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

• platinum disk (diameter = 1.6 mm) or a glassy carbon disk (3 mm) was used as the working electrode. The reference electrode was separated from the solution containing the substrate by a ceramic frit. Measured potentials were referenced to ferrocene/ferrocenium (Fc/Fc+) redox couple, measured before and

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• microscopy (AFM) (see Supporting Information File 1, Figure S2). In both images, rod-like DWCNTs were observed, while spaghetti-like agglomerates were hardly observed. The average length (L) and diameter (D) of the DWCNT samples were ≈2.9 μm and ≈2.1 nm, respectively. The L/D of the DWCNTs was 1378, which

• was larger than the value reported in previous research (L/D = 1088) [23]. Based on the transmission electron microscope (TEM) images, the average diameter of DWCNTs was ≈1.8 nm (Supporting Information File 1, Figure S1a). Since the observed DWCNT diameter based on the SEM images is ≈2.1 nm, the

• similar to the previously reported SWCNTs in sodium deoxycholate (SDOC) and sodium taurodeoxycholate (TDOC) aqueous dispersions [23]. The average diameter of DWCNTs in the present study was 2.1 nm, which was almost the same as that of SWCNTs in SDOC and TDOC [23]. Thus, the effect of stiffness of DWCNTs

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• ; Figure S36 in Supporting Information File 1). The formation of spherical particles with narrow size distribution and an average diameter of ≈2 nm was confirmed by DLS and DOSY NMR measurements (Figure 3e and Figure S27 in Supporting Information File 1). Based on molecular modeling, these data suggested

• )m was roughly estimated to be 0.1 mg mL−1. The DLS measurement of (PA-Im)n·(C60)m displayed an average particle diameter of ≈2 nm, which, in combination with molecular modeling, indicated a noncovalent surface functionalization of a single C60 molecule by five PA-Im amphiphiles (Figure 4d,e

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

• nm, further allowing us to analyze the luminescence dynamics in detail. To determine photoluminescence quantum yields (PLQY), a dedicated integrated sphere with an inner diameter of 120 mm was used in conjunction with the Edinburgh Instruments FLS980 spectrometer. This specialized setup enabled

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

• . Experimental General experimental procedures Column chromatography (60.4 cm length × 5.5 cm inner diameter) was carried out on silica gel 230–400 mesh (Merck). Analytical TLC was performed on Merck pre-coated silica gel 60 F254 plates, and spots were detected using ceric sulfate spray reagent and/or diluted

Organic thermally activated delayed fluorescence material with strained benzoguanidine donor

• Alexander C. Brannan,
• Elvie F. P. Beaumont,
• Nguyen Le Phuoc,
• George F. S. Whitehead,
• Mikko Linnolahti and
• Alexander S. Romanov

Beilstein J. Org. Chem. 2023, 19, 1289–1298, doi:10.3762/bjoc.19.95

• (CV) was performed using a three-electrode configuration consisting of a glassy carbon macrodisk working electrode (GCE) (diameter of 3 mm; BASi, Indiana, U.S.A.) combined with a Pt wire counter electrode (99.99%; GoodFellow, Cambridge, U.K.) and an Ag wire pseudoreference electrode (99.99

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• small value, which means that even at a partial pressure of 5 bar less than 1/2 the CD cavity is filled. The rationale for the poor binding is probably the large discrepancy between the size of CO2 and the CD cavity. 1 has a cavity of 174 Å3 while CO2 is a very small molecule with kinetic diameter of

• and 6 containing 3,6-anhydrides in the α-cyclodextrin structure were chosen because they have a smaller cavity according to modelling. In models the diameter of 5 was measured and it was 5.0 Å and that of 6 was 4.6 Å with an α-CD height of 7.9 Å to give the cavity volumes given in Table 2. These

Honeycomb reactor: a promising device for streamlining aerobic oxidation under continuous-flow conditions

• Masahiro Hosoya,
• Yusuke Saito and
• Yousuke Horiuchi

Beilstein J. Org. Chem. 2023, 19, 752–763, doi:10.3762/bjoc.19.55

• [23] or a static mixer [24]. Slug-flow is a simple method for passive mixing, but the formation of slug-flow depends on the tube diameter [23], and the reaction rate decreases as the tube diameter increases [25][26]. The gas–liquid biphasic reaction also displays the same characteristic, and a static

• with a static mixer, the reaction rate did not depend on the flow rate although the reaction conversion was higher than that in the standard tube reactor (Table 3, entries 3 and 4). The tube reactor with a static mixer had a large inner diameter and the linear velocity became correspondingly low. The

C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• File 1, p. S8). All the content of the loop is thus sent into the reactor. This system is coupled to a gas chromatography oven, in which the stainless-steel tubular reactor (length: 4.6 m, internal diameter of 0.8 millimeter, corresponding to a volume of 2.31 mL) is placed. The system pressure is

• degradation under longer heating. In addition, we found that the comp1 [Ru3(CO)11(L1)] was more efficient when the reaction mixture was preheated before being introduced into the reactor at 200 °C. The setup was thus modified (Scheme 3) to include a 0.8-millimeter-diameter stainless-steel preheating loop

Mechanochemical solid state synthesis of copper(I)/NHC complexes with K₃PO₄

• Ina Remy-Speckmann,
• Birte M. Zimmermann,
• Mahadeb Gorai,
• Martin Lerch and
• Johannes F. Teichert

Beilstein J. Org. Chem. 2023, 19, 440–447, doi:10.3762/bjoc.19.34

• -methylguanidino)ethyl)-3-mesityl-1H-imidazol-3-ium bromide (3, 75 mg, 0.16 mmol, 1.0 equiv), CuCl (17 mg, 0.16 mmol, 1.0 equiv) and K3PO4 (53 mg, 0.25 mmol, 1.5 equiv) were filled into a 12 mL steel vessel equipped with six steel balls (1 cm diameter). The beaker was sealed in an argon-filled glovebox. Milling

• procedure: steel vessel (12 mL), 6 steel balls (1 cm diameter), 450 rpm, 4 h). (dimer = [(NHC)2Cu+]Cl−). Supporting Information Supporting Information File 36: General procedures, experimental details, analytical data and copies of NMR spectra. Acknowledgements Prof. Dr. Martin Oestreich (TU Berlin) is

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• middle of the wells after centrifugation. Within 3 days, cells that interacted maximally with each other formed highly spherical tumors measuring about 200 μm in diameter (Figure 7). According to the results of the anticancer activity analysis performed in the 3D cell culture studies, at the end of the

Nostochopcerol, a new antibacterial monoacylglycerol from the edible cyanobacterium Nostochopsis lobatus

• Naoya Oku,
• Saki Hayashi,
• Yuji Yamaguchi,
• Hiroyuki Takenaka and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2023, 19, 133–138, doi:10.3762/bjoc.19.13

• lobatus is a freshwater species distributed in every climate zone but polar regions [8]. It grows on riverbed rocks or cobbles in shallow streams and forms spherical to irregularly lobed, hollow, gelatinous colonies, with sizes reaching up to 5.5 cm in diameter [9]. Although cosmopolitic, its occurrence

• According to a procedure described in [6], the antimicrobial potency of chromatographic fractions was evaluated by a paper disk-agar diffusion method. Fractions at each purification stage were diluted to the same concentration with MeOH, and 10 μL aliquots were impregnated into 6 mm-diameter paper disks

Modern flow chemistry – prospect and advantage

• Philipp Heretsch

Beilstein J. Org. Chem. 2023, 19, 33–35, doi:10.3762/bjoc.19.3

• diameter can both accelerate the transformations as well as lead to significantly less side products by continuously removing the products from the irradiation source. As an example, Noël and co-workers performed efficient irradiation in flow for the C(sp3)–H functionalization of gaseous hydrocarbons [8

Mechanochemical synthesis of unsymmetrical salens for the preparation of Co–salen complexes and their evaluation as catalysts for the synthesis of α-aryloxy alcohols via asymmetric phenolic kinetic resolution of terminal epoxides

• Shengli Zuo,
• Shuxiang Zheng,
• Jianjun Liu and
• Ang Zuo

Beilstein J. Org. Chem. 2022, 18, 1416–1423, doi:10.3762/bjoc.18.147

• alumina composite balls (3.20 mm and 2.16 mm in diameter, respectively). Considering the safety in the synthesis of unsymmetrical salens, the working speed was set to be 700 rev/min. Similarly to the above reaction conditions, amounts of chemicals and workup, the first reaction step between amino

From amines to (form)amides: a simple and successful mechanochemical approach

• Federico Casti,
• Rita Mocci and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 1210–1216, doi:10.3762/bjoc.18.126

• that milling balls of larger diameter led to more rapid transformations [59][60]. On the other side, previously reported procedures revealed a beneficial effect on the reaction rate when the volume fraction occupied by balls inside the reactor increases. In addition, it was found that in some certain

Thermally activated delayed fluorescence (TADF) emitters: sensing and boosting spin-flipping by aggregation

• Ashish Kumar Mazumdar,
• Gyana Prakash Nanda,
• Nisha Yadav,
• Upasana Deori,
• Upasha Acharyya,
• Bahadur Sk and
• Pachaiyappan Rajamalli

Beilstein J. Org. Chem. 2022, 18, 1177–1187, doi:10.3762/bjoc.18.122

• % water/THF) of BPy-pTC were characterized using scanning electron microscopy (SEM). The SEM image showed the spherical nanoaggregates of BPy-pTC, with 95 nm diameter (Figure 3f). The BPy-p3C compound emitted in the green region at λem = 530 nm in THF, with a PLQY of 3.6% (Figure 3a). Similar to BPy-pTC

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• low flow rate (10 μL/min) [43][44]. An alternative approach to obtain a narrower RTD is the reduction of the reactor diameter, as this would decrease the axial dispersion [45]. Replacing the glass column (i.d. 6.6 mm) with a PTFE capillary with a smaller inner diameter (i.d. 5/32”, 3.9 mm) resulted in

Electroreductive coupling of 2-acylbenzoates with α,β-unsaturated carbonyl compounds: density functional theory study on product selectivity

• Naoki Kise and
• Toshihiko Sakurai

Beilstein J. Org. Chem. 2022, 18, 956–962, doi:10.3762/bjoc.18.95

• ) was placed in the cathodic chamber of a divided cell (40 mL beaker, 3 cm diameter, 6 cm height) equipped with a platinum cathode (5 × 5 cm2), a platinum anode (2 × 1 cm2), and a ceramic cylindrical diaphragm (1.5 cm diameter). A 0.3 M solution of Bu4NClO4 in DMF (4 mL) was placed in the anodic chamber

Palladium-catalyzed solid-state borylation of aryl halides using mechanochemistry

• Koji Kubota,
• Emiru Baba,
• Tamae Seo,
• Tatsuo Ishiyama and
• Hajime Ito

Beilstein J. Org. Chem. 2022, 18, 855–862, doi:10.3762/bjoc.18.86

• ). The reactions were conducted in a Retch MM400 ball mill in a stainless-steel milling jar (1.5 mL) at 30 Hz using one stainless-steel ball (diameter: 5 mm) for 10 min. We used a commercially available temperature-controllable heat gun that was placed directly above the ball-milling jar to control the

• scale (Scheme 5). We carried out the reaction of 1a at 5 mmol in the presence of the optimized catalytic system using a 25 mL stainless-steel jar and four stainless-steel balls (diameter: 10 mm) at 25 Hz and a preset heat-gun temperature of 150 °C. The gram-scale borylation proceeded efficiently and

• mixture of 1 (0.30 mmol), 2 (0.36 mmol), KOAc (0.9 mmol), Pd(OAc)2 (0.006 mmol), t-Bu3·HBF4 (0.009 mmol), and H2O (60 μL) was milled in a 1.5 mL stainless-steel jar at 30 Hz using one stainless-steel ball that was 5 mm in diameter. The isolated yields are shown. The NMR yields are shown in parentheses

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• parameters are critical to the heat release of magnetic nanoparticles and can vary for different particle types. Coercivity is an inherent property of magnetic nanoparticles that reaches a maximum at a critical diameter of magnetic nanoparticles from multidomain to single domain structures. In hysteresis

• could be achieved with high flow rates (125 mL/min; reactor dimensions according to SI: 2 cm diameter and 1 cm height of catalyst filling) in an external electromagnetic field of 28 mT. Heating can be problematic when exothermic reactions are performed. To prevent catalyst deactivation, the group of

Rapid gas–liquid reaction in flow. Continuous synthesis and production of cyclohexene oxide

• Kyoko Mandai,
• Tetsuya Yamamoto,
• Hiroki Mandai and
• Aiichiro Nagaki

Beilstein J. Org. Chem. 2022, 18, 660–668, doi:10.3762/bjoc.18.67

• devices. For a reactor, widely-used 1/8 inch stainless-steel tubing with a relatively large inner diameter (2.17 mm) was used to establish a readily applicable flow system for industrial use. A solution of cyclohexene and isobutyraldehyde in 1,2-dichloroethane was pumped out by a diaphragm pump. The

• ratio of aldehyde and oxygen to 1:9. The liquid and gas phases were combined at a T-shaped mixer with a 1 mm inner diameter and flowed through a stainless-steel tube reactor immersed in heated silicon oil for reaction temperature control. The inner pressure was maintained at 0.9 MPa using a back

DDQ in mechanochemical C–N coupling reactions

• Shyamal Kanti Bera,
• Rosalin Bhanja and
• Prasenjit Mal

Beilstein J. Org. Chem. 2022, 18, 639–646, doi:10.3762/bjoc.18.64

• conditions: reactants were milled at 21 Hz in a 25 mL milling jar containing one stainless-steel grinding ball (15 mm in diameter). Optimization of the reaction conditions.a Supporting Information Supporting Information File 46: Experimental details, characterization data, copies of NMR spectra and X-ray

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• against the pathogenic fungal strains Aspergillus fumigatus and Candida albicans. The sensitivity of the organisms was assayed against the activity of tested compounds solutions (at 10 mg/mL concentration) using a modified agar well diffusion method with determination of the inhibition zone diameter in mm

• inhibition zone diameter using the agar well diffusion method. The structure–activity relationship (SAR) elaborated that piperazines with aliphatic groups on the nitrogen atom are more active than those with aromatic substituents against the fungus C. albicans. On the other hand, compounds comprising

• compounds 4a–v. In vitro antimicrobial activities of the synthesized compounds tested at 10 mg/mL by modified well diffusion agar method and expressed as mean inhibition zone diameter (mm). Minimum inhibitory concentrations (MIC, µg/mL) of the synthesized compounds determined by microdilution method

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• capillaries with a smaller inner diameter (50 µm). If the position of the equilibrium was investigated, high residence times were required, resulting in low flow rates and pressure built-up. To circumvent this bottle neck, a circular reactor was designed. A flow rate can be chosen in order to achieve the

• rate) when particles with the original size distribution were used. Since the diameter of the original particles is 0.5 mm and the inner diameter of the reactor is only 3 mm, wall effects occur [38][39]. When pestled particles were used, the mean residence time was 0.66 min by pumping 0.21 mL/min

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• -like nanostructure (diameter = 748 nm). After the loading of EsY into m-TPEWP5G, the worm-like structure changed into a nanorod (diameter = 652 nm) assembly via electrostatic interactions. In comparison, the diameter and length of the m-TPEWP5G assembly were slightly higher than that of m-TPEWP5G-EsY