Pd-Catalyzed asymmetric allylic amination with isatin using a P,olefin-type chiral ligand with C–N bond axial chirality

• Natsume Akimoto,
• Kaho Takaya,
• Yoshio Kasashima,
• Kohei Watanabe,
• Yasushi Yoshida and
• Takashi Mino

Beilstein J. Org. Chem. 2025, 21, 1018–1023, doi:10.3762/bjoc.21.83

• only approximately 1.3 days, also has a chiral induction ability. However, improvement is required in terms of the reactivity of the catalytic reaction. Subsequently, we investigated the effect of the base using (aR)-(−)-6 by testing various bases. The reaction in the presence of Na2CO3 delivered the

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• enamides contain an N-acyl group in place of the original alkyl group. The electron-withdrawing effect of the amide group delocalizes the nitrogen lone pair, thereby reducing the electron density and nucleophilicity of the enamide double bond. These features significantly diminish the reactivity of

• reactions [7][8], the exploration of enamides’ nucleophilic reactivity has only gained momentum in recent years. Inspired by pioneering work from various research groups [9][10][11][12][13][14][15], the potential of enamides in nucleophilic reactions has become recognized. Among them, enamide cyclizations

• the α-position of enamide to be an active cyclization site, with the alkyne tether acting as the nucleophile. Since it is well-established that alkynes, when activated by transition metals such as gold or platinum, can also function as electrophiles, modulating the reactivity of the decahydroquinoline

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

• publications [19][23][24] confirmed the structure with IR and MS data, or by reactivity. Herein, we report the full set of assigned 1H and 13C NMR data for both the base and the dihydrochloride salt. In the course of our efforts devoted to elaborating a new and efficient synthesis of brevicarine (2), we

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

• Abstract We present the first examples of alkene amino-sulfonoxylation reactions that leverage the unique reactivity of carbamate tethered N-alkoxy nitrenium ions. In almost all cases examined, the reactions deliver product with exquisite regioselectivity and diastereoselectivity. The protocols followed

• single regioisomer and diastereomer of B was formed (within the limits of 1H NMR detection), attesting to very selective reactivity. Here and in related projects, we found that many I(III) sources could generate a nitrenium ion, including iodosobenzene (PhIO) and iodomesitylene diacetate. However, unless

• new alkene amino-sulfonoxylation reaction that leverages the unique reactivity of carbamate tethered N-alkoxy nitrenium ions. In almost all cases examined, the reactions delivered product with exquisite regioselectivity and diastereoselectivity. The protocols followed were operationally very simple

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• diverse scaffolds have been reported in the literature, the identification and use of novel PCs with tunable and diverse optical and redox properties can pave the way to uncharted reactivity. In this context, sulfur-based cores, widely used as acceptors in photoelectric materials [9][10][11][12][13][14

• ). Giese addition using N-Cbz-Pro (12) and dimethyl maleate (13). Pinacol coupling of benzaldehyde (15). Supporting Information Supporting Information File 10: Reactivity studies, general experimental procedures, product isolation and characterization, spectroscopic data for new compounds, and copies of

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• reactivity of those two alcohols toward oxidation allowed for the selective conversion of desired alcohol to ketone 24 using PCC, producing a 50% overall yield, while the recovered undesired alcohol could be reverted to 21 by Swern oxidation. Direct enol triflation (Et3N/Tf2O, NaH/PhNTf2, DTBMP/Tf2O, etc

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

• , Koenigs, and co-workers demonstrated solvent-controlled bifurcation in the light-driven reactivity of cyclic diazo imides 41 with thiols 42, unveiling two mechanistically distinct pathways (Scheme 11) [40]. In dichloromethane (DCM), the reaction proceeds via a carbene intermediate, enabling cascade C(sp2

• enantioselective access to both enantiomers of chiral P(V) molecules 47 or 48 using a single chiral NBE catalyst. Time control Time control of chemical reactivity offers an inherent strategy to program synthetic pathways through kinetic discrimination of transient intermediates. Diverging from additive-dependent

• in the absence of a Brønsted acid additive, the opposite enantiomer 52 was obtained. Mechanistically, an initial kinetic resolution (KR) of (rac)-50 occurs via an Ir-catalyzed asymmetric allylic amination. Due to the higher reactivity of (S)-50, it reacts with 6-hydroxyisoquinoline within 6 minutes

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

• carboboration of unsaturated hydrocarbons [1][2][3][4][5][6][7]. In the course of our investigation of the copper-catalyzed borylative coupling of alkynes with allylic gem-dichlorides [3], we observed that alkyl 4,4-dichloro-2-butenoates deviated from the general reactivity trend. While allylic gem-dichlorides

• (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

• functionalized cyclopropane scaffolds depending on the nature of the carboxylic acid derivative. Chemodivergent reactivity observed in copper-catalyzed borylative couplings of allylic gem-dichlorides. Cu-Bpin-mediated dimerization of 4,4-dichoro-2-butenoic acid derivatives. Control experiments. Proposed

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

• prohibitively high in energy for selective reactivity [5]. The inception of energy transfer catalysis (EnT) has expedited discoveries concerning the photoactivation of organic molecules [15][16][17], enabling direct access to the triplet excited state through the use of a photocatalyst (Figure 1A, top

• ). Pioneering studies have leveraged this platform with great effect, typically invoking π→π* transitions of conjugated alkenes to lower the bond order and generate a triplet diradical, primed for further reactivity. This key intermediate is pivotal in a plenum of synthetic transformations including geometric

• reactivity in EnT catalysis has also been intensively pursued (Figure 1B). The controlled geometric isomerization of boron-containing conjugated dienes [42], styrenes [43][44][45] and β-boryl acrylates [46][47] has been established with great effect, while elegant [2 + 2] cycloaddition strategies to readily

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

• reactivity of the diazonium salt. When strong electron-withdrawing groups (EWGs) were introduced, the yield was also reduced, likely due to the low nucleophilicity of the aniline derivative and the ineffective formation of a diazonium salt. An annulation reaction of compound 2 was performed with either

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

• , while density functional theory (DFT) calculations provided insights into their electronic properties, including reactivity and stability. This comprehensive approach, integrating synthesis, biological evaluation, and computational methods, highlights the potential of 4-(1-methylamino)ethylidene-1,5

• forms 3a’–e’ will be attacked by methylamine (4) to yield the tetrahedral intermediate 6 and then, the intramolecular proton transfer will lead to intermediate 7. It has been proven that Schiff’ bases show normally higher reactivity than the corresponding carbonyl compounds towards nitrogen-containing

• necessary to elucidate the toxicological profiles of compounds 5c and 5e prior to consideration for drug development. Analysis of reactivity descriptors The primary reactivity descriptors, such as frontier molecular orbital energies (EHOMO and ELUMO), energy gap (ΔEL-H), ionization energy (IE), electron

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

• centers (Scheme 1b). Although both methodologies achieved high regioselectivity, their substrate scopes were limited, and most studies focused on the hydrocyanation of terminal allenes. Given the synthetic importance of nitriles that bear all-carbon quaternary centers and the distinctive reactivity of

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

• yield was observed with increased reaction temperature. 2-Isocyanobiaryl compounds showed better reactivity when they contained electron-withdrawing groups. Diarylphosphine oxides containing a methyl group reacted well under standard conditions, regardless of their position. Mechanistic studies showed

• on silver-catalyzed C–H phosphorylation revealed that variations in current intensity, frequency, and duty ratio influence product yield. To achieve optimal reactivity, the duty ratio must exceed 50%. Additionally, an analysis of silver deposition on carbon and platinum electrodes indicated that

• ferrocene and ruthenocene via coupling reaction. This method provides an efficient and versatile synthetic approach for producing phosphorylated metallocenes but also aids in interpreting the regioselectivity and reactivity of C−H functionalization in unsymmetric metallocenes. They used a platinum electrode

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

• substrates for this transformation. However, due to steric hindrance, ortho-substituted aniline 1s exhibited significantly lower reactivity, resulting in diminished yields of product 3sa. Notably, disubstituted anilines were also compatible with the protocol, furnishing the desired products 3ta–ya in

• to be compatible substrates, affording cyclo-O/S-containing STHQ derivatives 3ab and 3ac in good yields. Additionally, ester-functionalized cyclobutanones exhibited smooth reactivity with aniline, enabling the synthesis of substituted STHQ motifs 3ad and 3ae in satisfactory yields. Notably, when

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• reacted with 4-cyanophenylacetonitrile to give compound 10, followed by installing the bromobutyl handle with 4-bromobutanol under Mitsunobu conditions (Scheme 3). Next, HBC dyes 7, 8, 9, and 11 were tested for their reactivity with the Pepper aptamer. They were incubated together with the RNA in buffer

• the N-(3-tosyloxypropyl) HBC derivative 15 (Scheme 4). It should be noted that attempts to prepare and isolate N-(3-trifluoromethansulfonylpropyl)-modified HBC failed, probably due to rapid hydrolysis during workup. Next, the HBC dyes 12, 13, 14, and 15 were tested for their reactivity with the Pepper

• fluorophores with an electrophilic handle, three of which have been previously used in cellular applications [11]. Comparative reactivity analysis of all these fluorophores revealed that the N-(3-mesyloxypropyl) HBC 14 is the most efficient for covalent tethering to Pepper RNA. Moreover, the mesyloxyalkyl

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

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

• inception (Scheme 1). Early studies were mainly focused on palladium catalysts [5][6][7][8], as demonstrated by the independent pioneering works of Tsuji and Trost in the 1960s and 1970s, respectively. While palladium catalysts demonstrated excellent reactivity with soft stabilized nucleophiles in the

• (Scheme 3) [46]. Their methodology involves a stereoretentive I/Li exchange at −100 °C, followed by transmetalation with CuBr·P(OEt)3 to generate the secondary alkylcopper species 14. These organocopper species demonstrated remarkable reactivity in SN2-type additions to allylic bromides with exceptional

• without requiring stoichiometric organometallic reagents [49] (Scheme 10). The distinctive reactivity of the CuH species allows for precise control over the stereochemical outcome through the regio- and enantioselective hydrocupration of olefins 27, followed by stereospecific trapping with allylic

Photocatalyzed elaboration of antibody-based bioconjugates

• Marine Le Stum,
• Eugénie Romero and
• Gary A. Molander

Beilstein J. Org. Chem. 2025, 21, 616–629, doi:10.3762/bjoc.21.49

• oxygen [42]. Through energy transfer (EnT) from the ruthenium-based photocatalyst to triplet oxygen, singlet oxygen is produced in a targeted manner, which oxidizes histidine to an endoperoxide, significantly increasing its reactivity toward nucleophiles (Figure 4A). This strategy employs a

• comment, targeting a single class of amino acids, the most solvent-exposed would react preferentially to those buried within hydrophobic domains of the mAbs, and ideally the relative rates of their reactivity would translate directly to tightly controlled DARs. The time of irradiation, the wavelength of

• to study and alter biological systems at the molecular level [52][53]. Owing to the often-unique mechanisms characterized by photocatalytically promoted reactions, reactivity patterns might be developed that allow selective reactions at amino acids that are not currently used for conjugation of

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• substrate reactivity, minor side reactions, or minor losses during microwave irradiation. The remaining part may be caused by factors such as slight volatilization or incomplete conversion under specific use conditions. We found the synthetic procedure facile as the less polar hydantoin products (H2a–c, H2e

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

• /bjoc.21.45 Abstract Formaldehyde emerges as a cornerstone in multicomponent reactions, mainly prized for its robust reactivity. Yet, alongside these beneficial traits, this highly reactive C1-building block raises concerns, primarily regarding its toxicity. One notable issue is the challenge of

• of green MCRs due to its high reactivity under these conditions [7]. However, this reactivity also increases the potential for the formation of byproducts. Furthermore, formaldehyde is widely recognized to be toxic and is considered carcinogenic by the World Health Organization (WHO) both in solution

• phosphites can also undergo an addition to the C=O bond of the carbonyl component (Abramov reaction) giving α-hydroxy phosphonates 33 as byproducts (Scheme 26a) [72]. Competition between the two nucleophiles for the electrophilic carbonyl compound depends on their relative reactivity [74][77] and this lack

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• ). Further details on this are available in the experimental section. This suggests that the reaction is topochemical, with the bimane’s reactivity dependent on its crystal packing, since no [2 + 2] cycloaddition product was seen in the spectrum. While the reaction may also depend on the reactivities of the

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

• mRNA domain, namely the preQ1 class-I riboswitch (preQ1-I) from Thermoanaerobacter tengcongensis. By rigorously analyzing the high-resolution structures available for this ligand–RNA complex, the approach exploits the natural, sequence-inherent reactivity hotspots of RNA and thus avoids the use of

• 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

• -diaminopyrimidin-4(3H)-one to afford preQ0 (7), as originally reported by Townsend et al. [30]. The next step, namely the reduction of the nitrile moiety by hydrogenation is critical and notoriously difficult due to the low reactivity of this group in preQ0 [26]. We solved this problem by applying strongly acidic

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

• Chimiche e Geologiche, Università degli Studi di Cagliari, Cittadella Universitaria, SS554 bivio per Sestu, 09042-Monserrato (CA), Italy CIRCC (Interuniversity Consortium Chemical Reactivity and Catalysis), via Celso Ulpiani 27, 70126 Bari, Italy Department of Chemistry, Life Sciences and Environmental

• photon by a molecule causes the reorganization of the electron density around the atoms and unlocks unique reactivity modes [2][3]. In photochemical methods, light is directly absorbed by a functional group embedded in the substrate and can be exploited for example to cleave bonds or trigger

• spectroscopy (Scheme 1). During the reaction progress, the C=C bonds of bpe ligands undergo pedal-like motion prior to photodimerization [63]. For the single-crystal irradiation, the slow reactivity can be attributed to the hindered pedal motion in the single crystals, likely due to the presence of

Electrochemical synthesis of cyclic biaryl λ³-bromanes from 2,2’-dibromobiphenyls

• Andrejs Savkins and
• Igors Sokolovs

Beilstein J. Org. Chem. 2025, 21, 451–457, doi:10.3762/bjoc.21.32

• -substituted 1d could be also obtained under the developed conditions. Unsymmetrically substituted 4e and monosubstituted dibromides 4f,g demonstrated reactivity similar to that of their symmetrical analogues 4b,c with exception of the mono-MeO-substituted dibromide 4h. Notably, the presence of two stabilizing

• substrates that do not form the desired electrochemical oxidation product see Supporting Information File 1, Scheme S1). A series of control experiments was performed to rationalize the observed reactivity trends (Scheme 2). The measured redox potentials EP/2 for 2,2'-dibromo-1,1'-biphenyls 4a–g (from 1.77 V