Pseudallenes A and B, new sulfur-containing ovalicin sesquiterpenoid derivatives with antimicrobial activity from the deep-sea cold seep sediment-derived fungus Pseudallescheria boydii CS-793

• Zhen Ying,
• Xiao-Ming Li,
• Sui-Qun Yang,
• Hong-Lei Li,
• Xin Li,
• Bin-Gui Wang and
• Ling-Hong Meng

Beilstein J. Org. Chem. 2024, 20, 470–478, doi:10.3762/bjoc.20.42

• structures were solved by direct methods using the SHELXTL software package [18][19]. All non-hydrogen atoms were refined anisotropically. The H atoms were located by geometrical calculations, and their positions and thermal parameters were fixed during the structure refinement. The absolute structures were

Synthesis of 2,2-difluoro-1,3-diketone and 2,2-difluoro-1,3-ketoester derivatives using fluorine gas

• Alexander S. Hampton,
• David R. W. Hodgson,
• Graham McDougald,
• Linhua Wang and
• Graham Sandford

Beilstein J. Org. Chem. 2024, 20, 460–469, doi:10.3762/bjoc.20.41

• difluoromethylene units. To meet the demands of synthetic chemists within the life science discovery and manufacturing arenas, many fluorination methods have been developed over the years to introduce difluoromethylene groups into organic systems. Approaches using nucleophilic fluorination include halogen exchange

• ][31][32]. Since profit margins in the life science industries are always under constant pressure, less expensive methods of introducing fluorine selectively into active intermediates for manufacture on the industrial scale are required and, as a relatively inexpensive strategy, direct fluorination of

• substrates using fluorine gas has been used successfully for the production of 5-fluorouracil (generic, anticancer) and voriconazole (V-FEND, Pfizer, antifungal) [33]. Methods have been developed for the selective monofluorination of 1,3-dicarbonyl derivatives by fluorine gas using batch and continuous flow

(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• continues to be relevant. One of the methods for the synthesis of allenes was based on the interaction of bromoolefins with organolithium compounds, followed by the elimination of lithium fluoride [29][30][31]. It was logical to assume that in our case a similar reaction of the Grignard reagent 12 with

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• , respectively. The unsymmetrically substituted 1-(5-methylfuran-2-yl)ethan-1-one also reacted satisfactorily with 1,8-dibromonaphthalene to give acenaphtho[1,2-c]furan 18 in 53% yield. It is worth mentioning that at the present time, very few methods for the preparation of acenaphtho[1,2-c]furans have been

• yield of product 28 to 51%. Under these conditions, 4-bromo-3-iodotoluene and 1,2-dibromo-4,5-dimethylbenzene also gave the desired products 29 and 30 in 43% and 66% yield, respectively. Conclusion In summary, we report here complementary methods for the preparation of substituted fluoranthenes. The

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

• reaction between aldehydes with indoles, while focusing on the more environmentally friendly methods developed over the years. Keywords: aldehyde; BIMs; Friedel–Crafts reaction; green chemistry; indole; Review Medicinal properties In recent years, diindolylmethane (DIM, 1) and its derivatives known as

• highest fungicidal activity [11]. Brønsted or Lewis acid catalysis – conventional synthetic methods The indole moiety is part of many natural products, agrochemicals, and pharmaceuticals. In medicinal chemistry, indole and its derivatives are considered important compounds, since they exhibit valuable

• introduced nano n-propylsulfonated γ-Fe2O3 (NPS-γ-Fe2O3), which constitutes a magnetically recyclable heterogeneous catalyst that works in the exact same manner as HPA/TPI-Fe3O4 [103]. Some small differences between the two methods were the ability of ketones to form the respective BIMs, when NPS-γ-Fe2O3 was

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

• isonicotinate tert-butyl ester) in C(sp2)-borylation methods under photochemical and thermal conditions, respectively [65][66]. The activation of NHPI esters through EDA complex formation is also possible by employing a catalytic donor species, which enables a range of redox neutral transformations. In 2019

• significant advantages compared to other methods. It allows for single electron reduction to be facilitated by cost-effective carbon-based cathodes, eliminating the requirement for precious metal photocatalysts or exogeneous reductants such as Zn0. In the final section of this perspective, we explore examples

Elucidating the glycan-binding specificity and structure of Cucumis melo agglutinin, a new R-type lectin

• Jon Lundstrøm,
• Emilie Gillon,
• Valérie Chazalet,
• Nicole Kerekes,
• Antonio Di Maio,
• Ten Feizi,
• Yan Liu,
• Annabelle Varrot and
• Daniel Bojar

Beilstein J. Org. Chem. 2024, 20, 306–320, doi:10.3762/bjoc.20.31

• profiling, thereby advancing both diagnostic methods and biomarker discovery. Examples include arrays that can rapidly profile alterations in glycosylation patterns, pivotal in many diseases and inflammatory changes [10][11]. Traditionally, lectins are divided into classes based on structural similarity and

• binding specificity with orthogonal methods, we used a thermal shift assay. Herein, the binding of ligands is assessed by the stabilization of the protein, measured by a denaturation curve. Both the protein produced in mammalian and in bacterial cells exhibited similar melting temperatures here, of

• mg/mL was crystallized using hanging drop and vapor diffusion methods with a 2 µL drop in 1:1 ratio at 20 °C. Bipyramidal single crystals were obtained after one or two days in a solution containing 10–12% PEG Smear Medium, 0.1 M MES pH 6.5, 1× divalent (5 mM of CaCl2, MgCl2, CsCl2, CdCl2, NiCl2, and

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• obtained in 89% yield on a ≈10 mg scale from its sulfoxide precursor 4a. In anticipation of device fabrication, activation methods which do not require the addition of chemical reagents were next tested. Thermally-induced S-extrusion was first investigated by means of thermogravimetric analysis: the

• photoextrusion of S and SO2 fragments are classical methods in organic synthesis [54][58][59], whereas photoextrusion of SO from bisaryl sulfoxide moieties has been evidenced more recently by Wolf et al. [60][61]. Solutions of dinaphthothiepine 3a and its sulfoxide analogue 4a in dichloromethane were irradiated

• acenes, as described in the introduction. Chalcogen extrusion from bridged precursors: access to acenes Deoxygenation of endoxides belongs to the classical methods used in organic chemistry to generate polycylic aromatic hydrocarbons, through a reductive aromatization relying on a variety of chemical

Synthesis of spiropyridazine-benzosultams by the [4 + 2] annulation reaction of 3-substituted benzoisothiazole 1,1-dioxides with 1,2-diaza-1,3-dienes

• Wenqing Hao,
• Long Wang,
• Jinlei Zhang,
• Dawei Teng and
• Guorui Cao

Beilstein J. Org. Chem. 2024, 20, 280–286, doi:10.3762/bjoc.20.29

• ketimines as suitable three-carbon synthons in [3 + 2] and [3 + 3] annulations [11][12][13][14][15]. However, methods using N-sulfonyl ketimines as dienophiles in [4 + 2] annulation reactions to afford biologically important spiro compounds are still limited to date [16]. 1,2-Diaza-1,3-dienes [17][18][19

Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C₇₀ production

• Cristina Castanyer,
• Anna Pla-Quintana,
• Anna Roglans,
• Albert Artigas and
• Miquel Solà

Beilstein J. Org. Chem. 2024, 20, 272–279, doi:10.3762/bjoc.20.28

• (fulleroid) derivatives 2a and 2b. Supporting Information Supporting Information File 22: General materials and methods, experimental procedures and characterization of all new compounds. Acknowledgements Dr. Carles Fuertes-Espinosa is acknowledged for assistance in HPLC and UV–vis experiments. Funding We

Nucleophilic functionalization of thianthrenium salts under basic conditions

• Xinting Fan,
• Duo Zhang,
• Xiangchuan Xiu,
• Bin Xu,
• Yu Yuan,
• Feng Chen and
• Pan Gao

Beilstein J. Org. Chem. 2024, 20, 257–263, doi:10.3762/bjoc.20.26

• further potential in organic synthesis. Despite establishing a few preliminary methods for preparing organothianthrenium salts, their application potential is historically thwarted by harsh synthetic conditions and the poor durability of the resulting products [7]. Recently, Ritter and co-workers have

• generation of alkyl radicals [39]. After that, a series of methods for the modification of alkylthianthrenium salts have been developed, including the transition-metal-catalyzed cross-coupling with terminal alkynes [40], sulfonylation with DABCO·(SO2)2 [41][42][43], or alkylation of active alkenes [44][45

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• sophistication over the past decades. Most known processes, however, are still frequently hampered by lengthy protecting-group strategies and very costly purification procedures derived from the "stop-and-go" synthetic methods (Figure 1a). Those protocols are still far from the ideal synthesis, implying high

• because they are time-saving, waste-reducing, and atom efficient [1][2][3][4][5][6]. These efficient and straightforward synthetic methods make the isolation and purification of intermediate products after each reaction step superfluous, thereby drastically reducing the number of workup and purification

Substitution reactions in the acenaphthene analog of quino[7,8-h]quinoline and an unusual synthesis of the corresponding acenaphthylenes by tele-elimination

• Ekaterina V. Kolupaeva,
• Narek A. Dzhangiryan,
• Alexander F. Pozharskii,
• Oleg P. Demidov and
• Valery A. Ozeryanskii

Beilstein J. Org. Chem. 2024, 20, 243–253, doi:10.3762/bjoc.20.24

• (Figure 2) as a fully conjugated analog of acenaphthene 5 by classical methods were unsuccessful (Supporting Information File 1, Table S2). In all experiments, the starting compound remained unchanged or bound into a sparingly soluble precipitate even in high-boiling solvents such as o-dichlorobenzene or

• structure of compound 15 was confirmed by a combination of spectral methods, in particular, the disappearance of a singlet from H-5,8 protons at 7.8–7.9 ppm in the starting material 5 during functionalization (nitration, bromination), unambiguously indicates the occurrence of substituents precisely in these

Photochromic derivatives of indigo: historical overview of development, challenges and applications

• Gökhan Kaplan,
• Zeynel Seferoğlu and
• Daria V. Berdnikova

Beilstein J. Org. Chem. 2024, 20, 228–242, doi:10.3762/bjoc.20.23

• ]. As an alternative to the chemical synthesis of indigo, environmentally friendly biological approaches towards constructing the indigo scaffold are also being developed for nearly a century [5][6][7][8]. The biosynthetic methods include production of indigo by microorganisms and enzymatic synthesis

• the flash photolysis by a ruby laser (λ = 694 nm) in combination with photostationary methods [41]. The data on the absorption maxima, decay times, and extinction coefficients for Z-11a and Z-12 obtained in these measurements significantly differed from those reported by Pummerer and Marondel [40]. In

• toolkit of available synthetic methods makes several types of indigo photoswitches affordable and synthetically accessible. At the same time, the need to develop new synthetic approaches to obtain tailored indigo derivatives remains high [9]. In contrast to the recent review by Hecht and Huang [9

Copper-catalyzed multicomponent reaction of β-trifluoromethyl β-diazo esters enabling the synthesis of β-trifluoromethyl N,N-diacyl-β-amino esters

• Youlong Du,
• Haibo Mei,
• Ata Makarem,
• Ramin Javahershenas,
• Vadim A. Soloshonok and
• Jianlin Han

Beilstein J. Org. Chem. 2024, 20, 212–219, doi:10.3762/bjoc.20.21

• esters [28][29][30] have been widely explored, β-trifluoromethyl β-diazo esters have been less investigated, mainly due to the instability of such structures. Therefore, methods for the synthesis of β-trifluoromethyl β-diazo esters and their applications in organic synthesis are needed but remain

• conditions. A variety of unnatural unsymmetrical β-trifluoromethyl diacyl-β-amino esters were obtained in good yields, which are useful synthetic scaffolds [50][51][52] but difficult to obtain by other methods [53][54][55][56][57]. This work is the first example of the reaction of β-trifluoromethyl β-diazo

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

• Yumei Wang,
• Guangzhu Wang,
• Yanping Zhu and
• Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

• great attention in organic synthesis. Various methods [9], including reductive hydrogenation [10][11], kinetic resolution [12][13][14], functionalization of indole [15], and de novo construction of chiral 2-substituted indolines, have been developed [16][17][18][19][20]. In recent years, the metal

• -catalyzed asymmetric hydrogenation of indoles to synthesize chiral indolines has been widely studied (Scheme 1a) [21][22]. Representative examples include Ir- or Ru-catalyzed asymmetric hydrogenation of 2,3,3-trisubstituted 3H-indole [23][24]. Generally, these methods employ precious metals and/or

Metal-catalyzed coupling/carbonylative cyclizations for accessing dibenzodiazepinones: an expedient route to clozapine and other drugs

• Amina Moutayakine and
• Anthony J. Burke

Beilstein J. Org. Chem. 2024, 20, 193–204, doi:10.3762/bjoc.20.19

• not been reported previously (the methods a–c indicated in Scheme 1 have a different route, and none involve either a Chan–Lam or carbonylative cyclization). For the sake of health and safety, and given that our infrastructures did not permit the use of molecular CO, we felt more secure with a

Comparison of glycosyl donors: a supramer approach

• Anna V. Orlova,
• Nelly N. Malysheva,
• Maria V. Panova,
• Nikita M. Podvalnyy,
• Michael G. Medvedev and
• Leonid O. Kononov

Beilstein J. Org. Chem. 2024, 20, 181–192, doi:10.3762/bjoc.20.18

• , Russian Federation 10.3762/bjoc.20.18 Abstract The development of new methods for chemical glycosylation commonly includes comparison of various glycosyl donors. An attempted comparison of chemical properties of two sialic acid-based thioglycoside glycosyl donors, differing only in the substituent at O-9

• . Experimental General methods All methods and procedures followed those described in our previous publications [33][36][37]. The reactions were performed with the use of commercial reagents. Solvents for reactions were distilled and purified before the use according to the standard procedures. MeCN for

Synthesis of the 3’-O-sulfated TF antigen with a TEG-N₃ linker for glycodendrimersomes preparation to study lectin binding

• Mark Reihill,
• Hanyue Ma,
• Dennis Bengtsson and
• Stefan Oscarson

Beilstein J. Org. Chem. 2024, 20, 173–180, doi:10.3762/bjoc.20.17

• following acetylation without purification of the intermediate, why the synthesis is high-yielding (20% overall yield) and easily scalable (9 g of protected disaccharide 7 and 1 gram of target 2 were synthesized). Experimental General methods All reactions containing air- and moisture-sensitive reagents

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• diluted with ethyl acetate (20 mL) and washed with saturated sodium bicarbonate and brine successively. The organic layer was dried over anhydrous sodium sulfate and concentrated in vacuo. The residue was purified on preparative thin-layer chromatography (PTLC) to afford the desired product 3. Methods for

Visible-light-induced radical cascade cyclization: a catalyst-free synthetic approach to trifluoromethylated heterocycles

• Chuan Yang,
• Wei Shi,
• Jian Tian,
• Lin Guo,
• Yating Zhao and
• Wujiong Xia

Beilstein J. Org. Chem. 2024, 20, 118–124, doi:10.3762/bjoc.20.12

• ], Friedel–Crafts acylation [12], radical cascade reactions [2][13], and photoinduced radical cyclizations [14][15][16][17]. However, these methods often suffer from drawbacks such as harsh reaction conditions and the requirement of transition-metal catalysts. Although photocatalyzed cyclization reactions

Photoinduced in situ generation of DNA-targeting ligands: DNA-binding and DNA-photodamaging properties of benzo[c]quinolizinium ions

• Julika Schlosser,
• Olga Fedorova,
• Yuri Fedorov and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 101–117, doi:10.3762/bjoc.20.11

• photocyclization reaction has to be red-shifted. But with a focus on the improvement of these properties the benzo[c]quinolizinium ion should be considered as a promising platform for further development of DNA-binding and DNA-photodamaging reagents. Experimental General methods The commercially available

Electron-beam-promoted fullerene dimerization in nanotubes: insights from DFT computations

• Laura Abella,
• Gerard Novell-Leruth,
• Josep M. Ricart,
• Josep M. Poblet and
• Antonio Rodríguez-Fortea

Beilstein J. Org. Chem. 2024, 20, 92–100, doi:10.3762/bjoc.20.10

• electron microscopy (TEM) is a technique that has been used for a long time to provide images of molecules, but also to monitor the reactions triggered by the energy transfer of the electron beam to the atoms that build the molecules. In particular, the advances in TEM as well as in methods to anchor

• Computational methods). This significant amount of energy, which could be overestimated, comes from the π–π interactions between the C60 surface and the CNT wall and is modelled in a first approximation using Grimme’s corrections to the dispersion energy [16]. This interaction energy is comparable to those in

• somewhat different computational settings with a non-periodic electronic structure code as ADF, see values in parenthesis in the two first columns of Table 1 (also at PBE level, but using atomic orbitals instead of plane waves as basis sets, see Computational methods). Although reaction energies are

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• emphasis must also be placed on upscaling reactors and catalytic systems to facilitate the transition to cleaner energy sources. There are mainly three categories of solar to hydrogen generation methods based on semiconductors, namely photovoltaic-powered electrolysis (PV-E), photoelectrochemical (PEC

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• = 0.71073 Å). The data collections were done at 100 K. All data were integrated with SAINT and a multi-scan absorption correction using SADABS was applied [35][36]. The structure was solved by direct methods using SHELXT and refined by full-matrix least-squares methods against F2 by SHELXL-2019/2 [37][38