Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• stirring speed of 560 rpm. The regions of interests (ROIs) shown on frame of 1.2 s are denoted as left side (blue ROI), draft tube (green ROI), and right side (yellow ROI). The color of water changed first in the draft tube and then outside the draft tube until the mixing was complete. Thus, the liquid was

• with a heating rate of 10 °C min−1. The resulting yellow solid was then finely grounded using an agate mortar. For the photochemical deposition of the Pt co-catalyst, 6 g of the produced PCN were first dispersed in 340 mL of water and subjected to sonication for 90 min. Subsequently, a mixture

• Supporting Information File 1, Figure S2b), while maintaining a continuous flow of N2 in the headspace through a septum. The resulting suspension exhibited a yellow/greenish color and was subsequently washed with deionized water 3–5 times, followed by drying at 70 °C overnight and grinding. The synthesized

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

• ) degassed with N2 for 15 min was added, and the solution was heated to 105 °C for 18.5 h. The reaction mixture was then allowed to cool to rt, diluted with toluene (20 mL), and washed with 1 M NaOH (3 × 20 mL), and then with H2O (20 mL). The yellow precipitate in the aqueous phase was isolated by filtration

• and washed with H2O before it was purified by flash column chromatography (SiO2, 50%–100% CH2Cl2/heptane) yielding 16 (18 mg, 39 μmol, 25%) as a yellow solid. Rf = 0.18 (50% CH2Cl2/heptane); mp > 260 °C; 1H NMR (500 MHz, CD2Cl2) δ 7.84 (d, J = 7.5 Hz, 2H), 7.77 (d, J = 8.1 Hz, 2H), 7.75 (d, J = 7.5 Hz

• compound is shown below, in which the hydrogen atoms are omitted for clarity. Atoms are colored grey (carbon), white (hydrogen), brown (bromine), pale-yellow (silicon). Labels of bonds within five-membered ring. Synthesis of IF-DTF ketones 9–12 and dimer 13. Further functionalization of the IF-DTF ketone

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

• . (a) Photograph of the DWCNT film. Thicknesses were measured at 7 spots along the yellow dashed line. Scale bar is 1 cm. SEM image at spot (b) A and (c) D. Blue outlined arrows indicate the shear direction of bar-coating. The list of the thickness at each spot in Figure 5a. Supporting Information

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• with allyl alcohol (in both cases using a molar ratio of 1:1.05 and dichloromethane as the solvent). While in the latter case only the starting materials were observed after 24 h at room temperature, the reaction of 1 with acrylonitrile turned yellow during the same time and exclusively yielded the

• between P1 and C15 is slightly longer (1.824(2) Å in 2a; 1.828(3) in 2f) when compared to the P–CH2 distance of a tetra-n-butylphosphonium cation [45]. UV–vis spectroscopy All phosphonium phenolate compounds exhibit a bright yellow color in solution (see inset in Figure 3). Investigating the absorption

• screw-cap vial. The Michael acceptor acrylamide (14.9 mg, 0.21 mmol, 1.05 equiv) was dissolved in 0.5 mL dichloromethane in a separate vial and then added dropwise to the solution of 1. Zwitterion formation was indicated by a color change of the solution to yellow. The reaction mixture was stirred at

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

• methyl iodide yielding PA-CH3’, followed by ion exchange using an exchange resin to provide PA-CH3 as a yellow solid (74% yield over 2 steps; Figure 2a). Despite its large aromatic framework with a monocationic core, PA-CH3 was found to be soluble in water up to ≈0.9 mM. Using similar procedures

• -doped nanocarbon g-C3N4 was achieved using aromatic micelle (PA-OCH3)n (Figure 6a). The multiple N-atoms bestow g-C3N4 with unique properties that are responsible for its widespread use in catalysis [28]. Subjecting yellow solid PA-OCH3 (1.2 mg, 1.9 μmol) and pale yellow solid g-C3N4 (1.0 mg) to the

• grinding (3 min) and sonication (30 min) protocol provided a clear yellow aqueous solution of (PA-OCH3)n·(g-C3N4)m. The formation of the host–guest structure was confirmed by UV–visible analysis, which showed a new absorption band around 312 nm (Figure 6b). This result showcased the ability of amphiphile

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• )-5-Amino-1-benzyl-N'-(thiazol-2-yl)-1H-1,2,3-triazole-4-carboximidamide (3l). Compound 3l was obtained in 88% yield (117 mg) according to the general procedure B (NaOH: 20 mg, 0.5 mmol; amidine 1a: 77 mg, 0.5 mmol; azide 2c: 56 mg, 0.5 mmol; ethanol (2 mL)) as light yellow needles; mp 199–200 °C; 1H

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• ). Graphical representation of the ligands’ starting (in red, licorice) and final (in blue, licorice) positions in regard of the binding site of basic fibroblast factor (in yellow, new cartoon). Graphical representation of the ligand’s starting (in red, licorice) and final (in blue, licorice) poses in regard

• of the binding site of acidic fibroblast factor (in yellow, new cartoon). Graphical representation of the ligand 4 starting (in red, licorice) and final (in blue, licorice) position in regard of binding site of cathepsin K (in yellow, new cartoon). Comparison of the last frame of the US simulation

Construction of diazepine-containing spiroindolines via annulation reaction of α-halogenated N-acylhydrazones and isatin-derived MBH carbonates

• Xing Liu,
• Wenjing Shi,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 1923–1932, doi:10.3762/bjoc.19.143

• ): yellow solid, 0.370 g, 71%; mp 186–187 °C; 1H NMR (400 MHz, CDCl3) δ 8.61 (s, 1H, ArH), 7.75–7.72 (m, 2H, ArH), 7.57–7.53 (m, 1H, ArH), 7.47–7.43 (m, 2H, ArH), 7.35–7.31 (m, 2H, ArH), 7.30–7.27 (m, 5H, ArH), 7.26–7.23 (m, 1H, ArH), 7.22–7.18 (m, 2H, ArH), 7.05–7.02 (m, 1H, ArH), 6.96 (s, 1H, ArH), 6.73

• '-carboxylate (5a): yellow solid, 0.391 g, 68%; mp 189–191 °C; 1H NMR (400 MHz, CDCl3) δ 9.19 (s, 1H, ArH), 7.73–7.71 (m, 2H, ArH), 7.56–7.53 (m, 1H, ArH), 7.48–7.42 (m, 4H, ArH), 7.38–7.35 (m, 2H, ArH), 7.32–7.31 (m, 1H, ArH), 7.29–7.27 (m, 1H, ArH), 7.14 (t, J = 8.0 Hz, 2H, ArH), 7.09–7.05 (m, 3H, ArH), 6.86

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

• 10 000 cd m−2, electroluminescence ranging from blue to yellow, maximum current of 15 cd/A and higher EQE than 7%. Pyridine-3,5-dicarbonitrile-based TADF materials exhibit different visible light emission spectra (Figure 1). Recently, Chen and Lu reported two new orange-red/red TADF emitters composed

• be soluble in common organic solvents and to exhibit non-structured emission peaks in the green-yellow color region of the spectrum. The PL intensity of the compounds in solution was enhanced after deoxygenation, indicating the presence of triplet harvesting by the mechanism of thermally activated

• 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

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• organic layer was dried over Na2SO4, filtered and the solvent was evaporated under reduced pressure. The crude product was purified by flash column chromatography eluting with a mixture of n-hexane/CH2Cl2 3:1 and then crystallized from ethanol to give the title compound DMB-TT-TPA (8) as a yellow powder

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

• ) and triethylamine (1.09 mL, 8.26 mmol, 10.2 equiv) were dissolved in dichloromethane (8.8 mL). Then, a solution of 3,4,5-tris(octadecyloxy)benzoyl chloride (11, 729.3 mg, 0.77 mmol) in dichloromethane (22 mL) was added. To the resulting yellow solution further dichloromethane (12.6 mL) was added, and

• product was purified by preparative thin-layer chromatography (SiO2, hexane/ethyl acetate 2:1, Rf 0.36) to obtain the product (S)-14 as pale-yellow crystals. The products had the same spectroscopic data than those of reported (the absolute configuration was determined by the optical rotation of the

• temperature. Then, the solvent was evaporated, and the crude product was purified by preparative thin-layer chromatography (SiO2, hexane/ethyl acetate/AcOH 2:1:0.01, Rf 0.34) to obtain the product as a pale-yellow foam. To the best of our knowledge, the synthesis of (S)-17 has not been reported so far. TLC

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

• saturated aqueous NaHCO3 until a suspension formed, and cooled (0 °C). The precipitate was filtered, washed with ice-cold H2O, petroleum ether, and dried to give compound 13 (0.035 g, 61%) as a light yellow solid. An analytically pure sample (a light yellow solid) was obtained after crystallization from

• : Compound 13 (0.034 g, 59%) as a light yellow solid was prepared from macrocycle 5 (0.055 g, 0.17 mmol), СН(ОЕt)3 (4 mL) and НСООН (0.016 mL) (reflux, 8 h) as described in Method A. 5-Acetylamino-4-imino-2-methylpyrazolo[3,4-d]pyrimidine (14): A suspension of macrocycle 5 (0.304 g, 0.93 mmol) in AcOH (15 mL

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

• beige and light-yellow solids with 78% and 44% yield, respectively. Thermal analyses between 25 and 350 °C were performed in order to verify the hydration status of the bulk. Regarding hdz-CH3, a weight loss of 9.78% from around 80 to 190 °C was observed, suggesting the presence of two crystallization

• of the resulting hydrazone: a considerable amount of hdz-NO2 deprotonates immediately upon dilution in the aqueous-rich medium at pH 7.4, affording a deep yellow solution due to phenolate-based absorptions centered at around 440 nm. For this reason, we decided to investigate this deprotonation by

• spectrum of this precursor at pH 3.8 (dotted dark yellow curve). On the other hand, under similar arguments, the constituent at 284 nm is probably related to a TMP-based transition. In contrast, the intense component at 307 nm has no parallel in the spectra of precursors and was consequently attributed to

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• versatility of quinoxaline derivatives in tailoring the emission properties of TADF materials. The vacuum deposited OLEDs based on Qx63 and Qx64 emitted yellow and red light, achieving EQEs of 17.3% and 15.6%, respectively [63]. You and co-workers reported the strategic design of a series of butterfly-shaped

• indicated efficient charge transfer and exciton formation within the molecule, leading to red emission. The achieved EQE of 7.4% highlighted the potential application of this Qx-based TADF emitter as dopant in red-emitting OLED devices [65]. Huang et al. developed two yellow TADF emitters, Qx67 and Qx68

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

• -diacetylalternariol (2) (Figure 1), together with fifteen known compounds (Figure S1 in Supporting Information File 1). Compound 1 was obtained as a yellow oil. Its molecular formula, C12H14O4 that fits with six double bond equivalents, was established from the positive-ion mode HRESIMS (Figure S2, Supporting

• the stationary phase and the solvent mixture CH2CH2/MeOH 92:8 (v/v) as the mobile phase. The elution was performed for 25 min each with a flow rate of 2 mL/min, an automatic pressure in the range of 1–10 bar and the UV absorptions were set at 210, 254, and 366 nm to yield compounds 15 (3.2 mg, yellow

• oil, tR = 8 min), 9 (1.3 mg, yellow oil, tR = 14 min), 3 (2.76 mg, white neat solid, tR = 16 min), and 1 (0.79 mg, yellow oil, tR = 22 min), respectively. Series E (294 mg) was further purified to yield compounds 5 (0.95 mg, white amorphous powder, tR = 35.20 min), 17 (6.1 mg, white amorphous powder

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

• aldehydes to study the scope of this reaction (Scheme 1). It must be noted that in most of the cases, the reaction mixture changed its appearance from colorless to yellow or orange and that some solid precipitate formed during the reaction. The addition of water at the end of the reaction clearly led to the

• give a purple solution and present a strong absorption maximum at 517 nm. In the presence of an antioxidant compound DPPH is reduced forming DPPH-H and the color of the solution changes to yellow. The overall antioxidant capacity of compounds was measured after 30 minutes of incubation. We used the

• -Hydroxymethylfurfurylidene)-2-thioxothiazolidin-4-one (3j). ochre yellow solid obtained after 1 h at 60 °C in 36% yield (two-step yield). Mp 149 °C; 1H NMR (400 MHz, DMSO-d6) δ (ppm) 4.49 (s, 2H), 5.52 (br s, 1H, OH), 6.58 (d, J = 3.6 Hz, 1H), 7.11 (d, J = 3.6 Hz, 1H), 7.44 (s, 1H, =CH), 13.62 (br s, 1H, NH); 13C NMR (100

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• -oxoberberine has been reported as a white solid, while our oxidized product maintained the bright yellow color of berberine [38]. This same unexpected oxidation was observed, to varying degrees, in the production of our next two variants wherein the expected products B3 and B5, respectively were isolated as a

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

• benzoguanidine donor and compare it with the benchmark carbazole-based material (4CzIPN). Extended π-conjugation in 4BGIPN material results in yellow-green luminescence at 512 nm with a fast radiative rate of 5.5 × 10−5 s−1 and a photoluminescence quantum yield of 46% in methylcyclohexane solution. Such a

• : guanidine; organic; photoluminescence; TADF; yellow; Introduction Thermally activated delayed fluorescence (TADF) is a photoluminescence mechanism where excitons undergo thermally-assisted reverse-intersystem crossing from an excited triplet state to a higher-lying in energy singlet state to emit delayed

• dichloromethane solution for 4BGIPN at room temperature (Figure 2). The title compound crystallizes with two independent molecules in the unit cell of the triclinic (P−1, Figure 2c, yellow plates) and monoclinic chiral space group P21 (Figure 2a,b,d, yellow blocks). Due to very weak reflection data, the structure

Two new lanostanoid glycosides isolated from a Kenyan polypore Fomitopsis carnea

• Winnie Chemutai Sum,
• Sherif S. Ebada,
• Didsanutda Gonkhom,
• Cony Decock,
• Rémy Bertrand Teponno,
• Josphat Clement Matasyoh and
• Marc Stadler

Beilstein J. Org. Chem. 2023, 19, 1161–1169, doi:10.3762/bjoc.19.84

• , nm (log ε): 196.5 (1.7); NMR data (1H NMR: 500 MHz, 13C NMR: 125 MHz in methanol-d4) see Table 1; HRMS–ESI (m/z): [M + Na]+ calcd for C43H68NaO12+, 799.4603; found, 799.4604; [2M + Na]+ calcd for C86H136NaO13+, 1575.9314; found, 1575.9321. Forpinioside C (2): pale yellow oil; +30 (c 0.1, MeOH); UV

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

The effect of dark states on the intersystem crossing and thermally activated delayed fluorescence of naphthalimide-phenothiazine dyads

• Liyuan Cao,
• Xi Liu,
• Xue Zhang,
• Jianzhang Zhao,
• Fabiao Yu and
• Yan Wan

Beilstein J. Org. Chem. 2023, 19, 1028–1046, doi:10.3762/bjoc.19.79

• dried over anhydrous Na2SO4 and the solvent was evaporated under reduced pressure. The crude product was purified by column chromatography (silica gel, DCM/MeOH 50:1, v:v) and the product was obtained as yellow solid. Yield: 28 mg (76%); mp 100.1–101.0 °C; 1H NMR (CDCl3, 400 MHz) δ 8.87 (d, J = 7.63 Hz

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• comparison of their spectroscopic data with those reported in the literature (Figure 1). The new derivatives were characterized as explained below. Compound 1 was obtained as pale yellow gum, and its molecular formula was inferred from the positive HRESIMS at m/z 273.1464 [M + Na]+ (calcd for C15H22O3Na

• calculations. The CD spectrum matched well with the calculated ECD spectrum of 1a (Figure 4), revealing the absolute configuration of 1 to be 7R,10S, and it was named aquisinenoid F. Compound 2 was isolated as pale yellow gum, and was assigned the molecular formula C15H24O2 as inferred from the HRESIMS m/z

• 2 was eventually clarified to be 7S,8R,10S, and it was named aquisinenoid G. Compound 3 was isolated as pale yellow gum, and its molecular formula was determined to be C15H24O3 based on its HRESIMS m/z 275.1622 [M + Na]+ (calcd for C15H24O3Na, 275.1618), 13C NMR and DEPT spectra (Table 2

The unique reactivity of 5,6-unsubstituted 1,4-dihydropyridine in the Huisgen 1,4-diploar cycloaddition and formal [2 + 2] cycloaddition

• Xiu-Yu Chen,
• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2023, 19, 982–990, doi:10.3762/bjoc.19.73

• ) as eluent to give the pure product for analysis. 7,8-Diethyl 4-methyl 2-benzyl-3-methyl-5-(4-nitrophenyl)-2-azabicyclo[4.2.0]octa-3,7-diene-4,7,8-tricarboxylate (5e): yellow solid, 36%; mp 161–163 °C; 1H NMR (400 MHz, CDCl3) δ 8.07–8.05 (m, 2H, ArH), 7.37–7.34 (m, 2H, ArH), 7.33–7.29 (m, 3H, ArH

• ): [M + H]+) calcd for C29H31N2O8, 535.2075; found, 535.2076. 4,5-Diethyl 3-methyl 1-benzyl-2-methyl-3a-(4-nitrophenyl)-1,3a,4,6a-tetrahydrocyclopenta[b]pyrrole-3,4,5-tricarboxylate (6e): yellow solid, 35%; mp 153–155 °C; 1H NMR (400 MHz, CDCl3) δ 7.98 (d, J = 8.8 Hz, ArH), 7.45–7.37 (m, 5H, ArH), 7.30

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• volume of 100 mL, hence yielding the blue CAS assay solution. To perform the assay, 1 mL of the CAS assay solution was pipetted into a cuvette followed by the addition of 0.2 mL of the substance to be tested. A color change from blue to yellow indicated the presence of metal-chelating molecules. Filter

First synthesis of acylated nitrocyclopropanes

• Kento Iwai,
• Rikiya Kamidate,
• Khimiya Wada,
• Haruyasu Asahara and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2023, 19, 892–900, doi:10.3762/bjoc.19.67

• , 80 mmol), the mixture was extracted with ethyl acetate (30 mL × 3), and the organic layer was washed with brine (30 mL × 1), dried over magnesium sulfate, and concentrated to afford nitrostyrene 2a (17.4 g, 71%, mp 56–58 °C) as a yellow solid. Nitrostyrene 2b (mp 112–114 °C) was prepared in the same

• ethyl benzoylacetate (3f, 1.04 mL, 6 mmol) and triethylamine (84 μL, 0.6 mmol), and the resultant solution was stirred at room temperature for 14 h. After removal of the solvent under reduced pressure, the residual pale-yellow solid was extracted with hot hexane (20 mL × 4). The hexane was concentrated

• , and the residual yellow oil was subjected to column chromatography on silica gel to afford ethyl 2-benzoyl-3-(4-methylphenyl)-4-nitrobutanoate (4f) [28] (eluted with hexane/ethyl acetate 95:5, 1.43 g, 4.02 mmol, 67%) as a pale-yellow oil. Major isomer 1H NMR (400 MHz, CDCl3) δ 0.92 (t, J = 7.2 Hz, 3H