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

• ]. The vicinal diols 208 were preferably obtained in water, but bisperoxides 207 were isolated in high yields using Na2CO3 as the additive, and propylene carbonate (PC) as the solvent. The reaction mechanism involves the formation of tert-butylperoxy A and tert-butoxy B radicals during the iodine

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

• carbonate was added (300 mg, 2.04 mmol), and the reaction mixture was stirred at 100 °C overnight. After cooling the reaction mixture to room temperature, it was poured into methanol (200 mL), and the resulting precipitate was filtered, then washed with water (150 mL) to give the title compound as a dark

• mmol) and 1-bromooctane (2.12 mL, 12.28 mmol) were dissolved in N,N-dimethylformamide (60 mL). Then, potassium carbonate was added (1.13 g, 8.19 mmol), and the reaction mixture was stirred at 100 °C overnight. After cooling the reaction mixture to room temperature, it was poured into methanol (400 mL

• ]+ calcd for C50H48NaO4, 753.3409; found, 735.3445. Compound 2c 16,17-Dihydroxyviolanthrone (500 mg, 1.02 mmol) and 1-bromododecane (800 μL, 3.06 mmol) were dissolved in N,N-dimethylformamide (30 mL). Then, potassium carbonate was added (300 mg, 2.04 mmol), and the reaction mixture was stirred at 100 °C

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• solvent, whereas the arylation of ammonia was achieved by using ethyl acetate as solvent along with potassium carbonate as a base. Likewise, water was arylated using cesium carbonate as a base. The N-arylation reactions were performed under strict anhydrous conditions. The reported mechanistic hypothesis

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

• condensation of anomerically pure β-configured β-16a with indoxyl acetate, in the presence of an excess of sodium carbonate, afforded β-configured indirubin-N-rhamnoside β-17a in very good yield as the pure Z-configured isomer (Scheme 13) [22]. Gratifyingly, the product, which showed the characteristic red

• of non-glycosylated carboindirubin E-43f in 86% yield by reaction of indan-1-one (42a) with isatin using sodium carbonate in methanol (Scheme 28) [40]. For this compound, only moderate or no antiproliferative activities were observed against various cancer cell lines. 3-Alkylideneoxindole-N

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• substituted pybox ligand (Scheme 28, 26a–m). The thiophene unit of the carbonate could also be replaced by benzothiophene (Scheme 28, 26h) or furan (Scheme 28, 26m), and pyrrole (Scheme 28, 26j), phenol (Scheme 28, 26k); coumarin derivative (Scheme 28, 26n), and dibenzylamine (Scheme 28, 24a) could also

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

• mol %), cesium carbonate (1.5 equiv), palladium bis(trifluoroacetate) (5 mol %) in THF (2.0 mL) was added the respective boronic acid derivative 4 (2.0 equiv). The reaction solution was refluxed for 3.5 h. The reaction mixture was quenched by the addition of water (40 mL) at 0 °C and extracted with

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

• shaken for 15 min and then placed in an oven at 100 °C until the silica gel was completely dried. The impregnated silica gel was stored in the dark until use. Syntheses 1-(1-Propen-1-yl)piperidine (2): In a manner analogous to [27], potassium carbonate (2 g, 15 mmol), piperidine (10 mL, 0.1 mol), and

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• afforded the known aldehyde 2 in 65% yield [13]. Then, reaction with guanidinium carbonate in DMA at high temperature [12], gave the desired intermediate 2-aminobenzo[h]quinazoline (3). In a final step, classical Buchwald–Hartwig coupling [14][15][16][17] with bromobenzene under the conditions described

• ]quinazolin-2-amine (3): To a stirred solution of guanidinium carbonate (2.0 g, 0.011 mol) in DMA (15 mL) was added compound 2 (1.5 g, 0.008 mol). Then the reaction mixture was heated to stir at 150 °C for 16 h. After completion of the reaction (TLC), the mixture was poured into ice water, a solid was formed

• bromobenzene (0.384 mmol, 1.5 equiv), Xanthphos (0.051 mmol, 0.2 equiv) and cesium carbonate (0.769 mmol, 3 equiv). This mixture was degassed for 15 minutes under N2 atmosphere. Pd2(dba)3 (0.0256 mmol, 0.1 equiv) was added and the reaction mixture was stirred for 16 h at 100 °C. After cooling to room

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

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

• Hisanori Senboku and
• Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

• ][9][10][11], yielding phenylacetic acids. For example, Troupel et al. successfully performed electrochemical reduction of benzyl ethers and several esters such as acetate, trifluoroacetate, benzoate, and dibenzyl carbonate derived from benzyl alcohols, including 1-phenylethanol compounds, in the

• [13], plausible reaction pathways are proposed as seen in Scheme 6. At the cathode, one-electron reduction of the hydroxy group in diarylmethanol 1 generates H2 and the corresponding alkoxide ion A, which captures carbon dioxide to form carbonate ion B. Although it is currently unclear whether this

• proceeds in a stepwise or concerted manner, two-electron reduction of carbonate ion B generates the corresponding diphenylmethyl anion C, which reacts with carbon dioxide to produce a carbon–carbon bond that results in the formation of diphenyl acetate ion D. Electrochemical reduction of carbon dioxide

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• -trifluoromethylamine derivatives of high molecular complexity (Scheme 28). The process involves a highly enantioselective reaction of the isatin-derived Morita–Baylis–Hillman carbonate 137 with a novel α-CF3-substituted imine 136, derived from inexpensive benzothiophene-2,3-dione. A C2-symmetrical cinchona-derived

• equiv of isatin with a 50% excess of the α-CF3-substituted imine in toluene at room temperature in the presence of 10 mol % of organocatalyst 138 for times between 1 and 80 h. The reaction exhibited a broad scope in the isatin carbonate derivatives with high to excellent enantioselectivities (89–99

• corresponding free amines by hydrolysis with aqueous HCl. The reaction proceeded in good yields and with complete retention of stereointegrity. In a proposed mechanism, isatin carbonate 137 reacts with a quinuclidine unit of the catalyst 138 by an SN2’ attack to form cationic intermediate 142. The t-BuO− anion

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

• give 1,5-diacyl-5-hydroxypyrazolines 131. Cleavage of the protecting group with potassium carbonate in methanol finally provides the corresponding 5-acyl NH-pyrazoles 132 (Scheme 46) [149]. A novel approach to synthesizing pyrazoles via the initial formation of isoxazoles 138 through (3 + 2

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

• electrolyte with potassium carbonate as a base and two platinum electrodes. Mechanistically, condensation of the two reactants formed isatin-derived acylhydrazone 37. Hydrolysis of the latter in the presence of the inorganic base gave rise to potassium carboxylate 39. Meanwhile, two consecutive SET oxidations

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• -substituted indazole analogs in 44% and 40% yields, respectively, by treating compound 6 with methyl iodide and potassium carbonate in dimethylformamide (DMF) at room temperature for 17 h [40]. Other works have shown poor selectivity when 6 and other isomers similar to 6 were reacted with isopropyl iodide and

• potassium carbonate, isopropyl bromide and cesium carbonate, and bromocyclohexane with potassium carbonate, and only afforded yields not higher than 52% in various solvents [41][42][43]. Recently, Alam and Keeting [37] explored the regioselectivity in the alkylation of variously substituted indazoles

• cesium carbonate (766 mg, 2.352 mmol) followed by the necessary tosylate (1.5 equiv). The resulting mixture was stirred for 2 hours at 90 °C. The mixture was poured into EtOAc (500 mL) and washed with water (100 mL) and brine. The organic layer was dried and concentrated, the obtained residue was

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

• potassium carbonate was almost quantitative (97–99% yield). It is worth mentioning that the GBB reaction starting from the deacetylated substrate also leads to good results (83–91% of yield), but the overall yield is lowered due to a sluggish deacetylation reaction of 29. Sugar-based aldehydes were employed

Chiral bifunctional sulfide-catalyzed enantioselective bromolactonizations of α- and β-substituted 5-hexenoic acids

• Sao Sumida,
• Ken Okuno,
• Taiki Mori,
• Yasuaki Furuya and
• Seiji Shirakawa

Beilstein J. Org. Chem. 2024, 20, 1794–1799, doi:10.3762/bjoc.20.158

• -valerolactones 7 and 8, which are functionalized with sulfur and nitrogen, in high yields. Additionally, optically active δ-valerolactone 3a was converted to optically active epoxy-ester 9 upon treatment with potassium carbonate in methanol. Notably, the transformed products were obtained without any loss of

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• benzodiazepine with different bases (caesium carbonate, sodium hydroxide). However, the complete cyclisation to the pyrrolobenzodiazepinone was not achieved, so the described three-step strategy starting from 2-nitrobenzoic acid (Ugi reaction/cyclization to pyrrolidine/reduction sequence) remains as a better

• after the Ugi/cyclization sequence, yielded the corresponding piperazinoquinazoline 14 with a high global yield (Scheme 10). Moreover, the treatment of piperazinones 9c–e,k derived from 3-bromopropanamine with caesium carbonate in boiling acetonitrile for 1 h afforded the corresponding

• , without purification, was treated with caesium carbonate (1 equiv) and heated to reflux for an hour. Gratefully, the dipyrrolopiperazinone derivatives 12 were obtained with high yields and complete diastereoselectivity in an efficient and simple way (Scheme 11, Table 6). The structure of these systems was

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• out, resulting in the corresponding N-tosylhydrazones 51a–c. Afterwards, the compounds were subjected to microwave irradiation in the presence of (3-azidopropyl)boronic acid and potassium or cesium carbonate, yielding 3-spiropyrrolidines 52a–c in high overall yields as 1:1 mixture of diastereomers

• diol 141 with chloroacetyl chloride, followed by cyclization induced by formation of the alcoholate. On the other hand, amino diol 141b was N-alkylated with methyl bromoacetate and then microwaved in the presence of potassium carbonate to obtain morpholinone 144 (Scheme 38). Romero-Hernández and Merino

Electrocatalytic hydrogenation of cyanoarenes, nitroarenes, quinolines, and pyridines under mild conditions with a proton-exchange membrane reactor

• Koichi Mitsudo,
• Atsushi Osaki,
• Haruka Inoue,
• Eisuke Sato,
• Naoki Shida,
• Mahito Atobe and
• Seiji Suga

Beilstein J. Org. Chem. 2024, 20, 1560–1571, doi:10.3762/bjoc.20.139

• 1,1,2,2-tetrachloroethane as an internal standard. aPerformed in 1,4-dioxane/H2O (7:1), and the yield was determined by 1H NMR analysis using ethylene carbonate as an internal standard. Effect of cathode catalyst for the electrochemical reduction of 1a using a PEM reactora. Electrochemical reduction of 1a

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• for the heterobenzylic position, as shown by compound 4. In 2018, a subsequent publication by the same group detailed the use of increased lithium carbonate and NFSI loadings (conditions [B]) to access the difluorinated products [37]. This report also demonstrated a single example of 18F

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

• Simone Gräßle,
• Laura Holzhauer,
• Nicolai Wippert,
• Olaf Fuhr,
• Martin Nieger,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

• followed by the addition of diisopropylamine, either in a one-pot synthesis or in two consecutive steps (Table 1). Subsequently, different aliphatic and aromatic substituents were attached to the pyrazole nitrogen by nucleophilic substitution with suitable organohalides 16 and cesium carbonate [3]. Due to

Domino reactions of chromones with activated carbonyl compounds

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 1256–1269, doi:10.3762/bjoc.20.108

• attack of the sulfur to the bromide (intermediate AC) and subsequent ring-cleavage. In most reactions, DBU was employed as the base. In case of products derived from N-unsubstititued 3H-indole-2-thiones (R3 = H), employment of potassium carbonate proved to be advantageous. Similarly to the formation of

Novel analogues of a nonnucleoside SARS-CoV-2 RdRp inhibitor as potential antivirotics

• Luca Julianna Tóth,
• Kateřina Krejčová,
• Milan Dejmek,
• Eva Žilecká,
• Blanka Klepetářová,
• Lenka Poštová Slavětínská,
• Evžen Bouřa and
• Radim Nencka

Beilstein J. Org. Chem. 2024, 20, 1029–1036, doi:10.3762/bjoc.20.91

• , DCM, rt, overnight, b) BnBr, NaH, DMF, 0 °C to rt, 1 h, c) (R = Et) diethyl carbonate, LiHMDS, THF, −78 to 0 °C, 1 h, d) (R = allyl) allyl chloroformate, LiHMDS, THF, −78 to 0 °C, 1 h, e) POCl3, DMF, 90 °C, 30 min, f) (BnCO)2O, 100 °C, 1.5 h, g) methanesulfonic acid, DCM, 0 °C to rt, 4 h, h) CyOH

Enantioselective synthesis of β-aryl-γ-lactam derivatives via Heck–Matsuda desymmetrization of N-protected 2,5-dihydro-1H-pyrroles

• Arnaldo G. de Oliveira Jr.,
• Martí F. Wang,
• Rafaela C. Carmona,
• Danilo M. Lustosa,
• Sergei A. Gorbatov and
• Carlos R. D. Correia

Beilstein J. Org. Chem. 2024, 20, 940–949, doi:10.3762/bjoc.20.84

• the palladium source in combination with the pyrazinebisoxazoline ligand, (S)-PyraBox (L1), zinc carbonate as base, and methanol as solvent at 40 °C. These initial conditions furnished 2-methoxypyrrolidines arylated at the 4-position, compound 3, as Heck products as illustrated in Scheme 3. The

Methodology for awakening the potential secondary metabolic capacity in actinomycetes

• Shun Saito and
• Midori A. Arai

Beilstein J. Org. Chem. 2024, 20, 753–766, doi:10.3762/bjoc.20.69

• carbonate and terminal olefin functionalities [50]. Thus, artificial methods of genetic engineering and chemistry also play an important role in the identification of novel secondary metabolites. Culture conditions Medium composition, pH, oxygen supply, light Simply modifying the culture conditions is an