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

• , The Ural Branch of Russian Academy of Sciences, Goleva St. 13, 614081 Perm, Russian Federation 10.3762/bjoc.21.183 Abstract A synthetic strategy for the preparation of spiro[indoline-3,2'-pyrrolidine] derivatives has been developed, featuring a two-step sequence consisting of the reaction of 2

• -unsaturated ketone; dearomatization; indole; spirocyclization; spiro[indoline-3,2'-pyrrolidine]; Introduction Spiro[indoline-3,2'-pyrrolidine] derivatives represent an important class of organic compounds found in both natural products (e.g., coerulescine [1], horsfiline [2], and elacomine [3]) and synthetic

• synthesized spiro[indoline-3,2'-pyrrolidine] derivatives 4 were evaluated for antimicrobial activity via serial dilution assays across a concentration range of 0.5–1000 µg/mL. The minimum inhibitory concentration (MIC) and minimum bactericidal (fungicidal) concentration (MBC/MFC) against a diverse spectrum of

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• patterns that dictate the position of the macrocycle. Later, Leigh and co-workers introduced a new strategy for dynamically controlling asymmetric catalysis using a hydrazone-based rotaxane [72]. The axle features a hydrazone photoswitch and a pseudo-meso 2,5-disubstituted pyrrolidine organocatalytic unit

• . The photoisomerization of the hydrazone modulates the position of the tetraamide macrocycle around the pyrrolidine, breaking its symmetry and switching its handedness. This dynamic control was used to adjust the enantioselectivity of an enamine-mediated conjugate addition. In 2024, the same group

Recent advances in Norrish–Yang cyclization and dicarbonyl photoredox reactions for natural product synthesis

• Peng-Xi Luo,
• Jin-Xuan Yang,
• Shao-Min Fu and
• Bo Liu

Beilstein J. Org. Chem. 2025, 21, 2315–2333, doi:10.3762/bjoc.21.177

• racemic 87 was synthesized on a gram scale in 47% yield from 90 via a Norrish–Yang reaction. However, under the established photochemical conditions for generating 87, the corresponding pyrrolidine-derived species 93 is not formed (Scheme 11). In contrast, solution-phase irradiation of the same

• pyrrolidine-derived phenyl keto amide substrate 91 with blue LEDs produces the pyrrolidine-fused 4-oxazolidinone (N,O-acetal) 92, precluding preparation of the pyrrolidine analog of lycoplatyrine A (94) by this method. Compound 92 is presumably formed via either the radical mechanism [41] or possibly

• . Asymmetric total synthesis of lycoplatyrine A. Photoreaction of pyrrolidine-derived phenyl keto amide. Photoredox reactions of naphthoquinones. Synthetic study toward γ-rubromycin. Substituent-dependent conformational preferences. Total synthesis of preussomerins EG1, EG2, and EG3. Acknowledgements This

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

• mechanism involving single-electron oxidation of an enamine intermediate, addition of the resulting radical to the olefin, single-electron oxidation of the adduct to form a carbocationic intermediate, and intramolecular nucleophilic attack on the carbocation to form the pyrrolidine ring. The reaction

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

• metal-free methodology delivered synthetically versatile iodinated homoallylic alcohols bearing piperidine motifs and pyrrolidine-fused cyclopropanes. Importantly, the reaction was carried out with high operational simplicity and environmental compatibility under mild reaction conditions. In 2024, Chan

• afforded selective access to four indole derivatives through modulation of the alkyne's terminal substituents and nucleophile type (Scheme 14) [21][22]. The gold(I) catalyst activated the unsubstituted terminal alkynes to initiate a 5-exo-dig cyclization, generating a spiro[indoline-3,3'-pyrrolidine

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

• emitting diodes [28]. Formyl oxazolidine (V12) was a potential candidate to protect maize from herbicide harm [29]. Thiadiazole-linked thioacetamide (S5) exhibited exceptional inhibitory activity against Synechocystis sp. PCC6803 and Cy-FBP/SBPase [30]. Pyrrolidine compound MSC2530818 could be potentially

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

Discovery of cytotoxic indolo[1,2-c]quinazoline derivatives through scaffold-based design

• Daniil V. Khabarov,
• Valeria A. Litvinova,
• Lyubov G. Dezhenkova,
• Dmitry N. Kaluzhny,
• Alexander S. Tikhomirov and
• Andrey E. Shchekotikhin

Beilstein J. Org. Chem. 2025, 21, 2062–2071, doi:10.3762/bjoc.21.161

• substitution of the terminal chloride in 11 with various cyclic amines, including pyrrolidine, piperidine, and mono-tert-butoxycarbonyl (Boc)-protected piperazine, provided a set of aminoalkyl derivatives 12а–с (Scheme 4). This strategy enables the expansion of structural diversity within this scaffold and

• superior results compared to the parent structure and again pyrrolidine as the key part of the 12-aminomethyl fragment (in 10b) demonstrated the best activity. The introduction of an aminopropyl group at the position 5 of indolo[1,2-c]quinazolin-6(5H)-one (derivatives 12a–c) is also accompanied by the

Bioinspired total syntheses of natural products: a personal adventure

• Zhengyi Qin,
• Yuting Yang,
• Nuran Yan,
• Xinyu Liang,
• Zhiyu Zhang,
• Yaxuan Duan,
• Huilin Li and
• Xuegong She

Beilstein J. Org. Chem. 2025, 21, 2048–2061, doi:10.3762/bjoc.21.160

• analysis. The major one 48b was used for further study to install the pyrrolidine system. Thus, nucleophilic addition of an N,O-enolate, derived from precursor 49 with LDA, to the ketone functionality in 48b was implemented to generate a pair of inseparable regioisomers 50a and 50b, arose from C4 and C7

Aryl iodane-induced cascade arylation–1,2-silyl shift–heterocyclization of propargylsilanes under copper catalysis

• Rasma Kroņkalne,
• Rūdolfs Beļaunieks,
• Armands Sebris,
• Anatoly Mishnev and
• Māris Turks

Beilstein J. Org. Chem. 2025, 21, 1984–1994, doi:10.3762/bjoc.21.154

• stabilized allyl cation intermediates that undergo regioselective trapping by internal O- and N-nucleophiles furnishing functionalized heterocycles. This method provides access to tetrahydrofuran or pyrrolidine frameworks, each bearing a trifunctionalized (E)-configured vinyl side chain. The use of a shorter

• on intermediate allyl cation (Scheme 1C). The obtained tetrahydrofuran and pyrrolidine derivatives with highly substituted vinyl side-chains are regarded as privileged structures in medical chemistry [23][24]. Moreover, the resulting styryl functionality (Ph-C=C-) is often found in drug molecules as

• optimization see Supporting Information File 1. Next, we switched to internal N-nucleophiles. N-Nosylated starting material 7f under standard arylation conditions gave the 2-(1-(tert-butyldimethylsilyl)vinyl)-1-((4-nitrophenyl)sulfonyl)pyrrolidine (14) with a 56% yield. Most likely in this case sulfonamide N–H

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• , followed by reductive demercuration with LiBH4/Et3B to construct the pyrrolidine ring of compound 162. A three-step transformation of 162 yielded compound 163, which was subjected to base-mediated cyclization with concomitant debenzoylation to deliver oxazolidinone 164. Through a four-step sequence

Preparation of a furfural-derived enantioenriched vinyloxazoline building block and exploring its reactivity

• Madara Darzina,
• Anna Lielpetere and
• Aigars Jirgensons

Beilstein J. Org. Chem. 2025, 21, 1737–1741, doi:10.3762/bjoc.21.136

• successful as the reaction was stopped at the spirocycle 4d formation stage (Table 1, entry 9). The removal of the N-Alloc group in unsaturated ester S-3d was performed using a Pd catalyst and pyrrolidine as a nucleophile. The use of Pd(PPh3)4 as the catalyst led to a fast consumption of the starting

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• components of drug derivative formulations, present in more than 7,000 active pharmaceutical compounds [43], the possibility of introducing a pyridine ring into the enaminone structure could be useful for the development of new drug candidates. When pyrrolidine was used as amine reagent, the target enaminone

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

• Information File 1 for the syntheses of derivatives 1k, 1m–s). Encouragingly, all 16 amines were successfully converted to the corresponding 2-aminobenzoxazole derivatives with yields greater than 50%. Beyond piperidine, other cyclic amines, such as morpholine, piperazine, and pyrrolidine, also reacted

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

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

• achieved by a few-step transformation starting from brevicolline ((S)-1) isolated from natural sources (Scheme 2) [19]. When heating (S)-1 in benzoyl chloride, opening of the pyrrolidine ring and N-benzoylation occurred, resulting in compound 9. Debenzoylation of the latter to 10, followed by the catalytic

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

• , Vietnam Academy of Science and Technology (VAST), Hanoi 10072, Vietnam 10.3762/bjoc.21.65 Abstract Pyrrolidine-2,3-diones are important intermediates in the synthesis of numerous nitrogen-containing heterocycles which possess a broad spectrum of biological and pharmacological activities. In this article

• , we report the synthesis of 4-(1-methylamino)ethylidene-1,5-disubstituted pyrrolidine-2,3-diones via a reversible transimination reaction between Schiff’ base (C=N) linkage-containing pyrrolidine-2,3-dione derivatives and methylamine with yields of 80 to 92%. In addition to nuclear magnetic resonance

• interactions also contribute to the stabilization of the ligand–iNOS complexes. In particular, 4-(1-methylamino)ethylidene-5-phenyl-1-(3-nitrophenyl)pyrrolidine-2,3-dione (5e) exhibited the strongest binding affinity (−9.51 kcal/mol) and demonstrated significant inhibitory activity against nitric oxide (NO

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

• pyrrolidine moieties, the NH groups of which interact with the DNA bases and sugars, respectively. When fluorine is incorporated beta to each of the pyrrolidine nitrogens (i.e., 95, Figure 11), the pucker of each ring changes due to electrostatic attraction between the partially negative fluorine and the

• protonated amine. These conformational changes alter the DNA-binding mode, such that the pyrrolidine NH groups of 95 now interact with the DNA phosphates rather than the bases or the sugars [164]. Progressing now to a six-membered ring system, consider the scaffold, pipecolic acid (96, Figure 11) [165][166

Entry to 2-aminoprolines via electrochemical decarboxylative amidation of N‑acetylamino malonic acid monoesters

• Olesja Koleda,
• Janis Sadauskis,
• Darja Antonenko,
• Edvards Janis Treijs,
• Raivis Davis Steberis and
• Edgars Suna

Beilstein J. Org. Chem. 2025, 21, 630–638, doi:10.3762/bjoc.21.50

• F led to a drop in the pyrrolidine 6a yield due to the formation of a new side-product. We hypothesized that the side-product formation at increased amounts (>2.5 F) of passed charge results from undesired Shono oxidation of pyrrolidine 6a [10][11]. Indeed, CV studies of 6a revealed an irreversible

• feature at Ep = 1.78 V vs Ag/Ag+ (100 mV/s scan rate; see Figure 3A), and the electrolysis of pyrrolidine 6a under the optimized anodic decarboxylative cyclization conditions (entry 8, Table 1) afforded cyclic hemiaminal 12a (33% NMR yield), whose structure was proved by NMR experiments (Figure 3B). The

• KOH was not always beneficial. For instance, the anodic oxidation of benzamide 9k in the presence of KOH afforded pyrrolidine 6k only as a minor product and a mixture of 6k/10k/11k in 15:32:53 ratio, respectively, was formed. Finally, the loading of 9j was increased from 0.3 to 2.7 mmol to demonstrate

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

• secondary amines such as piperidine or pyrrolidine afford an aminal or an iminium ion, in general under high temperature or pressure conditions, which is not the case for the AHA coupling [69][70]. Despite these cases, the absence of evidence in terms of iminium ion generation confirms that the AHA coupling

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

• using a mixture of 12.1 (0.2 mmol), NaI (1 equiv), Koser’s reagent, and Na2CO3 (each 4 equiv), in the presence of 100 wt % of SAOED, pyrrolidine 12.2 was isolated in 90% yield. As far as the mechanochemical setup is concerned, the authors milled the reaction mixture at 30 Hz in a 5 mL stainless-steel

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• Figure 1 and Figure 2, it can be found that the C=C bond is located in the unit of the pyrrolidine-2,5-dione, while the scaffold of indolin-2-one is connected via a C–C single bond with the unit of the pyrrolidine-2,5-dione. Therefore, an allyl rearrangement must proceed in the reaction process, which is

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

• ] cycloaddition reaction with the nitroalkene produces the pyrrolidine XXVII, which then aromatizes by extrusion of HNO2 (Scheme 21) [38]. Substituted pyrrolidines 30 were achieved in an enantioselective form starting from amino acid esters, electron-poor olefins and 4-substituted-2-picolinaldehydes or 4

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

• reacted with aminoarylaldehydes 5 to form axially chiral 2-arylquinoline derivatives 6 (Scheme 2). Using the pyrrolidine derivative C2 as the most efficient organocatalyst, a range of quinoline derivatives were obtained in high yields and enantiomeric purities. The postulated mechanism consists of iminium

• process was inspired by the biocatalytic synthesis of aromatic polyketides by polyketide synthase from poly β-carbonyl substrates. Pyrrolidine-based organocatalyst C4 was able to promote a twofold atroposelective arene-forming 6-enolendo aldol condensation (Scheme 4). Sparr also realized a central-to

• transformation produced either the (Ra,Sa)-isomer using pyrrolidine tetrazole catalyst C6 or the (Sa,Sa)-diastereoisomer using quaternary ammonium salt C5 (Scheme 5). Catalyst-controlled formation of twofold and higher-order stereogenicity in axially chiral arenes was discussed in this account article [15

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3