Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• " of the methyl sulfur group in intermediate 22 for the cleavage of the C–S bond. In the end, the C–C bond is formed between intermediate 23 and the enol form from the methyl ketone 18. Sodium carbonate is added to prevent too much acidification of the reaction medium and to deprotonate the NH that

• acid or MP-glyoxylate (glyoxylic acid immobilized on macroporous polystyrene resin, starting from MP-carbonate, MP-CO3) instead of formaldehyde (Scheme 34) [88]. When glyoxylic acid (“free” or immobilized) is used, the reaction affords 2-unsubstituted 3-aminoimidazo heterocycles 42a as the only

• regioisomer with very good yields. For the immobilized glyoxylic acid, the best conditions required the use of the methanol-compatible resin, MP-carbonate. After coupling of the three components, decarboxylation at 50 °C released the product, while, when working with 'free' glyoxylic acid, decarboxylation

Asymmetric synthesis of β-amino cyanoesters with contiguous tetrasubstituted carbon centers by halogen-bonding catalysis with chiral halonium salt

• Yasushi Yoshida,
• Maho Aono,
• Takashi Mino and
• Masami Sakamoto

Beilstein J. Org. Chem. 2025, 21, 547–555, doi:10.3762/bjoc.21.43

• equivalent of 7a and 5.0 equivalents of 16a in the presence of stoichiometric potassium carbonate and 1.0 mol % of 9. When bromonium salt 9a was applied to the reaction, the desired product was obtained in 83% yield with 77% ee but almost no diastereoselectivity. The iodonium salt 9b also worked well and the

• chiral halonium salt. Next, the reaction temperature was optimized, and −40 °C was found to be optimal (Table 1, entries 7–9). Further optimization of the reaction conditions (amounts of potassium carbonate and pre-nucleophile, catalyst loading, and concentration) were conducted, and the reaction with

• 5.0 equivalents of pre-nucleophile and 1.0 equivalent of potassium carbonate in the presence of 1.0 mol % of 9 at 0.025 M of toluene and −40 °C was found to be optimal (Table 1, entries 10–13). Five equivalents of pre-nucleophile are required to obtain higher yields and enantioselectivities. Next, the

The effect of neighbouring group participation and possible long range remote group participation in O-glycosylation

• Rituparna Das and
• Balaram Mukhopadhyay

Beilstein J. Org. Chem. 2025, 21, 369–406, doi:10.3762/bjoc.21.27

• inversion in carbohydrates was illustrated extensively by Frush and Isbell [75] with silver carbonate as the promoter, drawing analogy with an SN2-type substitution mechanism with the formation of the acetoxonium ion intermediate [76]. An acyl protecting group in the vicinal C-2 position is widely accepted

• as a stereodirecting protecting group in the C-2 position which helped in the formation of 1,2-trans glycosides [129]. Taking their lead, Mikula and co-workers implemented 2-O-benzyloxycarbonyl-protected glycosyl donors for the implementation of the stereodirecting property of the carbonate group

Molecular diversity of the reactions of MBH carbonates of isatins and various nucleophiles

• Zi-Ying Xiao,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2025, 21, 286–295, doi:10.3762/bjoc.21.21

• diastereomeric ratios. The relative configurations of the various polycyclic compounds were clearly elucidated by determination of several single crystal structures. Keywords: allylic SN2 reaction; dimerization; isatin; MBH carbonate; 3-methyleneoxindole; Introduction Isatins (indoline-2,3-diones) possessing

• yields. The single crystal structure of the compound 6e was determined by X-ray diffraction (Figure 3). The similar reaction of more nucleophilic tri(tert-butyl)phosphine and MBH carbonate of isatin resulted in a mixture of products. After carefully screening the reaction conditions, we found that DABCO

• crystal structure of compound 8a. Reaction of arylamines and MBH carbonates of isatins. Reaction conditions: MBH carbonate of isatin (0.1 mmol), aromatic amine (0.1 mmol), DMAP (0.02 mmol, 20 mol %), toluene (5.0 mL), rt, 1 h; yields refer to isolated yields. Reaction of arylamines and MBH maleimides of

Recent advances in organocatalytic atroposelective reactions

• Henrich Szabados and
• Radovan Šebesta

Beilstein J. Org. Chem. 2025, 21, 55–121, doi:10.3762/bjoc.21.6

Reactivity of hypervalent iodine(III) reagents bearing a benzylamine with sulfenate salts

• Beatriz Dedeiras,
• Catarina S. Caldeira,
• José C. Cunha,
• Clara S. B. Gomes and
• M. Manuel B. Marques

Beilstein J. Org. Chem. 2024, 20, 3281–3289, doi:10.3762/bjoc.20.272

• reaction (Table 1, entry 1) [4]. In the presence of potassium carbonate, only starting material 4a was detected. A stronger base to generate the nucleophilic intermediate was tested, and sulfonamide 5aa was detected in trace amounts (Table 1, entry 2). Considering the low solubility of the hypervalent

Intramolecular C–H arylation of pyridine derivatives with a palladium catalyst for the synthesis of multiply fused heteroaromatic compounds

• Yuki Nakanishi,
• Shoichi Sugita,
• Kentaro Okano and
• Atsunori Mori

Beilstein J. Org. Chem. 2024, 20, 3256–3262, doi:10.3762/bjoc.20.269

• conditions. We carried out the palladium-catalyzed intramolecular coupling reaction of precursor 1a under similar conditions [23], which afforded smooth reaction with phenanthroline bisamide, with 10 mol % of palladium acetate as a catalyst in the presence of potassium carbonate and tetra-n-butylammonium

• resulted in a decreased yield (27%) (Table 1, entries 4 and 5). It was found that increasing the amount of potassium carbonate to a three-fold excess improved the yield of 2a to 59% in the reaction at 110 °C shown in entry 6 of Table 1. Next, the effect of the ligand of the palladium catalyst was examined

• . Experimental Typical experimental procedure for the C–H arylation of pyridine derivative 5-octyldibenzo[b,f][1,7]naphthyridin-6(5H)-one (2a): To a screw-capped test tube equipped with a magnetic stirring bar were added amide 1a (44.1 mg, 0.100 mmol), potassium carbonate (42.0 mg, 0.304 mmol

Synthesis of extended fluorinated tripeptides based on the tetrahydropyridazine scaffold

• Thierry Milcent,
• Pascal Retailleau,
• Benoit Crousse and
• Sandrine Ongeri

Beilstein J. Org. Chem. 2024, 20, 3174–3181, doi:10.3762/bjoc.20.262

• can be noticed that the presence of an amino acid is compatible with the conditions of the reaction and did not interfere or significantly decrease the yield of the reaction (Scheme 3). Then, the N-carboxylate hydrazides 5a–d were firstly oxidized with iodine in the presence of potassium carbonate to

• on an intramolecular Michael addition carried out in DMF and catalyzed by 10% of potassium carbonate. As previously observed [37], under these conditions, the 5-endo-trig cyclization was selective and the lactam resulting from the 5-exo-trig cyclization was not observed. Furthermore, in the case of

Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• centrifugation. In the same way as a calix[4]pyrrole was used as organocatalyst for cyclic carbonate synthesis from epoxide and CO2, as discussed in section 1.1, Gallo and co-workers investigated the organocatalytic activity of porphyrin/TBACl binary catalytic systems for the regioselective cycloaddition of CO2

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