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

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• was washed with water (2 × 60 mL), dried over MgSO4, and concentrated in vacuo. The intermediate (1.24 g) was used in the next reaction without purification. The crude, N-Boc-protected intermediate was dissolved in dichloromethane (25 mL) and the solution cooled to 0 °C with an ice bath. Next

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• dichloromethane solution of the corresponding keto amide 1 with a slight excess of 70% aqueous ethylamine over Na2SO4 and were used directly in the next step, without purification. These compounds are highly reactive at their α-position towards acylating reagents and this provides an opportunity to prepare the

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• Information File 1). However, only [2]rotaxane R2 could be isolated as pure compound in 3% yield, after several purification operations by column chromatography. The improved results obtained in the intramolecular macrocyclization for the clipping reaction as compared to the [1 + 1] strategy are in line with

• experimental data Commercially available reagents were used without further purification. Compounds 1 [43][47], 4 [48], 9 [49], 10 [44] and M2 [44] were synthesized according to procedures reported in the literature. Thin-layer chromatography (TLC) was performed on silica gel 60 coated aluminium F254 plates

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• purification, the operational simplicity of all the reactions, the high availability of all the reactants make the developed synthesis very promising. A plausible pathway of the hydrazine-promoted self-assembly of the macrocycle from the pyrazolopyrimidine based on the experimental data and the DFT

• the syntheses. Anhydrous N2H4 was obtained from N2H4·H2O according to the standard procedure. All other reagents were purchased from commercial sources and used without additional purification. FTIR spectra were recorded using a Bruker Alpha-T spectrophotometer in KBr. Band characteristics in the IR

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• -Aldrich and Vetec in the highest purity available and used without further purification. Syntheses of the compounds Compounds were synthesized by modifying the existing methodology in the literature [50]. The compounds were prepared by condensation between 3,4,5-trimethoxybenzoic acid hydrazide (TMP, 1.0

A deep-red fluorophore based on naphthothiadiazole as emitter with hybridized local and charge transfer and ambipolar transporting properties for electroluminescent devices

• Suangsiri Arunlimsawat,
• Patteera Funchien,
• Pongsakorn Chasing,
• Atthapon Saenubol,
• Taweesak Sudyoadsuk and
• Vinich Promarak

Beilstein J. Org. Chem. 2023, 19, 1664–1676, doi:10.3762/bjoc.19.122

• purchased from commercial resources and used without further purification. 1H NMR and 13C NMR spectra were recorded with a Bruker AVANCE III HD 600 (600 MHz for 1H and 151 MHz for 13C) using CDCl3 as a solvent containing TMS as an internal standard. High-resolution mass spectrometry (HRMS) analysis was

• under reduced pressure. The residue was crystallized from CH2Cl2/methanol to obtain compound 3 as a mixture with unreacted starting material and dibrominated product which was used in the next step without further purification. White solid (1.34 g, 2.32 mmol). HRMS–APCI–TOF m/z: [M + H]+ calcd for

A series of perylene diimide cathode interlayer materials for green solvent processing in conventional organic photovoltaics

• Kathryn M. Wolfe,
• Shahidul Alam,
• Eva German,
• Fahad N. Alduayji,
• Maryam Alqurashi,
• Frédéric Laquai and
• Gregory C. Welch

Beilstein J. Org. Chem. 2023, 19, 1620–1629, doi:10.3762/bjoc.19.119

• adding a methanol/water mixture; thus, no lengthy purification steps were required for any of the syntheses. Yields of 52.4%, 80.2%, 58.1%, and 68.3% were obtained for PDIN-FB, PDIN-B, CN-PDIN-FB, and CN-PDIN-B, respectively. All compounds were structurally characterized using 1H NMR spectroscopy, 13C

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• relatively low. Thermodynamics dominates the depolymerization of methacrylates [204][205]. Therefore, pyrolysis of PMMA gives a relatively high conversion to its monomer and the purification is straightforward [206][207]. Polyethylene and polypropylene make up a major fraction of commercial polymers. However

Cyclodextrins permeabilize DPPC liposome membranes: a focus on cholesterol content, cyclodextrin type, and concentration

• Ghenwa Nasr,
• Hélène Greige-Gerges,
• Sophie Fourmentin,
• Abdelhamid Elaissari and
• Nathalie Khreich

Beilstein J. Org. Chem. 2023, 19, 1570–1579, doi:10.3762/bjoc.19.115

• sulforhodamine B were purchased from Sigma-Aldrich, USA. 4-Amino-3-hydroxy-1-naphthalene sulfonic acid was purchased from Fluka, India. Sulfuric acid was purchased from ACROS Organics, Belgium and diethyl ether was purchased from VWR-Prolabo Chemicals, Belgium. Liposomes preparation, extrusion, and purification

• (Avanti Polar Lipids, Switzerland) of decreasing pore sizes resulting in a homogenous mixture of LUVs (large unilamellar vesicles). Finally, the purification of the SRB-loaded LUVs to eliminate unencapsulated SRB and lipid molecules from liposomes was carried out via a centrifugation (2 hours, 15 000 rpm

Secondary metabolites of Diaporthe cameroonensis, isolated from the Cameroonian medicinal plant Trema guineensis

• Bel Youssouf G. Mountessou,
• Élodie Gisèle M. Anoumedem,
• Blondelle M. Kemkuignou,
• Yasmina Marin-Felix,
• Frank Surup,
• Marc Stadler and
• Simeon F. Kouam

Beilstein J. Org. Chem. 2023, 19, 1555–1561, doi:10.3762/bjoc.19.112

• reversed phases (RP) were used for the purification of compounds. RP flash and p-HPLC systems (PLC 2050, Gilson, Wisconsin-USA; and Flash and prep HPLC, C-850, Büchi) were equipped with appropriate columns viz., VP Nucleodur C18 HTec (10 µm, 250 × 40 mm, Macherey-Nagel, Germany), Gemini C18 (10 µm, 250

• p-HPLC was obtained from a Milli-Q water purification system (Millipore, Schwalbach, Germany) and all organic solvents and reagents were of analytical grade. Evaporation of solvents from fractions was performed using rotary evaporators equipped with a vacuum controller and diaphragm pump vacuum (Hei

Synthesis of 5-arylidenerhodanines in L-proline-based deep eutectic solvent

• Stéphanie Hesse

Beilstein J. Org. Chem. 2023, 19, 1537–1544, doi:10.3762/bjoc.19.110

• classical organic solvents were used. The expected compounds are recovered by a simple filtration after hydrolysis and no purification is required. Those derivatives were studied for their antioxidant activities and the results are consistent with those reported in the literature indicating that phenolic

• purification steps as a real environmentally benign synthetic process should as far as possible exclude organic solvents from all stages. In a first attempt, vanillin was reacted with rhodanine for 2 h at room temperature in Pro/Gly (1:2) and product 3a was obtained in 57% yield by a simple filtration after

• (0.5 mmol) were sequentially added to the DES and the reaction mixture was stirred at 60 °C for the indicated time. Then, water (10 mL) was added at room temperature and the formed precipitate was collected by filtration and washed with 10 mL of water. No further purification was needed. (Z)-5-(5

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• were obtained from Sigma-Aldrich, Fluka, and Merck with purity class of 99% and were used without further purification. R[4]A (2,4,6,8-tetraisobutyl-1,3,5,7(1,3)-tetrabenzenacyclooctaphan-14,16,34,36,54,56,74,76-octaol) was synthesized according to the procedure described in the paper [32]. Calculation

Functions of enzyme domains in 2-methylisoborneol biosynthesis and enzymatic synthesis of non-natural analogs

• Binbin Gu,
• Lin-Fu Liang and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 1452–1459, doi:10.3762/bjoc.19.104

• elution buffer used for protein purification through Ni2+-NTA affinity chromatography. While domain B alone showed a substantial enzyme precipitation after 12 h at 4 °C, full length 2MIBS did not (Figure 1B), suggesting that the A domain increases enzyme solubility and long-term stability. This effect

• (Karlsruhe, Germany) and used without purification. Solvents for column chromatography were purchased in p.a. grade and purified by distillation. Thin-layer chromatography was performed with 0.2 mm precoated plastic sheets Polygram Sil G/UV254 purchased from Machery-Nagel (Düren, Germany). Column

• ). The combined extracts were dried with MgSO4 and concentrated under reduced pressure to afford the bromide, which was used for phosphorylation without purification. (NBu4)3HP2O7 (4.02 g, 4.46 mmol, 1.5 equiv) was dissolved in acetonitrile (1 mL), and the bromide (mixed with 10 mL acetonitrile) was