Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• is simplified thanks to the ability of 2-propanol to partition from the sodium hydroxide aqueous solution, which allows prompt extraction of the products. Once 2-propanol is evaporated, the products can also be isolated as free amines by dissolving the residue in diethyl ether, decanting it into

• NaOH (10 mL) was added under stirring. The mixture was extracted with 2-PrOH (3 × 10 mL), and the organic extracts were combined, thoroughly dried over MgSO4, and filtered. (I): The residue was concentrated under reduced pressure and dissolved in a large amount of diethyl ether. The amino products were

• precipitated under stirring with an excess of 2 N HCl in diethyl ether solution and the vessel was cooled to 5 °C. The solid was filtered, washed with cold diethyl ether, and dried under reduced pressure as the amine hydrochloride salt. (II) An excess of 4 N HCl in dioxane solution was added and the filtrate

Synthesis of acenaphthylene-fused heteroarenes and polyoxygenated benzo[j]fluoranthenes via a Pd-catalyzed Suzuki–Miyaura/C–H arylation cascade

• Merve Yence,
• Dilgam Ahmadli,
• Damla Surmeli,
• Umut Mert Karacaoğlu,
• Sujit Pal and
• Yunus Emre Türkmen

Beilstein J. Org. Chem. 2024, 20, 3290–3298, doi:10.3762/bjoc.20.273

• via the deprotection of the -OTIPS silyl ether under the reaction conditions. A final MOM-deprotection under acidic conditions led to the formation of the desired benzo[j]fluoranthene 28 in 82% yield. Conclusion In conclusion, we have demonstrated the successful synthesis of heterocyclic fluoranthene

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• such stimuli. When the rotaxane motif contains cyclophane or a crown ether, stimuli induced by a transition metal or an electrostatic interaction have been widely used. These interactions are easily controlled, and they induce relatively strong coordination interactions among the components, making

• acceptable to reduce the production costs, suggesting the industrial potential of this random modification protocol. As suggested by the recent study on the RCP made of crown ether-based [3]rotaxane crosslinker, the force distribution effect worked sufficiently to toughen RCPs, even when the translation

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• molecule of TBHP is oxidized by Fe(III) into tert-butylperoxy radical B. Radical A abstracts a hydrogen atom from ether 78 to give the C-centered radical C. The authors propose two further pathways for the formation of the target product 79. Pathway I: The C-centered radical C is oxidized to carbocation D

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

• Mike Brockmann,
• Jonas Lobbel,
• Lara Unterriker and
• Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

• –CH2–(CF2)n–COOCH3 (n = 2,4,6, Tf = triflate) were synthesized. The triflates were reacted with 2-hydroxy-3,4,5-trimethoxybenzaldehyde via Williamson ether syntheses. The resulting electron-rich compounds were used as aldehydes in the Rothemund reaction with pyrrole to form ester-substituted porphyrins

• –CH2–(CF2)n–COOCH3) with triflate as leaving group in terminal position are easily accessible and versatile building blocks for attaching long chain acids (pKa 0–1) to substrates in Williamson ether-type reactions. Keywords: acid-functionalized porphyrin; electron-rich porphyrin; nickel porphyrin

• ) as the aldehyde component due to its commercial availability. A OH group was introduced to serve as the nucleophile in the Williamson ether synthesis with the triflates 16, 17, and 18 (Scheme 2). Towards this end, 3,4,5-trimethoxybenzaldehyde (19) was iodinated using N-iodosuccinimide (NIS) to give

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• dichloromethane (3 × 20 mL). The combined organic extract was dried over MgSO4, filtered and concentrated under reduced pressure. The crude product was purified by silica column chromatography (SiO2, CH2Cl2/diethyl ether 98:2) to give the title compound as a dark solid (30.0 mg, 13%). Mp 295–296 °C; 1H NMR (400

• extracted with dichloromethane (3 × 20 mL). The combined organic extract was dried over MgSO4, filtered and concentrated under reduced pressure. The crude product was purified by column chromatography (SiO2, petroleum ether/CH2Cl2 1:9) to give the title compound as a dark solid (110 mg, 48%). Analysis is in

• × 20 mL). The combined organic extracts were dried over MgSO4, filtered and concentrated under reduced pressure. The crude product was purified by silica column chromatography (SiO2, CH2Cl2/diethyl ether 98:2) to give the title compound as a dark solid (120 mg, 36%). Mp 241–242 °C; 1H NMR (400 MHz

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• ). Dehydrogenation of the latter with DDQ afforded the anomerically pure indol-N-glycoside β-26a which upon benzylation and methylation gave products β-27a and β-27b, respectively. Iodination gave products β-28a and β-28b, however, due to the basic reaction conditions (I2, NaOH, DMF), ether rather than ester

Mechanochemical difluoromethylations of ketones

• Jinbo Ke,
• Pit van Bonn and
• Carsten Bolm

Beilstein J. Org. Chem. 2024, 20, 2799–2805, doi:10.3762/bjoc.20.235

• efficiently converted to the target products under solvent-free conditions. The reactions proceed at room temperature and are complete within 90 minutes, demonstrating both efficiency and experimental simplicity. Keywords: ball milling; difluorocarbene; difluoromethylations; difluoromethyl enol ether

• standard reaction conditions with difluorocarbene precursor TMSCF2Br (2, 2.0 equiv), activator KFHF (4.0 equiv), and grinding auxiliary CsCl (4.0 equiv), difluoromethyl enol ether 3a was obtained after 90 min reaction time at 25 Hz in 74% yield, determined by quantitative 1H NMR spectroscopy (Table 1

• ketone 1g provided the corresponding product 3g in 56% yield. Difluoromethyl enol ether 3h with three methyl groups was obtained in 56% yield and column chromatography allowed to isolate it in 42% yield. 2-Acetonaphthone was successfully converted to 3i in 66% yield. Besides aryl ketones, arylalkyl

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

• diethyl ether, toluene, hexane, and cyclohexane, (S)-20b was obtained in 30% to 40% yield and significant amounts of unreacted substrate were still observed, although formation of the byproduct 22b could be generally suppressed. We also examined the reaction using other bases instead of DBU. As shown in

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• oxide, activated, neutral, Brockmann I. Petroleum ether (40–60 °C) is abbreviated as PE. HPLC analysis was performed on Agilent HP 1100 equipped with a DAD detector (220 nm) and column ACE Excel 3 C18-AR (3 μm, 3 × 150 mm2). Mass analysis was performed on a Microsaic 4000 MiD® mass spectrometer. HRMS

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• First, we optimized the conditions of the Suzuki–Miyaura cross-coupling in reference to the report by Yang et al. (Table 1) [43]. Upon the treatment of multihalogenated vinyl ether 1a with phenylboronic acid 4a (1.3 equiv) and palladium diacetate (10 mol %) as a catalyst at 40 °C, Suzuki–Miyaura cross

• previous study by Thorand [44], we performed the reaction between fluorine-containing vinyl ether 1a and 1.05 equiv of trimethylsilylacetylene (5a) to afford the corresponding enyne 3a in 55% yield (Table 2, entry 1). Cross-coupling utilizing a palladium(II) catalysts containing phosphine ligands produced

• hardly proceeded at all, and the starting ether 1a was recovered in an 83% yield (Table 2, entry 6). Zero-valent tetrakis(triphenylphosphine)palladium and tris(dibenzylideneacetone)dipalladium allowed the reaction to undergo in 37% or 23% yields, respectively (Table 2, entries 9 and 10). In entry 11

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis

• Jonas Holste,
• Paul Weldon,
• Donald Boyer and
• Stefan Schulz

Beilstein J. Org. Chem. 2024, 20, 2644–2654, doi:10.3762/bjoc.20.222

• secretions of other snakes and reptiles. The most abundant compound cholesterol is a ubiquitous lipid in reptile skin and glands [2]. 1-O-Hexadecylglycerol is the second most abundant SGS component. Such ether lipids have previously been reported from the crotaline Crotalus atrox [6] or the phyton Loxocemus

• (DMDS, 50 µL) and a 0.24 M iodine solution in diethyl ether (5 µL). The mixture was allowed to stand sealed at 40 °C for 15 h. Subsequently, the mixture was diluted with pentane (200 µL) and washed with a saturated sodium thiosulfate solution. The organic phase was dried over sodium sulfate and

• for 18 h. After cooling down to room temperature, water, and diethyl ether were added. The phases were separated and the aqueous phase was extracted three times with diethyl ether. The organic phases were combined, dried over sodium sulfate, filtered, and concentrated for GC–MS analysis [44

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• orbital during enolate formation, thus providing mild redox conditions. After anodic oxidation, a carbon-centered radical at the α-position is formed, which undergoes stereocontrolled C–C-bond formation with the silyl ether, forming a trimethylsilyl (TMS)-ketyl radical. A second anodic one-electron

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• separatory funnel and 10 mL of water are added. The aqueous layer is extracted three times with 10 mL of diethyl ether. The organic layers are combined and washed with 10 mL of water. The organic layer is dried with MgSO4, filtered, and concentrated under vacuum. Compounds 2 are obtained after purification

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• unprotected alcohol is tolerated in our procedure, with product 3l delivered at 50% NMR yield; 3l is sensitive to column chromatography, and thus aziridine-opening to a cyclic ether was observed (31% isolated yield) during purification. Aziridination of cis- or trans-4-octene afforded aziridine 3m as a 1.3

Cell-free protein synthesis with technical additives – expanding the parameter space of in vitro gene expression

• Tabea Bartsch,
• Stephan Lütz and
• Katrin Rosenthal

Beilstein J. Org. Chem. 2024, 20, 2242–2253, doi:10.3762/bjoc.20.192

• dimethyl sulfoxide (DMSO), methanol (MeOH), methyl tert-butyl ether (MTBE), and n-hexane. Measurements in triplicates. 0.5–1% only for MC and CMC. PEG, MC, CMC: % % w/v. Other: % % v/v. Note: 2% PEG-8000 is present as a standard component in all reactions, unless otherwise stated. n.d.: not determined

• ), methylcellulose (MC), carboxymethylcellulose (CMC), choline chloride/urea (ChCl/urea), choline chloride/glycerol (ChCl/glycerol), and betaine/ethylene glycol (betaine/EG). The reference experiment is labeled as shaded bars. B) represents dimethyl sulfoxide (DMSO), methanol (MeOH), methyl tert-butyl ether (MTBE

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• ether (60–90 °C)/ethyl acetate 60:1, v/v) to give 2a (47.3 mg, 91%). Typical procedure for the preparation of β-keto amides 3 (3a as an example) A mixture of (E)-3-(ethylthio)-1-phenyl-3-(phenylamino)prop-2-en-1-one (1a, 70.8 mg, 0.25 mmol), NaOH (30 mg, 0.75 mmol) and PEG-400 (0.236 mL, 0.75 mmol) in

• organic solution was dried with anhydrous Na2SO4, and the crude product was purified by column chromatography on 30–400 mesh silica gel (petroleum ether (60–90 °C)/ethyl acetate 20:1, v/v) to give 3a (53.8 mg, 90%). Synthesis of α-keto thioesters and β-keto amides. Synthesis of β-keto thioesters 2

Electrochemical allylations in a deep eutectic solvent

• Sophia Taylor and
• Scott T. Handy

Beilstein J. Org. Chem. 2024, 20, 2217–2224, doi:10.3762/bjoc.20.189

• funnel with the aid of 10 mL of deionized (DI) water followed by 20 mL of diethyl ether. The organic layer was separated, dried with anhydrous magnesium sulfate, filtered, and the solvent removed in vacuo to afford the crude product, which was first analyzed by 1H NMR spectroscopy and then purified using

• potential conditions of 2 V with no reference electrode until 2.5 F/mol was passed. Following completion of each reaction, the mixture was transferred to a separatory funnel with the aid of 10 mL of DI water followed by 20 mL of diethyl ether. The organic layer was separated, dried with anhydrous magnesium

• funnel with the aid of 10 mL of DI water followed by 20 mL of diethyl ether. The organic layer was separated, dried with anhydrous magnesium sulfate, filtered, and the solvent removed in vacuo to afford the crude product, which was first analyzed by 1H NMR spectroscopy and then purified using flash

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

• 9-O-methyl ether, altenusin, dehydroaltenusin, altertenuol, and altenuene) were frequently found and isolated as fungal contaminants in food and feed and have been investigated in significant detail, further metabolites, which were much more rarely found as natural products, similarly show

• -methylalternariol (2), mostly referred to as alternariol 9-methyl ether, usually abbreviated with AME, and occasionally named djalonensone. It is almost as abundant as alternariol itself and it is hardly possible to catch up with the number of publications on this toxin; the SciFinder database gives at now more

• , 12, and 10 mm, respectively, at 50 μg/disk [148]. There is some evidence that not only alternariol and its 9-O-methyl ether can be present as sulfated conjugates, but that further toxins could similarly be sulfated in the organisms, e.g., altenusin and dehydroaltenusin [149]. Substituted alternariol

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• . Analytical thin-layer chromatography (TLC) was performed on aluminium plates coated with silica gel by using a suitable mixture of EtOAc and petroleum ether for development purpose. Column chromatography was performed by using silica gel (100–200 mesh) with an appropriate mixture of EtOAc and petroleum ether

• product which was then purified by silica gel column chromatography (as suitable mixture of ethyl acetate and petroleum ether) to give the anticipated products in 12 (85%), 15 (80%), and 17 (90%) yields. 1-(5,5,10,10,15,15-Hexabutyl-10,15-dihydro-5H-diindeno[1,2-a:1',2'-c]fluoren-2-yl)ethan-1-one (12

• ): White solid; yield 85%; (0.9 g, starting from 1 g of 10); Rf 0.50 (5% ethyl acetate/petroleum ether); mp 117–120 °C; 1H NMR (400 MHz, CDCl3) δ 8.47 (d, J = 8.3 Hz, 1H), 8.38 (d, J = 6.2 Hz, 2H), 8.08 (s, 1H), 8.02 (d, J = 8.2 Hz, 1H), 7.48 (d, J = 7.5 Hz, 2H), 7.40 (p, J = 7.1 Hz, 4H), 2.97 (m, 6H

From perfluoroalkyl aryl sulfoxides to ortho thioethers

• Yang Li,
• Guillaume Dagousset,
• Emmanuel Magnier and
• Bruce Pégot

Beilstein J. Org. Chem. 2024, 20, 2108–2113, doi:10.3762/bjoc.20.181

• of aryl sulfoxides with difluoroenoxysilanes as nucleophile under mild reaction conditions [46]. This provided access to organosulfur compounds ortho-functionalized by CF2H. At the same time Peng and co-workers described the dearomatization of aryl sulfoxides using the same difluoroenol silyl ether

• was mixed with a sufficient volume of a saturated NH4Cl solution, then extracted 3 times with diethyl ether. The combined organic layers were dried over MgSO4, filtered, concentrated under reduced pressure, and purified by preparative TLC or flash chromatography. [3,3]-Rearrangement of aryl sulfoxides

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• vinyl ether enables the synthesis of 3-alkoxyalkenones 74, presenting an elegant route. Subsequently, these compounds undergo a three-component reaction with various hydrazines, forming 1,3-substituted pyrazoles 75 (Scheme 26) [104]. However, one limitation is the formation of 1,5-substituted pyrazoles

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• solvent for ethyl glyoxylate phenylhydrazone 72a while methyl tert-butyl ether was preferred for aromatic and aliphatic aldehyde-derived hydrazones 72b. Styrenes, enamines as well as electron poor aliphatic alkenes were all suitable dipolarophiles. From a mechanistic point of view, the authors proposed

1,2-Difluoroethylene (HFO-1132): synthesis and chemistry

• Liubov V. Sokolenko,
• Taras M. Sokolenko and
• Yurii L. Yagupolskii

Beilstein J. Org. Chem. 2024, 20, 1955–1966, doi:10.3762/bjoc.20.171

• synthesis of 1,2-difluoroethylene based on perfluoropropyl vinyl ether as starting material can be found (Scheme 7). Consequently, two methods to prepare 1,2-difluoroethylene in the laboratory have been described to date. Even though at least five approaches to HFO-1132 can be found in patent literature, it

• -Difluoroethylene synthesis from perfluoropropyl vinyl ether. Deuteration reaction of 1,2-difluoroethylene. Halogen addition to 1,2-difluoroethylene. Hypohalite addition to 1,2-difluoroethylene. N-Bromobis(trifluoromethyl)amine addition to 1,2-difluoroethylene. N-Chloroimidobis(sulfonyl fluoride) addition to 1,2

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162