Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• recorded on a Bruker Avance III 500HD superconducting NMR spectrometer using DMSO-d6 as the solvent and tetramethylsilane (TMS) as the internal standard. Single crystals suitable for X-ray diffraction analysis were grown from a dichloromethane/n-hexane solvent system; diffraction data were collected on a

• final pure product, 5-(3-(9H-carbazol-9-yl)phenyl)-2-(p-tolyl)isoindoline-1,3-dione (1), was obtained as a solid in a yield of 1.36 g (90%). 1H NMR (500 MHz, DMSO-d6) δ 8.34 (s, 1H), 8.31(d, 1H), 8.27 (d, 2H), 8.13 (s, 1H), 8.07–7.98 (m, 2H), 7.84 (t, 1H), 7.74 (d, 1H), 7.53–7.42 (m, 4H), 7.33 (s, 4H

• ), 7.30 (d, 2H), 2.37 (s, 3H); 13C NMR (126 MHz, DMSO-d6) δ 167.23, 145.94, 140.78, 140.61, 138.29, 133.75, 133.11, 132.41, 131.58, 131.15, 129.34, 128.56, 127.85, 127.57, 127.08, 126.82, 126.05, 124.56, 123.30, 122.35, 121.02, 120.64, 110.24; EIMS (m/z): [M]+ calcd for C33H22N2O2, 478.1681; found

Synthesis of diaryl phosphates using phytic acid as a phosphorus source

• Kazuya Asao,
• Seika Matsumoto,
• Haruka Mori,
• Riku Yoshimura,
• Takeshi Sasaki,
• Naoya Hirata,
• Yasuyuki Hayakawa and
• Shin-ichi Kawaguchi

Beilstein J. Org. Chem. 2026, 22, 213–223, doi:10.3762/bjoc.22.15

• (SHIMADZU, Kyoto, Japan) and JMS GC-mate II (JEOL, Tokyo, Japan) instruments. The melting points were determined using a Q-200 differential scanning calorimeter (TA Instruments, New Castle, DE, USA). The NMR spectra were recorded in a deuterated solvent (D2O, methanol-d4 or dimethyl sulfoxide (DMSO)-d6

• )), and the residual solvent was set to the chemical shift reference for 1H NMR (H2O, δ 4.79 ppm; MeOH, δ 3.31 ppm; DMSO, δ 2.50 ppm). All NMR spectra were compared with those reported in previous studies [15][46][47][48] and found to be consistent with the references. The spectra are provided in

Streptoquinolines A and B, new antibacterial meroterpenoids produced by Streptomyces sp. TMPU-A0679

• Akiho Yagi,
• Hitomi Tomura,
• Ami Konno and
• Ryuji Uchida

Beilstein J. Org. Chem. 2026, 22, 185–191, doi:10.3762/bjoc.22.12

• and 1620–1680 cm−1 indicated the presence of hydroxy and carbonyl groups, respectively. Streptoquinoline A (1): The molecular formula of 1 was elucidated as C28H35NO6 based on HRESIMS measurements. The 13C NMR spectrum (in DMSO-d6) showed 28 signals, which were classified into five methyl carbons

• , seven sp3 methylene carbons, two sp3 methine carbons, two sp2 methine carbons, two sp3 quaternary carbons, two oxygenated sp3 quaternary carbons, five sp2 quaternary carbons, and three carbonyl carbons from an analysis of the HMQC spectrum. The 1H NMR spectrum (in DMSO-d6) exhibited signals

• . Streptoquinoline B (2): The molecular formula of compound 2 was elucidated as C28H35NO6 based on HRESIMS measurements. The 13C NMR and 1H NMR spectra (in DMSO-d6) of compound 2 showed chemical shift values that were almost identical to those of compound 1 (Table 2). Furthermore, 2D NMR experiments revealed similar

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• isotope effect observable as changes in the 13C NMR chemical shift [18][19]. DFT calculations were based on a truncated model (Figure 6a) containing the essential elements for intramolecular hydrogen bonding. The structure was considered both in vacuum as well as with DMSO or water as implicit solvents

• bond [21]. When measuring 13C NMR spectra in DMSO-d6 containing different D2O/H2O ratios, isotope effects were clearly observed at several positions (Figure 6c and Figure 6d), with a particularly pronounced upfield shift of the phenol ipso-carbon atom (C14, Δδexp = 0.21 ppm). This two-bond isotope

• ·HCl as a white solid (643 mg, 1.84 mmol, 74%). Rf (50% (EtOAc/EtOH 3:1 + 2% aqueous NH3)/n-heptane) 0.47; 1H NMR (600 MHz, DMSO-d6, δ) 10.24 (bs, 1H), 8.98 (bs, 2H), 7.38 (dd, J = 7.5; 1.7 Hz, 1H), 7.35 (s, 1H), 7.24 (td, J = 7.7; 1.7 Hz, 1H), 7.14 (s, 1H), 6.96 (dd, J = 8.2; 1.2 Hz, 1H), 6.85 (td, J

A new synthesis of Tyrian purple (6,6’-dibromoindigo) and its corresponding sulfonate salts

• Holly Helmers,
• Mark Horton,
• Julie Concepcion,
• Jeffrey Bjorklund and
• Nicholas C. Boaz

Beilstein J. Org. Chem. 2026, 22, 167–174, doi:10.3762/bjoc.22.10

• Scheme 5A, dimethyl sulfoxide (DMSO) did not react with the benzyl bromide and instead only returned the starting material. The addition of 1.2 equivalents of silver nitrate promoted the substitution of the benzyl bromide with DMSO to yield an alkoxysulfonium ion 8 [22]. Following substitution, the

• ) yields a mixture of regioisomers 3 and 7. Benzylic bromination of 4-bromo-2-nitrotoluene (3). A) Treatment of 4-bromo-2-nitrobenzyl bromide (6) with DMSO did not yield the alkoxysulfonium ion intermediate 8. B) Silver nitrate-mediated Kornblum oxidation yields 4-bromo-2-nitrobenzaldehyde (4) in fair

Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• and 13C NMR spectra were recorded on a Bruker Avance III 400 or JEOL JNM-ECZ600R spectrometer at 25 °C in chloroform-d1 or DMSO-d6. 1H NMR chemical shifts are expressed in parts per million (δ) relative to trimethylsilane (TMS) as a reference. Mass spectra were obtained with a Thermo Scientific

• . for C58H38N4O2Pt2, 1212.2343; found, 1212.2342; 1H NMR (400 MHz, DMSO-d6) δ 8.81 (d, J = 5.2 Hz, 2H), 8.41 (d, J = 8.0 Hz, 2H), 8.25 (t, J = 8.0 Hz, 2H), 8.14 (d, J = 8.0 Hz, 2H), 8.00–8.07 (m, 4H), 7.93 (d, J = 8.0 Hz, 2H), 7.85 (d, J = 8.4 Hz, 2H), 7.67–7.75 (m, 2H), 7.50–7.57 (m, 6H), 7.32 (dd, J

• = 1.2 and 8.4 Hz, 2H), 7.20–6.95 (m, 6H), 3.77 (s, 6H); 13C NMR (100 MHz, DMSO-d6) δ 164.1, 157.6, 155.0, 154.0, 150.8, 147.1, 142.2, 140.1, 137.6, 133.7, 130.7, 129.1, 128.5, 127.8, 127.2, 126.8, 126.7, 126.1, 125.0, 124.1, 123.6, 119.3, 119.2, 117.9, 113.4, 110.1, 109.5, 106.2, 56.3; IR(KBr) νmax

Symmetrical D–π–A–π–D indanone dyes: a new design for nonlinear optics and cyanide detection

• Ergin Keleş,
• Alberto Barsella,
• Nurgül Seferoğlu,
• Zeynel Seferoğlu and
• Burcu Aydıner

Beilstein J. Org. Chem. 2026, 22, 131–142, doi:10.3762/bjoc.22.6

• photophysical properties of the dyes. The sensitivity/selectivity properties of the dyes to anions were investigated in DMSO and aqueous media, revealing that the dyes were selectively responsive only to cyanide anions. Changes after interactions were determined through absorption spectra and color changes

• spectrometry methods (Figures S1–S10 in Supporting Information File 1). Optical properties of dyes Photophysical properties of dyes 2a–c were assessed in four different organic solvents with various polarities (DMSO, acetone, chloroform, and THF) via absorption spectra and DFT calculations (Table 2). Figure 2a

• −, HSO4−, and NO3−) in the form of the corresponding tetrabutylammonium (TBA) salt. Firstly, a titration study was conducted by the addition of 20 equiv of anions to dyes in organic solvent as DMSO (Figure 3). A significant response was only observed during the addition of cyanide. Upon addition of

Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene

• Dmitry N. Platonov,
• Alexander Yu. Belyy,
• Rinat F. Salikov,
• Kirill S. Erokhin and
• Yury V. Tomilov

Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2

• (methoxycarbonyl)cycloheptatriene 3 (pKa(DMSO) = 8.65) [20][21] with potassium tert-butoxide and subjected to reactions with electrophilic reagents. The reactions gave two primary products 4 and 5 (Scheme 1) through an attack to either the most available i-position or the most nucleophilic but sterically hindered

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

• (Scheme 30A) [125]. Decades later, Dolby demonstrated that a 70:30 E/Z mixture of precursors could be selectively converted into the pure E-alkenyl chloride 135 by treatment with NaOH in DMSO (Scheme 30B) [126]. Related strategies involving the addition of chlorine to alkenylsilanes or alkenylboranes

Competitive cyclization of ethyl trifluoroacetoacetate and methyl ketones with 1,3-diamino-2-propanol into hydrogenated oxazolo- and pyrimido-condensed pyridones

• Svetlana O. Kushch,
• Marina V. Goryaeva,
• Yanina V. Burgart,
• Marina A. Ezhikova,
• Mikhail I. Kodess,
• Pavel A. Slepukhin,
• Alexandrina S. Volobueva,
• Vladimir V. Zarubaev and
• Victor I. Saloutin

Beilstein J. Org. Chem. 2025, 21, 2716–2729, doi:10.3762/bjoc.21.209

• : 2479556), and 4dct (e, CCDC: 2479557) showing with the thermal ellipsoids at 50% probability. ORTEP view of compound 5ctc (a, CCDC: 2479558), 5ctt (b, CCDC: 2479559) showing with the thermal ellipsoids at 50% probability. The fragments of the 1H NMR spectra (400 MHz, DMSO-d6) of diastereomers 4acc (a

• ), 4аct (b), 4аtt (c), 4atc (d). Fragments of 1H NMR spectra (400 MHz, DMSO-d6) of hexahydrooxazolo[3,2-a]pyridin-5-ones 5ctc (a) and 5ctt (b). The reaction of ethyl trifluoroacetoacetate (1), acetone (2a) and 1,3- diaminopropan-2-ol (3). Three-component reaction of ethyl trifluoroacetoacetate (1), alkyl

Synthesis of new tetra- and pentacyclic, methylenedioxy- and ethylenedioxy-substituted derivatives of the dibenzo[c,f][1,2]thiazepine ring system

• Gábor Berecz,
• András Dancsó,
• Mária Tóthné Lauritz,
• Loránd Kiss,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2645–2656, doi:10.3762/bjoc.21.205

• . The pulse programs were taken from the Bruker software library (TopSpin 3.5) and full 1H and 13C assignments were achieved with widely accepted strategies. 1H assignments were accomplished using general knowledge of chemical shift dispersion with the aid of the 1H–1H coupling pattern. CDCl3 or DMSO-d6

Thiazolidinones: novel insights from microwave synthesis, computational studies, and potentially bioactive hybrids

• Luan A. Martinho,
• Victor H. J. G. Praciano,
• Guilherme D. R. Matos,
• Claudia C. Gatto and
• Carlos Kleber Z. Andrade

Beilstein J. Org. Chem. 2025, 21, 2618–2636, doi:10.3762/bjoc.21.203

• scans) and 151 MHz for 13C NMR (20,480 scans), using an overnight experiment in DMSO-d6 at a concentration of 0.1 M. Specifically, the spectra showed either an absence of expected signals or a lack of signal multiplicity, which was apparent in both the 1H NMR and, more prominently, in the 13C NMR

• spectra (Scheme 7b). A remarkable feature of the 13C NMR spectra of compounds 3n and 4n in DMSO is the attenuation/absence of peaks corresponding to the carbon atoms at the ortho and meta positions of the six-membered ring. It is known that quaternary carbon atoms have very long relaxation times, but this

• behavior is not expected from hydrogen-bonded carbon atoms in aromatic rings. Since peak intensities depend on spin-lattice relaxation times, the absence of peaks implies some degree of molecular rigidity, which could be related to two factors: the viscosity of DMSO and the conjugation between the six

Efficient solid-phase synthesis and structural characterization of segetalins A–H, J and K

• Liangyu Liu,
• Wanqiu Lu,
• Quanping Guo and
• Zhaoqing Xu

Beilstein J. Org. Chem. 2025, 21, 2612–2617, doi:10.3762/bjoc.21.202

• electrospray ionization mass spectrometry (HRESIMS) data for all compounds matched the calculated exact masses for their respective molecular formulas. NMR spectroscopic analysis in appropriate deuterated solvents (e.g., DMSO-d6, D2O) fully corroborated the amino acid sequence and cyclic connectivity

Visible-light-driven NHC and organophotoredox dual catalysis for the synthesis of carbonyl compounds

• Vasudevan Dhayalan

Beilstein J. Org. Chem. 2025, 21, 2584–2603, doi:10.3762/bjoc.21.200

• presence of NHC (10 mol %) and 4CzIPN (2 mol %) and Na2HPO4 in DMSO at rt for 10–24 h. The key to success lies in the photocatalytic dual system, which combines two organocatalysts (NHC/4CzIPN) and visible light irradiation to permit a novel umpolung single-electron reduction of respective imino ester 2

Synthesis and characterization of a isothiouronium-calix[4]arene derivative: self-assembly and anticancer activity

• Giuseppe Granata,
• Loredana Ferreri,
• Claudia Giovanna Leotta,
• Giovanni Mario Pitari and
• Grazia Maria Letizia Consoli

Beilstein J. Org. Chem. 2025, 21, 2535–2541, doi:10.3762/bjoc.21.195

• groups by sodium borohydride and then converted to chloromethyl groups by treatment with thionyl chloride, to give compound 2. The reaction of compound 2 with thiourea in THF gave compound 3 as a white solid in 96% yield. Compound 3 was characterized by 1H and 13C NMR in DMSO-d6 as a solvent (Figure 1

• (DMSO-d6). 1H NMR (400.13 MHz, DMSO-d6, 297 K) δ 0.83 (t, J = 6.6 Hz, 12H, 4 × dodecyl CH3), 1.22 (br s, 72H, 36 × dodecyl CH2), 1.34 (br s, 8H, 4 × dodecyl CH2), 1.82 (t, 8H, 4 × dodecyl CH2), 3.13 (d, J = 14.3 Hz, 4H, 2 × ArCH2Ar), 3.78 (t, 8H, 4 × dodecyl OCH2), 4.23 (s, 8H, 4 × ArCH2S), 4.26 (d, J

• = 14.3 Hz, 4H, 2 × 4 ArCH2Ar), 6.66 (s, 8H, 8 × ArH); 13C NMR (100.6 MHz, DMSO-d6, 297 K) δ 13.9 (q, dodecyl CH3), 22.2, 26.2, 29.0, 29.5, 29.8, 30.1 (t, dodecyl CH2), 31.5 (t, ArCH2Ar), 34.7 (t, CH2S), 75.0 (t, OCH2), 127.8 (d, ArH), 128.8 (s, ArC-CH2S), 135.0 (s, ArC-CH2S), 156.0 (s, ArCO), 169.4 (s, C

Pentacyclic aromatic heterocycles from Pd-catalyzed annulation of 1,5-diaryl-1,2,3-triazoles

• Kaylen D. Lathrum,
• Emily M. Hanneken,
• Katelyn R. Grzelak and
• James T. Fletcher

Beilstein J. Org. Chem. 2025, 21, 2524–2534, doi:10.3762/bjoc.21.194

• modification of the base-catalyzed conditions reported by Kwok [53], where a stoichiometric plus additional catalytic amount of tetraethylammonium hydroxide base in DMSO solvent was used to promote tandem trimethylsilyl deprotection and cycloaddition in one preparation (Figure 3). Isolated yields of this

Effect of a photoswitchable rotaxane on membrane permeabilization across lipid compositions

• Udyogi N. K. Conthagamage,
• Lilia Lopez,
• Zuliah A. Abdulsalam and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2498–2512, doi:10.3762/bjoc.21.192

• same amount of DMSO but no axle over five irradiation cycles alternating 370 nm and 467 nm light. As seen in Figure 7a, the release occurs only in vesicles containing axle 3, ruling out nonspecific effects such as membrane degradation from direct light exposure or solvent heating (HEPES buffer and

• small amounts of DMSO). We also monitored the absorption spectra of LUVs suspended in HEPES buffer in the presence of DMSO and observed no changes (Supporting Information File 1, Figure S23), confirming that the liposomes did not undergo chemical degradation in the absence of axle 3. In contrast, LUVs

• reversible photoswitching of the azobenzene. When irradiating axle 3 in solution using DMSO as solvent, we observed similar irreversible changes in its absorption, indicating a degradation of the axle upon light exposure (Supporting Information File 1, Figure S23d). We then investigated which wavelength was

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

• K2CO3 in DMSO to give the desired product [26]. Route III, previously elaborated in our group, utilizes the nucleophilic substitution of the Cl atom in 3-chlorothiophene-2-carboxylates by methyl thioglycolate in the presence of KOt-Bu, followed by KOt-Bu-mediated cyclization to the 3-hydroxy-TTs [27

The high potential of methyl laurate as a recyclable competitor to conventional toxic solvents in [3 + 2] cycloaddition reactions

• Ayhan Yıldırım and
• Mustafa Göker

Beilstein J. Org. Chem. 2025, 21, 2389–2415, doi:10.3762/bjoc.21.184

• (h), and DMSO (p) according to the guidelines outlined in the CHEM21 solvent selection guide [92]. A series of risk assessments was conducted, including ecological and environmental risk assessments, as well as pesticide similarity and biodegradability assessments of methyl laurate in comparison with

• were measured using Bruker ultrashield plus biospin 400 MHz NMR spectrometer and chloroform-d (CDCl3) or hexadeuterodimethyl sulfoxide (DMSO-d6) as a solvent. Chemical shifts (δ) are reported in ppm and J values in hertz. The elemental analyses were performed using a Leco CHNS-932 elemental analyzer

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• -1,4-dione was reduced with Na2S2O4 to triphenylene-1,4-diol (3) which was immediately treated with MeI under basic conditions (NaOH, DMSO) to give the known 1,4-dimethoxytriphenylene (W2) in 31% yield [47]. We also selected commercially available W3 and W4 to prepare comparators G2W3 and G2W4 to

• insoluble in water as required for their use as solid state sequestrants. Unlike most acyclic CB[n]-type receptors, G2W1–G2W4 are soluble in organic solvents (G2W1 and G2W2: soluble in CHCl3, CH2Cl2, DMSO, and TFA but insoluble in methanol, acetone, acetonitrile, and hexane; G2W3: soluble in DMSO and TFA

• but insoluble in CHCl3, CH2Cl2, methanol, acetone, acetonitrile, and hexane; G2W4: soluble in CHCl3, CH2Cl2, acetonitrile, DMSO, and TFA but insoluble in methanol, acetone, and hexane). The new hosts G2W1–G2W4 were fully characterized spectroscopically (1H and 13C NMR, IR, MS) and the data is in

Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• ready availability of enamine 9a; however, direct double halogenation of 6 may also be possible using an excess of halogenation agent in DMSO [31]. The Baeyer–Villiger oxidation using H2O2 in MeCN gave the desired chiral lactones 11a and 11b in moderate to good yield following an acidic workup to cleave

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

• dihydrochromenone skeleton 24 (Scheme 6, path a). When DMSO was employed instead, the strongly coordinating solvent diverted the reaction towards 5-exo-dig cyclization, furnishing a Z-configured tetrasubstituted alkene product 26 (Scheme 6, path b). The isocoumarin-fused dihydrochromenones prepared by this strategy

Research towards selective inhibition of the CLK3 kinase

• Vinay Kumar Singh,
• Frédéric Justaud,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Blandine Baratte,
• Thomas Robert,
• Stéphane Bach,
• Chada Raji Reddy,
• Nicolas Levoin and
• René L. Grée

Beilstein J. Org. Chem. 2025, 21, 2250–2259, doi:10.3762/bjoc.21.172

• kinase activities are expressed in % of maximal activity, i.e., measured in the absence of inhibitor but with an equivalent dose of DMSO (solvent of the tested compounds). ATP concentration used in the kinase assays was 10 µM (values are means, n = 2). Kinases are from human origin (Homo sapiens) except

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

• using widely accepted strategies [46][47]. DMSO-d6 or CDCl3 were used as the solvents and tetramethylsilane (TMS) as the internal standard. Chemical shifts (δ) and coupling constants (J) are given in ppm and in Hz, respectively. High-resolution mass spectra were recorded on an Agilent 2750 GC/Q-TOF mass

• KGaA, Darmstadt, Germany), adjusting the pH with HCl. Water for buffer and eluent preparation were provided by a Millipore Milli-Q water purification system. Kinetic aqueous solubility assay. All compounds were dissolved in DMSO to make stock solutions at 10 mM concentration. In the case of 7i, 7j, and

• (E)-9b, the highest concentration achieved in DMSO was 0.5 mM, while for (E)-9a it was 1 mM (DMSO solubility results of the compounds can be found in Supporting Information File 1). 5 μL of the stock solutions was pipetted into a 96-well plate containing 495 μL PBS (pH 6.5) in each well to achieve

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

• that this report provided a switchable and green synthetic methodology for skeletally diverse indoles. Divergent electrochemical cyclization of 2-ethynylanilines was developed to synthesize indoles and iodoindoles (Scheme 4) [188]. Treatment of 2-ethynylanilines 10 with KI in DMSO/H2O in an undivided

• generation of 12a in Cu rod electrodes, the Cu anode was expected to liberate Cu+ into the reaction mixture. The reaction of this Cu+ with DMSO and I− afforded (DMSO)nCuI, which was coordinated with C≡C to give B. The intermediate C was obtained by cyclization of B and deprotonation. Further protonation of C

• afforded 12a and regenerated (DMSO)nCuI. Notably, this reaction, using KI as the only additive and performing under ambient conditions in a non-volatile aqueous solvent, was a simple, selective, efficient and sustainable electrosynthesis of indole derivatives. 3-Selenylindoles were also formed by