Copper-catalyzed domino cyclization of anilines and cyclobutanone oxime: a scalable and versatile route to spirotetrahydroquinoline derivatives

• Qingqing Jiang,
• Xinyi Lei,
• Pan Gao and
• Yu Yuan

Beilstein J. Org. Chem. 2025, 21, 749–754, doi:10.3762/bjoc.21.58

• the desired product. Keywords: copper catalysis; cyclobutane-fused tetrahydroquinolines; domino cyclization reaction; green synthesis; Introduction Tetrahydroquinolines (THQs) represent a privileged scaffold in medicinal chemistry, exhibiting a broad spectrum of biological activities and serving as

Orthogonal photoswitching of heterobivalent azobenzene glycoclusters: the effect of glycoligand orientation in bacterial adhesion

• Leon M. Friedrich and
• Thisbe K. Lindhorst

Beilstein J. Org. Chem. 2025, 21, 736–748, doi:10.3762/bjoc.21.57

• scaffold molecules, respectively [14][15], – differing inhibitory properties in carbohydrate-specific bacterial adhesion resulted. To further investigate the effect of relative ligand orientation in carbohydrate recognition, we and others have utilized photoswitchable glycoconjugates [16][17][18][19

• conjugated to the 3- and the 6-position of a methyl mannoside scaffold (Figure 1, 1 (6βGlc3αMan)) [24]. Orthogonal photoswitching of the two glycoantennas is guaranteed by (i) ortho-fluorination of one azobenzene moiety and (ii) S-azobenzene versus O-azobenzene conjugation, resulting in significantly shifted

• functionalization of the ABF4 unit. The EE/ZE/EZ/ZZ isomeric mixture obtained after irradiation of the homobivalent photoswitchable glycocluster 6αMan3αMan 2 had to be determined by integration of the anomeric 1H/13C cross peak of the scaffold mannoside in the 1H,13C HSQC spectrum because the proton signals in the

Origami with small molecules: exploiting the C–F bond as a conformational tool

• Patrick Ryan,
• Ramsha Iftikhar and
• Luke Hunter

Beilstein J. Org. Chem. 2025, 21, 680–716, doi:10.3762/bjoc.21.54

• pendant aryl moiety, is better for target-binding and hence 41 is a ≈10-fold more potent inhibitor of BACE-1 than 40. Several further examples of cyclic ethers will be examined in section 5 (sugars). The anomeric effect applies in acyclic ethers, too. Consider the non-fluorinated scaffold, Ph–O–CH3 (42

• -hybridised oxygen atom. When one fluorine is introduced into this scaffold in the form of a fluoromethyl group (43, Figure 6), the gross conformation is little changed, but notably the fluorine preferentially resides at an endo position (oriented back towards the aryl moiety) which enables nO → σ*C–F

• elucidate the bioactive conformations, of other simple linear amines too. A gauche alignment of the vicinal C–N and C–F bonds is consistently seen [156], whether the scaffold is a primary amine (e.g., tetrafluorovaline, 91 [157]), a secondary amine (e.g., N-methyl-ᴅ-aspartate(92) [158][159]), or a tertiary

Semisynthetic derivatives of massarilactone D with cytotoxic and nematicidal activities

• Rémy B. Teponno,
• Sara R. Noumeur and
• Marc Stadler

Beilstein J. Org. Chem. 2025, 21, 607–615, doi:10.3762/bjoc.21.48

• products can serve as effective scaffold for the design and synthesis of derivatives with improved biological activities [5][6][7]. Massarilactones are produced by marine and endophytic fungi and bear close biogenetic similarity to several other fungal PKS1-derived metabolites including rosigenin, the

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

• steps and achieved 12% overall yield. In May 2024, the Qin group reported the second total synthesis of (±)-simonsol C (Scheme 2) [5]. An effective strategy to form the 6/5/6 benzofuran scaffold was developed which specifically involved a basic dearomatization and reductive elimination with Zn/AcOH to

• scaffold of simonsol C, utilizing an alkaline dearomatization as the key reaction, followed by a functional-group-selective Wittig reaction and concurrent oxy-Michael addition [6]. A bromophenol acetal was used in the intramolecular alkylative dearomatization, which was first reported by Magnus et al. [8

Sequential two-step, one-pot microwave-assisted Urech synthesis of 5-monosubstituted hydantoins from L-amino acids in water

• Wei-Jin Chang,
• Sook Yee Liew,
• Thomas Kurz and
• Siow-Ping Tan

Beilstein J. Org. Chem. 2025, 21, 596–600, doi:10.3762/bjoc.21.46

• Pharmaceutical and Medicinal Chemistry, Heinrich Heine University Düsseldorf, 40225 Düsseldorf, Germany 10.3762/bjoc.21.46 Abstract The hydantoin scaffold is renowned for its wide-ranging biological activities, including antibacterial, antiviral, anticancer, anti-inflammatory, and anticonvulsant effects. In

• accessibility of these bioactive compounds for pharmaceutical applications. Keywords: amino acids; hydantoin; microwave-assisted; one-pot reaction; Urech synthesis; Introduction The hydantoin moiety is a scaffold found in many biologically active compounds exhibiting a diverse range of properties, including

• (63–86%) [16]. As many of these protocols employ toxic, highly reactive and moisture-sensitive reagents, our work will exploit microwave technology and the environmentally benign nature of amino acids to construct the hydantoin scaffold. Microwave irradiation technology has proven significant

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

• recent years, multicomponent reactions (MCRs) have become one of the most important synthetic tools coming close to fulfilling the requirements of ideal reactions. They are ideally suited also for the generation of high chemical diversity compounds from simple reagents, either through scaffold

• diversification or scaffold decoration [4]. In these reactions, three or more compounds react together in one single reaction step to generate a more complex product where most of the atoms of starting materials are present [5]. This high atom economy positions MCRs as ecofriendly (green) reactions because their

• this context, quinoline and its derivatives are privileged structures in several natural products and biologically active compounds, rendering this scaffold an important synthetic target. An attractive strategy to afford tetrahydroquinolines and quinolines is the Povarov reaction, a type of aza-Diels

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• , School of Chemistry, Trinity College Dublin, The University of Dublin, Trinity Biomedical Sciences Institute, 152-160 Pearse Street, Dublin D02 R590, Ireland 10.3762/bjoc.21.37 Abstract Bimanes, a class of molecules based on the 1H,7H-pyrazolo[1,2-a]pyrazole-1,7-dione scaffold, were first introduced by

• development of a novel scaffold for topochemically active monomers. Bimanes Bimanes, a class of bicyclic compounds first synthesized by Kosower and Pazhenchevsky in 1978 [16], are based on a 1H,7H-pyrazolo[1,2-a]pyrazole-1,7-dione scaffold. The general structure of a bimane is depicted in Figure 1a. The term

• bimane scaffold and b) the two isomers of bimanes with their respective naming conventions. a) Structures of the bimanes studied and b) the reaction scheme of the [2 + 2] photocycloaddition of Cl2B. Synthetic approach to bimanes. View of the molecular structures in the crystal of the functionalized

Unraveling aromaticity: the dual worlds of pyrazole, pyrazoline, and 3D carborane

• Zahra Noori,
• Miquel Solà,
• Clara Viñas,
• Francesc Teixidor and
• Jordi Poater

Beilstein J. Org. Chem. 2025, 21, 412–420, doi:10.3762/bjoc.21.29

• their broader use. With this in mind, Lee and colleagues have recently developed an efficient synthetic method for producing o-carborane-fused pyrazoles as a novel scaffold, without using transition metals. Their approach involves reacting B(4)-acylmethyl and B(3,5)-diacylmethyl o-carborane with 2-azido

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

• are synthesized by incorporation of benzothiazine, pyrazole, and amide moieties in a new scaffold to create multifunctional derivatives of pyrazolo-1,2-benzothiazine. The presented compounds have been synthesized and analyzed using spectroscopic and spectrometric techniques including FTIR, HRMS, 1H

• , makes them a suitable linker unit [34]. The leading example is paracetamol highlighting the utility of an amide containing scaffold in medicinal chemistry. A series of novel scaffolds adjoining benzothiazine with a pyrazole moiety has been reported with antioxidant activity and antibacterial potential

• dry DMF. The five-membered ring of this esterified benzisothiazole 2 was then expanded to form a six-membered cycle via a ring-expansion reaction in anhydrous conditions. In this reaction, the benzisothiazole scaffold was converted into a benzothiazine backbone 3 followed by N-methylation to obtain

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

• Figure 1 and Figure 2, it can be found that the C=C bond is located in the unit of the pyrrolidine-2,5-dione, while the scaffold of indolin-2-one is connected via a C–C single bond with the unit of the pyrrolidine-2,5-dione. Therefore, an allyl rearrangement must proceed in the reaction process, which is

Streamlined modular synthesis of saframycin substructure via copper-catalyzed three-component assembly and gold-promoted 6-endo cyclization

• Asahi Kanno,
• Ryo Tanifuji,
• Satoshi Yoshida,
• Sota Sato,
• Saori Maki-Yonekura,
• Kiyofumi Takaba,
• Jungmin Kang,
• Kensuke Tono,
• Koji Yonekura and
• Hiroki Oguri

Beilstein J. Org. Chem. 2025, 21, 226–233, doi:10.3762/bjoc.21.14

• region of the DNA double helix, leading to the formation of a reversible covalent bond [9][10][11][12]. In this process, the oxygen functional groups at the C8 and C18 positions of the core scaffold interact with the DNA bases through multipoint hydrogen bonds (HBs), allowing recognition of approximately

• of lower oxidation state aromatic rings at the A- and E-rings of saframycins. Rational and systematic modification of both ends of the THIQ scaffolds would facilitate the development of reversible covalent DNA binders with tailored sequence preferences. Biosynthetically, the pentacyclic core scaffold

• avenues for the development of fluorescent probes based on the bis-THIQ alkaloidal scaffold. Further efforts to develop a concise and modular synthetic process for saframycins are currently underway. Representative bis-tetrahydroisoquinoline (THIQ) alkaloids and their analogues. Oxygen atoms on both the A

Heteroannulations of cyanoacetamide-based MCR scaffolds utilizing formamide

• Marios Zingiridis,
• Danae Papachristodoulou,
• Despoina Menegaki,
• Konstantinos G. Froudas and
• Constantinos G. Neochoritis

Beilstein J. Org. Chem. 2025, 21, 217–225, doi:10.3762/bjoc.21.13

• under the umbrella of C1 chemistry was to provide a straightforward access to the privileged scaffold of fused heteroannulated pyrimidones, which demonstrate a broad range of biological activities [28][29][30][31][32][33][34][35], including use as emissive nucleoside analogues [36][37][38]. Moreover

• was observed at an average wavelength of 384 nm for 5a–e, 439 nm for 6a–e and 430 nm for 7a–e (see Supporting Information File 1 for detailed information). In support of the proposed scaffold 7b, we were able to solve its crystal structure (Figure 3). An intermolecular bifurcated hydrogen bond network

• pyrimidine scaffold. Representative fluorescence spectrum of compounds 5b (λex = 330 nm) and 6e (λex = 430 nm) at 0.2 M in DMSO. Molecular geometry observed within the crystal structure of compound 7b (CCDC 2376493). Strategies towards targeted adducts: A) Niementowski quinazoline synthesis utilizing

Dioxazolones as electrophilic amide sources in copper-catalyzed and -mediated transformations

• Seungmin Lee,
• Minsuk Kim,
• Hyewon Han and
• Jongwoo Son

Beilstein J. Org. Chem. 2025, 21, 200–216, doi:10.3762/bjoc.21.12

• , styrene derivatives bearing both electron-rich and electron-poor groups underwent the desired transformation with high yields and enantioselectivities (23g and 23h). However, the styrene scaffold bearing a trifluoromethyl group showed reduced enantioselectivity (23i). Styrenes containing heterocyclic

Cu(OTf)₂-catalyzed multicomponent reactions

• Sara Colombo,
• Camilla Loro,
• Egle M. Beccalli,
• Gianluigi Broggini and
• Marta Papis

Beilstein J. Org. Chem. 2025, 21, 122–145, doi:10.3762/bjoc.21.7

• reactions starting from different reagents. In a first approach proposed by Meshram and co-workers, pyridin-2-one, O-tosylhydroxylamine and acetophenone treated in an ionic liquid assembled through the cascade formation of three C–N bonds to give the imidazo[1,2-a]pyridine scaffold 33 (Scheme 25) [43]. The

Facile one-pot reduction of β-nitrostyrenes to phenethylamines using sodium borohydride and copper(II) chloride

• Laura D’Andrea and
• Simon Jademyr

Beilstein J. Org. Chem. 2025, 21, 39–46, doi:10.3762/bjoc.21.4

• ; phenethylamine; Introduction The phenethylamine scaffold represents a recurring motif among natural and synthetic drug molecules. The latter are mainly constituted by a varied class of substituted phenylethylamines exhibiting psychoactive properties, and typically employed for medical and recreational use [1][2

Ceratinadin G, a new psammaplysin derivative possessing a cyano group from a sponge of the genus Pseudoceratina

• Shin-ichiro Kurimoto,
• Kouta Inoue,
• Taito Ohno and
• Takaaki Kubota

Beilstein J. Org. Chem. 2024, 20, 3215–3220, doi:10.3762/bjoc.20.267

• a rare nitrile that contains a cyano group as aminoacetonitrile. The biosynthesis of the 8,10-dibromo-9-methoxy-1,6-dioxa-2-azaspiro[4.6]undeca-2,7,9-trien-4-ol scaffold has been proposed by Scheuer, Clardy and co-workers [5], but how the cyano group in 1 is biosynthesized remains unknown and is of

Discovery of ianthelliformisamines D–G from the sponge Suberea ianthelliformis and the total synthesis of ianthelliformisamine D

• Sasha Hayes,
• Yaoying Lu,
• Bernd H. A. Rehm and
• Rohan A. Davis

Beilstein J. Org. Chem. 2024, 20, 3205–3214, doi:10.3762/bjoc.20.266

• from the amide proton linked the propyl-2-pyrrolidine moiety to the brominated acrylamide fragment and thus the full chemical structure of 4 was elucidated and assigned to ianthelliformisamine D. A refined literature search using Scifinder Scholar [16] revealed that compound 4 contains a novel scaffold

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

• synthesis of tripeptides incorporating new fluorinated heterocyclic hydrazino acids, based on the tetrahydropyridazine scaffold is described. Starting from simple fluorinated hydrazones, these non-proteinogenic cyclic β-amino acids were easily prepared by a zinc-catalyzed aza-Barbier reaction followed by an

• intramolecular Michael addition. Preliminary conformational studies on tripeptides including this scaffold in the central position show an extended conformation in solution (NMR) and in the solid state (X-ray). Keywords: fluoroalkyl groups; heterocycles; hydrazino acids; peptides; tetrahydropyridazines

• tetrahydropyridazine scaffold is also found in numerous natural linear or cyclic peptides such as svetamycins or antrimycins as dehydropiperazic acid (Figure 2) [10]. Whereas many publications have been devoted to the synthesis and structure of piperazic acid derivatives (dehydro, chloro, hydroxy, …) [11][12], nothing

Multicomponent reactions driving the discovery and optimization of agents targeting central nervous system pathologies

• Lucía Campos-Prieto,
• Aitor García-Rey,
• Eddy Sotelo and
• Ana Mallo-Abreu

Beilstein J. Org. Chem. 2024, 20, 3151–3173, doi:10.3762/bjoc.20.261

• quinazolinone scaffold. They have obtained new benzochromenopyrimidinones, abbreviated as BCPOs, whose synthesis has been accomplished in two steps. First, a microwave-assisted reaction of ethyl cyanoacetate, selected aromatic aldehydes, and 2-naphthol was performed. The second step was the condensation of the

• oxazepane scaffold 11 (Scheme 11). Replacing the nitrogen in the bioactive lactam 11 (γ-secretase inhibitor in AD therapy) with an oxygen should reduce the hydrogen bond donating (HBD) ability of the compounds. The method employs readily available starting materials, resulting in the desired compounds in a

• single step. The oxazepine scaffold can be easily accessed using the Ugi four-component reaction. By modifying this scaffold, the researchers aimed to reduce the hydrogen-bond donating properties. The Passerini reaction, employing bifunctional salicylaldehydes and isocyanides successfully yielded

Controlled oligomerization of [1.1.1]propellane through radical polarity matching: selective synthesis of SF₅- and CF₃SF₄-containing [2]staffanes

• Jón Atiba Buldt,
• Wang-Yeuk Kong,
• Yannick Kraemer,
• Masiel M. Belsuzarri,
• Ansh Hiten Patel,
• James C. Fettinger,
• Dean J. Tantillo and
• Cody Ross Pitts

Beilstein J. Org. Chem. 2024, 20, 3134–3143, doi:10.3762/bjoc.20.259

• phenomenon is quite sensitive to changes in the fluorinated sulfur reagent scaffold (see Supporting Information File 1 for more details). This second instance of controlled oligomerization of 1 using CF3SF4Cl was also studied at the PWPB95-D4/def2-QZVPP//PCM(Et2O)-ωB97X-D/def2-TZVP level of theory (Figure 3

Synthesis of the 1,5-disubstituted tetrazole-methanesulfonylindole hybrid system via high-order multicomponent reaction

• Cesia M. Aguilar-Morales,
• América A. Frías-López,
• Nadia V. Emilio-Velázquez,
• Alejandro Islas-Jácome,
• Angelica Judith Granados-López,
• Jorge Gustavo Araujo-Huitrado,
• Yamilé López-Hernández,
• Hiram Hernández-López,
• Luis Chacón-García,
• Jesús Adrián López and
• Carlos J. Cortés-García

Beilstein J. Org. Chem. 2024, 20, 3077–3084, doi:10.3762/bjoc.20.256

• representative studies include antibacterial, anti-inflammatory, antioxidant, selective inhibitor of COX-2 [34], and anti-HIV activity [35]. In this context, even though indole is considered a privileged scaffold present in some anticancer agents [36], a few examples of methanesulfonylindoles are studied as

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• studies, because translating their modular biosynthetic logic into a chemical synthetic scheme is rather straightforward [86]. Aside from constructing the core molecular scaffold of these natural products, further modifications may be installed either before or after the assembly of the amino acid or

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• (small-molecule concept) offer a distinctive advantage in the synthesis of new biologically active molecules, as they are synthetic bioisosters of purine bases. Imidazo[1,2-a]pyrimidine derivatives exhibit a wide range of pharmacological properties [4][5][6]. For example, this scaffold is a key

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

• -indolenines, specially the spiro-heterocyclic indolenines, can be considered as a privileged scaffold, present in several natural products with interesting biological activities, as depicted in Figure 1 [4][5][6][7]. Among the known methods of synthesizing spiro-heterocyclic indolenines, the dearomative