3,3'-Linked BINOL macrocycles: optimized synthesis of crown ethers featuring one or two BINOL units

• Somayyeh Kheirjou,
• Jan Riebe,
• Maike Thiele,
• Christoph Wölper and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2025, 21, 1719–1729, doi:10.3762/bjoc.21.134

• coupling (vide supra). To this end, Me-2 was reacted with the bistosylated ethylene glycols 85/6/7/8 in the presence of Cs2CO3 as a base (CH3CN, 80 °C). To our delight, we could isolate the macrocyles Me-M15/6/7/8 in significantly higher yields of 21/54/75/38%. Cesium carbonate was chosen as the base

Recent advances in oxidative radical difunctionalization of N-arylacrylamides enabled by carbon radical reagents

• Jiangfei Chen,
• Yi-Lin Qu,
• Ming Yuan,
• Xiang-Mei Wu,
• Heng-Pei Jiang,
• Ying Fu and
• Shengrong Guo

Beilstein J. Org. Chem. 2025, 21, 1207–1271, doi:10.3762/bjoc.21.98

• single-electron-transfer (SET) process, leading to the formation of hybrid alkyl–Pd radical intermediates. The optimized conditions employed cesium carbonate as the base in 1,4-dioxane, under blue LED irradiation at room temperature, affording the desired products in moderate to good yields. The

• single-electron reductant and an organocatalyst. The optimized conditions involve using an NHC precursor, cesium carbonate as the base, and 1,4-dioxane as the solvent at 110 °C, yielding structurally diverse oxindoles 88 with satisfactory efficiency. The substrate scope was systematically investigated

Synthetic approach to borrelidin fragments: focus on key intermediates

• Yudhi Dwi Kurniawan,
• Zetryana Puteri Tachrim,
• Teni Ernawati,
• Faris Hermawan,
• Ima Nurasiyah and
• Muhammad Alfin Sulmantara

Beilstein J. Org. Chem. 2025, 21, 1135–1160, doi:10.3762/bjoc.21.91

• -substituted acrylic acid 51 (Scheme 7). After optimization, the iridium complex (Ra)-50, in the presence of cesium carbonate, was identified as the most efficient catalyst, producing compound 52 in 97% yield with an enantiomeric excess of 97.6%. Subsequently, compound 52 was treated with Meldrum’s acid in the

• the correct stereochemistry of the newly formed three stereocenters. Additionally, replacing cesium carbonate with triethylamine proved crucial for achieving efficient asymmetric hydrogenation in this case. Subsequently, the carboxylic acid group of 57 was reduced with LiAlH4 in THF to produce primary

Recent advances in the electrochemical synthesis of organophosphorus compounds

• Babak Kaboudin,
• Milad Behroozi,
• Sepideh Sadighi and
• Fatemeh Asgharzadeh

Beilstein J. Org. Chem. 2025, 21, 770–797, doi:10.3762/bjoc.21.61

• (Scheme 21). In another attempt, Liu et al. [66] also reported the electrochemical phosphorylation of carbazoles and indoles in the presence of 1,3-dimethylimidazolium iodide (DMMI) as a mediator in the oxidation–reduction process. The reaction proceeded in an undivided cell using cesium carbonate as a

• . In this method, they have reported an electrochemical reaction of alcohols (aliphatic and aromatic) and diphenylphosphine in an undivided cell, using carbon and nickel electrodes as the anode and cathode, respectively, at a constant current for 4 h in the presence of cesium carbonate as a base

• proceeded via the anodic oxidation of diarylphosphines to diarylphosphine oxides, followed by further anodic oxidation to give phosphine oxide radicals. In the subsequent step treatment of alkoxide radicals (formed via the deprotonation of alcohols with cesium carbonate and anodic oxidation), the phosphine

Total synthesis of (±)-simonsol C using dearomatization as key reaction under acidic conditions

• Xiao-Yang Bi,
• Xiao-Shuai Yang,
• Shan-Shan Chen,
• Jia-Jun Sui,
• Zhao-Nan Cai,
• Yong-Ming Chuan and
• Hong-Bo Qin

Beilstein J. Org. Chem. 2025, 21, 601–606, doi:10.3762/bjoc.21.47

• DIPEA, affording compound 17 with an 89% yield [11]. For the following alkylation step with tert-butyl bromoacetate, three bases were tested: potassium carbonate, cesium carbonate, and sodium hydride. Considering the targeted alkylation of a phenolic hydroxy group and the pKa requirements of this

• reaction, weaker bases like potassium carbonate and cesium carbonate should theoretically suffice. However, the reaction outcomes with these two bases did not meet the desired expectations, as some starting material remained after 5 hours of reaction. Extending the reaction time did not lead to full

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

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

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

• 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

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

• 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

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

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

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

• co-workers reported that the combination of NHPI esters and cesium carbonate (Cs2CO3) gave rise to a new absorption band in the visible region, suggesting the formation of a photoactive charge-transfer complex [70]. This activation mode was initially employed in a decarboxylative coupling reaction

• (Scheme 30B). Then, cesium carbonate deprotonates the enol OH in 145, to provide the enolate form of Breslow’s intermediate 146, which is a suitable reducing agent to trigger the fragmentation of NHPI ester 58 (E°ox = −0.97 V vs SCE in MeCN). Hence, it is proposed that enolate 146 induces the single

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• . Yet, we did not try to purify them any further. Before closing this section, it should be stressed that we were not able to isolate any dithiocarboxylate betaines when aldiminium salt 3b or triazolium salt 5a were treated with cesium carbonate and carbon disulfide in acetonitrile in the presence of

Consecutive four-component synthesis of trisubstituted 3-iodoindoles by an alkynylation–cyclization–iodination–alkylation sequence

• Nadia Ledermann,
• Alae-Eddine Moubsit and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2023, 19, 1379–1385, doi:10.3762/bjoc.19.99

• alkynyl-substituted 3-iodoindole 6 as product in 42% isolated yield in the sense of a pseudo-five-component reaction (Scheme 3). Finally, the 3-iodoindole 5a and arylboronic acids 7 were employed in a standard Suzuki protocol with cesium carbonate as a base to give rise to the formation of 1,2,3

• , 63.81; H, 3.74; N, 2.96. Synthesis of 1,2,3-trisubstituted indole 8b (typical procedure) 3-Iodoindole 5a (167 mg, 0.50 mmol), (p-tolyl)boronic acid (7b, 204 mg, 1.50 mmol), Pd(PPh3)4 (28.9 mg, 25.0 μmol), and cesium carbonate (652 mg, 2.00 mmol) were placed in an oven-dried Schlenk tube with magnetic

Lewis acid-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence to access phosphoric esters

• Jin Yang,
• Dang-Wei Qian and
• Shang-Dong Yang

Beilstein J. Org. Chem. 2022, 18, 1188–1194, doi:10.3762/bjoc.18.123

• catalyst through a similar transformation under solvent-free conditions [44]. Recently, Zhang’s group disclosed a cesium carbonate-catalyzed Pudovik reaction–phospha-Brook rearrangement sequence and extended the phosphorus source from phosphate to phosphonate [45]. Despite of these important advancements

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

Synthesis of new pyrazolo[1,2,3]triazines by cyclative cleavage of pyrazolyltriazenes

• Nicolai Wippert,
• Martin Nieger,
• Claudine Herlan,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2021, 17, 2773–2780, doi:10.3762/bjoc.17.187

• chains to the pyrazole moiety. The addition of several aliphatic bromides or iodides 14 in combination with potassium or cesium carbonate in DMSO gave a mixture of the regioisomeric compounds 12 and 13 due to the addition of the alkyl substituents to one of both pyrazole-nitrogen atoms. As shown in Table

Recent advances in organocatalytic asymmetric aza-Michael reactions of amines and amides

• Pratibha Sharma,
• Raakhi Gupta and
• Raj K. Bansal

Beilstein J. Org. Chem. 2021, 17, 2585–2610, doi:10.3762/bjoc.17.173

• ) in the presence of cesium carbonate and an N-benzylquininium salt as catalyst (cat. 48) (solid–liquid phase-transfer conditions) to give the corresponding adducts in 40–90% yields with excellent ee of up to 99% (Table 10) [44]. A different type of asymmetric aza-Michael addition was developed by Wang

Regioselective N-alkylation of the 1H-indazole scaffold; ring substituent and N-alkylating reagent effects on regioisomeric distribution

• Ryan M. Alam and
• John J. Keating

Beilstein J. Org. Chem. 2021, 17, 1939–1951, doi:10.3762/bjoc.17.127

• effect of varying these reaction parameters, using n-pentyl bromide as the prototypical N-alkylating reagent (Table 1). Early investigations revealed that the combination of cesium carbonate (Cs2CO3) in dimethylformamide (DMF) at room temperature (≈ 20 °C) afforded a mixture of N-1 and N-2 regioisomers

Development of N-F fluorinating agents and their fluorinations: Historical perspective

• Teruo Umemoto,
• Yuhao Yang and
• Gerald B. Hammond

Beilstein J. Org. Chem. 2021, 17, 1752–1813, doi:10.3762/bjoc.17.123

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

Total synthesis of decarboxyaltenusin

• Lucas Warmuth,
• Aaron Weiß,
• Marco Reinhardt,
• Anna Meschkov,
• Ute Schepers and
• Joachim Podlech

Beilstein J. Org. Chem. 2021, 17, 224–228, doi:10.3762/bjoc.17.22

• a 73% yield. The Suzuki coupling of boronate 6a and aryl bromide 9a using palladium acetate and cesium carbonate in the presence of the ligand SPhos [25] yielded biaryl 10a with virtually quantitative yield (98%, Scheme 4). Unfortunately, the removal of non-identified byproducts and of 9a (which had

Synthesis of 4-substituted azopyridine-functionalized Ni(II)-porphyrins as molecular spin switches

• Jannis Ludwig,
• Tobias Moje,
• Fynn Röhricht and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2589–2597, doi:10.3762/bjoc.16.210

• of 1e (top), 1h (left) and 1j (right) in acetone water (1:9) (solid line) and after deprotonation using cesium carbonate (dashed line) in the PSS at 505 nm (green) and 435 nm (blue). Synthesis of the nitroso compounds 3 and 6 using the two different methods described by Wegner et al. [19][20][21] and

Design and synthesis of a bis-macrocyclic host and guests as building blocks for small molecular knots

• Elizabeth A. Margolis,
• Rebecca J. Keyes,
• Stephen D. Lockey IV and
• Edward E. Fenlon

Beilstein J. Org. Chem. 2020, 16, 2314–2321, doi:10.3762/bjoc.16.192

• changing the order of these steps would be beneficial. Alkylation of terephthalate 12 with azido-bromide 6 using cesium carbonate as the base provided high yields (82%) of core diazide 14 (Scheme 3). Click cycloaddition of 14 with an excess of dialkyne 10 also proceeded in high yields (87%) to give diester

Convenient access to pyrrolidin-3-ylphosphonic acids and tetrahydro-2H-pyran-3-ylphosphonates with multiple contiguous stereocenters from nonracemic adducts of a Ni(II)-catalyzed Michael reaction

• Alexander N. Reznikov,
• Dmitry S. Nikerov,
• Anastasiya E. Sibiryakova,
• Victor B. Rybakov,
• Evgeniy V. Golovin and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2020, 16, 2073–2079, doi:10.3762/bjoc.16.174

• detected in the reaction even after 72 h in the presence of 1 equiv of potassium phosphate or carbonate with TEBAC (0.1 equiv, Table 1, entries 4 and 5). If potassium fluoride or cesium carbonate were used as a base, the initial phosphonate 6e was consumed in a few hours, but unidentified products were