters (Bpin) and 1,8-diaminonaphthalene boramides (Bdan), showing broad vinylboron substrate scope across alkyl, aryl, and heteroaryl substituents. The practical utility of the enantioenriched alkylboronic

• showed a broad scope, tolerating both 1,1-diborylalkanes with N-tosyl-protected amines and TBS-protected alcohols, as well as substrates containing alkenes and alkynes. Various allylic bromides 46 with electron-rich and electron-deficient aryl substituents worked well, giving homoallylic boronic esters

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• groups, including an additional substitution on C-7, showed potent activity against nematodes. These acyl substituents, particularly the third cinnamoyl group on C-7, may significantly enhance the biological activity. This modification likely represents a key structural feature influencing its activity

• 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

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• the oxazinane skeleton is an interesting scaffold for the design of synthetic routes for drug targets. The reaction works very well with a broad range of aromatic disulfides. Ortho, meta, and para-substituents with different electronic properties afford moderate to excellent yields. The reaction fails

Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

• Constantine V. Milyutin,
• Andrey N. Komogortsev and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

• considered transformation using 2H-furo[3,2-b]pyran-2-ones 1 without electron-donating substituents at the aromatic ring. Also, the considered protocol failed for interactions of furanone 1a with diverse anilines. In this case a complex mixture of products was obtained after 24 h reflux in AcOH (Scheme 2d

•  4). The suggested method allows one to utilize arylhydrazines both with donor and acceptor substituents in the aromatic ring. Besides that, heterocyclic hydrazines also can be used in the considered transformation. In addition, we have tried to carry out the process under investigation with

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• ; chiral halonium salt; contiguous stereocenters; halogen bonding; Mannich reaction; Introduction Halogen bonding (XB) has attracted intense research attention for its unique interaction between halogen atoms and electron-rich substituents [1]. XB has been applied to various fields of chemistry, such as

Vinylogous functionalization of 4-alkylidene-5-aminopyrazoles with methyl trifluoropyruvates

• Judit Hostalet-Romero,
• Laura Carceller-Ferrer,
• Gonzalo Blay,
• Amparo Sanz-Marco,
• José R. Pedro and
• Carlos Vila

Beilstein J. Org. Chem. 2025, 21, 533–540, doi:10.3762/bjoc.21.41

• results in terms of yield and diastereoselectivity, when methyl or ethyl trifluoropyruvate were used as reactants. Next, we tested the influence of different substituents on the cyclohexenyl ring of the aminopyrazole 3, observing lower yields for homoallylic alcohols 5baa and 5caa in both conditions used

• the starting material 3ea, prepared from 2-indanone, the corresponding product was not observed, probably due to an increase in steric hindrance. Finally, 4-cyclohexenyl-5-aminopyrazoles bearing different substituents at the N-1 or C-3 position afforded the corresponding trifluoromethyl carbinols 5aba

Deep-blue emitting 9,10-bis(perfluorobenzyl)anthracene

• Long K. San,
• Sebastian Balser,
• Brian J. Reeves,
• Tyler T. Clikeman,
• Yu-Sheng Chen,
• Steven H. Strauss and
• Olga V. Boltalina

Beilstein J. Org. Chem. 2025, 21, 515–525, doi:10.3762/bjoc.21.39

• for material scientists [12][13][14]. One of the structural features favorable for an efficient anthracene-based blue emitter is the introduction of bulky substituents in the 9 and 10 positions, which results in a solid-state packing with limited π–π intermolecular interactions, which, in turn, tends

• to suppress undesirable fluorescence self-quenching [15]. Not only do bulky substituents disrupt intermolecular interactions of this type, they can also provide higher chemical stability and reduce or prevent the photodimerization and photo-oxidation to which all acenes are prone [13]. Furthermore

• , bulky fluorinated substituents, such as perfluoroalkyls and perfluoroaryls, have been predicted by DFT [16] and shown experimentally [17], to improve the air- and photostability of acene-containing materials, by increasing their electron affinity and/or by sterically blocking reactive sites

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• ]. Moreover, the parent diazocine is insoluble in water (precipitation in water/DMSO > 9:1). Substitution with polar substituents such as CH2NH2 provides water solubility, however, it does not restore the high Z → E conversion rates of the parent system in organic solvents, which is a disadvantage, since

• substitution. Substituents such as halogen atoms must be introduced into the N-acetyl diazocine structure during the synthesis of the building blocks. In the present work we start from mono- and dihalogenated N-acetyl diazocine 2–4 (Figure 2) and focus on the further derivatization via cross-coupling reactions

• corresponding arylated N-acetyl diazocines 7, and 9–13 in yields from 68 to 88% (Table 4). The yields increased slightly if boronic acids with electron-withdrawing groups were used. An influence of bulky substituents like carboxyl groups in ortho-position of the phenylboronic acids on the reaction was not

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• -functionalized aldehydes with at least one stereocenter in the C3 position. The results, which are collected in Table 5, show that the kinetic resolution depends on the characteristics of the substituents. The best results were achieved for the Michael adduct 12, derived from acetylacetone, with R1 = Ph (entry

• substituents present in the starting Michael adducts. Furthermore, it has been observed that the enantioselectivity of Michael adducts decreases with time in the presence of a catalyst derived from diarylprolinol. Experimental General Information 1H NMR (400 or 500 MHz) and 13C NMR (100 MHz) spectra were