Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions

• Udyogi N. K. Conthagamage,
• Lilia Lopez,
• Zuliah A. Abdulsalam and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192

• first minutes of rotaxane insertion. Likewise, azobenzene photoswitching did not induce permeabilization in the more rigid and thicker EYPC/Chol 6:4 bilayers, which showed minimal release (5%). Furthermore, we discovered that when the unthreaded axle is irradiated with light, an unknown, irreversible

• File 1, Figure S4). The data also shows that most of the release for rotaxane 1 and 2 occurred immediately upon rotaxane insertion, whereas release caused by axle 3 increased gradually. Bilayers composed solely of EYPC exist in the liquid-disordered (Ld) phase, characterized by high fluidity and

• loosely packed lipids, which makes them inherently more permeable [16]. The insertion of rotaxanes or axle further increases this permeability, indicating that all molecules effectively disrupt the bilayer of this lipid composition. However, the rotaxanes with the macrocycle threaded onto the axle caused

Assembly strategy for thieno[3,2-b]thiophenes via a disulfide intermediate derived from 3-nitrothiophene-2,5-dicarboxylate

• Roman A. Irgashev

Beilstein J. Org. Chem. 2025, 21, 2489–2497, doi:10.3762/bjoc.21.191

• cyclization to furnish the TT framework [2][23][24]. Despite the wide structural diversity of TT derivatives, 3-hydroxy-substituted analogues remain rare, with only a few synthetic strategies described for their preparation, as illustrated in Scheme 1. One such route involves sulfur insertion into a thiophen

Catalytic enantioselective synthesis of selenium-containing atropisomers via C–Se bond formations

• Qi-Sen Gao,
• Zheng-Wei Wei and
• Zhi-Min Chen

Beilstein J. Org. Chem. 2025, 21, 2447–2455, doi:10.3762/bjoc.21.186

• alkyne insertion step may be rate-limiting, as it involves the participation of selenol, alkyne, and the rhodium catalyst. The Rh(III) mechanism appears to be more plausible than route B, which can be attributed to the enhanced ion-pairing effect resulting from the higher oxidation state of rhodium

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

• vibralactone, a potent inhibitor of pancreatic lipase, is reported. The synthesis of the challenging all-carbon quaternary center within the cyclopentene ring was achieved through intramolecular alkylidene carbene C–H insertion. Keywords: alkylidene carbene; C–H insertion; total synthesis; vibralactone

• lactone 13 through allylic oxidation and cross metathesis. For the construction of the cyclopentene ring, an alkylidene carbene-mediated C–H insertion would be applied [35]. The synthetic route could be traced back to β-lactone 14, which contains two continuous stereogenic centers with trans configuration

• deprotection followed by C–H insertion. However, when attempting to remove the ketal protecting group, only decomposition of the starting material was observed. A plausible explanation for this outcome is that the β-lactone ring, located at the β-position of the methyl ketone, may undergo facile β-elimination

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• solvent-controlled selective syntheses of two polycyclic compounds (Scheme 6) [13]. Using PdCl2 as the catalyst and DMF as the solvent, substrate 22 underwent a 6-endo-dig cyclization and subsequent enone insertion, forming a palladium–carbon bond intermediate. Protonolysis yielded isocoumarin-fused

• distinct from those generated through thermal Diels–Alder cycloaddition of (Z)-100. However, when [ReCl(CO)5] was used as the catalyst, a regioselective C–H bond insertion pathway was observed for substrate (E)-100, leading to the formation of tricyclic products 104 and 105 (Scheme 21, path b). This

Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• spectrometer equipped with a Direct Insertion Probe (EI+ ionization) or on a Bruker Q-TOF Maxis Impact mass spectrometer (ESI+ ionization) coupled with a Waters Acquity I-Class UPLC system equipped with a diode array detector. The reactions were followed by analytical thin-layer chromatography on silica gel 60

Electrochemical cyclization of alkynes to construct five-membered nitrogen-heterocyclic rings

• Lifen Peng,
• Ting Wang,
• Zhiwen Yuan,
• Bin Li,
• Zilong Tang,
• Xirong Liu,
• Hui Li,
• Guofang Jiang,
• Chunling Zeng,
• Henry N. C. Wong and
• Xiao-Shui Peng

Beilstein J. Org. Chem. 2025, 21, 2173–2201, doi:10.3762/bjoc.21.166

• reversible C–H activation to give the six-membered intermediate C. Substitution of the acetate ligand in C by 3 caused the generation of complex D. The six-membered ruthenacycle E was then obtained by migratory insertion of acetylene into the Ru–C bond. Finally, reductive elimination of E formed the target

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

The application of desymmetric enantioselective reduction of cyclic 1,3-dicarbonyl compounds in the total synthesis of terpenoid and alkaloid natural products

• Dong-Xing Tan and
• Fu-She Han

Beilstein J. Org. Chem. 2025, 21, 2085–2102, doi:10.3762/bjoc.21.164

• insertion [74] with ketone 91 and deprotection of the dithiane group delivered alleneketone 92. Sequential treatment of 92 with TsNHNH2 and NaH, the trimethylenemethane (TMM) diyl-mediated cycloaddition via intermediates 93 and 94 proceeded uneventfully to form the tetracyclic product 95. Next, reductive

Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• -substrates with the potential to react with metal carbenoids in many different ways [14], for example through O–H, N–H or formal C–H insertion, cyclopropanation, or oxazole [20] formation. The 16 co-substrates, selected from available compounds in our laboratory, are shown in Figure 2 (panel A). Many of

• these substrates had more than one potentially reactive site to enable, for example, O–H insertion (C1–5, C8, C11 and C14), N–H insertion (C3, C6, C12, C13 and C15), formal C–H insertion (C1, C3, C4, C12, C15 and C16), oxazole formation (C9 and C10) and cyclopropanation (C7, C10, C14 and C16). To start

• reactions, a product with molecular weight consistent with O–H insertion into water was also observed. For these 18 substrate/co-substrate combinations, the reaction with the highest estimated yield was selected for mass-directed purification (Table 2). In total, 23 intermolecular reaction products were

Influence of the cation in hypophosphite-mediated catalyst-free reductive amination

• Natalia Lebedeva,
• Fedor Kliuev,
• Olesya Zvereva,
• Klim Biriukov,
• Evgeniya Podyacheva,
• Maria Godovikova,
• Oleg I. Afanasyev and
• Denis Chusov

Beilstein J. Org. Chem. 2025, 21, 1661–1670, doi:10.3762/bjoc.21.130

• ). Insertion of D into β-position to nitrogen atom in the product was likely to be caused by fast exchange via keto–enol tautomeric equilibrium in the starting cyclohexanone or equilibrium between iminium cation and enamine (Scheme 4b). Reduction of the iminium cation led to insertion of D into α-position of

Catalytic asymmetric reactions of isocyanides for constructing non-central chirality

• Jia-Yu Liao

Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129

• ], insertion reactions [16][17][18], cycloaddition reactions (e.g., [4 + 1], [3 + 2]) [19][20], and others [21][22][23]. Particularly, isocyanides have been widely exploited toward the preparation of centrally chiral structures through transition-metal-catalyzed or organocatalytic asymmetric reactions [24][25

• reaction type and the chirality type of resulting products. Perspective Isocyanide-based transformations Palladium-catalyzed isocyanide insertion reactions In 2018, Luo, Zhu, and co-workers developed a palladium-catalyzed enantioselective reaction between ferrocene-derived vinyl isocyanides 1 and aryl

• iodides (Scheme 1a) [27]. This transformation proceeded via two key steps, isocyanide insertion and desymmetric C(sp2)–H bond activation. By using phosphoramidite L1 as the chiral ligand, planar chiral pyridoferrocenes 2 were obtained in 61–99% yield with 72–99% ee. In addition, this catalytic system

Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Marcin Palusiak,
• Heinz Heimgartner,
• Marta Denel-Bobrowska and
• Agnieszka B. Olejniczak

Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113

• thiocarbonyl S-methanides (thiocarbonyl ylides), derived from cycloaliphatic thioketones, are efficiently trapped by enolizable 1-substitued 5-mercapto-1H-tetrazoles and formation of the corresponding N–H or S–H insertion products, i.e., thioaminals or dithioacetals, respectively, was observed. In some

• analysis of the isolated products of S–H and N–H insertion was carried out based on spectroscopic data (1H and 13C NMR) and the structures of two representatives were established by using the X-ray single crystal diffraction analysis method. Biological activity (cytotoxicity) of some selected products

• derived from 5-mercapto-1H-tetrazoles was also examined. Keywords: 2,5-dihydro-1,3,4-thiadiazoles; enolizable 5-mercapto-1H-tetrazoles; insertion reactions; thiiranes; thiocarbonyl ylides; X-ray analysis; Introduction Cycloaddition reactions, including 1,3-dipolar cycloadditions, are considered as one

Copper catalysis: a constantly evolving field

• Elena Fernández and
• Jaesook Yun

Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109

• . In their contribution, Son et al. focus on transformations via the formation of copper nitrenoids, particularly amidations via oxidative insertion to N–O bonds and reductive elimination, and a small number of other reactions. The final Review by Cho, Lee, and co-workers is useful for the scientific

Microwave-enhanced additive-free C–H amination of benzoxazoles catalysed by supported copper

• Andrei Paraschiv,
• Valentina Maruzzo,
• Filippo Pettazzi,
• Stefano Magliocco,
• Paolo Inaudi,
• Daria Brambilla,
• Gloria Berlier,
• Giancarlo Cravotto and
• Katia Martina

Beilstein J. Org. Chem. 2025, 21, 1462–1476, doi:10.3762/bjoc.21.108

• functionality, respectively. Figure 5 shows the FTIR spectra measured on the silica support functionalised with the aminopropyl group, and the subsequent insertion of copper. The successful grafting of the amino ligand is testified by the characteristic stretching and bending modes of the NH2 group (νNH2 and

• δNH2, at around 3370, 3300 and 1596 cm−1, respectively) and by the νCH2 and δCH2 vibrations (curve a) [64][65]. The broad absorption in the high frequency region is characteristic of hydrogen bonding between Si–OH and NH2 groups in functionalised silica materials. After insertion of Cu(I), small

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

• methods for oxetane synthesis, mainly due to its practicality and versatility. 1.1.1.1 Substitution of a leaving group: In 2017, Moody et al. developed a new route towards spiro-oxetanes 8 utilising a combination of 1,4-C–H insertion and Williamson etherification (Scheme 3) [38]. The methodology commences

• from esters of functionalised arylacetic acid 5 or 6 and involves two separate protocols: first, a metallacarbene, which undergoes the insertion, is generated from the corresponding diazo precursor formed either in flow via hydrazone oxidation (PS-TsNIK packed column), or in batch mode via diazo

• the precursor 60 from diazomalonate based on a Rh-catalysed O–H insertion, and further applied this cyclisation methodology to a preparation of tetrasubstituted oxetanes 62, including bicyclic analogues. In 2024, Liu, Shi, Wei and co-workers published the first radical cyclisation of ethers leading to

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

• with α-carbonylalkyl bromides using palladium (Scheme 29) [17]. This reaction was initiated by a Heck insertion and required Ag2CO3 as an oxidant. It proceeded via a tandem C–Br/C–H functionalization and cyclization steps, ultimately realizing an oxidative radical pathway. The process exhibited a broad

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

• to perform the carboxylation of alkenylpyrazole 194 to the corresponding cinnamic ester 195 catalyzed by Rh(III) via a pyrazole-directed oxidative addition of the alkenyl C–H (196) accompanied by CO2 insertion to give Rh(I) carboxylate intermediate 197 (Scheme 60A) [103]. A gram scale operation has

• via oxidative Pd insertion into the Cu-activated thioester followed by transmetalation with alkenylboronic acid to give complex 210 (Scheme 61A) [105]. The method has been scaled up to a gram scale. Similarly, Hu and co-workers (2021) utilized alkenylboronic ester 211 and Boc2O to synthesize methyl

• fluoroalkenyl radical 233, followed by Pd insertion (234) and carboxylation (235) (Scheme 63A) [109]. Recently, Wang and co-workers (2024) reported a photoredox-promoted carboxylation of gem-difluoroalkene 236 by using formate salts, which also involves formation of a fluoroalkenyl radical intermediate 238

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

• , thereby offering unprecedented control over chemo-, regio-, and stereoselectivity parameters in catalytic manifolds. In 2015, the Jiang group developed a palladium-catalyzed regioselective three-component C1 insertion reaction (Scheme 1) [19]. In this reaction, an o-iodoaniline 1, phenylacetylene, and

• , tetrabutylammonium iodide (TBAI), and water significantly accelerated aryne generation, thereby increasing its local concentration. This favored aryne coordination to the palladium center, followed by CO insertion and reductive elimination to furnish phenanthridinones. In contrast, when dppm was introduced

• preferentially occupied the palladium coordination site. Sequential insertion of CO and aryne, followed by reductive elimination, culminated in acridone formation. This ligand-dependent mechanistic dichotomy underscores the critical interplay between aryne availability, steric modulation, and electronic effects

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

• (Scheme 3a). Based on the well accepted metathesis reaction of Cu(I) alkoxides with B2pin2 and the reactivity of the resulting Cu–Bpin complex towards α,β-unsaturated esters and hydrocarbons [8][9][10][11][12][13][14][15], we hypothesized that the first step of the reaction may deal with the insertion of

• the copper–boron bond into 1. The dual functionality of this substrate imposed a question related to the regioselectivity of the Cu–Bpin insertion since it can potentially behave as an α,β-unsaturated ester or an allylic substrate [16][17][18][19]. To shed some light into this issue, we ran the

• ). This result suggests that Cu–Bpin insertion into 1 generates a copper enolate which may engage in further steps for the formation of the dimerization product. The presence of the two chlorine atoms was found to be key for the outcome of the reaction. No dimerization product was observed when the

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

• and the overall structure of the complex highly influence the oxidation potential of Pd(II). At first, a complex of phenylpyridine with palladium (including insertion of Pd to C–H bond) and dialkyl phosphonate was formed, followed by anodic oxidation to give the final coupling product. In 2023, Zhou

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

• copper complex formation and subsequent selective olefin insertion results in the high levels of enantioselectivity (98:2 er) observed experimentally. DFT calculations further elucidated the origin of the high diastereoselectivity (up to 96:4 dr) in the allylic substitution step (Scheme 13b). Analysis of

• bearing various functionalities. Notably, no erosion of enantiomeric excess was observed during any of the transformations. Double CuH insertion into alkynes for regiodivergent allylic substitution Generating chiral secondary alkylcopper species in situ through sequential hydrocupration of terminal

• calculations. The first hydroboration catalytic cycle is initiated by L*CuH species (L* = a chiral ligand) formed in situ through the combination of CuBr, LiOMe, and HBpin in the presence of a chiral ligand. Subsequent alkyne migratory insertion provides a vinyl cuprate intermediate Int B, followed by σ-bond

Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• depicted in Figure 2. The reaction is initiated by formation of the five-membered copper-containing intermediate INT-5 through coordination of Cu(OAc)2 with the N-iminoquinolinium ylide species 5. This process is followed by decarboxylative N–O bond insertion into 4, yielding the N-acyl copper(III

• ) nitrenoid intermediate INT-7. Subsequent nitrene insertion, protodemetalation, and intramolecular cyclization furnish the desired 1,2,4-triazole. 1.3 Three-component formation of N-acyl amidines In 2019, N-acyl amidines were prepared from dioxazolones using a copper catalyst with terminal alkynes and

• dioxazolone 7. Subsequently, nitrene insertion of INT-12 into the Cu–C bond, forms INT-13, which then undergoes isomerization and protodemetalation, followed by catalyst regeneration, as suggested by the DFT calculations. Finally, the nucleophilic addition of the amine to the electrophilic intermediate INT-15

Synthesis of 2H-azirine-2,2-dicarboxylic acids and their derivatives

• Anastasiya V. Agafonova,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2024, 20, 3191–3197, doi:10.3762/bjoc.20.264

• situation. Dibenzyl ester 11c was prepared using traditional activation of carboxylic acid 6a, although the yield was only 23%. A higher yield of the branched ester 11d (86%, as a mixture of diastereomers) was obtained by carbene insertion, generated by blue LED irradiation of methyl 2-diazo-2-phenylacetate

• reaction of more branched alcohols failed. Such esters could be prepared from the dicarboxylic acids using traditional activation or OH-insertion reaction of carbenes formed by irradiation of the appropriate diazo compound. Approaches to 2H-azirine-2,2-dicarboxylic acid derivatives. Synthesis of 2H-azirine

Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds

• Radell Echemendía,
• Carlee A. Montgomery,
• Fabio Cuzzucoli,
• Antonio C. B. Burtoloso and
• Graham K. Murphy

Beilstein J. Org. Chem. 2024, 20, 3182–3190, doi:10.3762/bjoc.20.263

• reaction could be easily performed on a 1 mmol scale, which gave the desired product 3a in 71% yield (Scheme 3a). Lastly, product 3a was subjected to our previously developed S–H insertion reaction protocol with sulfoxonium ylides [36], which generated a new 2,2,2-trifluoroethylcoumarine-based compound 4