Z-Selective semihydrogenation of alkynes via Ni/Lewis acid synergistic catalyzed system using DMF as hydrogen source and solvent

• Lei Kang,
• Haifeng Gao and
• Luo Yang

Beilstein J. Org. Chem. 2026, 22, 1004–1012, doi:10.3762/bjoc.22.79

• dual-catalytic system has been developed for the Z-selective semihydrogenation of alkynes. Utilizing DMF as both the hydrogen donor and reaction medium, this method affords Z-alkenes in high yield with excellent stereoselectivity under mild conditions. The protocol employs cost-effective and readily

• available catalysts, and demonstrates broad applicability across a wide range of substrates. Keywords: alkynes; DMF; Ni/Lewis acid catalysis; Z-selective semihydrogenation; Introduction Z-Olefins represent important structural units in natural products, pharmaceuticals, and functional materials, making

• . Dimethylformamide (DMF), a commonly utilized polar aprotic solvent, has recently attracted interest as a hydrogen donor in catalytic reductions [37][38][39][40]. While DMF is classified as a substance of high concern (SVHC) due to its reproductive toxicity and potential health hazards upon improper handling [41

The role of spacer length and flexibility in peptide self-assembly

• Julian Link,
• Albin Lahu,
• Manfred Wagner,
• Tanja Weil and
• David Y. W. Ng

Beilstein J. Org. Chem. 2026, 22, 986–996, doi:10.3762/bjoc.22.77

• , using (benzotriazol-1-yloxy)tripyrrolidinophosphonium hexafluorophosphate (PyBOP®) and N,N’-diisopropylethylamine (N,N’-DIPEA) in peptide-grade dimethylformamide (DMF). After the coupling, the peptides were cleaved from the resin under acidic conditions (95% TFA) in the presence of TIPS (2.5%) and H2O

• swollen in DMF (15 mL) at room temperature for one hour before transferring it into the peptide synthesizer. In the peptide synthesizer, DMF was removed through the draining process and DMF (3.5 mL) was added prior to the coupling. Prior to every coupling, the Fmoc-protecting group was cleaved by one

• deprotection step using a solution of 8% piperidine (DMF, 2.1 mL) for 80 s at 110 °C. The amino acids (0.5 M in DMF, 1.0 mL), DIC (0.75 M in DMF, 1.0 mL) and Oxyma Pure (0.26 M in DMF, 1.5 mL) were added to the resin and the solution was heated to 105 °C for 60 s and held at that temperature for 30 s. The

Recent advances in copper-catalyzed direct hydroamination of alkenes with (hetero)aromatic amines

• Hyejeong Lee and
• Yunmi Lee

Beilstein J. Org. Chem. 2026, 22, 925–947, doi:10.3762/bjoc.22.73

• )-catalyzed tandem oxidative amidation/aza-Michael reaction for the efficient synthesis of 3-substituted N-pyridinylisoindolinones 28 from 2-aminopyridines 25 and alkyl (E)-3-(2-formylphenyl)acrylates 26 (Scheme 9b) [47]. Under open-flask conditions at 80 °C in DMF, the reaction proceeded efficiently in the

Palladium-catalyzed benzocyclization reactions of quinoline-2-carboxamides via sequential C–H/N–H functionalization

• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2026, 22, 905–914, doi:10.3762/bjoc.22.71

• reaction between quinoline-2-carboxamide 1a and 1-bromo-2-iodobenzene (2a) was tested. When 1a was treated with 1.0 equiv of 2a, 10 mol % Pd(OAc)2, 40 mol % PPh3, and 3.0 equiv of Cs2CO3 in dimethylformamide (DMF) at 140 °C, the desired lactam 3aa was obtained in 19% yield (Table 1, entry 1). This result

• catalyst (Table 1, entry 7). When the reaction temperature was reduced to 110 °C, 120 °C, or 130 °C, product 3aa was obtained in lower yields in all cases compared with entry 7 (Table 1, entries 8–10). Using o-xylene as the solvent gave results similar to those obtained with DMF (Table 1, entry 11

Knoevenagel condensation of 4,5- and 1,8-diazafluorenes

• Darya S. Cheshkina,
• Christina S. Becker,
• Alina A. Sonina and
• Maxim S. Kazantsev

Beilstein J. Org. Chem. 2026, 22, 803–812, doi:10.3762/bjoc.22.62

• several electron-donor and electron-acceptor-substituted benzaldehydes (viz. 4-methoxybenzaldehyde, 4-bromobenzaldehyde, 3-nitrobenzaldehyde, and unsubstituted benzaldehyde) were first carried out under basic conditions, using t-BuONa in DMF or t-BuOH (Scheme 1 and Table 1). Both diazafluorenes 1 and 2

• reacted under such conditions, but only acceptor-substituted aldehydes were able to react in DMF, specifically 4-bromobenzaldehyde and 3-nitrobenzaldehyde. Though, the reaction in tert-butanol was successful for all studied substrates. These observations were attributed to solvation phenomena

• . Specifically, solvation by aprotic DMF having a high dipole moment promotes the formation of the [Na+–diazafluorenyl−] ion pair, whose anion displays insufficient nucleophilicity for interaction with weakly electrophilic aldehydes (e.g., benzaldehyde and 4-methoxybenzaldehyde). On the other hand, tert-butanol

Design, synthesis, and biological evaluation of FXR/ASK1 dual-target modulators

• Xi Zhang,
• Jingyan Wang,
• Ziqiang Zhao,
• Caiyi Wang,
• Zenghui Ye,
• Wei-Yuan Ma,
• Jian-Xing Xu and
• Fengzhi Zhang

Beilstein J. Org. Chem. 2026, 22, 771–781, doi:10.3762/bjoc.22.59

• preparation of triazole intermediates IXa–d is shown in Scheme 5. Firstly, compound VI was reacted with hydrazine hydrate in methanol to obtain hydrazide VII which was mixed with DMF/DMA and heated to provide intermediate VIII. The obtained VIII was not purified and directly reacted with different amines to

• FXR/ASK1 modulation strategy for MASH. Synthesis of compound 2. Conditions: (a) NH2OH·HCl, NaOH, EtOH/H2O, 70 °C, 12 h; (b) NCS, DMF, 40 °C, 2 h; (c) methyl 3-cyclopropyl-3-oxopropanoate, triethylamine, EtOH, rt, 12 h, 64% yield; (d) LiAlH4, THF, 0 °C, 2 h, 68% yield; (e) PBr3, DCM, 0 °C, 12 h, 79

• % yield. Synthesis of compounds IXa–d. Conditions: (a) N2H4·H2O, MeOH, rt, 12 h; (b) DMF–DMA, 80 °C, 12 h; (c) amines (for IXa,c,d) or (R)-alanine methyl ester (for IXb), AcOH, MeCN, 90 °C, 16 h, 66–80% yield; (d) absolute stereochemistry is R. Synthesis of compounds Z1–15. Conditions: (a) K2CO3, KI, MeCN

Photoorganocatalytic trifluoromethylation of (het)arenes in green conditions

• Egor N. Boronin,
• Svetlana E. Kaurkina,
• Milena M. Svetlakova,
• Anton S. Bolshakov,
• Maxim V. Arsenyev,
• Vasilii F. Otvagin,
• Alexey Yu. Fedorov,
• Timothy Noël and
• Alexander V. Nyuchev

Beilstein J. Org. Chem. 2026, 22, 662–671, doi:10.3762/bjoc.22.50

• -light irradiation was selected as the optimal set of conditions for further investigations, with subsequent experiments benchmarked against entry 5 (2 mol % PC, 78% yield, Table 1). We next investigated the effect of solvent on the reaction outcome. Chloroform, acetone, acetonitrile, DMF, DMSO, and THF

Towards the targeted protein degradation of CK2: design and synthesis of CAM4066-based PROTACs

• Sophie Day-Riley,
• Sona Krajcovicova,
• Aryaman Raj Sokhal,
• Jan L. Venne,
• Paul Brear,
• Marko Hyvönen,
• Benjamin C. Whitehurst,
• Jason S. Carroll and
• David R. Spring

Beilstein J. Org. Chem. 2026, 22, 611–619, doi:10.3762/bjoc.22.47

• -diisopropylethylamine; DME = 1,2-dimethoxyethane; DMF = dimethylformamide; HOBt = 1-hydroxybenzotriazole; TFA = trifluoroacetic acid. (A) Synthesis of final VHL PROTACs; (B) Synthesis of final CRBN PROTACs. Abbreviations: Boc = tert-butoxycarbonyl; CRBN = cereblon; DIPEA = N,N-diisopropylethylamine; DMF

Design and synthesis of an erdafitinib-based selective FGFR2 degrader

• Yumeng Jin,
• Shidong Wang,
• Sihan Pan,
• Shuqi Huang,
• Weichen Zhou,
• Xiaohao Huang,
• Lei Zheng and
• Lingfeng Chen

Beilstein J. Org. Chem. 2026, 22, 583–591, doi:10.3762/bjoc.22.44

• . Synthesis of PROTACs towards FGFR2. Reagents and conditions: (a) K2CO3, Pd (dppf)Cl2, 1,4-dioxane/H2O 4:1, 100 °C, 5 h; (b) 3,5-dimethoxyaniline, Pd2(dba)3, BINAP, Cs2CO3, toluene, 100 °C, 12 h; (c) (2-bromoethoxy)-tert-butyldimethylsilane, NaH, DMF, rt, 12 h; (d) tetrabutylammonium fluoride, THF rt, 12 h

• ; (e) methanesulfonic anhydride, TEA, DCM, rt, 3 h; (f) isopropylamine, DIPEA, MeCN, 100 °C, 12 h; (g) EDCI, HOBt, DIPEA, DMF, rt, 12 h. Supporting Information Supporting Information File 6: Experimental details and spectral data for all compounds. Acknowledgements The graphical abstract was created

Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• melifoliones should be synthesized first, to get enough quantity for oxidation to the corresponding quinols in a second experiment. Using the method of Wang and Lee [5], 1 could be prepared regio-specifically in good yield by heating phloroacetophenone and citral in DMF under catalysis of ethylenediammonium

• -position in regard to the OH-group at C-10b (Table 2). Synthesis of melifoliones Melifolione A (1) was prepared according to the method of Wang and Lee [5] by heating phloroacetophenone and citral with ethylene-diammonium diacetate (EDDA) in DMF. However, reaction of the educts in pyridine at 60 °C led to

• made to cyclize 5 into melifolione B (2) with the following results (Scheme 1) Heating of 5 in DMF at 100 °C yielded melifolione A (1) with traces of melifolione B (2). When 5 was heated in acetic acid at 80 °C, only benzoxocin 6 could be isolated. Reaction of 5 with catalytic amounts of p

Modern synthetic pathways towards eribulin and its subunits

• Sebastian Dominik Graf

Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37

• ; ii. TBDPSCl, imidazole, DCM, 0 °C to rt; iii. MeI, Ag2O, DMF, 0 °C to rt; (g) i. Pd/C, H2, EtOAc; ii. I2, PPh3, imidazole, DCM, 0 °C to rt; (h) vinylmagnesium bromide, CuI, HMPA, THF, −30 °C; (i) OsO4, (DHQ)2PYR, 0 °C; (DHQ)2PYR: hydroquinine 2,5-diphenyl-4,6-pyrimidinediyl diether. Synthesis of 27

• . (a) i. NaH, BnBr, THF, rt; ii. iodobenzoic acid, MeCN, 80 °C; iii. (EtO)2POCH2COOEt, NaH, THF, 0 °C; (b) vinylmagnesium bromide, CuI, THF, TMSCl, HMPA, −78 °C to rt; (c) 2 M HCl, THF, H2O, 65 °C; (d) i. Ag2O, 2,6-DCBCl, DMF, TBAI, rt, darkness; ii. LiAlH4, THF, 0 °C to rt; iii. TBDPSCl, imidazole

• , DCM, 0 °C to rt; iv. NaH, MeI, DMF, 0 °C; (e) I2, MeCN, −20 °C; 2,6-DCBCl: 2,6-dichlorobenzyl chloride. Synthesis of 31 and 33. (a) i. MMTrCl, iPr2NEt, DCM, rt; ii. K2CO3, MeOH, DCM, rt; iii. TBDMSCl, imidazole; (b) i. n-BuLi, THF, −78 °C, Sia2BH, −10 °C to rt; ii. H2O2, 3 M NaOH, 0 °C; (c) i. TsCl

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• corresponding hydroxamic acid, with no detectable acid-derived by-products. Solubility tests revealed that PCP HA is soluble exclusively in highly polar aprotic solvents (DMSO, DMF) and remains completely insoluble in other common organic solvents (chloroform, ether, etc.) and water. The absence of ligand

Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes

• Wiktoria A. Pytel,
• John W. R. Schwabe and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35

• , 67%; e) TFA, DCM, 0 °C to rt, 20 h; (f) MP-carbonate resin, MeOH, rt, 3 h, 95%; g) benzyl bromide, 1,4-dioxane/DMF 1:1, 90 °C, 19 h, 45%; h) 3, 5, HATU, DIPEA, DMF, 0 °C to rt, 40 h, 59%; i) H2, 10% Pd/C, THF, rt, 19 h, 99%; j) N-hydroxysuccinimide, EDC, DMF, 0 °C to rt, 16 h, 90%; k) TFA, DCM, 0 °C

Synthesis and stereochemical analysis of dynamic planar chiral oxa[7]orthocyclophene

• Yukiho Hashimoto,
• Yuuya Kawasaki,
• Kazunobu Igawa and
• Katsuhiko Tomooka

Beilstein J. Org. Chem. 2026, 22, 436–442, doi:10.3762/bjoc.22.30

• -alkene 7 in 81% yield. The hydroxy group of 7 was substituted with chlorine using oxalyl chloride in DMF, and the TIPS group was removed by treatment with hydrochloric acid to afford the chloroalcohol 2a (74% yield in two steps). After several attempts to cyclize compound 2a via Williamson etherification

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• -Bu4NF·3H2O, THF, 50 °C. Synthesis of 2-azidoethylated p-aminocalix[4]arenes. Conditions: i) HNO3 (fuming, 10 equiv per calixarene aromatic unit, c ≈ 2.5 M), AcOH, dichloromethane, rt, 48 h; ii) FeSO4·7H2O, NH4Cl, Zn, EtOH, THF, H2O, 50 °C; iii) Boc2O, Et3N, dichloromethane, rt; iv) NaN3, DMF, 60 °C

Design, synthesis and biological evaluation of 2,5-diaryloxazolo[4,5-d]pyrimidin-7-ylamines as selective cytotoxic agents against HeLa cells

• Maryna V. Kachaeva,
• Agnieszka B. Olejniczak,
• Marta Denel-Bobrowska,
• Victor V. Zhirnov,
• Yevheniia S. Velihina,
• Stepan G. Pilyo and
• Volodymyr S. Brovarets

Beilstein J. Org. Chem. 2026, 22, 390–398, doi:10.3762/bjoc.22.27

• essential medium (MEM, Sigma-Aldrich), fetal bovine serum (FBS, Sigma-Aldrich), antibiotics (Sigma-Aldrich), trypsin (Life Technologies), 3-(4,5-dimethylthiazol-2-yl)-2,5-diphenyltetrazolium bromide (MTT, Sigma-Aldrich), dimethylformamide (DMF, Sigma-Aldrich), sodium dodecylsulfate (SDS, Sigma-Aldrich

• -diphenyltetrazolium bromide (MTT) dye solution (5 mg/mL) for 2 h and lysed with 100 μL of solvent solution containing: 45 mL of dimethylformamide (DMF), 13.5 g of sodium dodecylsulfate (SDS), and 55 mL distilled water [23]. After overnight incubation at 37 °C optical density at 550 nm and with a reference wavelength

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• , such methods often exhibit limited substrate scope, generally restricted to amides with low steric hindrance, such as DMF or DMAC. In recent years, several new strategies have emerged to overcome these limitations: (i) transition-metal-free activation using electrophilic reagents, (ii) strong-base

• in 60% yield and 98% ee. Furthermore, nylon 6,6 was cleanly depolymerized to its monomer 98 in 32% yield. The Mukherjee group employed dihydrogen tetrametaphosphate as a Lewis acid to activate formamides for transamidation (Scheme 17) [65]. In the presence of one equivalent of [PPN]2[P4O12H2], DMF

Synthesis of tricyclic fused pyrrolidine nitroxides from 2-alkynylpyrrolidine-1-oxyls

• Mark M. Gulman,
• Yuliya F. Polienko,
• Sofia Yu. Trakhininа,
• Yuri V. Gatilov,
• Tatyana V. Rybalova,
• Sergey A. Dobrynin and
• Igor A. Kirilyuk

Beilstein J. Org. Chem. 2026, 22, 344–351, doi:10.3762/bjoc.22.22

• literature data on reactivity of 5-azidopentyne derivatives in intramolecular Huisgen cycloaddition reactions are contradictory. Some authors successfully obtained 5-azidopentyne derivatives upon nucleophilic substitution at 80 °C in DMF, and additional heating at 170 °C was necessary for cyclization to

• triazoles to occur [25]. However, there are also examples where the corresponding triazoles were isolated instead of 5-azidopentyne derivatives under the same conditions (DMF, 80 °C) [26]. The nitroxides 3a–f were treated with excess of NaN3 in milder conditions, in DMSO at 60 °C, and a single product was

A mild and atom-efficient four-component cascade strategy for the construction of biologically relevant 4-hydroxyquinolin-2(1H)-one derivatives

• Dmitrii A. Grishin,
• Kseniia I. Sharkovskaia,
• Ilya G. Kolmakov,
• Daria A. Ipatova,
• Rostislav A. Petrov,
• Nikolai D. Dagaev,
• Dmitry A. Skvortsov,
• Maria G. Khrenova,
• Valeriy V. Andreychev,
• Sergei A. Evteev,
• Yan A. Ivanenkov,
• Roman L. Antipin,
• Olga А. Dontsova and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2026, 22, 244–256, doi:10.3762/bjoc.22.18

• the presence of catalytic DMF in ethanol (Scheme 3a) [40]. A small amount of ethanol ensured homogeneity of the reaction mixture, allowed gradual temperature increase, and prevented sudden charring. DMF, with its high boiling point, acted as a homogenizer by preventing solidification after ethanol

• -unsaturated malonate 6 with 2a–c, various bases (sodium methoxide, triethylamine, potassium hydroxide) and solvents (ethanol, DMF, pyridine) were tested, mostly at room temperature, with an additional attempt at refluxing in ethanol/DMF. The desired malonate Michael adduct 7 (isolated and fully characterized

• , see Supporting Information File 1) was obtained exclusively when potassium hydroxide was used as base in the reaction between 2b and arylidenemalonate 6 in DMF at room temperature. The malonate Michael adduct 7 was then subjected to various decarboxylation conditions. The Krapcho protocol (NaCl or

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

• -withdrawing leaving groups [49][50][54], and the transesterification of alkyl phosphates has rarely been observed [55]. A possible reaction pathway is shown in Figure 5. First, triethylamine increases the solubility of phytic acid in DMF by improving its lipophilicity and accelerates the formation of

• those utilized for commercial phytic acid (Scheme 4), the reaction mixture became dark, and black precipitates were formed during the reaction. After the distillation of excess phenol and DMF, the insoluble burnt material was removed via filtration. Finally, 500 mg (44% yield) of 2a was obtained, and

• mmol, 50 wt % aqueous solution) was added to dimethylformamide (DMF, 60 mL), after which triethylamine (126 mmol) and 1a (420 mmol) were poured into the reaction mixture. Esterification reaction conditions using the extracted phytic acid. The yield refers to the isolated yield. Supporting Information

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

• Vertex Pharmaceuticals describes the synthesis of alkenyl chloride 21 on a 360 and 580 mmol scale (Scheme 6A) [51]. The addition of a few drops of DMF was not commented. Surprisingly a significant decrease in yield was observed at the larger 580 mmol scale compared to the 360 mmol scale. Scott reported a

• -workers reported the serendipitous discovery that N-acyl-2,3-dihydro-4-pyridinones react with the Vilsmeier reagent to afford the corresponding alkenyl chlorides (Scheme 14) [67]. Notably, dihydropyridones failed to react with POCl₃ in the absence of DMF. In 2003, Wähälä reported a closely related

• , absence of DMF – the alkenyl chloride 96 was isolated in 95% yield (Scheme 20D). The transformation is mechanistically and conceptually closely related to earlier findings reported by Moughamir and Mestdagh (see Scheme 18). In 2015, Kartika and co-workers reported a metal and acid-free synthesis of

Sustainable electrochemical synthesis of aliphatic nitro-NNO-azoxy compounds employing ammonium dinitramide and their in vitro evaluation as potential nitric oxide donors and fungicides

• Alexander S. Budnikov,
• Nikita E. Leonov,
• Michael S. Klenov,
• Andrey A. Kulikov,
• Igor B. Krylov,
• Timofey A. Kudryashev,
• Aleksandr M. Churakov,
• Alexander O. Terent’ev and
• Vladimir A. Tartakovsky

Beilstein J. Org. Chem. 2025, 21, 2739–2754, doi:10.3762/bjoc.21.211

• ), and ammonium dinitramide (ADN) (1–5 equiv, 1–5 mmol, 62–310 mg) in 10 mL of MeCN, acetone, DMF, MeOH or HFIP was electrolyzed using constant current conditions (I = 15–240 mA) at 23–25 °C under magnetic stirring. After passing 1–3 F∙mol−1 of electricity (reaction time 7–161 min), electrodes were

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

• intermediates 6 and 7. Conditions: i) 1,3-benzodioxol-5-amine (n = 1)/2,3-dihydro-1,4-benzodioxin-6-amine (n = 2), PhNEt2, MeOH, rt, 1 h, 95%/92%; ii) MeI, K2CO3, DMF, 4 h/1 h, 97%/98%; iii) NaOH, MeOH/H2O, reflux, 1 h, 97%/99%; iv) 1. PCl5, DCM, reflux, 8.5 h/9 h; 2. SnCl4, 0–5 °C, 2 h/1 h → rt, 2 h; 76%/84

• % (8: 2%). Synthesis of tetracyclic compounds 20 and 21. Conditions: i) NaBH4, DMF, EtOH, rt, 4.5 h/23 h, 95%/98%; ii) SOCl2, DCM, rt, 1.5 h/3.5 h, 100%/94%; iii) 20a,c–e: HNR1R2, dioxane or MeCN, rt, 1 h, 56–84%; 21a,c–p: HNR1R2, dioxane or MeCN, rt, 40 min–3.5 h, 48–93%. Synthesis of tianeptine

• , rt, 1 h, 91%; viii) NaBH4, NaOH, H2O, rt, 69 h, 83%; ix) SOCl2, DCM, rt, 2 h, crude: 100%; x) Br(CH2)2OH, MeCN, rt, 6 h, 61%; xi) K2CO3, MeCN, rt, 5 h, 71%. Synthesis of tetracyclic compounds 38. Conditions: i) NaBH4, DMF/EtOH, rt, 3 h, 89%; ii) SOCl2, DCM, rt, 1.5 h, 94%; iii) 38a–c: R1R2NH, MeCN

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

• strategy for the total synthesis of segetalins A–H, J and K (1–10), bioactive cyclopeptides isolated from Vaccaria segetalis. Linear precursors were assembled on cost-effective 2-chlorotrityl chloride resin via Fmoc-SPPS, followed by PyBOP-mediated head-to-tail cyclization in DMF (10−3 M). After RP-HPLC

• resin as the solid support, enabling mild cleavage of the partially protected linear peptide precursor [21]. Efficient Fmoc deprotection was achieved using a solution of 1% pyridine and 1% 1,8-diazabicyclo[5.4.0]undec-7-ene (DBU) in N,N-dimethylformamide (DMF) [22]. For the assembly of the linear

• sequences, coupling efficiency was significantly enhanced using a 1:1 mixture of 1-hydroxybenzotriazole (HOBt) and 2-(1H-benzotriazol-1-yl)-1,1,3,3-tetramethyluronium hexafluorophosphate (HBTU) in DMF [23]. Finally, we obtained crude linear peptides with 75% to 95% yields (Table 1). The critical head-to

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• (HOBt) and 1,3-diisopropylcarbodiimide (DIC) in DMF, resulting in SG-NHCO-BU1 with BU1 covalently attached through amide bonds (Scheme 1). The material was thoroughly washed with DMF, water, and methanol to remove byproducts and unreacted BU1. The grafting reaction was conducted using a 9:1 (w/w) ratio

• (Scheme 1). The latter reaction was also done using a 9:1 (w/w) ratio of a-SG to BU1, by treatment of a-SG with the macrocycle in DMF at ambient temperature (Scheme 1). The material was then isolated by filtration and washed with DMF and methanol. The prepared a-SG, SG-NHCO-BU1, and SG-BU1 materials were

• toluene, ethanol and acetone to remove unreacted APTES and dried in vacuo (50 °C) overnight in order to get a-SG [15][16]. Further, to prepare covalent SG-NHCO-BU1, a-SG (0.9 g) was suspended in DMF (15 mL) and shaken at ambient temperature for 30 min. BU1 (0.1 g, 1 equiv) was dissolved in a minimum