Halogenated butyrolactones from the biomass-derived synthon levoglucosenone

• Johannes Puschnig,
• Martyn Jevric and
• Ben W. Greatrex

Beilstein J. Org. Chem. 2025, 21, 2297–2301, doi:10.3762/bjoc.21.175

• Baeyer–Villiger oxidation affording the fluorinated, chlorinated, and brominated dideoxyribonolactones. Keywords: butyrolactone; cyrene; fluorine; halogenation; levoglucosenone; Introduction The γ-butyrolactone ring is a privileged scaffold found in natural products and can be used as a valuable

Pathway economy in cyclization of 1,n-enynes

• Hezhen Han,
• Wenjie Mao,
• Bin Lin,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2025, 21, 2260–2282, doi:10.3762/bjoc.21.173

• under gold(I) catalysis through a substituent-controlled strategy (Scheme 8) [15]. Substrates with heteroaryl substituents underwent 6-endo-dig cyclization via gold-heteroatom coordination, furnishing the lactone-fused pyran scaffold 34 (Scheme 8, path a). Substrates with aryl substituents at the

Synthesis of triazolo- and tetrazolo-fused 1,4-benzodiazepines via one-pot Ugi–azide and Cu-free click reactions

• Xiaoming Ma,
• Zijie Gao,
• Jiawei Niu,
• Wentao Shao,
• Shenghu Yan,
• Sai Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2025, 21, 2202–2210, doi:10.3762/bjoc.21.167

• /bjoc.21.167 Abstract A one-pot Ugi–azide reaction followed by intramolecular Cu-free azide–alkyne cycloaddition generates a polycyclic scaffold 7 bearing polycyclic triazole, tetrazole, and benzodiazepine rings. This method could be extended for obtaining a more complicated scaffold 8 containing a

• methods for the synthesis of tetrazoles [25][26][27][28], the Ugi–azide reaction is a good approach for constructing 1,5-disubstituted-tetrazoles (1,5-DS-T) [29][30][31]. This scaffold can be subsequently linked to 1,2,3-triazole [32], 4H-chromen-4-one [33], pyrrolo[3,4-b]indolizine [34], and other

• in 36–90% yields (Scheme 4). As shown in Scheme 2, we also propose the synthesis of triazole-, tetrazole-, and piperazinone-fused 1,4-benzodiazepines 8. For the synthesis of this unique polycyclic scaffold, 2-isocyanoacetate 9 played a critical role in the formation of the piperazinone ring. Thus

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• benzo[a]carbazole (a very important scaffold in the pharmaceutical industry) from the commercially available 2-phenylindole and bio-renewable 1-hydroxypropan-2-one (acetol) using a sulfone-containing Brønsted acidic medium as catalyst. The process was applied to a number of substituted 2-phenylindoles

• hydrolysis (Scheme 59). Furfural was employed as starting scaffold in a protocol developed to form acetals as fuel additives. The acyclic acetal is generated in situ from crude furfural with propanol in dimethyl carbonate using a nanoporous aluminosilicate material Al-13-(3.18) as catalyst, and then

• versatile scaffold for bioactive molecules) with up to 99% yield and 96% ee were prepared (Scheme 69). The large electron-donating groups of 3,5-di-tert-butyl-4-methoxyphenyl (DTBM) improved the activities of the CuI–thiophene-2-carboxylate catalyst (CuTc) while the use of (R)-DTBM-GarPhos as the chiral

Discovery of cytotoxic indolo[1,2-c]quinazoline derivatives through scaffold-based design

• Daniil V. Khabarov,
• Valeria A. Litvinova,
• Lyubov G. Dezhenkova,
• Dmitry N. Kaluzhny,
• Alexander S. Tikhomirov and
• Andrey E. Shchekotikhin

Beilstein J. Org. Chem. 2025, 21, 2062–2071, doi:10.3762/bjoc.21.161

• polycyclic structures, DNA was not the primary target for their antiproliferative effects, as confirmed by FID assay and fluorescence titration studies. This study represents the first comprehensive evaluation of indolo[1,2-c]quinazolines as potential scaffold for the development of antitumor agents

• reports that focused on natural alkaloids or limited antimicrobial studies, this study expands the pharmacological scope by demonstrating selective antiproliferative effects and identifying promising SAR trends. The originality of the research lies in linking strategic scaffold functionalization

• exceptional potential as ligands targeting secondary structures of nucleic acids, particularly G-quadruplexes (G4) [21][22]. The indolo[1,2-c]quinazolin-6(5H)-one scaffold 1 exemplifies this design principle, with its rigid polycyclic framework mimicking topologies of established DNA/RNA-interactive molecules

Asymmetric total synthesis of tricyclic prostaglandin D2 metabolite methyl ester via oxidative radical cyclization

• Miao Xiao,
• Liuyang Pu,
• Qiaoli Shang,
• Lei Zhu and
• Jun Huang

Beilstein J. Org. Chem. 2025, 21, 1964–1972, doi:10.3762/bjoc.21.152

• effective tool in clinical applications [6]. However, the scarcity of metabolite 4 has prevented it from being used more widely, and thus synthesis methods for 4 are required. Compound 4 contains a cyclopentanol scaffold with stereogenicity at C8, C9, C11, and C12 (Scheme 1A). In addition, 4 is

• by the anomeric effect [23] in the tricyclic scaffold. Compound 13 could be produced from olefin 14 via cross-metathesis. The regio- and diastereoselective connection of C8 and C12 in compound 14 could be realized through a transition-metal-mediated oxidative radical cyclization through TS-1 from β

• nitrate (CAN) [29][30] and Fe(ClO4)3·9H2O [31], failed to afford desired product 14 (Table 1, entries 6 and 7). To explore the synthesis of fully functionalized tricyclic core scaffold 12, methods for incorporating the side chain at C14 and for the stereocontrolled introduction of the allyl moiety at C8

Enantioselective desymmetrization strategy of prochiral 1,3-diols in natural product synthesis

• Lihua Wei,
• Rui Yang,
• Zhifeng Shi and
• Zhiqiang Ma

Beilstein J. Org. Chem. 2025, 21, 1932–1963, doi:10.3762/bjoc.21.151

• transformation involving acyl-group migration, [4 + 2] cycloaddition and aromatic Pummerer-type reaction, provided chiral spiro compound 59 with the 6/6/5/5/6/6 scaffold, and this intermediate was further elaborated to 60 in six additional steps. Lipases from Pseudomonas genus Pseudomonas is a genus of Gram

• 226. Regioselective hydrolysis of 226 with TFA yielded a dihydropyran intermediate, which was benzylated to deliver 227. Desilylation of 227 gave diol 228, which underwent intramolecular Michael reaction to form bicyclic compound 230 as a single stereoisomer (87% yield over two steps). This scaffold

Chiral phosphoric acid-catalyzed asymmetric synthesis of helically chiral, planarly chiral and inherently chiral molecules

• Wei Liu and
• Xiaoyu Yang

Beilstein J. Org. Chem. 2025, 21, 1864–1889, doi:10.3762/bjoc.21.145

• effects of the CPAs, which establish a chiral microenvironment within the chiral scaffold that governs the stereoselectivity of asymmetric reactions. Chiral molecules, characterized as three-dimensional structures that are nonsuperimposable with their mirror image, have significant applications in

• terminal aromatic rings [17]. Despite lacking asymmetric stereogenic centers, this nonplanar scaffold exhibits intrinsic P/M chirality due to the helical arrangement of the π-extended skeleton. Renowned for their high thermal stability and structural rigidity, chiral helicenes have emerged as prominent

• the 1,3-phenyl rings (see 53d) or 1,3-diamino substitution (see 53e) on the calix[4]arene scaffold were also amenable to this method, which yielded a series of structurally diverse novel quinoline-containing inherently chiral calix[4]arenes. Moreover, by using CPA 4 as the optimal catalyst, the

Approaches to stereoselective 1,1'-glycosylation

• Daniele Zucchetta and
• Alla Zamyatina

Beilstein J. Org. Chem. 2025, 21, 1700–1718, doi:10.3762/bjoc.21.133

• functional and protecting groups on the pyranose scaffold can profoundly influence the reaction mechanism, toggling it between SN2 and SN1 pathways [104][105]. Supporting this, the torsional restriction imparted by the 4,6-O-benzylidene group in 2-azido-substituted GlcN lactols was found to favor the

On the aromaticity and photophysics of 1-arylbenzo[a]imidazo[5,1,2-cd]indolizines as bicolor fluorescent molecules for barium tagging in the study of double-beta decay of ¹³⁶Xe

• Eric Iván Velazco-Cabral,
• Fernando Auria-Luna,
• Juan Molina-Canteras,
• Miguel A. Vázquez,
• Iván Rivilla and
• Fernando P. Cossío

Beilstein J. Org. Chem. 2025, 21, 1627–1638, doi:10.3762/bjoc.21.126

• were performed by using the Gaussian 16 suite of programs [56]. Conclusion From the computational study reported in this paper, we conclude that the benzo[a]imidazo[5,1,2-cd]indolizine scaffold is a convenient fluorophore for barium tagging in neutrinoless double-beta decay. This fluorophore exhibits

• scaffold. The chemical synthesis, photophysical properties and suitability for barium tagging will be published in due course. Two possible double beta decay modes. Left: with emission of two electronic antineutrinos (ββ2ν). Right: neutrinoless double beta decay (ββ0ν). General structure of first

General method for the synthesis of enaminones via photocatalysis

• Paula Pérez-Ramos,
• Raquel G. Soengas and
• Humberto Rodríguez-Solla

Beilstein J. Org. Chem. 2025, 21, 1535–1543, doi:10.3762/bjoc.21.116

• intermediates in the synthesis of several derivatives with important applications in medicinal chemistry. Furthermore, many marketed drugs feature the enaminone structural moiety. In this context, we have developed a photoredox and nickel catalytic system to rapidly forge the enaminone scaffold from 3

• act as both electrophiles and nucleophiles [7]. This makes enaminones very reactive, providing an excellent scaffold for organic synthesis. Thus, enaminones are valuable building blocks in the preparation of several carbocyclic [8][9][10][11], heterocyclic [12][13][14][15][16][17][18] as well as

Heterologous biosynthesis of cotylenol and concise synthesis of fusicoccane diterpenoids

• Ye Yuan,
• Zhenhua Guan,
• Xue-Jie Zhang,
• Nanyu Yao,
• Wenling Yuan,
• Yonghui Zhang,
• Ying Ye and
• Zheng Xiang

Beilstein J. Org. Chem. 2025, 21, 1489–1495, doi:10.3762/bjoc.21.111

• Nozaki–Hiyama–Kishi reaction and a one-pot Prins cyclization/transannular hydride transfer to construct the 5-8-5 tricyclic scaffold. Enzymatic oxidations were used to install the hydroxy group at the C-3 position. Ten fusicoccanes were synthesized in 8–13 steps each. Despite these efforts, a strategy

• brassicicene biosynthesis-related gene cluster (BGC) in Alternaria brassicicola and Pseudocercospora fijiensis [34][35]. The 5-8-5 tricyclic scaffold is transformed into various fusicoccane natural products catalyzed by P450s, dioxygenases, dehydrogenases, and reductases. Therefore, we propose to harness the

Advances in nitrogen-containing helicenes: synthesis, chiroptical properties, and optoelectronic applications

• Meng Qiu,
• Jing Du,
• Nai-Te Yao,
• Xin-Yue Wang and
• Han-Yuan Gong

Beilstein J. Org. Chem. 2025, 21, 1422–1453, doi:10.3762/bjoc.21.106

• [fluorene-9,9'-xanthene]) scaffold, they successfully converted initially non-emissive helicenes into efficient TADF luminophores with tunable emission wavelengths ranging from sky-blue to deep red. Particularly, the enantiomeric forms of the 75b derivatives emerged as rare examples of red-emissive CPL

N-Salicyl-amino acid derivatives with antiparasitic activity from Pseudomonas sp. UIAU-6B

• Joy E. Rajakulendran,
• Emmanuel Tope Oluwabusola,
• Michela Cerone,
• Terry K. Smith,
• Olusoji O. Adebisi,
• Adefolalu Adedotun,
• Gagan Preet,
• Sylvia Soldatou,
• Hai Deng,
• Rainer Ebel and
• Marcel Jaspars

Beilstein J. Org. Chem. 2025, 21, 1388–1396, doi:10.3762/bjoc.21.103

• siderophores because the isolates share common structural scaffold and are analogues of previously confirmed siderophores, including pseudomonine and salicylic acid [26][27][28] which were also isolated from the same culture as well. The experimental work to confirm these types of compounds as siderophores was

High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters

• Kelsey Plasse,
• Valerie Wright,
• Guoshu Xie,
• R. Bernadett Vlocskó,
• Alexander Lazarev and
• Béla Török

Beilstein J. Org. Chem. 2025, 21, 1374–1387, doi:10.3762/bjoc.21.102

• of catalyst- and solvent-free processes is desirable. Chalcones are a privileged scaffold in medicinal chemistry and are used for the synthesis of a multitude of products [43]. The cyclization between chalcones and hydrazines usually occur via a C=O/NH2 condensation and a subsequent NH addition to

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• nanographenes. In the literature terms such as “azulene-embedded nanographenes” or “azulene-embedded PAHs” generally refer to any conjugated carbon scaffold composed of sp2 carbons with adjacent pentagonal and heptagonal rings. However, in many cases, the distinctive electronic structure of azulene is absent

• hydrocarbon-based azulene-embedded nanographenes. The synthesis of smaller non-alternant PAHs containing azulene moiety dates to the 1950s. The most common strategy involved synthesizing a partially saturated scaffold, which was then dehydrogenated in the final step. One of the earliest examples of the

• to the dication induced an aromaticity switch, resulting in the pentagon–heptagon pair adopting an aromatic character. The group later extended this strategy to scaffold 91 decorated with two imide substituents, which was isolated in 4% yield [66]. Annulation of substituted azulenes Scholl-type

Investigations of amination reactions on an antimalarial 1,2,4-triazolo[4,3-a]pyrazine scaffold

• Henry S. T. Smith,
• Ben Giuliani,
• Kanchana Wijesekera,
• Kah Yean Lum,
• Sandra Duffy,
• Aaron Lock,
• Jonathan M. White,
• Vicky M. Avery and
• Rohan A. Davis

Beilstein J. Org. Chem. 2025, 21, 1126–1134, doi:10.3762/bjoc.21.90

• scaffold for aminations with 14 commercially available primary amines. Reacting scaffold 1 with excess primary amine at room temperature for 16 h generated the desired amine analogues in respectable yields (18–87%) and high purity (≥95%) following chromatography workup. The structures of the 14 previously

• engrafted with human erythrocytes, after oral administration of the compounds [5][9]. Triazolopyrazines halogenated on the pyrazine ring represent synthetically useful targets for elaboration of this active scaffold, and the regioselectivity of amine nucleophiles (amongst others) has been explored by Korsik

• C19H1635ClN5Na, 372.0991), that enabled a molecular formula of C19H16ClN5 to be assigned to 2. The 1H NMR spectrum of 2 displayed two aromatic doublets corresponding to nuclei on the triazolopyrazine scaffold [δH 7.76 (H-5), 7.38 (H-6)], and displayed two resonances [δH 7.93 (H-11, H-15), 7.69 (H-12, H-14

Recent total synthesis of natural products leveraging a strategy of enamide cyclization

• Chun-Yu Mi,
• Jia-Yuan Zhai and
• Xiao-Ming Zhang

Beilstein J. Org. Chem. 2025, 21, 999–1009, doi:10.3762/bjoc.21.81

• antitumor, antibacterial, antiviral, and antioxidizing properties. Previous synthetic strategies for these molecules typically rely on multi-step procedures to assemble the tricyclic core. However, the direct catalytic enantioselective formation of this scaffold from a linear precursor remains underexplored

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

• in triarylmethyl radicals is by touching the triphenylmethyl scaffold itself, rather than only its substitution pattern. A variety of studies have been concerned with the pyridine-diphenylmethyl (PyBTM) motif, which has one of the para-carbons replaced by a nitrogen (see Figure 3) [56]. Surprisingly

Studies on the syntheses of β-carboline alkaloids brevicarine and brevicolline

• Benedek Batizi,
• Patrik Pollák,
• András Dancsó,
• Péter Keglevich,
• Gyula Simig,
• Balázs Volk and
• Mátyás Milen

Beilstein J. Org. Chem. 2025, 21, 955–963, doi:10.3762/bjoc.21.79

• , versatile key triflate intermediate 3, which allowed the introduction of substituents attached by a C–C bond to position 4 of the β-carboline scaffold by cross-coupling reactions. Sonogashira reaction of compound 3 with N-(3-butynyl)phthalimide (4) led to coupled compound 5. Cleavage of the phthalimide

A convergent synthetic approach to the tetracyclic core framework of khayanolide-type limonoids

• Zhiyang Zhang,
• Jialei Hu,
• Hanfeng Ding,
• Li Zhang and
• Peirong Rao

Beilstein J. Org. Chem. 2025, 21, 926–934, doi:10.3762/bjoc.21.75

• convergent approach leveraging an AcOH-interrupted Nazarov cyclization to establish the [5,5,6,6]-tetracyclic scaffold with precise stereochemical fidelity. Results and Discussion Our retrosynthetic analysis toward krishnolides A (7) and C (8) is delineated in Scheme 1B. We hypothesized that these two

Silver(I) triflate-catalyzed post-Ugi synthesis of pyrazolodiazepines

• Muhammad Hasan,
• Anatoly A. Peshkov,
• Syed Anis Ali Shah,
• Andrey Belyaev,
• Chang-Keun Lim,
• Shunyi Wang and
• Vsevolod A. Peshkov

Beilstein J. Org. Chem. 2025, 21, 915–925, doi:10.3762/bjoc.21.74

• , which features a pyrrolodiazepine core, has been studied both alone and in combination with diazepam for its antianxiety and sedative effects [11]. Flumazenil comprises an imidazobenzodiazepine scaffold and its intravenous administration is used to treat benzodiazepine overdoses [12][13] and to reverse

• procedures and harsh reaction conditions, resulting in limited substituent and scaffold diversity [18][19]. In this regard, multicomponent reactions (MCRs) have gained increasing attention for their operational simplicity, efficiency, robustness, atom economy, and potential for diversity-oriented synthesis

• formation of the tricyclic triazolo[1,5-a][1,4]benzodiazepine scaffold 10 (Scheme 1b) [39]. Triple bond-containing Ugi adducts showed a great promise for the assembly of various seven-membered nitrogen-containing heterocyclic cores through transition-metal-catalyzed alkyne hydroarylations [40][41][42][43

Cu–Bpin-mediated dimerization of 4,4-dichloro-2-butenoic acid derivatives enables the synthesis of densely functionalized cyclopropanes

• Patricia Gómez-Roibás,
• Andrea Chaves-Pouso and
• Martín Fañanás-Mastral

Beilstein J. Org. Chem. 2025, 21, 877–883, doi:10.3762/bjoc.21.71

• . However, when the reaction was carried out with KOt-Bu, we observed the selective conversion of 9 into product 20 featuring a different cyclopropane scaffold. Slight modification of the reaction conditions allowed us to obtain product 20 in 56% yield as a single diastereomer (Scheme 5a). Taking advantage

Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

• Lewis McGhie,
• Hannah M. Kortman,
• Jenna Rumpf,
• Peter H. Seeberger and
• John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

• scaffold (Figure 1A, bottom), with increasing excited state energy moving from stilbenes and conjugated dienes to simple dienes, styrenes and enones (not shown) [28]. Consequently, small truncated chromophores, such as simple alkenes remain an intractable challenge for efficient EnT due to prohibitively

Synthesis and photoinduced switching properties of C₇-heteroatom containing push–pull norbornadiene derivatives

• Daniel Krappmann and
• Andreas Hirsch

Beilstein J. Org. Chem. 2025, 21, 807–816, doi:10.3762/bjoc.21.64

• ) derivatives. Push–pull substitution on the 2 and 3 position as well as introduction of oxygen or nitrogen at position 7 of the NBD scaffold have led to the development of a new family of photoswitches. We studied the potential conversion of norbornadiene to quadricyclane (QC) isomers. As main investigation

• , it is essential not only to achieve a high storage density and good quantum efficiency for the isomerization process but also to ensure large half-lifes and durability in switching reliability [20]. By making structural adjustments to the parent carbon scaffold, it is possible to target specific

• variations in the switching properties. However, it is important to note that altering one property typically impacts other characteristics as well [21][22]. In this regard, both the substitution of the NBD periphery to produce push–pull derivatives and the variation of the central scaffold itself have been