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

• , illisimonin A was obtained only as a minor product. When O2 was replaced with the nitroaromatic compound 66 [38], the diastereoselectivity was reversed, thereby providing illisimonin A in 57% yield as a single diastereomer. The authors proposed that a hydrogen bond between the nitro group of 66 and the C8

Isoorotamide-based peptide nucleic acid nucleobases with extended linkers aimed at distal base recognition of adenosine in double helical RNA

• Grant D. Walby,
• Brandon R. Tessier,
• Tristan L. Mabee,
• Jennah M. Hoke,
• Hallie M. Bleam,
• Angelina Giglio-Tos,
• Emily E. Harding,
• Vladislavs Baskevics,
• Martins Katkevics,
• Eriks Rozners and
• James A. MacKay

Beilstein J. Org. Chem. 2025, 21, 2513–2523, doi:10.3762/bjoc.21.193

• -nitroaniline into benzyl acrylate to afford compound 17 in 57% yield (Scheme 3). Aniline 17 then was subjected to a three-step Boc protection, nitro reduction, and coupling with isoorotic acid derivative 6 that afforded 18 in 39% yield over 3 steps. The benzyl ester was then cleaved under hydrogenolysis

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

• . Nucleophilic substitution of the nitro group with sulfur nucleophiles, including thioacetate or disulfide anions as well as thioacetamide, yielded bis(thiophen-3-yl)disulfide and sulfide derivatives. The disulfide served as a suitable precursor for the preparation of 3-alkylthio-substituted thiophene-2,5

• TTs from the activated 3-nitrosubstituted thiophenes [29][30]. This strategy provides an effective access to the 3-hydroxy-TTs via the nucleophilic substitution of the nitro group in 3-nitrothiophene precursors using S-nucleophiles, such as alkyl thioglycolates or mercaptoacetone (Scheme 1, route V

• ). Herein, we wish to report a modified strategy based on route IV involving the stepwise construction of the TT framework. This approach is accomplished via the nucleophilic substitution of the nitro group with a S-nucleophile to obtain the thiophene-3-thiolate or its equivalent, followed by further S

Palladium-catalyzed regioselective C1-selective nitration of carbazoles

• Vikash Kumar,
• Jyothis Dharaniyedath,
• Aiswarya T P,
• Sk Ariyan,
• Chitrothu Venkatesh and
• Parthasarathy Gandeepan

Beilstein J. Org. Chem. 2025, 21, 2479–2488, doi:10.3762/bjoc.21.190

• functionalization of carbazoles via C–H activation [48][49][50][51][52][53][54][55][56][57][58][59][60][61]. Among the variously substituted carbazole scaffolds, nitro-substituted carbazoles exhibit a diverse range of medicinal properties and serve as key starting materials for the synthesis of bioactive compounds

• and functional materials (Scheme 1a) [62][63][64][65][66]. Traditional electrophilic aromatic substitution methods for the nitration of carbazole typically result in a mixture of 1-nitro-, 2-nitro-, and 3-nitro-substituted isomers (Scheme 1b) [67]. Therefore, developing a method for the regioselective

• were ineffective in improving the reaction outcome (Table 1, entry 6). Other palladium complexes promoted the formation of 2a but with diminished efficiency (Table 1, entries 7 and 8). Varying the amount of AgNO3 did also not lead to a better yield (Table 1, entry 9), and alternative nitro sources also

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

• products were obtained in good to high yields. However, two notable exceptions were identified. First, when a nitro group was introduced at the para-position of the benzoyl moiety the starting chalcone was recovered unchanged. Second, the use of an α,β-unsaturated ketone bearing an N-methylpyrrole moiety

Pd-catalyzed dehydrogenative arylation of arylhydrazines to access non-symmetric azobenzenes, including tetra-ortho derivatives

• Loris Geminiani,
• Kathrin Junge,
• Matthias Beller and
• Jean-François Soulé

Beilstein J. Org. Chem. 2025, 21, 2234–2242, doi:10.3762/bjoc.21.170

• nitro (3j, 35%), as well as electron-donating groups such as methoxy (3d, 77%), dimethylamino (3k 55%) , and thiomethoxy (3l, 71%). Moreover, the reaction tolerated C–F (3f, 86%) and C–Cl (3g, 66%) bonds, enabling orthogonal functionalization. It should be noted that, as a general trend – and in

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

• case of 7c and 7h, a substantial amount of (Z)-isomer was also obtained. In view of the expected similar electronic effect of the sulfonamide and the nitro functional groups on the Fischer indole cyclization, first we applied those reaction conditions for the 7a → 3a transformation (Scheme 1) which

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

Continuous-flow-enabled intensification in nitration processes: a review of technological developments and practical applications over the past decade

• Feng Zhou,
• Chuansong Duanmu,
• Yanxing Li,
• Jin Li,
• Haiqing Xu,
• Pan Wang and
• Kai Zhu

Beilstein J. Org. Chem. 2025, 21, 1678–1699, doi:10.3762/bjoc.21.132

• engaged in the development of continuous-flow nitration systems. Keywords: continuous-flow; kinetics; nitration; optimization; scale up; Introduction Nitro compounds hold an extremely important position in the field of organic chemistry, mainly because they are easily obtainable and can be converted

• complete nitration process encompasses three key dimensions: the selection of starting materials and nitrating reagents, the implementation of the nitration reaction, and the specific application scenarios of the nitration products. The nitration reaction serves as a pivotal synthetic pathway for nitro

• -flow configurations demonstrate superior safety and efficiency. While the synthetic significance of nitration is underscored by the broad utility of nitro derivatives, persistent technical challenges including regioselectivity control, over-nitration phenomena, and substrate oxidation side reactions

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

• an important role in medicinal and pharmaceutical chemistry [23][24][25] (Scheme 1a). Sodium hypophosphite exhibited good chemoselectivity – it selectively reduced imines while leaving other functional groups intact, e.g., nitro (NO₂), cyano (CN), alkene (C=C), and benzyloxy (OBn) groups. In contrast

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

• , was observed for the spiro-compound 5l, which contains a p-nitro group in the aromatic core of the nitrile oxide fragment. This compound was obtained in excellent yield of 93% and 88% using the dropwise and diffusion mixing technique, respectively. This result may be explained by the optimal

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• compounds is provided by the variation of substituents in positions 2–5 of the 1,2-thiazole ring. Thus, arylsulfonyl groups containing a methyl, fluorine, chlorine, or nitro group at the aryl moiety, or a mesyl substituent were introduced into position 2 of the thiazole ring and various aryls, quinolinyl

High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters

• Kelsey Plasse,
• Valerie Wright,
• Guoshu Xie,
• R. Bernadett Vlocskó,
• Alexander Lazarev and
• Béla Török

Beilstein J. Org. Chem. 2025, 21, 1374–1387, doi:10.3762/bjoc.21.102

• Mannich reactions [20], lipase-catalyzed esterification [21], nitro-aldol [22], Michael [23], and aza-Michael reactions [24][25], Diels–Alder reactions [26][27] and Friedel–Crafts alkylation of indoles [28]. Many high pressure reactions were applied in natural product synthesis [29]. The high pressure

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

• electron-withdrawing groups on the aromatic ring were well tolerated (19a–c), although substrates with strong electron-withdrawing groups, such as nitro (–NO₂), resulted in no product (19d). Additionally, alkyl, phenyl, and benzyl substituents on the nitrogen atom of N-arylacrylamides were compatible (19e

• methoxy (-OMe) and halogens (-F, -Cl, -Br), as well as electron-withdrawing functionalities like trifluoromethyl (-CF₃) and ester groups (-CO₂Me). However, highly electron-deficient substrates, such as those bearing cyano (-CN) or nitro (-NO₂) groups, did not react. Additionally, the study explored

• -substituted acrylamides. Compounds such as N-methyl, N-ethyl, N-isopropyl, N-phenyl, and N-benzyl-substituted acrylamides were efficiently transformed into products 37a–e under the optimized conditions. However, substrates with strong electron-withdrawing groups, such as those bearing nitro substituents (37f

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

• representation is compared to all other SMILES with an added dummy atom. 5. Duplicates are removed when the directing group has equivalent resonance forms, as shown in Figure 8. The equivalent heteroatoms are detected using SMARTS patterns for nitro and carboxylate groups. For the remaining combinations of C–H

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

• ) reported a carboxyl group activation of cinnamic acid (7) by applying pivalic anhydride in a single step to afford the corresponding amide 8 in excellent yield (Scheme 3B) [35]. Moreover, pivalic anhydride is easier to handle than its chloride counterpart. Wang and co-workers (2022) utilized 5-nitro-4,6

• in situ nitro reduction using Mn powder to afford the amide intermediate 42. The acid halide once again was applied for cinnamic acid amidation. Xiao and co-workers (2021) performed a transesterification and aminolysis of the tert-butyl ester 43 simply by using PCl3 through in situ generation of the

• proceeding via C–N-bond cleavage of the oxidized tertiary amine 116 (Scheme 35) [70]. Cinnamic acid (7) was activated by forming the acyl radical 118 after −OPyf group cleavage from 117. Recently, Li and co-workers (2024) studied visible-light-mediated FeCl3-catalyzed reductive transamidation of nitro

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

• in good yield, although with slightly decreased enantioselectivity. The introduction of the chloro group at the same position led to a moderate yield for (S)-13d, while the enantioselectivity remained high. In contrast, the reaction with the isatin derivative bearing a nitro group at the 5-position

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

• debenzylated to brevicarine (2), isolated as a dihydrochloride salt. Müller et al. accomplished an alternative synthesis of brevicarine (2, Scheme 4) [23]. Compound 21 was obtained by treatment of nitrovinylindole 19 with N-methylpyrrole (20). Catalytic hydrogenation of the pyrrole ring and the nitro group of

Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

• ]. In 2015, García-Valverde and co-workers described an alternative synthesis of benzo[e][1,4]diazepines 6, exploring the nitro group of 2-nitrobenzoic acid as a masked amino group. The release was achieved through the post-Ugi reduction of the nitro group with SnCl2 triggering concomitant

• trifluoromethyl and nitro groups. Furthermore, substrates 15m–o derived from aliphatic amines, also performed well, furnishing pyrazolodiazepines 16m–o in up to 89% yield. The structure of 16m, a representative compound of this series, was confirmed through single-crystal X-ray diffraction (scXRD) analysis

Unraveling cooperative interactions between complexed ions in dual-host strategy for cesium salt separation

• Zhihua Liu,
• Ya-Zhi Chen,
• Ji Wang,
• Qingling Nie,
• Wei Zhao and
• Biao Wu

Beilstein J. Org. Chem. 2025, 21, 845–853, doi:10.3762/bjoc.21.68

• , only two examples provide clear evidence of cooperative interactions based on single crystal structures [28][29], where the 18-crown-6 complexed K+ cation forms ion-dipole interactions with the carbonyl (C=O) or nitro (NO2) groups of the anion-bound receptors (KF and K2CO3). Recently, we demonstrated

• stabilized by the binding with 18-crown-6 and three ion-dipole interactions with O=C (urea unit) and O–N (terminal nitro group). Distances of Cs–O are measured at 3.0 Å and 3.4 Å. Regarding type-(II) cesium binding, four cesium cations are observed to interact with two urea units and two nitro groups through

• receptor L. The carbonate anion is encapsulated inside the hexaurea cavity and stabilized by 12 × N–H···O hydrogen bonds. Two types of Cs+ complexations are observed, (I) one 18-crown-6-complexed Cs+ interacts with carbonyl (O=C) and nitro (-NO2) groups through three ion-dipole interactions. (II) The other

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

• drug dexamethasone (IC50 = 13.25 ± 1.39 µM). At a concentration of 100 µM, the NO inhibition of pyrrolidine-2,3-dione derivatives 5a, 5b, and 5e was 53.65%, 50.22%, and 63.65%, respectively, as compared to 85.04% of dexamethasone. It is clear that the presence of a nitro group or halogen atom on the

• benzene ring at the 5-position of pyrrolidine-2,3-dione core in compounds 5c and 5d could relate to the lower inhibitory activity of 23.76% and 38.41% at the concentration of 100 µM, respectively, as compared to 5a and 5b. However, the existence of a nitro group on the aromatic ring attached to the 1

• , Trp194, Gly202, Pro350, Phe369, and Tyr489, further contributing to the stabilization of the ligand–protein complexes. More importantly, the occurrence of an electron-withdrawing group, nitro group (NO2), on the aromatic ring linked to the 1-position of the pyrrolidine-2,3-dione core may help compound 5e

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

• atmosphere, indicating that anodic oxidation is the main pathway of the reaction, and oxygen may have a positive effect. (Table 3). Functional groups at the 4-position moderately reduced the reaction yield. The nitro group was incompatible in this system, likely due to its preferential reduction ability

• desired products were obtained with moderate yields for aldehydes containing strong electron-withdrawing groups, indicating that this method is suitable for forming P–C bonds. Products with nitro, chlorine, or bromine groups at the para position had higher yields compared to those with the groups at the

• corresponding phosphorylated propargyl alcohols (Scheme 19). The reaction yield showed that this method is not sensitive to electron-withdrawing or electron-donating groups at different positions on the aromatic ring. Most likely, the 3-substituted pyridine substrate and the enynes with nitro or carbonyl groups

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

• undesired cathodic reduction. Indeed, trace amounts of 2-aminoproline derivative 6g (<4%) could be obtained by replacing SS as the cathode material with platinum that has a low overpotential for hydrogen evolution reaction [14]. To avoid the undesired cathodic reduction of the nitro group, the electrolysis

Cryptophycin unit B analogues

• Thomas Schachtsiek,
• Jona Voss,
• Maren Hamsen,
• Beate Neumann,
• Hans-Georg Stammler and
• Norbert Sewald

Beilstein J. Org. Chem. 2025, 21, 526–532, doi:10.3762/bjoc.21.40

• formation and N-Boc-protection [24] provided nitroarene 5 in 40% yield over three steps. Reduction of the nitro group was performed with Pd/C and hydrogen to obtain aniline 6 in 98% yield, which served as a precursor for mono- and dimethylated unit B derivatives 7 and 8, respectively. While dimethylaniline

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

• except the preparation of the aminoaniline building block tert-butyl (2-amino-5-bromophenyl)carbamate (5), which was prepared by Boc-protection of the 5-bromo-2-nitroaniline (6) and subsequent reduction of the nitro group (see Supporting Information File 1, section II.1). Cross-coupling reactions Stille