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

• diastereoselectivity (up to 7:1). Keywords: alcohols; diastereoselectivity; nitrogen heterocycles; pyrazoles; vinylogous reaction; Introduction Vinylogy refers to the transmission of electronic effects through a conjugated π-system, enabling the extension of a functional group's nucleophilic or electrophilic

• 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

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

• [17]. As a starting point for further derivatization, the synthesis and characterization of monohalogenated N-acetyl diazocines 2 and 3 (Figure 1) have been performed [22]. Unfortunately, diazocines in general, and N-acetyl diazocines in particular cannot be derivatized by electrophilic aromatic

Synthesis of electrophile-tethered preQ₁ analogs for covalent attachment to preQ₁ RNA

• Laurin Flemmich and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 483–489, doi:10.3762/bjoc.21.35

• an electrophilic handle for the covalent attachment of the ligand to the RNA. The simplicity of the underlying design of irreversibly bound ligand–RNA complexes has provided a new impetus in the fields of covalent RNA labeling and RNA drugging. Here, we present short and robust synthetic routes for

• highly electrophilic warheads otherwise typically employed in RNA-small molecule crosslinking [18][19][20][21]. Instead, primary alkyl halides (or mesylates, Scheme 1, in particular compounds 3a, 3b and 4c) were found to be potent yet mild alkylators that minimize off-target reactivity, while providing

• ). Synthesis of preQ1 and DPQ1 derivatives with electrophilic handles For the synthesis of haloalkyl- and mesyloxyalkyl-modified preQ1 and DPQ1 ligands 3a,b and 4a–e (for target structures see Scheme 1), a divergent synthetic route was sought that provided flexibility with respect to linker length and nature

Photomechanochemistry: harnessing mechanical forces to enhance photochemical reactions

• Francesco Mele,
• Ana M. Constantin,
• Andrea Porcheddu,
• Raimondo Maggi,
• Giovanni Maestri,
• Nicola Della Ca’ and
• Luca Capaldo

Beilstein J. Org. Chem. 2025, 21, 458–472, doi:10.3762/bjoc.21.33

• acylation of electrophilic olefins (Scheme 11C). Compared to solution-phase photocatalysis, photomechanochemical conditions allowed to reduce the reaction time from 24 h to 3 h while maintaining comparable yields. Finally, the authors proved that photomechanochemistry contributes to the initial rate

Beyond symmetric self-assembly and effective molarity: unlocking functional enzyme mimics with robust organic cages

• Keith G. Andrews

Beilstein J. Org. Chem. 2025, 21, 421–443, doi:10.3762/bjoc.21.30

• phosphodiesters by 105–107 by electrophilic activation of ester and nucleophilic activation of water or peroxide at the metal ion [101][102]. The takeaway message is that polarization is most effective when it is bifunctional. In enzymes, there is never just a nucleophile – there is always a metal, “oxyanion hole

Identification and removal of a cryptic impurity in pomalidomide-PEG based PROTAC

• Bingnan Wang,
• Yong Lu and
• Chuo Chen

Beilstein J. Org. Chem. 2025, 21, 407–411, doi:10.3762/bjoc.21.28

• instability, where the cleavage of the phthalimide and glutarimide rings comprises the major metabolic pathways [9][10]. Computational analysis confirms that C1, C3, C2’, and C4’ are the most electrophilic sites of thalidomide (Figure 4). As expected, introducing a fluorine atom to C4 activates it toward SNAr

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• glycosylation. Conventional glycosylation involves the ‘nucleophilic substitution’ of the leaving group at the sp3 anomeric centre of the donor moiety with a suitable carbohydrate or non-carbohydrate-based aglycon with the help of an electrophilic promoter to form the equatorial glycoside 7 or the axial

Synthesis of new condensed naphthoquinone, pyran and pyrimidine furancarboxylates

• Kirill A. Gomonov,
• Vasilii V. Pelipko,
• Igor A. Litvinov,
• Ilya A. Pilipenko,
• Anna M. Stepanova,
• Nikolai A. Lapatin,
• Ruslan I. Baichurin and
• Sergei V. Makarenko

Beilstein J. Org. Chem. 2025, 21, 340–347, doi:10.3762/bjoc.21.24

• physicochemical methods, as well as by X-ray diffraction analysis. The obtained compounds, due to the combination of different heterocyclic structures in their molecules, may be interesting as potential biologically active substances. In turn, the presence of active electrophilic centers in their structures

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• main reaction products. Keywords: aldol condensation; [4 + 2]-cycloaddition; diffusion mixing; formaldehyde; Knoevenagel condensation; three-component reactions; Introduction Formaldehyde is a reactive electrophilic reagent widely used as a C1 building block in multicomponent reactions [1][2][3]. Its

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

• advancements in the synthetic transformations of dioxazolones, with particular examples of copper salts. Keywords: amidation; copper salts; dioxazolones; electrophilic nitrogen; N-acyl nitrene; Introduction Dioxazolones, first synthesized and reported by Beck and co-workers [1], have been employed as

• electrophiles in various nucleophilic transformations due to their susceptibility to rapid decomposition into the corresponding isocyanates (Scheme 1a) [2][3]. They have attracted increasing interest as electrophilic amide sources in amidation using transition-metal catalysts such as ruthenium, rhodium, 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

Recent advances in electrochemical copper catalysis for modern organic synthesis

• Yemin Kim and
• Won Jun Jang

Beilstein J. Org. Chem. 2025, 21, 155–178, doi:10.3762/bjoc.21.9

• terminal alkyne 2 in the presence of a chiral copper catalyst and base, which reacts with the electrophilic iminium intermediate 15 to yield the desired chiral product 14. Active Cu(I) is regenerated either through cathodic reduction or by reaction with TEMPO–H. A year after the Mei group’s report, the Xu

• standard conditions. Subsequently, radical-polar coupling between electrophilic Ni-bound α-carbonyl radical intermediate 45 and remaining nucleophilic Cu-enolate 44 provides a chiral product 42 containing vicinal quaternary stereocenters with high stereoselectivity, and all three possible stereoisomers of

• performed using electrophilic chlorinating reagents or stable and readily available chloride sources with stoichiometric amounts of chemical oxidants. However, in this catalytic system, chloride (Cl−) from HCl was used as the chlorinating agent, and electrophilic chlorine (Cl+) was generated in situ by the

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• alkyltrifluoroborate into its corresponding alkyl radical. o-Halo-substituted aryl selenides and sulfides 13 can be achieved by a three-component coupling reaction performed with an aryne precursor, potassium halides and electrophilic chalcogen species as reactants, in the presence of Cu(OTf)2 (Scheme 10) [23]. Under

• these conditions the reaction between aryl thiosulfonates with arynes to give sulfones is competitive. Cu(OTf)2 is essential to remove the sulfinate anions in the reaction medium, avoiding side reactions arising from their attack to the electrophilic arynes. The so-obtained products are susceptible of

• corresponding saturated compounds. Subsequent nucleophilic addition of the cyclic vinyl ether to the iminium salt generates an intermediate XXI susceptible of intramolecular electrophilic attack to give a tricyclic structure XXII. The final deprotonation provides the desired product 24. The multicomponent

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

• ]. Yang et al. developed a SPINOL-derived CPA C54-catalyzed electrophilic substitution of diazodicarboxamides 233 and azaborinephenols 232 leading to axially chiral products 234 (Scheme 68) [100]. Excellent enantioselectivities and very good yields were reported in almost all cases. More modest yields

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• . A plausible mechanism is proposed, suggesting a possible radical pathway. Keywords: electrophilic amination; hypervalent iodine reagents; sulfinamide; sulfonamide; Introduction Iodine(III) compounds, known as λ3-iodanes, have been extensively applied in organic synthesis. Although initially used

• in electrophilic transfer reactions, with emphasis on umpolung reactivity of usually nucleophilic functional groups. Thus constituting a powerful synthetic tool, opening room for new synthetic disconnections [10]. Within the benziodoxol(on)e class, a range of HIRs featuring nitrogen-containing groups

• benziodoxolone was generated in situ, via a reaction of chlorobenziodoxolone with sulfinate salts, followed by the addition of amines or hydrazines, respectively. On the follow-up on our research, we envisaged to extend the diversity of BBX reagents as electrophilic amine reagents and investigated their

Efficient synthesis of fluorinated triphenylenes with enhanced arene–perfluoroarene interactions in columnar mesophases

• Yang Chen,
• Jiao He,
• Hang Lin,
• Hai-Feng Wang,
• Ping Hu,
• Bi-Qin Wang,
• Ke-Qing Zhao and
• Bertrand Donnio

Beilstein J. Org. Chem. 2024, 20, 3263–3273, doi:10.3762/bjoc.20.270

• chains and derived from the classical triphenylene core self-assembling in columnar mesophases based on this paradigm. These mesogenic compounds were simply obtained in good yields by the nucleophilic substitution (SNFAr) of various types of commercially available fluoroarenes with the electrophilic

• variety of triphenylene derivatives (Figure 1) [44][45][46][47] based on the nucleophilic substitution of various electrophilic perfluoroarenes, including C6F2H4, C6F6, C10F8, and C6F5-Ph, by nucleophilic organolithium reagents. e.g., 2,2’-dilithio-4,4’,5,5’-tetrakis(alkoxy)-1,1’-biphenyls, 2Li-BPn

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

• fluoroalkyliodonium salts as sources of electrophilic trifluoroethyl synthon. Given the non-nucleophilic nature of the iodoarene byproduct, this protocol should not suffer from further reactivity that decomposes the ylide. We describe here the coupling of α-carbonyl sulfoxonium ylides with polyfluoroalkyl(aryl

• discovered by Umemoto has proven an effective electrophilic trifluoroethyl transfer reagent [34][35], and to further explore the potential of fluoroalkyliodonium salts we evaluated the reactivity of such compounds in the context of sulfoxonium ylide derivatization. As depicted in Table 1, we began our

• with them being viable electrophilic sites for halogen bond formation with 1a, supporting the mechanism in path 1. We also expressed the LUMO and LUMO+1 molecular orbitals of 2a’ (Figure 3, middle and right, respectively), which showed lobes centered on the I–C bonds to both the trifluoroethyl and

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• intramolecular SNAr reactions. Ugi-4CR/deprotection/cyclization (UDC) strategy: In the UDC approach a protected amine and an electrophilic functional group like esters or ketones are used. Convertible isocyanides can also be employed. Once the Ugi reaction is completed, the protecting group is removed, and the

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• , the carbon-centered radicals in both INT1 and INT4 are closer to strong electron-withdrawing groups than are the radical centers in INT2 and INT5, rendering INT1 and INT4 relatively more electrophilic. Inductive effects drop off steeply with distance, and it is also established that a substituent (or

• , e.g., a radical or cation) on the transannular carbon atom of a bicyclopentyl moiety can interact through space [35][63][64]. The consequence is ostensibly that more "nucleophilic" INT2 and INT5 are better matched for Cl atom abstraction from the "electrophilic" reagent (SF5Cl or CF3SF4Cl). To test

• -chloropyrimidyl-SF4Cl) was determined to be significantly less "electrophilic" than SF5Cl or CF3SF4Cl, consistent with a reduction in the radical polarity matching effect (see Supporting Information File 1 for details). This was difficult to predict or rationalize based on calculation of free energies of

Hypervalent iodine-mediated intramolecular alkene halocyclisation

• Charu Bansal,
• Oliver Ruggles,
• Albert C. Rowett and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 3113–3133, doi:10.3762/bjoc.20.258

• structures. HVI reagents are characterized by their diverse reactivity as oxidants and electrophilic reagents. In addition, they are inexpensive, non-toxic and considered to be environmentally friendly. An important application of HVI reagents is the synthesis of halogenated cyclic compounds, in particular

• fluoride ion to displace PhI. In pathway B (bottom), the nitrogen is oxidised by the iodane, generating an electrophilic intermediate B. Nucleophilic attack by the double bond subsequently forms the 6-membered ring intermediate C, which is either immediately attacked by fluoride to form both cis and trans

• difluoroiodobenzene 10 is formed in situ, which is activated by HF. Two possible mechanisms were given for the synthesis of pyrrolidines 14, which are the same two proposed for the synthesis of piperidines 6 (Scheme 1). Either an alkene-activated iodonium is formed or an activated electrophilic nitrogen is generated

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• electrophilic CO2, leading to the formation of 18-IV. The negatively charged oxygen in 18-IV is then responsible for removing the chloride atom leading to the major isomer as a final product. The results of this study suggest that nonplanarity or distortion of the tetrapyrrolic macrocyclic core is not a

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• alkenes 41 was disclosed (Scheme 17) [59]. The target 6-trifluoromethyl peroxides 42 were synthesized in good yields under mild conditions. The electrophilic CF3 radical A, generated from CF3SO2Na through single-electron oxidation by using Mnn/TBHP system, is captured by the carbon–carbon double bond to

• fragment: In 2016 a radical difunctionalization of styrenes 163 using electrophilic perfluoroalkyl compound 164 and tert-butylperoxy radicals with the formation of (1-(tert-butylperoxy)-2-perfluoroalkyl)ethylbenzene 165 was developed (Scheme 52a) [115]. The proposed mechanism includes the Co(II)/Co(III

• catalytic cycle. A Pd-catalyzed synthesis of di-tert-butylperoxyoxoindole derivatives 210 from acrylic acid anilides 209 and TBHP was developed (Scheme 65) [134]. The authors proposed that the initially formed diperoxide A undergoes electrophilic attack by cationic Pd(II) on an aromatic C–H bond with the

Structure and thermal stability of phosphorus-iodonium ylids

• Andrew Greener,
• Stephen P. Argent,
• Coby J. Clarke and
• Miriam L. O’Duill

Beilstein J. Org. Chem. 2024, 20, 2931–2939, doi:10.3762/bjoc.20.245

• concentrated on iodine [19], making it highly electrophilic, while a nonbonding pair of electrons is mainly centred on the axial substituents, causing a build-up of electron density on these positions (Figure 1A) [1][20]. Stabilisation of this charge on the axial substituents by strong electron-withdrawing

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• unsymmetrical forms of these salts serve as effective electrophilic arylating reagents in various organic syntheses. The use of diaryliodoniums in C–C and carbon–heteroatom bond formations, particularly under metal-free conditions, has further enhanced the popularity of these reagents. In this review, we

• concentrate on various arylation reactions involving carbon and other heteroatoms, encompassing rearrangement reactions in the absence of any metal catalyst, and summarize advancements made in the last five years. Keywords: arylation reaction; diaryliodonium salts; electrophilic arylation reagent; metal-free

• arylation; rearrangement reaction; Introduction The chemistry of hypervalent iodine compounds is well-established and they are prevalent as oxidants and electrophilic reagents in organic conversions [1][2][3]. They have gained significant attention due to their high reactivity and ability to carry out

C–H Trifluoromethylthiolation of aldehyde hydrazones

• Victor Levet,
• Balu Ramesh,
• Congyang Wang and
• Tatiana Besset

Beilstein J. Org. Chem. 2024, 20, 2883–2890, doi:10.3762/bjoc.20.242

• transformation, experiments with different SCF3 sources were conducted. First, we hypothesized that trifluoromethylthiolated succinimide, which might be in situ generated from NBS and AgSCF3, could be the active species. When the reaction was carried out in the presence of this electrophilic source and 1a, no