Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• sesquiterpenoids (1, 2), together with three known related analogs (3–5) [10][11][12][13] have been isolated and identified from the bioactive fraction of P. boydii CS-793. Details of the isolation and purification, structure elucidation, and biological evaluation of compounds 1–5 are described herein. Results and

• Discussion For chemical investigation, the solvent EtOAc was used to extract the fermentation culture of the fungus P. boydii CS-793 to afford an organic extract. Isolation and purification of the crude extract with a combination of column chromatography (CC) by Lobar LiChroprep RP-18, silica gel, Sephadex

• chromatography (TLC) was performed with precoated Si gel GF254 plates (Merck, Darmstadt, Germany). Solvents used for extraction and purification were distilled prior to use. Peptone from yeast extract was purchased from Sigma-Aldrich. Rice, monosodium glutamate, and corn steep liquor were purchased from China

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• of PdCl(C3H5)(dppb) (30.5 mg, 0.05 mmol) at 150 °C during 16 h in DMA (4 mL) under argon affords the coupling products 1–18 after evaporation of the solvent and purification on silica gel. Eluent EtOAc/heptane 1:9 for compounds 3–8, 10–18; heptane for compounds 1, 2, and 9. General procedure for the

• DMA (4 mL) under argon affords the coupling products 19–27 after evaporation of the solvent and purification on silica gel. Eluent EtOAc/heptane 1:9 for compounds 19–24; heptane for compounds 25 and 26; EtOAc/heptane 2:8 for compound 27. General procedure for the palladium-catalyzed synthesis of 9

• (4 mL) under argon affords the coupling products 28–30 after evaporation of the solvent and purification on silica gel. Eluent EtOAc/heptane 1:9 for all compounds. Structure of fluoranthene. Pd-catalyzed access to fluoranthenes. Scope of the Pd-catalyzed direct arylation reaction of arenes with 1,8

Facile approach to N,O,S-heteropentacycles via condensation of sterically crowded 3H-phenoxazin-3-one with ortho-substituted anilines

• Eugeny Ivakhnenko,
• Vasily Malay,
• Pavel Knyazev,
• Nikita Merezhko,
• Nadezhda Makarova,
• Oleg Demidov,
• Gennady Borodkin,
• Andrey Starikov and
• Vladimir Minkin

Beilstein J. Org. Chem. 2024, 20, 336–345, doi:10.3762/bjoc.20.34

• . Results and Discussion We found that a convenient way toward 6,8-di-tert-butyl-2-(arylamino)-3H-phenoxazin-3-ones 4 involves the short-term heating (30 min) of a molten mixture of 1 and an arylamine at 250 °C, followed by purification of the products by column chromatography. No preliminary grinding of

• potential for testing as potential donors for organic solar cells or as dye sensitizers for dye-sensitized solar cells [24][25]. Experimental All reagents and solvents were purchased from commercial sources (Aldrich) and used without additional purification. The compounds were characterized by 1H, 13C, and

Discovery of unguisin J, a new cyclic peptide from Aspergillus heteromorphus CBS 117.55, and phylogeny-based bioinformatic analysis of UngA NRPS domains

• Sharmila Neupane,
• Marcelo Rodrigues de Amorim and
• Elizabeth Skellam

Beilstein J. Org. Chem. 2024, 20, 321–330, doi:10.3762/bjoc.20.32

• . heteromorphus CBS 117.55 on rice solid medium yielded an organic-soluble extract, which was subjected to fractionation using preparative HPLC-PDA-ELSD and purification by semipreparative HPLC-PDA; this led to the isolation of a new cyclic peptide 1, along with unguisin B (2, Figure 2). The structure of the new

• performed on a Shimadzu LC-20AP preparative liquid chromatograph (SCL-40 System Controler Deliver and LH-40 Liquid Handler) coupled to a Shimadzu SPD-M40 Photo Diode Array Detector (PDA) system using a RP-18 column (Phenomenex, Kinetex 250 × 30 mm i.d., 5 µm, flow rate of 18.0 mL min−1). The purification of

• consisted of H2O + 0.05% formic acid (eluent A) and MeCN + 0.05% formic acid (eluent B), which was eluted of 20–100% of B with flow rate of 18 mL min−1, yielding 20 fractions. Fractions Fr13 and Fr15 were subjected to a purification by semipreparative HPLC-UV using a Premier RP18 column (250 mm × 10 mm i.d

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• and subsequent reverse Ni-NTA affinity chromatography resulted in significant co-purification of E. coli contaminants, necessitating an extra purification step, where cation exchange chromatography allowed us to obtain pure fractions of CMA16–291. Of note, this additional purification step was not

• necessary for the purification of the CMA1 N-terminal domain (Figure 1d). Expression of the CMA1 C-terminal domain did not yield sufficiently pure and monodisperse protein for further biochemical and structural analyses. Cucumis melo agglutinin binds C2-substituted, beta-linked galactose We then set out to

• polymerase (Takara #TAKR045A); then the product was digested by DpnI and finally transformed in NEB5α strain (New England Biolabs, #C2992H). Both gene and vector were digested by NcoI and XhoI restriction enzymes (New England Biolabs) prior to purification on agarose gel using Monarch Gel extraction kit and

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• devices [1][2][3][4][5][6][7][8]. In this regard, the planar character of most (non-substituted) π-CPCs represents a challenge, as it results in very low solubility in common organic solvents due to favorable intermolecular π–π stacking interactions. This inherently hampers the purification of the target

• endoperoxide formation. To overcome these issues, the “precursor approach” was developed and relies on the synthesis, purification and characterization of soluble and stable precursors of the target active π-CPCs, followed by their (solution) processing and their final deprotection once assembled in thin-films

• purification by column chromatography prior to their on-surface deposition. By way of example, the synthesis of decacene precursor 59 was achieved in three synthetic steps by iterative [4 + 2] cycloadditions with an overall yield of 4.7% (Scheme 17). The synthesis of epoxyacene 59 started with the mono-Diels

Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• by chromatographic purification in 88% yield (Table 1, entry 1). Reducing the amount of DIPEA gave diminished yield (Table 1, entry 2). Adding more base was unnecessary to get a higher yield (Table 1, entry 3). Subsequently, the use of other bases was not appropriate for promoting the generation of

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• sophistication over the past decades. Most known processes, however, are still frequently hampered by lengthy protecting-group strategies and very costly purification procedures derived from the "stop-and-go" synthetic methods (Figure 1a). Those protocols are still far from the ideal synthesis, implying high

• atom efficiency, step and pot economies, decreased number of purification steps, or protecting-group-free synthesis. Multi-step domino [1][2] and one-pot [3] reactions represent a new powerful toolbox in organic synthesis to install molecular complexity economically and sustainably, starting from

• triggers the next, which in the end yields a complex product. In contrast to a conventional “stop-and-go” method, only a single workup and purification is needed (Figure 1b), and therefore these reaction cascades can be considered superior to stepwise synthetic approaches in the context of green chemistry

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• several minutes with a good yield (Scheme 4). The spectral data fully confirmed the purity and asymmetric structure of product 11. It should be emphasized that the isolation and purification of nitro compounds 10 and 11 is complicated by their low solubility in traditional organic solvents, sensitivity to

• activator of NBS, as was previously shown by the example of a very successful bromination of 6-methylquinoline at position 5 with a preparative yield of 74% [27]. Indeed, under the new conditions, we obtained dibromo derivative 15 in high yield without heating and subsequent purification (Scheme 7). The

Optimizations of lipid II synthesis: an essential glycolipid precursor in bacterial cell wall synthesis and a validated antibiotic target

• Milandip Karak,
• Cian R. Cloonan,
• Brad R. Baker,
• Rachel V. K. Cochrane and
• Stephen A. Cochrane

Beilstein J. Org. Chem. 2024, 20, 220–227, doi:10.3762/bjoc.20.22

• prolonged reaction times did not enhance the product yield, and the subsequent purification of the target product became a difficult task. However, when we conducted the reaction at lower temperatures, the degradation of glycosyl donor 1a slowed down, and the reaction proceeded at a moderate rate

• Supporting Information File 1 for comprehensive information on the synthesis details of the tetrapeptide). To avoid loss of valuable material through HPLC purification, crude 7 is used directly in the next step, and purification performed after the final prenyl phosphate coupling and global deprotection

• % (from compound 7) following reversed-phase HPLC purification (Scheme 2). Similarly, farnesyl, geranylgeranyl, and solanesyl-lipid II analogues 8–10 were synthesized with overall yields of 13%, 21%, and 11%, respectively, using the corresponding prenyl phosphates (Scheme 2). Conclusion In conclusion, we

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• celite and washed with DCM, then, the solvent was evaporated under reduced pressure to give a crude mixture. Further purification by flash chromatography (hexane/AcOEt 1:1), gave the desired compound 5,10-dihydro-11H-dibenzo[b,e][1,4]diazepin-11-one (4a) as a yellow solid yield (0.032 g, 80%). Mp 249–251

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• -acetyl groups. After this procedure the initially formed disaccharides with various O-protective groups were transformed to the same known disaccharide 4 [36]. This procedure significantly simplifies the analysis of the reaction results and purification of the product. For the correct determination of

• during purification by silica gel chromatography. On the other hand, NMR analysis of the crude reaction mixtures may be misleading due to possible overlap of the signals of H-3eq belonging both to disaccharide and monosaccharide derivatives sometimes present in such glycosylation mixtures. At low

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• removed from the reaction mixture in vacuo. Sulfation was then performed through addition of SO3·NMe3 to the DMF solution. Consumption of 1 was observed by TLC after 72 hours and stirring with Dowex® 50WX4 (Na+ form) resin resulted in formation of target 2. Purification by flash chromatography, however

• following acetylation without purification of the intermediate, why the synthesis is high-yielding (20% overall yield) and easily scalable (9 g of protected disaccharide 7 and 1 gram of target 2 were synthesized). Experimental General methods All reactions containing air- and moisture-sensitive reagents

• /v) for 16 hours. The solution was then reduced to dryness and purification by flash chromatography on silica gel (EtOAc→EtOAc/MeOH, 17:3) yielded 8 as a dark orange/brown syrup (3.82 g, 53% over 3 steps). Rf = 0.4 (EtOAc/MeOH, 19:1); [α]D +76 (c 1.0, CH3OH); 1H NMR (500 MHz, CD3OD) δ 5.42 (d, J

Perspectives on push–pull chromophores derived from click-type [2 + 2] cycloaddition–retroelectrocyclization reactions of electron-rich alkynes and electron-deficient alkenes

• Michio Yamada

Beilstein J. Org. Chem. 2024, 20, 125–154, doi:10.3762/bjoc.20.13

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• of isolated product result from significant losses during the purification process, the content and yield of the benzo[c]quinolizinium ions were determined directly after irradiation of 2c, 2e–g by photometric analysis of the reaction mixture (Figure 3, red spectra). The yield of the product 3d could

• yields, so that it may be concluded that the small amounts of isolated product result from losses during work-up and purification. DNA-binding properties of benzoquinolizinium derivatives 3c,e–g The styrylpyridines 2d–g and the benzo[c]quinolizinium derivatives 3c,e–g were investigated with respect to

• chemicals (Alfa, Merck, Fluorochem or BLDpharm) were of reagent grade and used without further purification. 1H NMR spectra were recorded with a JEOL ECZ 500 (1H: 500 MHz and 13C: 125 MHz) and a Varian VNMR S600 (1H: 600 MHz and 13C: 150 MHz) at T = 25 °C. The 1H NMR and 13C{1H} NMR spectra were referenced

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• molecular sieves, or by drying over 3 Å molecular sieves. All remaining anhydrous solvents were obtained from a solvent drying tower (IT model PS-MD-05). HPLC grade solvents were used unless otherwise specified. Purification by chromatography was performed using silica gel (flash: 40–63 μm, Sepacore® Flash

• mmol), Pd(PPh3)2Cl2 (15 mg, 0.021 mmol), and CuI (5.0 mg, 0.026 mmol). The reaction mixture was stirred at rt under a N2 atmosphere for 4 h before it was filtered through a plug of SiO2 (CH2Cl2 as eluent) and concentrated under reduced pressure. Purification by flash column chromatography (SiO2, 10–15

Identification of the p-coumaric acid biosynthetic gene cluster in Kutzneria albida: insights into the diazotization-dependent deamination pathway

• Seiji Kawai,
• Akito Yamada,
• Yohei Katsuyama and
• Yasuo Ohnishi

Beilstein J. Org. Chem. 2024, 20, 1–11, doi:10.3762/bjoc.20.1

• NMR system (JEOL, Tokyo, Japan) (Table S1 and Figures S9–S13 in Supporting Information File 1). Production and purification of recombinant proteins pColdI-cmaA1, pColdI-cmaA3, and pColdI-cmaA6 were constructed by cloning each gene (which was amplified by PCR using pHKO4-cmaI-D as a template) into the

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• (Fluorochem, Aldrich) and used without further purification. Ionic liquids (ILs, Iolitec) were kept under vacuum (7 mbar) under stirring at 40 °C for 16 h before use. NMR spectra were recorded at ambient temperature on Bruker Avance spectrometer operating at 400 MHz (1H NMR) and 100 MHz (13C{1H} NMR) or on a

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• green fluorescent protein (GFP) gene construct using Gibson assembly. Sanger sequencing confirmed the authenticity of the long ODNs. To demonstrate the applications of the long ODN synthesis method, the GFP gene was expressed in E. coli. Results Long ODN synthesis and CBP purification The 800 nt (all

• and 401 nt long synthetic ssODNs, and functional in biological systems. Discussion For ODN purification using CBP, one major concern has been the damage of the ODN under the radical acrylamide polymerization conditions. Although some work has been done to prove that this is unlikely [22][23][24][25

• results further confirmed that ODN damage by radicals during CBP purification is unlikely. Another concern for long ODN synthesis is the perceived low quantity of product [29]. For example, for a 400 nt ODN synthesis, if the average stepwise yield is 99.0% as usually observed in trityl assay for the

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• yields (ca. 80%). NMR analysis showed that compounds 4a and 4c required further purification. Thus, they were recrystallized from acetonitrile, which led to a non-negligible loss of materials, thereby leading to final yields in the 50–60% range. Synthesis of MIC·CS2 zwitterions The synthesis of 1,4

Biphenylene-containing polycyclic conjugated compounds

• Cagatay Dengiz

Beilstein J. Org. Chem. 2023, 19, 1895–1911, doi:10.3762/bjoc.19.141

• are in situ formed from 23, resulting in the formation of symmetric polycyclic structures 24a and 24b. These isomers obtained as a mixture are then subjected to treatment with p-TsOH in acetic acid, without the need for further purification, to yield the desired products 25a and 25b in 71 and 42

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• purification. Thin-layer chromatography (TLC) was performed using Merck Silica gel 60 F254 plates and visualized by UV (254 nm) fluorescence. Zeochem silica gel (ZEOprep 60/35–70 microns – SI23501) was used for column chromatography. 1H and 13C NMR spectra were recorded on a Bruker 400 spectrometer at 400 and

• volume and after cooling the precipitate was filtered. The crude product was washed with cold MeOH and EtOAc and dried under reduced pressure yielding 2 (7.40 g, 35%) as white powder, which was used in the next reaction without further purification. 1H NMR (400 MHz, DMSO-d6) 7.67–7.66 (m, 2H), 7.37–7.33

• dried over Na2SO4. After the solvent was removed, the crude yellow product was carefully washed twice with acetonitrile to remove the starting materials. Further purification was achieved using flash chromatography on silica gel (eluent: dichloromethane/petroleum ether 1:2). Compound 4 (0.86 g, 61%) was

Controlling the reactivity of La@C₈₂ by reduction: reaction of the La@C₈₂ anion with alkyl halide with high regioselectivity

• Yutaka Maeda,
• Saeka Akita,
• Mitsuaki Suzuki,
• Michio Yamada,
• Takeshi Akasaka,
• Kaoru Kobayashi and
• Shigeru Nagase

Beilstein J. Org. Chem. 2023, 19, 1858–1866, doi:10.3762/bjoc.19.138

• reduction of La@C2v-C82 is an easy and effective method for controlling its reactivity and selectivity via ionization for the production of La@C2v-C82 derivatives. Experimental General: All chemicals and solvents were obtained from Wako, TCI, and Aldrich and were used without further purification unless

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• two steps and readily entered the diazo transfer reaction with 4-nitrophenylsulfonyl azide (4-NsN3). The resulting diazo reagent 5 was produced in a high yield after undergoing straightforward chromatographic purification. The use of a Boc group at the nitrogen atom of the diazo imide significantly

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• -tosylimines. Experimental General method: All reagents and solvents were purchased from Sigma-Aldrich, Fisher Scientific, or Acros Organics and were used without further purification. 1H NMR (400 MHz), 13C NMR (100 MHz), and 19F NMR (376 MHz) spectra were recorded on a Bruker 400, Ultra Shield high