Synthesis, characterization, antimicrobial, cytotoxic and carbonic anhydrase inhibition activities of multifunctional pyrazolo-1,2-benzothiazine acetamides

• Ayesha Saeed,
• Shahana Ehsan,
• Muhammad Zia-ur-Rehman,
• Erin M. Marshall,
• Sandra Loesgen,
• Abdus Saleem,
• Simone Giovannuzzi and
• Claudiu T. Supuran

Beilstein J. Org. Chem. 2025, 21, 348–357, doi:10.3762/bjoc.21.25

• types of CAs (CA II, CA IX and CA XII). Among these low active compounds, the highest inhibition (Ki = 72.9 μM) was shown by compound 7b for the CA IX type. This compound also exhibited low to negligible inhibition with Ki values of 77.4 and 90.9 μM for CA XII and CA II, respectively. The compounds with

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

Synthesis, structure and π-expansion of tris(4,5-dehydro-2,3:6,7-dibenzotropone)

• Yongming Xiong,
• Xue Lin Ma,
• Shilong Su and
• Qian Miao

Beilstein J. Org. Chem. 2025, 21, 1–7, doi:10.3762/bjoc.21.1

• Abstract The polycyclic skeleton of tris(4,5-dehydro-2,3:6,7-dibenzotropone) is a key structural fragment in carbon schwarzites, a theoretical form of negatively curved carbon allotrope. This report presents a new synthesis of this compound using a Ni-mediated Yamamoto coupling reaction and structural

• HOMO level (−5.47 eV). Conclusion In conclusion, we developed a new synthesis of tris(4,5-dehydro-2,3:6,7-dibenzotropone) (1) through a Ni-mediated Yamamoto coupling reaction. Upon crystallization from the same solution in hexane, this compound yielded colorless and yellow crystal polymorphs, adopting

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

• synthesis of highly electron-rich benzo[j]fluoranthenes. However, before moving to this compound class, we wanted to confirm the success of our methodology on a model electron-rich substrate. For this purpose, we checked the reaction between 1,8-diiodonaphthalene (12) and 2,3-dimethoxyphenylboronic acid

• this purpose, we first concentrated our efforts on the synthesis of highly electron-rich benzo[j]fluoranthene 18 possessing four methoxy groups (Scheme 2). This compound was previously synthesized by Swieca and Spiteller in six steps (longest linear sequence, LLS) starting from 1,5-dihydroxynaphthalene

• -dihydroxynaphthalene (1,8-DHN, 19) [48][55], by N-iodosuccinimide (NIS) in 87% yield (Scheme 2). Afterwards, naphthylboronic ester 22 was obtained via the Miyaura borylation [44] of iodonaphthalene 21 in 62% yield. Whereas this compound acts as the boronic ester coupling partner of our fluoranthene synthesis

Synthesis of 2H-azirine-2,2-dicarboxylic acids and their derivatives

• Anastasiya V. Agafonova,
• Mikhail S. Novikov and
• Alexander F. Khlebnikov

Beilstein J. Org. Chem. 2024, 20, 3191–3197, doi:10.3762/bjoc.20.264

• -azirine-2,2-dicarboxylic acid derivative, dimethyl 3-phenyl-2H-azirine-2,2-dicarboxylate, has been reported to date. This compound was prepared by a Rh2(Piv)4-catalyzed isomerization of methyl 5-methoxy-3-phenylisoxazole-4-carboxylate [19]. The described linear synthesis, unfortunately, allows obtaining

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

• 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

• viability and in induction of apoptosis [50]. The presence of this compound results in downregulation of the caspase antagonistic proteins c-FLIP and XIAP via caspase-8 and caspase-3 in the (extrinsic) apoptosis cascade. Similarly as discussed above for the activity of 3-alkylideneoxindole-N-glycosides

• activity was observed against HCEC. The activities were higher as compared to those observed for selenoindirubin-N-glycosides β-38a–h employed in the same assay. Kornienko et al. reported the reaction of isatin with thiohydantoin (47a) to give condensation product 48e (Scheme 31) [40]. This compound only

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

• reacts with an isocyanide and an electron-rich aniline in a three-component Ugi-type reaction to give an α-aminoamidine. This compound might undergo an additional visible light-mediated oxidation to furnish a second iminium intermediate, which acts as electrophile in an intramolecular electrophilic

• -THIQ is transformed into iminium ion 1a, this compound instantly takes part in the Ugi-type reaction with 3,5-dimethoxyaniline and t-BuNC giving the α-aminoamidine 2d. After 4 h, 2d starts to be converted slowly into the final product 3d, thanks to a second oxidation and a final cyclization. This study

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• [5][6][7][8][9][10][11][12][13]. For example, 2-hydroxymethyl-5-hydroxypyran-4-one (kojic acid) is a well-known skin whitening agent extensively used in the cosmetic, medicine and food industries. The action of this compound is based on inhibition of tyrosinase activity, which helps to protect

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• (100), 595.3 (40), 596.3 (10), [M − BF4]+ calcd for C43H36N3, 594.29; (negative) 86.0 (20), 87.0 (100); [M – C43H36N3]− calcd for BF4, 87.00. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12-Tris(2,6-dimethylphenyl)-4,8,12-triazatriangulenium as a PF6− ion

• (0.21); MALDI–TOF MS (m/z) (% intensity): (positive) 594.3 (100), 595.3 (40), 596.3 (10), [M − F6P]+ calcd for C43H36N3, 594.29; (negative) 145.1 (100), [M − C49H30N3]− calcd for F6P, 144.96. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12-Tris(2,6

• –TOF MS (m/z) (% intensity): (positive) 594.3 (100), 595.3 (40), 596.3 (10), [M − C24BF20]+ calcd for C43H36N3, 594.29; (negative) 678.0 (20), 679.0 (100), 680.0 (20), [M – C43H36N3]– calcd for C24BF20, 678.98. This compound was further characterized by single-crystal X-ray diffraction analysis. 4,8,12

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

• not improve the results (Table 1, entry 4). A better yield was obtained by adding first the phenylselenyl chloride and stirring the mixture for 15 min at 0 °C before adding 1a (Table 1, entry 5). During all these reactions the formation of compound 3a was observed as by-product. This compound results

Evaluating the halogen bonding strength of a iodoloisoxazolium(III) salt

• Dominik L. Reinhard,
• Anna Schmidt,
• Marc Sons,
• Julian Wolf,
• Elric Engelage and
• Stefan M. Huber

Beilstein J. Org. Chem. 2024, 20, 2401–2407, doi:10.3762/bjoc.20.204

• donors in recent years. Herein, a new structural motif for this compound class was developed: iodoloisoxazolium salts, bearing a cyclic five-membered iodolium core fused with an isoxazole ring. A derivative of this class was synthesized and investigated in the solid state by X-ray crystallography

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• participation of the catechol group in the first redox transition, the microelectrolysis of 3 was carried out at a controlled potential of 1.35 V in MeCN (2 h, 0.8 F/mol). After electrolysis, a decrease in the current intensity of the first oxidation peak is observed on the CVs of this compound (conversion

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

• and PIDA [30][33]. During this experiment, a small amount of hydrolysis product 4-(trifluoromethyl)benzenesulfonamide was also observed (1.2 mM, signals at 8.0, 7.9, and 5.86 ppm), but this compound did not greatly contribute to the broadening of O–H proton signal of HFIP as a separate 4.0 mM sample

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

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

• than 500 entries to this compound. It was first isolated together with alternariol from Alternaria tenuis (synonymous to A. alternata) [33][54]. Its correct structure was proposed, based on chemical methods, shortly after [42] and was later unambiguously confirmed by total synthesis [62] and finally by

• NMR spectroscopy; no biological activity could be elucidated. Sabilactone (35) was isolated from the plant Sabina vulgaris Antoine [195][196], but no further information could be revealed for this compound. The strong resemblance of autumnariol (36) and autumnariniol (37) with alternariol and 4

• Pleosporales sp. [246]. The structure of decarboxyaltenusin was elucidated by chemical [37] and NMR-spectroscopic methods [210] and was later unambiguously confirmed by total synthesis [247]. This compound turned out to be cytotoxic against the human colorectal HCT116 cell line (IC50: 73 µM) [232], showed

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

• difunctionalization led to lower yields (2e,f). The product of rearrangement 2a was oxidized into the sulfoxide and re-engaged under the optimized conditions to afford the compound of bis-rearrangement 2g in a good yield of 49%. This compound is then the result of an iterative rearrangement. Difluorinated 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

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

• the methods for the preparation of HFO-1132 as well as reactions demonstrating the chemical behavior of this compound. From the reactions not included in this Review article, mechanistic studies on 1,2-difluoroethylene ozonolysis [77][103][104][105][106][107][108] and studies on the stability of

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

• C-3 or C-17 steroidal positions [49]. As an example, epi-androsterone was condensed with sulfanilamide resulting in the formation of substituted imine 90. Subsequent cycloaddition with thioglycolic acid under refluxing conditions in dioxane furnished the spiro N-aryl-1,3-thiazolidin-4-one 91. This

• compound underwent further transformation through reaction with p-fluorobenzaldehyde in dry ethanol, yielding the corresponding 4-fluoroarylidene derivative 92 in an overall yield of 27%. The described reaction sequence was successfully replicated using testosterone and progesterone to produce a N-aryl-1,3

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• ). Compound 15 reacted with diethyl phosphonate in the presence of a strong base (sodium methoxide) to afford diethyl [hydroxy(4-nitrophenyl)methyl]phosphonate (16) in 81% yield (Scheme 4). The hydrogenolysis of this compound under H2 on Pd/C afforded quantitatively diethyl [hydroxy(4-aminophenyl)methyl

• yield (13%). It was not possible to isolate neither di- or triphosphonate derivatives and with this compound it was not possible to prepare a doped membrane (Scheme 7). Preparation and proton conduction of doped membranes Previous studies in our group [26][27][28][29] have shown that the incorporation

pKalculator: A pK_a predictor for C–H bonds

• Rasmus M. Borup,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2024, 20, 1614–1622, doi:10.3762/bjoc.20.144

• pKa values. In the case of compound 3, most chemists would expect the pKa of pyrazole C–H sites to be considerably lower than those on the benzene ring, suggesting that factors other than pKa determine the site of borylation for this compound. In the case of compound 5, the most likely explanation is

Tetrabutylammonium iodide-catalyzed oxidative α-azidation of β-ketocarbonyl compounds using sodium azide

• Christopher Mairhofer,
• David Naderer and
• Mario Waser

Beilstein J. Org. Chem. 2024, 20, 1510–1517, doi:10.3762/bjoc.20.135

• additional KI in the presence of DBPO) and then resubmitted this compound to our ammonium salt-catalyzed azidation reaction conditions, observing full conversion to 2a as well. Considering all these details we thus propose a mechanistic scenario as outlined in Scheme 2. The catalyst gets oxidized to Bu4NIO

Sustainable tandem acylation/Diels–Alder reaction toward versatile tricyclic epoxyisoindole-7-carboxylic acids in renewable green solvents

• Ayhan Yıldırım

Beilstein J. Org. Chem. 2024, 20, 1308–1319, doi:10.3762/bjoc.20.114

• in good agreement with those reported for this compound in the literature. In all synthesized compounds, Ha and Hb protons are only in endo conformation and therefore the amide and carboxylic acid functional groups are arranged in exo conformation. The fact that the flexible 2n and 2o compounds in

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• + Na]+, [2M + Na]+, and [3M + Na]+. Spectroscopic data of this compound, including FTIR as well as 1H and 13C NMR, matched those reported earlier [54]. Relative extent of polymerization To compare the relative polymerization tendency, we conducted reactions of arylamines with SeO2 in acetonitrile in

• 100.11°. Since the NH2 groups in this molecule were further away from each other compared to the monoselenide 11, the hydrogen bonding arrangement led to a two-dimensional packing with a repeating zigzag pattern. Curiously, this compound showed an unusual Se···C σ-hole–π chalcogen bonding. Such

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

• of RdRp from all members of the genus Orthoflavivirus [20][21][22][23] and was crystallized in complex with the RdRp from DENV-3 [20]. In 2021, our group reported this compound to also exhibit inhibitory activity against feline infectious peritonitis virus (FIPV) and SARS-CoV-2 RdRp and to hinder

• pyridobenzoxazole derivative 2 was designed based on the modified approach published by Dejmek et al. (Scheme 1) [24]. In this work, we first synthesized the intermediate 6 from readily available 2′,5′-dihydroxyacetophenone (5) following a published procedure [27]. This compound was then easily converted to the

Spin and charge interactions between nanographene host and ferrocene

• Akira Suzuki,
• Yuya Miyake,
• Ryoga Shibata and
• Kazuyuki Takai

Beilstein J. Org. Chem. 2024, 20, 1011–1019, doi:10.3762/bjoc.20.89

• . Ferrocene (FeCp2) is a “sandwich” compound where the two cyclopentadienyl (Cp or C5H5-) rings sit above and below the Fe2+ ion [16]. The electronic structure of FeCp2 satisfies the 18-electron rule, so this compound is stable due to a closed L-shell structure in view of the atomic orbitals of Fe and it is a