Rhodium-catalysed connective synthesis of diverse reactive probes bearing S(VI) electrophilic warheads

• Scott Rice,
• Julian Chesti,
• William R. T. Mosedale,
• Megan H. Wright,
• Stephen P. Marsden,
• Terry K. Smith and
• Adam Nelson

Beilstein J. Org. Chem. 2025, 21, 1924–1931, doi:10.3762/bjoc.21.150

• isolated and structurally characterised (using, where appropriate, HMBC, COSY and nOe NMR methods; see Figure 3). In general, the yields of these products were rather low, which may stem from poor (co-)substrate solubility in some cases; and/or competitive O–H insertion into adventitious water. On the

• ). Outcomes of reactions between α-diazoamide substrates and co-substrates. Supporting Information Supporting Information File 40: Experimental part and NMR spectra of synthesised compounds. Acknowledgements We thank Dan Cox, Samuel Liver, Chris Arter, Jeanine Williams, Mark Howard, Alex Heyam, Lawrence

Synthesis of N-doped chiral macrocycles by regioselective palladium-catalyzed arylation

• Shuhai Qiu and
• Junzhi Liu

Beilstein J. Org. Chem. 2025, 21, 1917–1923, doi:10.3762/bjoc.21.149

• introduced. In contrast, when bulky 3,5-bis(trifluoromethyl)phenyl groups were introduced, only inherent chiral macrocyclic products (MC3) were obtained in high yield. Their molecular structures are unambiguously characterized by NMR, mass spectra and X-ray crystallographic characterization. In addition

• characterized by NMR spectroscopy, mass spectrometry, and X-ray crystallography. Single crystals suitable for X-ray diffraction measurements of compounds 3a, MC2, and MC3 were successfully obtained to reveal their molecular structures. In the crystal structure of 3a (Figure 2a), the two pyrene units are nearly

Synthesis, biological and electrochemical evaluation of glycidyl esters of phosphorus acids as potential anticancer drugs

• Almaz A. Zagidullin,
• Emil R. Bulatov,
• Mikhail N. Khrizanforov,
• Damir R. Davletshin,
• Elvina M. Gilyazova,
• Ivan A. Strelkov and
• Vasily A. Miluykov

Beilstein J. Org. Chem. 2025, 21, 1909–1916, doi:10.3762/bjoc.21.148

• as thick liquids with good yields (44–67%) and purity. The structures of glycidyl esters of phosphorus acids 1–3 were confirmed by 31P, 1H NMR, IR spectroscopy, and elemental analysis (see Experimental part for additional information). The 31P{1H} NMR spectrum of diglycidyl methylphosphonate (1

• ) shows a singlet at +32 ppm; for diglycidyl methylphosphate (2) and triglycidyl phosphate (3) also a singlet in the region 0–1 ppm is observed, despite the presence of a chiral carbon atom in the oxirane fragment. In the 1H NMR spectra of esters 1–3 the characteristic signals of the oxirane fragment at

• 2.41–3.24 ppm and the POCH2- fragment at 3.66–4.36 ppm can be observed. The NMR data for the glycidyl esters of phosphorus acids 1–3 are comparable to those of related compounds. Biological activity of glycidyl esters of phosphorus acids To evaluate the biological activity of diastereomeric mixtures of

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• extracted three times with CH2Cl2. The combined organic layers were dried over Na2SO4, filtered and concentrated under vacuum. Yields were calculated on the reaction crude by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene as internal standard. In the case of the large-scale reaction the crude was

• /cm2), total charge 2.2 F/mol, dry DMF (0.125 M). Yields reported are isolated yields. Reactions were performed on a 0.5 mmol scale. Continuous flow synthesis of piperazine 2a. The yield was determined by 1H NMR spectroscopy using 1,3,5-trimethoxybenzene as internal standard. Reactions were performed

• procedures and physical data for the new compounds, copies of 1H and 13C NMR spectra of the prepared compounds. Acknowledgements The authors thank Prof. A. Puglisi (Università degli Studi di Milano) for valuable discussions. For the single-crystal X-ray diffraction analysis the Unitech COSPECT (Università

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

• leaving group and activated, electron-poor dipolarophiles has been reported [31][32]. Treatment of aldehyde 4 with hydroxylamine in toluene at 60 °C for 1–3 h resulted in loss of the aldehyde as judged by 1H NMR spectroscopy of the crude mixture. When this was carried out in the presence of N

• -methylmaleimide with the mixture being heated under reflux for 3–4 h, we were pleased to obtain the spirooxindole product 5, which was formed as a mixture of stereoisomers (Scheme 3). The ratio of isomers was determined by 1H NMR spectroscopy and the major isomer could be isolated after careful column

• fumarate was also successful and gave a mixture of the stereoisomeric cycloadducts 7 (Scheme 5). The yield was high and three inseparable stereoisomers could be detected by 1H NMR spectroscopy. In each case we assume that the methyl ester groups are trans to one another due to the expected concerted nature

Systematic pore lipophilization to enhance the efficiency of an amine-based MOF catalyst in the solvent-free Knoevenagel reaction

• Pricilla Matseketsa,
• Margret Kumbirayi Ruwimbo Pagare and
• Tendai Gadzikwa

Beilstein J. Org. Chem. 2025, 21, 1854–1863, doi:10.3762/bjoc.21.144

• respective isocyanate in acetonitrile at 80 °C; KSU-1 reacted with isopropyl, tert-butyl, n-hexyl, and tetradecyl isocyanate to generate KSU-1iPr and KSU-1t-Bu, KSU-1n-Hex, and KSU-1C14, respectively. Successful post synthetic reaction was observed by proton nuclear magnetic resonance (1H NMR) spectroscopy

• at the hydroxy. To prevent excessive reaction at the amine, both reactions were stopped at 2 hours. Aside from 1H NMR, the independent functionalization of KSU-1 with isocyanates was also confirmed by conducting electrospray ionization mass spectrometry (ESI–MS) on samples of the MOF products

• , diluted in CDCl3 and conversions were determined by analyzing the 1H NMR specta of the samples (Figure 3). The results showed a general increase in catalytic efficiency as we increased the lipophilicity of the MOF pores. However, the observed differences in conversion between the lipophilicized catalysts

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

• of the metastable isomer [5][6][7], thus they are also important factors to consider when choosing the solvent and the concentration of the solution. The half-life can be extrapolated by monitoring the photoswitch in the metastable form over time by various spectroscopic methods (UV–vis, NMR) in the

• presence of H-bond acceptors [102][104][107]. The presence and the nature of the H-bond can be identified by 1H NMR spectroscopy since the N–H proton has a characteristic chemical shift depending on the H-bond acceptor [101]. Arylhydrazones based on pyridine have been intensively studied since the H-bond

Fe-catalyzed efficient synthesis of 2,4- and 4-substituted quinolines via C(sp²)–C(sp²) bond scission of styrenes

• Prafull A. Jagtap,
• Manish M. Petkar,
• Vaishnavi R. Sawant and
• Bhalchandra M. Bhanage

Beilstein J. Org. Chem. 2025, 21, 1799–1807, doi:10.3762/bjoc.21.142

• -disubstituted quinolone 3a along with 36% of 4-substituted quinolone 3a′ were observed during GC and GC–MS analysis, and the structures of both quinoline moieties were identified by 1H and 13C NMR spectroscopy. Encouraged by this result, we next examined the feasibility of the reaction with methanol as solvent

[3 + 2] Cycloaddition of thioformylium methylide with various arylidene-azolones in the synthesis of 7-thia-3-azaspiro[4.4]nonan-4-ones

• Daniil I. Rudik,
• Irina V. Tiushina,
• Anatoly I. Sokolov,
• Alexander Yu. Smirnov,
• Alexander R. Romanenko,
• Alexander A. Korlyukov,
• Andrey A. Mikhaylov and
• Mikhail S. Baranov

Beilstein J. Org. Chem. 2025, 21, 1791–1798, doi:10.3762/bjoc.21.141

• were formed, and the transformation rate was extremely low. This outcome may be attributed to the electron-acceptor properties of the oxygen atom, which likely disrupt the cycloaddition process. NMR analysis confirmed that each heterocyclic ring formed products exclusively as a single diastereomer

• , with only trace amounts (or none) of the alternative form (dr >19:1). Moreover, comparison of NMR data within each series of heterocycles allowed us to reliably assert that the same isomer was observed in each specific group of substances. However, NMR data alone could not unambiguously assign the

• . Optimization of the reaction conditionsa. Supporting Information Supporting Information File 22: Experimental part, X-ray data and copies of NMR spectra. Acknowledgements A.A. Korlyukov and A.R. Romanenko are grateful to Ministry of Science and Higher Education of the Russian Federation (Contract No. 075

Synthesis of chiral cyclohexane-linked bisimidazolines

• Changmeng Xi,
• Qingshan Sun and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1786–1790, doi:10.3762/bjoc.21.140

• of chiral cyclohexane-linked bisimidazoline ligands. Supporting Information Supporting Information File 20: Analytical data and copies of 1H and 13C NMR spectra of compounds 2 and 4, copies of HRMS spectra of unknown compounds 4 and 5. Funding This research was supported by the National Key R & D

Unique halogen–π association detected in single crystals of C–N atropisomeric N-(2-halophenyl)quinolin-2-one derivatives and the thione analogue

• Mai Uchibori,
• Nanami Murate,
• Kanako Shima,
• Tatsunori Sakagami,
• Ko Kanehisa,
• Gary James Richards,
• Akiko Hori and
• Osamu Kitagawa

Beilstein J. Org. Chem. 2025, 21, 1748–1756, doi:10.3762/bjoc.21.138

• their spectral data, copies of 1H and 13C{1H} NMR charts of compounds 1–4, chiral MPLC and HPLC chart in compounds 1a,b, 2a, evaluation of rotational barriers of compounds 1a,b, and X-ray crystal data of rac-1a,b, (P)-1a,b, rac-2a (check CIF). Funding This work was partly supported by JSPS KAKENHI (C

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

• proposed mechanism of product 7 formation. Electrochemical oxidation of protected amino alcohol 2d to ester 3d. Supporting Information Supporting Information File 8: Experimental procedures, characterization data and copies of NMR spectra. Funding This project has received funding from the European

Convenient alternative synthesis of the Malassezia-derived virulence factor malassezione and related compounds

• Karu Ramesh and
• Stephen L. Bearne

Beilstein J. Org. Chem. 2025, 21, 1730–1736, doi:10.3762/bjoc.21.135

• removal of the benzyl groups by hydrogenation was problematic (vide infra). The NMR spectral characteristics of the resulting material were identical to those reported for malassezione either isolated from cultures [11][20] or prepared from the isonitrile [18]. To further demonstrate the utility of the

• . Concentration under reduced pressure refers to the removal of solvent using a rotary evaporator, unless stated otherwise. All NMR spectra were obtained using a Bruker ASCEND 400 MHz spectrometer at the Nuclear Magnetic Resonance Research Resource (NMR-3, Dalhousie University). Chemical shifts (δ in ppm) for

• reporting NMR spectral data are: bm, broad multiplet; bs, broad singlet; bt, broad triplet; d, doublet; dd, doublet of doublets; m, multiplet; q, quartet; s, singlet; and t, triplet. High-resolution (HR) electrospray ionization (ESI) mass spectra (MS) were collected using a Bruker microTOF Focus orthogonal

3,3'-Linked BINOL macrocycles: optimized synthesis of crown ethers featuring one or two BINOL units

• Somayyeh Kheirjou,
• Jan Riebe,
• Maike Thiele,
• Christoph Wölper and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2025, 21, 1719–1729, doi:10.3762/bjoc.21.134

• that we reacted either (S)- or (R)-H-2 with the dichloride (S)-iPr-62 to give the diastereomeric macrocycles (S,S)-HiPr-M22 and (R,S)-HiPr-M22 in 73/49% yield, respectively. The 1H NMR spectra of the C2-symmetric derivatives (S,S)-H/iPr-M22 (see Figure 8a/b) differ most significantly in the splitting

• -62; ii) Me/(S)-H/(R)-H/iPr-2 (1.0 equiv), Cs2CO3 (3.2 equiv), CH3CN, 80 °C. 1H NMR spectra of a) (S,S)-H-M22, b) (S,S)-iPr-M22, c) (S,S)-HiPr-M22, and d) (R,S)-HiPr-M22 (all: 400 MHz, CDCl3, 298 K, for labelling see Figure 7). Supporting Information Synthetic procedures and NMR spectra for all new

Structural analysis of stereoselective galactose pyruvylation toward the synthesis of bacterial capsular polysaccharides

• Tsun-Yi Chiang,
• Mei-Huei Lin,
• Chun-Wei Chang,
• Jinq-Chyi Lee and
• Cheng-Chung Wang

Beilstein J. Org. Chem. 2025, 21, 1671–1677, doi:10.3762/bjoc.21.131

• define the stereochemistry of pyruvate ketals as either R- or S-configurations. Typically, S-configuration exhibits 13C NMR shifts between δ 17–24 ppm and 1H NMR shifts δ 1.60–2.10 ppm, whereas the R-configuration shows 13C shifts downfield at δ 24-27 ppm and 1H shifts at δ 1.40–2.00 ppm [19][20][21][22

• (4) was treated with methyl pyruvate in acetonitrile (Table 1, entry 1) to produce pyruvylated galactose 5. The use of polar solvents such as acetonitrile promotes the formation of the more thermodynamically favorable diastereomer [21][28][29]. For the property of the R-isomer of 5, the 13C NMR

• 1H-13C HSQC NMR analysis was performed to further characterize the structure of 14 (see Supporting Information File 1). 1H NMR coupling constants revealed the presence of one α-glycosidic bond at C1′ (δ 5.49, J = 4.3 Hz) and two β-glycosidic bonds at C1 (δ 4.22, bs) and C1′′ (δ 5.56, J = 3.8 Hz). The

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

• ), K2CO3 (0.181 mmol, 0.125 equiv), H3PO2 (0.725 mmol, 0.5 equiv.), neat, 110 °C. Yield was determined by NMR, isolated yield in parentheses. a48 h. Reaction profile and DFT energies of intermediates and transition states. M062X functional with the basis set 6-311+G(d,p) on the model reaction between

• K2CO3/H3PO2 reducing system. Cation influence in acidic and neutral conditions.a Supporting Information Supporting Information File 60: Optimization details, experimental procedures, calculation details and copies of NMR and HRMS spectra. Funding This work was supported by the RSF (Grant № 24-73-00162

• ). The NMR data were collected using the equipment of the Center for molecular composition studies of INEOS RAS with financial support from the Ministry of Science and Higher Education of the Russian Federation (Contract No. 075-00276-25-00).

Formal synthesis of a selective estrogen receptor modulator with tetrahydrofluorenone structure using [3 + 2 + 1] cycloaddition of yne-vinylcyclopropanes and CO

• Jing Zhang,
• Guanyu Zhang,
• Hongxi Bai and
• Zhi-Xiang Yu

Beilstein J. Org. Chem. 2025, 21, 1639–1644, doi:10.3762/bjoc.21.127

• synthesis of 1. Formal synthesis of SERMs molecule VI. Supporting Information Supporting Information File 54: Experimental procedures, product characterizations, and copies of the 1H and 13C NMR spectra. Acknowledgements We thank Zhiqiang Huang for testing the stoichiometric Heck reaction in this

Synthesis of optically active folded cyclic dimers and trimers

• Ena Kumamoto,
• Kana Ogawa,
• Kazunori Okamoto and
• Yasuhiro Morisaki

Beilstein J. Org. Chem. 2025, 21, 1603–1612, doi:10.3762/bjoc.21.124

• and twisted, which caused the different chiroptical properties. Experimental General 1H and 13C NMR spectra were recorded on a JEOL JNM ECZ-500R instrument at 500 and 125 MHz, respectively. Samples were analyzed in CDCl3, and the chemical shift values were expressed relative to Me4Si as an internal

• %) as a light yellow solid. Rf = 0.73 (CHCl3/hexane = 1:2 v/v); 1H NMR (CDCl3, 500 MHz) δ 1.20 (s, 42H), 2.97–3.08 (m, 4H), 3.49–3.53 (m, 4H), 7.06 (s, 2H), 7.21 (s, 2H), 7.37–7.40 (m, 4H), 7.60–7.62 (m, 2H), 7.70–7.73 (m, 2H) ppm; 13C NMR (CDCl3, 125 MHz) δ 11.48, 18.84, 32.32, 32.57, 92.38, 93.65

• by recyclable HPLC (CH2Cl2 as an eluent) to afford (Sp)-4 (11.8 mg, 0.025 mmol, 45%) as a light yellow solid. Rf = 0.43 (CHCl3/hexane = 1:2 v/v). 1H NMR (CDCl3, 500 MHz) δ 2.98–3.09 (m, 4H), 3.39 (s, 2H), 3.43–3.55 (m, 4H), 7.09 (s, 2H), 7.21 (s, 2H), 7.37–7.41 (m, 4H), 7.62–7.65 (m, 2H), 7.70–7.73

3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles

• Julia I. Pavlenko,
• Pavel A. Sakharov,
• Anastasiya V. Agafonova,
• Derenik A. Isadzhanyan,
• Alexander F. Khlebnikov and
• Mikhail S. Novikov

Beilstein J. Org. Chem. 2025, 21, 1595–1602, doi:10.3762/bjoc.21.123

• diastereomer and characterized by NMR and HRMS data. Compound 13 is likely formed from aziridine 14 via the N→N acetyl group transfer and subsequent isomerization of the acetylaziridinyl substituent. The constitutional isomer of indole 9a, indole 15, having a nucleophilic reaction center in the β-position of

• charge by the joint Cambridge Crystallographic Data Centre. Supporting Information File 24: Full experimental details, characterization data and copies of NMR spectra for all new compounds. Acknowledgements This research was carried out using resources of the Centre for Magnetic Resonance, the Research

Chemical synthesis of glycan motifs from the antitumor agent PI-88 through an orthogonal one-pot glycosylation strategy

• Shaokang Yang,
• Xingchun Sun,
• Hanyingzi Fan and
• Guozhi Xiao

Beilstein J. Org. Chem. 2025, 21, 1587–1594, doi:10.3762/bjoc.21.122

• was obtained in 60% overall yield from 20 via sequential global deprotection of the Bn, Cbz, and Bz groups. The structures of the synthetic glycan motifs 1–4 were supported by their 1H and 13C NMR spectra and MALDI–TOF as well as ESI mass spectra. In particular, the anomeric proton signals of 1–4 were

• highlighted in the 1H NMR spectra of synthetic glycans motifs 1–4 (see Supporting Information File 1). Conclusion In summary, the monophosphorylated glycan motifs 1–4 from PI-88 have been collectively synthesized via a one-pot orthogonal glycosylation strategy on the basis of glycosyl PVB, which avoids such

• -pot synthesis of glycans 1 and 2. One-pot synthesis of glycan 3. One-pot synthesis of glycan 4. Supporting Information Supporting Information File 22: Experimental procedures and spectral data for all new compounds including 1H NMR, 13C NMR, and HRMS. Funding The financial support from the National

pH-Controlled isomerization kinetics of ortho-disubstituted benzamidines: E/Z isomerism and axial chirality

• Ryota Kimura,
• Satoshi Ichikawa and
• Akira Katsuyama

Beilstein J. Org. Chem. 2025, 21, 1568–1576, doi:10.3762/bjoc.21.120

• bond rotation was investigated by variable temperature nuclear magnetic resonance (VT-NMR) spectra (Figure 3) in DMSO-d6 [27]. In the case of the molecular form of amidine 1 (Figure 3a), the signals corresponding to the two methyl groups resulting from the amidine E/Z isomerism were observed separately

• not coalesced even at 383 K, indicating that the C–N bond rotation was sufficiently slow on the NMR time scale (Figure 3b). To separate each E/Z isomer, amidine 2 with two different substituents on the same nitrogen atom, was prepared, and racemic 2 was analyzed by reversed-phase high performance

• details, see Supporting Information File 1). The NMR and HPLC experiments clearly indicate that protonation of the amidine moiety increases the rotational barrier of the C–N bond, a result which is consistent with our DFT study. Since it was found that the E/Z isomers of amidine could be isolated as a TFA

Synthesis of an aza[5]helicene-incorporated macrocyclic heteroarene via oxidation of an o-phenylene-pyrrole-thiophene icosamer

• Yusuke Matsuo,
• Aoi Nakagawa,
• Shu Seki and
• Takayuki Tanaka

Beilstein J. Org. Chem. 2025, 21, 1561–1567, doi:10.3762/bjoc.21.119

• , along with decamer 3 (30%). High-resolution atmospheric-pressure-chemical-ionization time-of-flight mass-spectrometry (HR-APCI-TOF-MS) showed a molecular ion peak for 4 at m/z = 1479.4320 (calcd for C100H66N6S4, m/z = 1479.4305). The 1H NMR spectrum of 4 in acetone-d6 exhibited two NH signals at 9.07

• and evaporation of the solvent to afford a crude product, which was recrystallized from THF to give 5 in 58% yield. Due to its poor solubility in common organic solvents, the 1H NMR spectrum could only be recorded in DMSO. At room temperature, the 1H NMR spectrum in DMSO-d6 exhibited broad signals in

• the range of 6–7 ppm, which sharpened significantly at 100 °C (Figure 3). The 1H NMR spectrum at 100 °C displayed distinct signals at 12.01 and 11.54 ppm due to NH protons, a singlet for the pyrrole β-protons at 6.97 ppm, and doublets for the thiophene β-protons at 6.26 and 5.95 ppm. HR-APCI-TOF-MS

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

• form two new carbon–heteroatom bonds in a 1,2,4-oxadiazoline ring through both variants of orbital overlap. It should be noted that, in this case, NMR spectroscopy is not applicable to assign the product structure due to the presence of only quaternary carbon atoms in the tetrasubstituted 1,2,4

• -substituted aromatic group, we have observed atropoisomerism (Figure 2) what is manifested by the appearance of a second set of signals in their NMR spectra. As the previously studied similar structures (Y = N–R) [22], products 5b and 5d (Y = O) were formed through the addition of a dipole molecule, resulting

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• Supporting Information File 1. 1H, 13C, and 19F NMR spectra were collected on a Bruker Avance 300 MHz or Bruker Avance-III 500 MHz instrument and processed by MestReNova v. 14.3.1-31739 (2022) MestreLab Research S. L. GC analyses were performed on an HP 5890 N Series II instrument with Restek RTX®-50

• . Its purification was performed by vacuum distillation (18–20 mmHg, 114–116 °C) and stored under argon before subsequent use. The purity (>99.99%) was checked by 1H and 13C NMR spectroscopy. 1H NMR (300 MHz, CDCl3, TMS) δ 5.10 (s, 1H, CH), 4.71 (s, 1H, CH), 4.05 (d, J = 7.3 Hz, 1H, CH), 3.96 (t, J

• = 6.3 Hz, 1H, CH), 2.73–2.02 (m, 4H, CH2); 13C NMR (75 MHz, CDCl3, TMS) δ 200.3 (CO), 101.5 (CH), 73.1 (CH), 67.6 (CH2), 31.1 (CH2), 29.9 (CH2). The NMR data correspond to the published results. Methyl 4-methoxyvalerate and ethyl 4-ethoxyvalerate were prepared using the published method [47]. The

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

• oxidative state PC1* that interacts with morpholine (8a) to generate the corresponding aminium radical cation. To gain a better understanding of the process, the formation of the enaminone product 9a was monitored overtime by 1H NMR, which confirmed that the the reaction was complete within 2 h. Furthermore

• : Additional optimization details, mechanistic studies, experimental details, characterization data and NMR spectra for enaminones 9. Acknowledgements We would like to thank Prof. Jose Manuel Costa-Fernández for his help with the spectroscopic studies. Funding This work has received financial support from MCI