Synthesis of functionalized, 13-alkyl-substituted coralyne derivatives and investigation of their interactions with duplex and abasic site-containing DNA

• Laurin Beckmann,
• Jason Lennard Kunze,
• Hannah Karola Strunk,
• Maurice Michel and
• Heiko Ihmels

Beilstein J. Org. Chem. 2026, 22, 1057–1066, doi:10.3762/bjoc.22.84

• through oxime formation with the aldehyde functionality of ring-opened ribose [37][38]. Thus, a coralyne–(aminooxy)alkyl conjugate might offer the combination of selective covalent attachment with intercalation of the coralyne unit (Scheme 1), thus providing a more efficient blocking of the AP site, along

• to give the aminooxy-functionalized coralyne derivative 2g in quantitative yield (Scheme 4). To examine exemplarily whether the latter product can be subsequently employed for oxime ether formation, it was also generated in the presence of benzaldehyde, which furnished the corresponding oxime

• -functionalized coralyne derivative 2g binds to AP site-containing DNA, as the observed effect is characteristic of AP–DNA ligands. Moreover, this result is in agreement with the control experiment that demonstrated the general ability of compound 2g to form oxime ethers with aldehydes (Scheme 4). As a result

Synthesis of novel 1,2,4-oxadiazole-isoxazoline hybrids and their in silico potential with adenosine receptors

• Pshtiwan S. Mohammed,
• Mohammed K. S. Dalo,
• Onur C. Yazıcı,
• Muhammet Yildirim and
• Akın Sağırlı

Beilstein J. Org. Chem. 2026, 22, 1033–1047, doi:10.3762/bjoc.22.82

• , may also contribute to reduced yields for compounds 6a–j. The structures of benzaldoximes 2a–k were simply characterized by IR stretching peaks corresponding to O–H, C=N, aromatic C=C, aromatic C–H, oxime C–H, and N–O groups (approximately 3250, 1600, 1500, 3040, and 1005 cm−1) (see Experimental

Synthesis and optical resolution of 4,5-diaminohomoadamantane: a promising scaffold for chiral ligands and bioactive compounds

• Polina A. Man’kova,
• Vadim A. Shiryaev,
• Olga S. Podlipnova,
• Marat M. Khisyamov,
• Dmitry S. Nikerov,
• Alexander N. Reznikov and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2026, 22, 1013–1022, doi:10.3762/bjoc.22.80

• -diaminohomoadamantane was isolated as a mixture of trans- and cis-isomers 8a,b, we decided to synthesize trans-4,5-diaminohomoadamantane through ring opening of aziridine 9. This compound was obtained from homoadamantanone oxime by reduction with LiAlH4 [41]. Since the aziridine ring-opening reaction usually proceeds

Site-specific labelling of native peptides and proteins: chemical and enzymatic strategies

• Antonio Angelastro,
• Jonathan Bargh,
• Subhajit Guria,
• Victor Laserna and
• Louis Luk

Beilstein J. Org. Chem. 2026, 22, 857–881, doi:10.3762/bjoc.22.67

• product can be reacted with hydroxylamine-containing payloads to afford oxime-linked conjugates (Scheme 3c) [29][30]. Additionally, dibromomaleimides 8 [31][32] and dibromopyridazinediones 9 (Scheme 3d) [33] bearing payloads at the N-position can rebridge cysteines through an addition–elimination

• to conjugation such as hydrazone or oxime ligation [125][126][127][128]. However, while this approach is still a valid strategy for protein functionalisation, potential undesired side reactions such as amino acid oxidation need to be carefully taken into consideration. Use of galactose oxidase (GOase

Design, synthesis, and biological evaluation of FXR/ASK1 dual-target modulators

• Xi Zhang,
• Jingyan Wang,
• Ziqiang Zhao,
• Caiyi Wang,
• Zenghui Ye,
• Wei-Yuan Ma,
• Jian-Xing Xu and
• Fengzhi Zhang

Beilstein J. Org. Chem. 2026, 22, 771–781, doi:10.3762/bjoc.22.59

• MASH. Results and Discussion Chemistry The synthetic routes to the target compounds are outlined in Schemes 4–8. The synthesis of isoxazole intermediate 2 commenced with the condensation of commercially available benzaldehyde I with hydroxylamine to afford oxime intermediate II. Subsequent treatment of

Regioselective approach to 5-arylsulfonylisoxazoles and their antimicrobial activity

• Artem S. Sazonov,
• Dmitry A. Vasilenko,
• Denis V. Porfiriev,
• Yuri K. Grishin,
• Rimma A. Gazzaeva,
• Alisa P. Chernyshova,
• Maxim A. Kryakvin,
• Anna A. Baranova,
• Vera A. Alferova and
• Elena B. Averina

Beilstein J. Org. Chem. 2026, 22, 592–602, doi:10.3762/bjoc.22.45

• 5-sulfonylisoxazoles (Scheme 1, approaches A, B, C). As shown in Scheme 1, nitrile oxides are generated in situ by oxidation of aldoximes with chloramine T (approach A) or by dehydrohalogenation of the corresponding oxime halide under basic conditions (approaches B and C). Subsequently, the nitrile

Modern synthetic pathways towards eribulin and its subunits

• Sebastian Dominik Graf

Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37

• and further treated with Lindlar catalyst and DIBAL-H to afford the alkene and aldehyde motifs of 195, respectively. Oxime formation and oxidation yielded an intermediate nitrile oxide, which underwent an intramolecular [3 + 2]-cycloaddition with the adjacent ethene substituent towards isoxazoline 196

A new synthesis of Tyrian purple (6,6’-dibromoindigo) and its corresponding sulfonate salts

• Holly Helmers,
• Mark Horton,
• Julie Concepcion,
• Jeffrey Bjorklund and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2026, 22, 167–174, doi:10.3762/bjoc.22.10

• with yields ranging from 18 to 60.5% yield relative to starting 3 [8][9][11][12]. Chromium-free oxidation of 3 to 4 has been reported via the condensation of 3 with an alkyl nitrate to yield an oxime. Subsequent hydrolysis of the oxime yields the desired aldehyde 4, but only in low yield [6][7

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• oximes (X = H) with ADN were unsuccessful, as the NO group or oxime group did not participate in the desired N=N coupling (Scheme 1, substrates S1–S4). These substrates underwent either deep oxidation or degradation. Ultimately, in the reaction of 1-nitrosocyclohexane-1-carbonitrile (S5) and 1-nitro-1

• nucleophilic substitution of –ONO2 groups. To clarify the reaction mechanism, cyclic voltammetry (CV) studies were conducted. CV curves of cyclohexanone oxime (S1), 1-bromo-1-nitrosocyclohexane (S2), 1-chloro-1-nitrosocyclohexane (S3), 1-nitrosocyclohexyl acetate (S4), 1-nitro-1-nitrosocyclohexane (1c), 1

• , respectively. 1-Bromo-1-nitrosocyclohexane (S2, brown curve) exhibits a broad oxidation peak around +1.84 V, whereas cyclohexanone oxime (S1, orange curve) shows no significant oxidation up to +2.4 V. However, its reaction with ADN in the optimized reaction conditions resulted in a complex mixture of oxime

Recent advances in total synthesis of illisimonin A

• Juan Huang and
• Ming Yang

Beilstein J. Org. Chem. 2025, 21, 2571–2583, doi:10.3762/bjoc.21.199

• -mediated N–O bond cleavage afforded carbamate 90. The carbamate was converted to a carbonyl group via Boc deprotection with TFA, oxidation of the resulting amine to the oxime with Na2WO4 and H2O2, and subsequent reduction with TiCl3·HCl to give 91. The LaCl3·2LiCl-mediated methyl addition to the carbonyl

Rapid access to the core of malayamycin A by intramolecular dipolar cycloaddition

• Yilin Liu,
• Yuchen Yang,
• Chen Yang,
• Sha-Hua Huang,
• Jian Jin and
• Ran Hong

Beilstein J. Org. Chem. 2025, 21, 2542–2547, doi:10.3762/bjoc.21.196

• from the use of crotyl bromide as a mixture of geometric isomers. After installation of the crotyl group, hydrolysis of the acetonide group and oxidative cleavage of diol 16, oxime 17 was prepared through the condensation of the aldehyde with hydroxylamine in overall 59% yield. Upon oxidation with

Ex-situ generation of gaseous nitriles in two-chamber glassware for facile haloacetimidate synthesis

• Nikolai B. Akselvoll,
• Jonas T. Larsen and
• Christian M. Pedersen

Beilstein J. Org. Chem. 2025, 21, 2465–2469, doi:10.3762/bjoc.21.188

• [14][15][16][17]. Recently, 2,2,2-trifluoroacetaldehyde O-(aryl)oxime has been introduced as a precursor for trifluoroacetonitrile allowing to work under mild conditions at room temperature (Figure 1) [18]. Whether one prepares a precursor or the actual reagent, a separate setup is needed and hence

An Fe(II)-catalyzed synthesis of spiro[indoline-3,2'-pyrrolidine] derivatives

• Elizaveta V. Gradova,
• Nikita A. Ozhegov,
• Roman O. Shcherbakov,
• Alexander G. Tkachenko,
• Larisa Y. Nesterova,
• Elena Y. Mendogralo and
• Maxim G. Uchuskin

Beilstein J. Org. Chem. 2025, 21, 2383–2388, doi:10.3762/bjoc.21.183

• -arylindoles with α,β-unsaturated ketones, followed by Fe(II)-catalyzed spirocyclization of readily accessible oxime acetates. The method exhibits a broad substrate scope and good functional group tolerance. The synthesized spirocyclic compounds showed no significant antimicrobial activity. Keywords: α,β

• under heating furnished chiral spiroindolylpyrroles in excellent yields and enantioselectivity (Scheme 1, path d) [11]. Moreover, a copper-catalyzed reaction of oxindole-derived alkenes with acetophenone O-acetyl oxime has also been employed to construct the spiroindolylpyrrole scaffold (Scheme 1, path

• . For instance, an intramolecular SN2-type cyclization of β-3-indolyl ketone oximes using MsCl and Et₃N affords spiro[indoline-3,2'-pyrrolidines] (Scheme 1, path f) [13]. A subsequent Cu-catalyzed spirocyclization of β-3-indolyl ketone oxime acetates was developed. This process involves homolytic N–O

Synthetic study toward vibralactone

• Liang Shi,
• Jiayi Song,
• Yiqing Li,
• Jia-Chen Li,
• Shuqi Li,
• Li Ren,
• Zhi-Yun Liu and
• Hong-Dong Hao

Beilstein J. Org. Chem. 2025, 21, 2376–2382, doi:10.3762/bjoc.21.182

• ][21]. Additionally, a series of vibralactone homodimers and oxime esters 10–12 were reported by the groups of Liu and Zhang, respectively [22][23]. Through modification of the primary hydroxy group, a structure-based optimization of vibralactone (6) was carried out by Liu and co-workers and yielded

Enantioselective radical chemistry: a bright future ahead

• Anna C. Renner,
• Sagar S. Thorat,
• Hariharaputhiran Subramanian and
• Mukund P. Sibi

Beilstein J. Org. Chem. 2025, 21, 2283–2296, doi:10.3762/bjoc.21.174

• preparation of chiral β-aminoalcohols [63]. Chiral copper(I) complexes convert imidate radicals, formed transiently through energy-transfer catalysis, to oxazolines. The transformation includes a regioselective and enantioselective HAT process. Upon blue LED irradiation, oxime imidates (derived from alcohols

Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• of an oxime, itself prepared in situ from an aldehyde. The stereochemistry of one of the spirooxindoles was determined by single crystal X-ray diffraction studies via crystallisation using encapsulated nanodroplet crystallisation (ENaCt) protocols. The chemistry involves cascade or tandem

• possibility to access the core of this ring system with the nitrone intermediate shown in Scheme 1A. As a model study, we describe here efforts towards an intermolecular variant with the oxindole shown in Scheme 1B; in this case a leaving group X will be displaced by the oxime to give an intermediate nitrone

• aldehyde 4 could now be tested in the cascade chemistry. This entails the addition of hydroxylamine to form the oxime, followed by cyclisation (with displacement of the tosylate) to give the nitrone for the desired dipolar cycloaddition reaction. Related chemistry (without the oxindole) with a halide

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• chiral cyclohexylidene oxime ethers with high enantioselectivity [56]. In 2024, through the utilization of this method, Liu and co-workers disclosed the enantioselective synthesis of inherently chiral 7-membered tribenzocycloheptene oximes 76 through CPA 18-catalyzed asymmetric condensation between 7

Facile synthesis of hydantoin/1,2,4-oxadiazoline spiro-compounds via 1,3-dipolar cycloaddition of nitrile oxides to 5-iminohydantoins

• Juliana V. Petrova,
• Varvara T. Tkachenko,
• Victor A. Tafeenko,
• Anna S. Pestretsova,
• Vadim S. Pokrovsky,
• Maxim E. Kukushkin and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 1552–1560, doi:10.3762/bjoc.21.118

• precursors 4a–c were then prepared by the reaction of compounds 3a–c with N-chlorosuccinimide (NCS) in dimethylformamide (DMF). The ester group-containing chloro oxime 4d was obtained by the treatment of glycine ethyl ester hydrochloride with sodium nitrite and hydrochloric acid [25] and used thereafter as

• congruence of the electronic properties of the substituents in the dipole and dipolarophile, as well as very low solubility of the product 5l in diethyl ether. An unexpected result was obtained during the 1,3-dipolar cycloaddition reaction between 2f and chloro oxime 4d. In contrast to reactions involving

• decomposing even at room temperature. Taking these into account, we have synthesized compound 5c using an alternative route starting from the chloro oxime 4a and 5-iminothiohydantoin 2j (Scheme 4), obtained similarly to other dipolarophiles [22]. The total yield of the product 5c in this case turned out to be

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• for high-efficiency chiral optoelectronic and quantum materials. In 2024, Kivala’s group selectively synthesized highly distorted [6]helicenes 29a and 29b incorporating azocine units via a regioselective Beckmann rearrangement from oxime precursor 29c [43] (Table 8). For comparative evaluation, the

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

Enhancing chemical synthesis planning: automated quantum mechanics-based regioselectivity prediction for C–H activation with directing groups

• Julius Seumer,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2025, 21, 1171–1182, doi:10.3762/bjoc.21.94

• activation [34]. Overview of the predictive workflow: For the shown substrate on the left, three unique activation sites are possible (labelled “Ha−c” with two directing groups, a pyridine (blue) and an oxime-ether (red) group. The latter has two potentially directing atoms, nitrogen and oxygen. The

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• and co-workers (2021) utilized oxime chloride and cinnamic acid to synthesize O-acylhydroxamate 68 in good yield (Scheme 23A) [57]. In the presence of a base, oxime chloride was converted to electrophilic nitrile oxide 69 and reacted with carboxylic acid to form the cyclic intermediate 70. On the

• formation of an active α-ketenyl phosphorus ylide 345 (Scheme 77A) [130]. Similarly, Lin and co-workers (2024) employed PPh3 to selectively catalyze the esterification reaction of cyclopropenone 309 and amides to give the corresponding esters 346–348 containing an oxime ether in good yields (Scheme 77B

Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

• Benedek Batizi,
• Patrik Pollák,
• András Dancsó,
• Péter Keglevich,
• Gyula Simig,
• Balázs Volk and
• Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

• ammonium derivative 14 with the potassium salt of compound 15 resulted in the ring-opened derivative 16. Removal of the benzylthiocarbonyl moiety, then Beckmann rearrangement of the oxime obtained from ketone 17 and subsequent cyclization gave β-carboline derivative 18, which was dehydrogenated and

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

• report the copper-catalyzed synthesis of tetrahydroquinoline derivatives via a domino reaction of aniline with cyclobutanone oxime. This method demonstrates a selective approach for generating bioactive tetrahydroquinoline scaffolds, which have broad applications in pharmaceutical chemistry. The reaction

• 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

• cyclobutanone oxime using a copper-catalyzed reaction under ambient air conditions (Scheme 1c). Results and Discussion With these considerations in mind, we explored the feasibility of synthesizing cyclobutane-fused spirotetrahydroquinolines (STHQs) through the reaction of arylamines with cyclobutanone oxime