Preparation of spirocyclic oxindoles by cyclisation of an oxime to a nitrone and dipolar cycloaddition

• Beth L. Ritchie,
• Alexandra Longcake and
• Iain Coldham

Beilstein J. Org. Chem. 2025, 21, 1890–1896, doi:10.3762/bjoc.21.146

• silica gel 60F254 plates and visualised by UV irradiation at 254 nm or by staining with an alkaline KMnO4 dip. Flash column chromatography was performed using silica gel (40–63 micron mesh). Infrared spectra were recorded on a Perkin Elmer Spectrum RX Fourier Transform–IR System and only selected peaks

• EtOAc/petrol 1:4, to give the tosylate 3 (1.30 g, 79%) as an amorphous solid; Rf 0.57 (EtOAc/petrol 1:1); IR (film, cm−1) νmax: 2943, 1708, 1647, 1611, 1599, 1494, 1468, 1455, 1425, 1359, 1314, 1292, 1258, 1178, 1119, 1023, 976, 936, 885, 831, 816, 776, 752; 1H NMR (400 MHz, CDCl3) δ 7.66–7.59 (m, 2H

• aldehyde 4 (562 mg, 41%) as needles; mp 94–96 °C; Rf 0.35 (EtOAc/petrol 1:1); IR (film, cm−1) νmax: 2942, 1712, 1614, 1581, 1495, 1472, 1260, 1190, 1177, 1122, 1096, 1064, 1019, 815, 785, 755; 1H NMR (400 MHz, CDCl3) δ 9.44 (t, J = 1.0 Hz, 1H), 7.69–7.62 (m, 2H), 7.36–7.28 (m, 3H), 7.20 (dd, J = 7.5, 1.0

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

• -linear optical properties, switching with two-photon absorption of near-IR wavelengths [3][27]. This could open the way to laser-storage devices and to application in biological systems, where longer wavelengths are preferred due to improved tissue penetration [28]. When the push–pull character is not so

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

• by DME, DMSO or acetone diminished the product yields (Table 1, entries 7–9). The reactivity of acridinium PC1 was superior to that of other photocatalysts, including 4-CzlPN (PC2) and [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 (PC3) (Table 1, entries 10 and 11). Attempts to increase the temperature of the process

Highly distinguishable isomeric states of a tripodal arylazopyrazole derivative on graphite through electron/hole-induced switching at ambient conditions

• Himani Malik,
• Sudha Devi,
• Debapriya Gupta,
• Ankit Kumar Gaur,
• Sugumar Venkataramani and
• Thiruvancheril G. Gopakumar

Beilstein J. Org. Chem. 2025, 21, 1496–1507, doi:10.3762/bjoc.21.112

• tapping mode and an ATM300 from RHK Technology, respectively. Aluminum-coated silicon cantilevers from Nanosensors (PPP-NCHR) were used as AFM probes. The force constant and resonance frequency of the cantilevers during the imaging were 30–34 N/m and ≈300 kHz, respectively. A Pt/Ir (80:20) tip was

Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides

• Nadezhda M. Metalnikova,
• Nikita S. Antonkin,
• Tuan K. Nguyen,
• Natalia S. Soldatova,
• Alexander V. Nyuchev,
• Mikhail A. Kinzhalov and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110

• spectrum of the crude mixture (Supporting Information File 1, Figure S4). Despite its higher reductive potential, fac-Ir(ppy)3 gave a lower yield of 26% for 2aa compared to [Ru(bpy)3](PF6)2 (Table 1, entry 3). Inspired by the first positive results, we tested various cyanoarene-based catalytic systems

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

• by the same research group [65][66], the Ir catalyst initially interacts through hydrogen bonds with the quinolone substrate 84, and then upon irradiation, energy transfer occurs to the unbound ketone which enantioselectively reacts with the bound quinolone. Unfortunately, investigations of the

• reduction of the Ni(II) pre-catalyst) via oxidative addition, radical coupling and reductive elimination. The last step is a single-electron transfer between the resulting Ir(II) and Ni(I) complexes, regenerating the active catalysts and closing the two cycles. In 2021, Romanov-Michailidis and Knowles et al

• from the photoexcited Ir complex, Giese-type addition of the resulting triplet diradical 164 to the electron-deficient alkene, intersystem crossing generating a singlet diradical 166 and intramolecular radical recombination. In 2022, Bull and colleagues disclosed an unprecedented synthesis of 3-aryl-3

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• the photocatalyst [Ir(dF(CF3)ppy)2(4,4'-d(CF3)bpy)]PF6 in combination with a base (NBu4OP(O)(OBu)2) (Scheme 1) [59]. The generation of amidyl radical 5 involved a stepwise PCET process catalyzed by the combined effect, in the presence of photocatalyst and the base. Subsequently, amidyl radical 5

• radical anion 15 was reduced by the photocatalyst Ir(Fppy)3 from the reagent 11. The resulting anion 14 underwent aromatization to release a nitrile anion, subsequently yielding product 12. This strategy also successfully produced products 16 and 17 with yields of 85% and 56%, respectively, from

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-aminoalkyl radicals generated from tertiary arylamines using photoredox catalysis (Scheme 13) [9]. In this system, Ir[dF(CF3)ppy]2(dtbbpy)PF6 was used as a photosensitizer to trigger the α-C–H activation of N,N-dimethylaniline, generating an alkyl radical under 30 W blue LED (454 nm) irradiation

• -transfer (SET) process occurred efficiently under blue LED irradiation in the presence of Ir[dF(CF3)ppy]2(dtbbpy)PF6 as the photocatalyst. This was followed by deprotonation and radical migration, yielding α-aminoalkyl radical A, which added to the intramolecular C=C bond of N,N-dimethylaniline to produce

• carbocyclization with diethyl malonate, yielding fluorinated pyrroloquinazolinones in acceptable to high yields [11]. The reaction was conducted in an undivided cell with a carbon cloth anode and a platinum (Pt) cathode, using K2CO3 (10 mol %) as the base, Ir(ppy)3 (3 mol %) as the photocatalyst, and an equivalent

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

• -workers (2022) functionalized Weinreb amides through organophotocatalytic N–O cleavage via 114 and 115 to give the corresponding primary amides 111–113 in good yields (Scheme 34) [27]. Xie and co-workers (2022) synthesized cinnamamide 83 mediated by [Ir(dF(CF3)ppy)2(dtbbpy)]PF6 (PC-1) as photocatalyst

Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts

• Valentina Benazzi,
• Arianna Bini,
• Ilaria Bertuol,
• Mariangela Novello,
• Federica Baldi,
• Matteo Hoch,
• Alvise Perosa and
• Stefano Protti

Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84

• (whose EREDonset value were in the range −1.60 and −1.92 V vs Ag/AgCl, a set comparable to that reported in the literature for fac-Ir(ppy) [37], which was effectively used in the photoredox-catalyzed reduction of sulfonium salts [29]) and derivatives 1a–d (EAr3S+/Ar3S• = −1.35 to −1.46 V vs Ag/AgCl; see

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• into the near-IR (λem = 780 nm, ϕ = 0.8% in toluene). While the ϕ of TTM-TTM is low, no photoluminescence has been reported for PTM-PTM. ΔEST of TTM-TTM is at −1.22 kcal mol−1 indicating a singlet ground state as well; however, the value is larger than for PTM-PTM, requiring heating to observe

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

• request/cif. Supporting Information File 6: ORTEP diagram of compound 31, synthetic procedures, IR, 1H, 13C, 19F and 2D NMR spectra of compounds 2, 5, 6, 24–28 and 30–32. Supporting Information File 7: Crystallographic information file of compound 31. Supporting Information File 8: Checkcif file for

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

• achieved selective synthesis of either enantiomer of a target product by controlling the reaction duration (Scheme 13) [42]. When performing the asymmetric intermolecular allylic amination of 6-hydroxyisoquinoline (49) with tert-butyl(1-phenylallyl)carbonate ((rac)-50) using an Ir catalyst derived from [Ir

• 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

• cycloaddition reactions with substituted furans as diene component to produce the corresponding epoxy-cycloaddition adducts. The authors developed an Ir/Sc tandem catalytic reaction to convert these adducts into polysubstituted 3-haloisoquinolines 99 in one pot. After obtaining isoquinoline compounds 99 with

Dicarboxylate recognition based on ultracycle hosts through cooperative hydrogen bonding and anion–π interactions

• Wen-Hui Mi,
• Teng-Yu Huang,
• Xu-Dong Wang,
• Yu-Fei Ao,
• Qi-Qiang Wang and
• De-Xian Wang

Beilstein J. Org. Chem. 2025, 21, 884–889, doi:10.3762/bjoc.21.72

• . Synthesis of ultracycles. Supporting Information Supporting Information File 4: Experimental details and characterization data (including 1H NMR, 13C NMR, IR, and HRMS of precursor compounds and ultracycles, X-ray data for B4aH, theoretical calculations, and NMR titration data). Funding Financial support

Data accessibility in the chemical sciences: an analysis of recent practice in organic chemistry journals

• Sally Bloodworth,
• Cerys Willoughby and
• Simon J. Coles

Beilstein J. Org. Chem. 2025, 21, 864–876, doi:10.3762/bjoc.21.70

• about many standard formats [73]. Open formats in NMR, mass spectrometry, UV–vis-, IR, and Raman spectroscopy have been recently reviewed [74]. Often a very simple first step is to export coordinate spectroscopic data to CSV, and there are numerous online tools for conversion of proprietary to open file

• community risks becoming left behind without urgent cultural change. Journal data policies for the study timeframe, 01 February – 31 March 2023. ‘All data’ refers to: spectroscopic data (NMR, IR, UV–vis, Raman, circular dichroism and mass spectrometry), chromatography (GC, HPLC, SEC), physical data (m.p

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

• demonstrated the efficient sensitization of an alkene-containing four boron substituents using Ir(ppy)3 as a suitable sensitizer in the presence of styrene, indicating a prominent role of the adjacent p-orbital [51]. While simple alkenylboronic esters have been employed as triplet diradical quenchers to

• interactions to achieve directionality (E→Z), synonymous with conventional photocatalyzed isomerization processes [19], it serves as a rapid reaction probe to support sensitization via the generation of a photostationary state equilibrium. The use of Ir(ppy)3 (Table 1, entry 1), an efficient sensitizer for the

Acyclic cucurbit[n]uril bearing alkyl sulfate ionic groups

• Christian Akakpo,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 717–726, doi:10.3762/bjoc.21.55

• and 150 or 100 MHz for 13C. Melting points were measured on a Meltemp apparatus in open capillary tubes and are uncorrected. IR spectra were measured on a Thermo Nicolet NEXUS 670 FT/IR spectrometer by attenuated total reflectance (ATR) and are reported in cm−1. Mass spectrometry was performed using a

• high vacuum to yield C1 as a white solid (0.3444 g, 68% yield). Mp > 300 °C; IR (ATR, cm−1): 3456 (w), 1720 (m), 1472 (m), 1378 (w), 1226 (m), 1101 (s), 1023 (m), 972 (w), 790 (w); 1H NMR (400 MHz, D2O) 6.71 (s, 4H), 5.67 (d, J = 15.4 Hz, 2H), 5.57 (d, J = 15.8 Hz, 4H), 5.46 (d, J = 8.9 Hz, 2H), 5.42

Asymmetric synthesis of fluorinated derivatives of aromatic and γ-branched amino acids via a chiral Ni(II) complex

• Maurizio Iannuzzi,
• Thomas Hohmann,
• Michael Dyrks,
• Kilian Haoues,
• Katarzyna Salamon-Krokosz and
• Beate Koksch

Beilstein J. Org. Chem. 2025, 21, 659–669, doi:10.3762/bjoc.21.52

• (HREIMS) were measured on a MAT 711 (Varian MAT, Bremen, Germany). Electron energy for EI was set to 70 eV. Infrared spectra (IR) were measured on an ALPHA II (Bruker, Billerica, USA) spectrometer. Characteristic absorption bands are given in wave numbers (cm−1). Qualitative thin-layer chromatography (TLC

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

• terminus. In search of complementary approaches, other transition metals including W [9], Mo [10], Ru [11][12], Rh [13][14][15], and Ni [16][17] have been explored. Among these alternatives, Ir catalysis emerged as a particularly powerful complement to Pd catalysis. The field of iridium-catalyzed allylic

• phosphoramidite ligands significantly advanced this field, with contributions from numerous research groups including Hartwig, Helmchen, Carreira, Alexakis, and You [19]. In general, soft nucleophiles that typically possess conjugate acids with pKa values less than 25 have been utilized in most Pd and Ir

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

• for the formation of intermediates. Gao et al. studied the generation of metal acetylide A by IR spectroscopy [65]. When subsequent additions of 1 equiv FeCl3 were made in a solution of alkyne and TMG, the C–H stretch peak at 3277 cm−1 started to decrease as the temperature increased from 30 to 100 °C

Organocatalytic kinetic resolution of 1,5-dicarbonyl compounds through a retro-Michael reaction

• James Guevara-Pulido,
• Fernando González-Pérez,
• José M. Andrés and
• Rafael Pedrosa

Beilstein J. Org. Chem. 2025, 21, 473–482, doi:10.3762/bjoc.21.34

• –240 mesh). Chiral HPLC analysis was performed using different chiral columns. IR spectra were recorded on an FTIR instrument. High-resolution mass spectra were performed by positive electrospray ionization using a quadrupole-time-of-flight detector (ESI+-Q-TOF) instrument. All compounds were purchased

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

• -tetrafluorobenzene as an internal standard. Isolated yields are given in parentheses. A: Background and iR drop-corrected CVs of 5 mM 4a at different scan rates (solvent: HFIP, working electrode: glassy carbon, supporting electrolyte: 0.1 M TBA-BF4). B: Plot of the peak current densities (jp) vs v0.5. C

Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• 1,2-benzoquinone and o-chloroanil, respectively [1][25]. The structures of compounds 7 and 8 obtained by methods A and B were confirmed by 1H NMR, IR spectroscopy and mass spectrometry (Supporting Information File 2). A distinctive feature of the 1H NMR spectra of 7 in CDCl3 is the signal of the

• and DMSO-d6. The signals were referenced to the signals of residual proton signals of corresponding deutero-solvents. IR spectra were recorded on a Varian Excalibur 3100 FTIR instrument using the attenuated total internal reflection technique. Mass spectra were obtained on a Finnigan Mat Incos 50

• , 98%, Alfa Aesar) and tetrachloro-o-benzoquinone (o-chloranil, 3) (97%, ACROS organics) were used as the starting reagents. NMR and IR spectra were recorded on the equipment of the Center for Collective Usage “Molecular Spectroscopy” of Southern Federal University. X-ray diffraction study The unit

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

• IR spectra of compounds 5a–6d containing an alkoxyfuropyran fragment shows that in the case of methyl esters 5a, 6a, and 6c the absorption band of the alkoxycarbonyl function is shifted to a lower frequency region (1714–1721 cm−1), while ethyl esters 5b, 6b, and 6d are characterized by higher

• . In turn, in the IR spectra (KBr) of compounds 7a–f, absorption bands of the ester fragment in the region of 1714–1750 cm−1 and absorption bands of the carbonyl group of the amide fragment in the region of 1674–1688 cm−1 are observed, which suggests the existence of these compounds in the solid phase

• expands the possibilities of further transformation and obtaining new compounds on their basis. Experimental General information IR spectra were recorded on a Shimadzu IRPrestige-21 FT-IR spectrometer for samples in KBr pellets over 400–4000 cm−1 range. The electronic absorption spectra were recorded on a

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

• and mechanistic investigations of the near-IR-photocatalyzed aza-Henry reaction, the authors have proposed either a single-electron transfer or an energy transfer mechanism. Additionally, the reaction displayed an unexpected sensitivity to the light wavelength used. Employing a higher-energy light