[3 + 2] Cycloaddition of thioformylium methylide with various arylidene-azolones in the synthesis of 7-thia-3-azaspiro[4.4]nonan-4-ones

• Daniil I. Rudik,
• Irina V. Tiushina,
• Anatoly I. Sokolov,
• Alexander Yu. Smirnov,
• Alexander R. Romanenko,
• Alexander A. Korlyukov,
• Andrey A. Mikhaylov and
• Mikhail S. Baranov

Beilstein J. Org. Chem. 2025, 21, 1791–1798, doi:10.3762/bjoc.21.141

• authors have shown that arylidene-azolones are very promising substrates for these transformations, since their exo-cyclic double bond easily reacts with various 1,3-dipoles [16][17][18][19][20]. Thioformylium methylide is a well known 1,3-dipole, which is readily generated from chloromethyl

• transformations. For example, compound 7e underwent both sulfone formation and S/O atoms exchange in the heterocyclic core. For derivatives 6 and 8, any oxidation conditions resulted in even more complex product mixtures (presumably due to the additional sulfur atom in the second ring), whose structures could not

Synthesis of chiral cyclohexane-linked bisimidazolines

• Changmeng Xi,
• Qingshan Sun and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1786–1790, doi:10.3762/bjoc.21.140

• bisimidazolines are efficient chiral ligands in metal-catalyzed asymmetric organic transformations. Chiral cyclohexane-linked bisimidazolines were prepared from optically active cyclohexane-1,2-dicarboxylic acid and 1,2-diphenylethane-1,2-diamines via the monosulfonylation of 1,2-diphenylethane-1,2-diamines

• bisoxazolines [1][2][3][4][5][6][7][8][9] and bisimidazolines [10][11][12][13][14][15] are efficient chiral ligands and have been widely applied in various metal-catalyzed asymmetric organic transformations. Various chiral bisoxazoline ligands have been prepared from diacids and enantiopure vicinal amino

Continuous-flow-enabled intensification in nitration processes: a review of technological developments and practical applications over the past decade

• Feng Zhou,
• Chuansong Duanmu,
• Yanxing Li,
• Jin Li,
• Haiqing Xu,
• Pan Wang and
• Kai Zhu

Beilstein J. Org. Chem. 2025, 21, 1678–1699, doi:10.3762/bjoc.21.132

• generated during the dilution process. While many nitration processes usually exhibit rapid kinetics, specific transformations like partial dinitration reactions demonstrate notably slower reaction rates, substantially compromising process throughput. Although thermal activation via temperature elevation

Influence of the cation in hypophosphite-mediated catalyst-free reductive amination

• Natalia Lebedeva,
• Fedor Kliuev,
• Olesya Zvereva,
• Klim Biriukov,
• Evgeniya Podyacheva,
• Maria Godovikova,
• Oleg I. Afanasyev and
• Denis Chusov

Beilstein J. Org. Chem. 2025, 21, 1661–1670, doi:10.3762/bjoc.21.130

• metals other than sodium have been severely understudied in reductive transformations. While at least the structure of LiH2PO2 is known [30][31], rubidium hypophosphite is not described in the literature. There is only a very limited number of KH2PO2 utilization examples in copolymerization [32] and

• confirmed by D-experiments. The whole sequence of transformations was finished by the reduction of the charged iminium cation with the hypophosphite anion forming N,N,N-dimethylbenzylammonium phosphite in exergonic manner with a total Gibbs free energy gain of −26.8 kcal/mol (Step_5). Noteworthy, the target

Catalytic asymmetric reactions of isocyanides for constructing non-central chirality

• Jia-Yu Liao

Beilstein J. Org. Chem. 2025, 21, 1648–1660, doi:10.3762/bjoc.21.129

• Jia-Yu Liao College of Pharmaceutical Sciences, Zhejiang University, Hangzhou, 310058, China 10.3762/bjoc.21.129 Abstract Beyond the conventional carbon-centered chirality, catalytic asymmetric transformations of isocyanides have recently emerged as a powerful strategy for the efficient synthesis

• become a hot topic in synthetic organic chemistry. Isocyanides (also termed isonitriles) are a class of highly versatile building blocks in organic synthesis, participating in a wide range of transformations including multicomponent reactions (e.g., the well-known Passerini and Ugi reactions) [13][14][15

• reaction type and the chirality type of resulting products. Perspective Isocyanide-based transformations Palladium-catalyzed isocyanide insertion reactions In 2018, Luo, Zhu, and co-workers developed a palladium-catalyzed enantioselective reaction between ferrocene-derived vinyl isocyanides 1 and aryl

Photocatalysis and photochemistry in organic synthesis

• Timothy Noël and
• Bartholomäus Pieber

Beilstein J. Org. Chem. 2025, 21, 1645–1647, doi:10.3762/bjoc.21.128

• demonstrate its broad applicability [11]. This renewed momentum was driven by contributions from numerous groups across the field. At the same time, advances in technology – particularly the accessibility of various light sources (most notably LEDs) – made photochemical transformations much more practical to

• catalysis, and this arsenal of catalysts is constantly expanding. In this thematic issue, the Dell’Amico group describes the development of a new class of organic donor–acceptor photocatalysts that show promising activity for several transformations [18]. Additionally, Hoffmann and co-workers contributed a

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

• , the reaction is 136Xe → 136Ba2+ + 2e− + 2. The ββ0ν analog would consist of simply 136Xe → 136Ba2+ + 2e−. Both transformations are extraordinarily rare events. For instance, the estimated half-life for the ββ0ν decay is at least higher than 2.3·1026 years, whereas the current best estimate of the age

Transition-state aromaticity and its relationship with reactivity in pericyclic reactions

• Israel Fernández

Beilstein J. Org. Chem. 2025, 21, 1613–1626, doi:10.3762/bjoc.21.125

• concerted mechanisms has not been considered. For instance, very little is known about the influence of TS-aromaticity (if any) on the barrier heights of catalyzed pericyclic reactions and related transformations. Our group has been focused on this aspect in recent years by exploring the interplay between

• the aromaticity of the transition state and the activation barriers of different pericyclic reactions spanning from the parent Diels–Alder reactions to higher-order cycloadditions or even transition-metal-mediated transformations [22][23][24][25][26][27][28][29]. By selecting illustrative examples, in

• reactions [74][75] constitute representative DGTRs. In general, concerted DGRTs are thermally allowed [σ2s + σ2s + π2s] transformations according to the Woodward–Hoffmann rules [15], and therefore proceed through a highly synchronous six-membered transition state. Not surprisingly and similar to the ene

3-Aryl-2H-azirines as annulation reagents in the Ni(II)-catalyzed synthesis of 1H-benzo[4,5]thieno[3,2-b]pyrroles

• Julia I. Pavlenko,
• Pavel A. Sakharov,
• Anastasiya V. Agafonova,
• Derenik A. Isadzhanyan,
• Alexander F. Khlebnikov and
• Mikhail S. Novikov

Beilstein J. Org. Chem. 2025, 21, 1595–1602, doi:10.3762/bjoc.21.123

• methanol. The driving force of this process is the formation of an aromatic thiophene system. To demonstrate the practicability and synthetic utility of this method for the synthesis of benzo[4,5]thieno[3,2-b]pyrrole derivatives, several transformations of compound 3b were carried out (Scheme 4

Azide–alkyne cycloaddition (click) reaction in biomass-derived solvent Cyrene^TM under one-pot conditions

• Zoltán Medgyesi and
• László T. Mika

Beilstein J. Org. Chem. 2025, 21, 1544–1551, doi:10.3762/bjoc.21.117

• been characterized as an ideal solvent for click reactions, the limited solubility of most organic substrates could limit its application. Thus, the transformations of either water-insoluble or solid compounds require a solvent to establish high reaction performance, i.e. homogeneous solutions with low

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

• ]. Thus, the use of visible light as an energy source provides more efficient chemical transformations and minimize the use of harmful reagents, the generation of waste and the consumption of energy, fulfilling several principles of Green Chemistry and promoting greener opportunities for organic synthesis

• moieties, respectively, since they could enable further chemical transformations. Unfortunately, when 2-methyl-3-bromochromone was employed as the substrate, the process failed to afford the desired enaminone product, which was possibly caused by a combination of increased steric hindrance and decreased

Azobenzene protonation as a tool for temperature sensing

• Antti Siiskonen,
• Sami Vesamäki and
• Arri Priimagi

Beilstein J. Org. Chem. 2025, 21, 1528–1534, doi:10.3762/bjoc.21.115

• other transformations that can offer useful functionalities. These include ionization via protonation of one of the nitrogens forming the azo bond [12][13], azo–hydrazone tautomerization [14][15], and binding of analytes to side groups [16]. Such transformations depend on the azobenzene structure but

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

• with limited chemical transformations is highly desirable and should enable the discovery of new fusicoccane derivatives with improved biological activity. Inspired by the biosynthetic machinery of terpenoids, we have reported a hybrid synthetic strategy for accessing bioactive terpenoids by combining

• enzymatic terpene cyclization and chemical synthesis [30][31][32][33]. Briefly, the carbon scaffolds are forged by terpene cyclases, followed by concise chemical transformations to yield the desired natural products. Here, we describe heterologous biosynthesis of cotylenol by engineering the biosynthetic

Photoredox-catalyzed arylation of isonitriles by diaryliodonium salts towards benzamides

• Nadezhda M. Metalnikova,
• Nikita S. Antonkin,
• Tuan K. Nguyen,
• Natalia S. Soldatova,
• Alexander V. Nyuchev,
• Mikhail A. Kinzhalov and
• Pavel S. Postnikov

Beilstein J. Org. Chem. 2025, 21, 1480–1488, doi:10.3762/bjoc.21.110

• of benzamides (Scheme 1A) [6]. Over the years, the basic reaction has been modified to imply various metal-containing catalysts [7][8][9][10][11][12][13][14][15][16][17][18], metal-free transformations that employ heteroarenes under harsh conditions [19], or using diazonium salts as arylating agents

• [20][21]. However, diazonium salts are distinguished by their inherent instability complicating their use in such transformations. Moreover, among the various arylation strategies, photochemical methods remain relatively underexplored, with only a few examples reported [22][23]. These methods often

Copper catalysis: a constantly evolving field

• Elena Fernández and
• Jaesook Yun

Beilstein J. Org. Chem. 2025, 21, 1477–1479, doi:10.3762/bjoc.21.109

• one of the most dynamic and versatile areas of contemporary chemical research. Once viewed primarily as a cost-effective alternative to noble metals, copper has emerged as a powerful and versatile catalyst, capable of mediating a wide array of chemical transformations through both two-electron and

• single-electron pathways. This duality has enabled access to previously elusive molecular transformations, positioning copper at the center of modern synthetic strategy. This thematic issue captures the dynamic nature of the field, featuring five insightful Review articles and five original research

• straightforward reactions. Complementarily, the Review article by Jang and Kim provides a deep understanding of recent advances in the combination of electrochemistry and copper catalysis for various organic transformations [3]. Their contribution elaborates various C–H functionalizations, olefin additions

Reactions of acryl thioamides with iminoiodinanes as a one-step synthesis of N-sulfonyl-2,3-dihydro-1,2-thiazoles

• Vladimir G. Ilkin,
• Pavel S. Silaichev,
• Valeriy O. Filimonov,
• Tetyana V. Beryozkina,
• Margarita D. Likhacheva,
• Pavel A. Slepukhin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2025, 21, 1397–1403, doi:10.3762/bjoc.21.104

• ]. These data [1][2][3][4][5] inspired researchers to expand the chemistry of these compounds and to search for new synthetic methods and chemical transformations [14][15]. Unlike the aromatic congeners, the chemistry of non-aromatic dihydro-1,2-thiazoles is less represented in the literature [16][17][18

Oxetanes: formation, reactivity and total syntheses of natural products

• Peter Gabko,
• Martin Kalník and
• Maroš Bella

Beilstein J. Org. Chem. 2025, 21, 1324–1373, doi:10.3762/bjoc.21.101

• additions and hydrolyses (in case of esters and amides), as well as epimerisations at the α-carbons, oxetanes are stable to such chemical transformations. In case of the gem-dimethyl group, which is commonly used to block metabolically labile sites at the expense of raising lipophilicity, bridging the two

• transformations of 3-oxetanone leading to advanced oxetane building blocks. In chapter 3, we review the reactivity of oxetanes with regards to ring openings and ring expansions including both symmetric and enantioselective variants. Finally, chapter 4 covers isolations, biological activities and total syntheses

• -, particularly 2-methylideneoxetanes have become valuable intermediates in oxetane chemistry as they readily undergo a variety of chemical transformations, including ring-opening reactions with nucleophiles, epoxidations, cyclopropanations and [3 + 2] cycloadditions with nitrile oxides [51][52]. In addition

Recent advances in amidyl radical-mediated photocatalytic direct intermolecular hydrogen atom transfer

• Hao-Sen Wang,
• Lin Li,
• Xin Chen,
• Jian-Li Wu,
• Kai Sun,
• Xiao-Lan Chen,
• Ling-Bo Qu and
• Bing Yu

Beilstein J. Org. Chem. 2025, 21, 1306–1323, doi:10.3762/bjoc.21.100

• across diverse bond activation challenges, particularly in C(sp³)–H, C(sp²)–H, S–H, Ge–H, and B–H bond transformations. The proposed system architecture emphasizes synergistic reagent cooperation rather than isolated component performance, representing a paradigm shift in photoredox catalysis design

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

• achieved using Suzuki and Sonogashira cross-coupling reactions. One of the first examples was the synthesis of diazuleno[1,2,3-cd:10,20,30-fg]pyrene, which was later subjected to on-surface transformations [94]. More recently, a more general approach was reported by Langer and co-workers, who described the

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

• rapid construction of complex molecular architectures. This review aims to summarize the diverse strategies for inducing intramolecular transformations of N-arylacrylamides using various carbon radical reagents, including methods initiated by photonic, thermal, or electrochemical processes, which have

• been extensively investigated by researchers. Keywords: carbon radical reagents; intramolecular transformations; N-arylacrylamides; oxidative difunctionalization; radical reactions; Introduction Alkenes, as abundant and versatile feedstocks, have been widely employed in organic synthesis

• transformations, (4) electrochemical approaches, and (5) metal-free or electron donor–acceptor (EDA)-driven systems. The substrate scope, limitations, and mechanistic aspects of these radical cascade cyclization strategies are critically examined. Review N-Arylalkenes: alkyl C(sp3)–H radicals Early investigations

Synthesis of β-ketophosphonates through aerobic copper(II)-mediated phosphorylation of enol acetates

• Alexander S. Budnikov,
• Igor B. Krylov,
• Fedor K. Monin,
• Valentina M. Merkulova,
• Alexey I. Ilovaisky,
• Liu Yan,
• Bing Yu and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2025, 21, 1192–1200, doi:10.3762/bjoc.21.96

• various synthetically useful transformations, including alkene synthesis via Horner–Wadsworth–Emmons reaction [14][15], heterocycle construction [16][17], and the synthesis of chiral β-amino and β-hydroxy phosphonic acids [18][19]. Furthermore, they exhibit metal-complexing abilities [20], and anti

• efficiency, strong basic or acidic conditions, and excess of organohalides as starting materials. Recent years have witnessed the upsurge of free-radical oxidative phosphorylation transformations that became a reliable strategy for the construction of C–P bonds in organophosphorus chemistry [2][32][33][34

Enhancing chemical synthesis planning: automated quantum mechanics-based regioselectivity prediction for C–H activation with directing groups

• Julius Seumer,
• Nicolai Ree and
• Jan H. Jensen

Beilstein J. Org. Chem. 2025, 21, 1171–1182, doi:10.3762/bjoc.21.94

• activation, transforming these inert bonds into reactive carbon–transition metal (C–M) bonds. Subsequent transformations of these complexes enable the formation of an array of new functional groups, such as carbon–carbon and carbon–heteroatom bonds, underpinning a plethora of synthetic applications

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

• and deprotection steps, functional group transformations, stereocontrolled allylation, cross-metathesis, and Horner–Wadsworth–Emmons (HWE) olefination. This method highlights the power of catalytic stereocontrol, achieving the complex architecture of borrelidin fragments with efficiency and precision

Salen–scandium(III) complex-catalyzed asymmetric (3 + 2) annulation of aziridines and aldehydes

• Linqiang Wang and
• Jiaxi Xu

Beilstein J. Org. Chem. 2025, 21, 1087–1094, doi:10.3762/bjoc.21.86

• [5] and the FDA-approved antibiotic linezolid [6] (Figure 1). Both chiral oxazolidines [7][8] and oxazolidinones [9][10] have been utilized as chiral auxiliary groups in many asymmetric organic transformations. Oxazolidine derivatives have been prepared mainly from condensation of vicinal amino

Recent advances in synthetic approaches for bioactive cinnamic acid derivatives

• Betty A. Kustiana,
• Galuh Widiyarti and
• Teni Ernawati

Beilstein J. Org. Chem. 2025, 21, 1031–1086, doi:10.3762/bjoc.21.85

• relatively new prima donna of functional groups explored in drug design, were smoothly prepared. 2.4 Miscellaneous reactions Cyclopropenone, the smallest Hückel aromatic system, has been subjected to the ring opening reactions, driven by the release of ring strain. Numerous transformations of cyclopropenone