Synthesis and acaricidal activity against Varroa destructor of α- and γ-costic acid dimers

• Alessandro Santarsiere,
• Ernesto Santoro,
• Maria Letizia Ciavatta,
• Marianna Carbone,
• Sonia Ganassi,
• Cosimo Tedino,
• Antonio De Cristofaro,
• Antonio Evidente and
• Stefano Superchi

Beilstein J. Org. Chem. 2026, 22, 1088–1096, doi:10.3762/bjoc.22.87

• then removed under reduced pressure. 1H NMR analysis of crude showed the presence of compound 5 with minor impurities coming from unreacted 1. Compound 5 was employed for the subsequent transformations without further purification. 1H NMR (500 MHz) δ 6.19 (s, 1H), 5.59 (s, 1H), 5.30 (brs, 1H), 4.30 (m

One-pot four-component sequential synthesis of S-alkyl dithiocarbamates using lipase as a biocatalyst

• Mansour Shahedi,
• Pargol Tahmasebi pour and
• Zohreh Habibi

Beilstein J. Org. Chem. 2026, 22, 1048–1056, doi:10.3762/bjoc.22.83

• multicomponent transformations. The operational simplicity, mild conditions, and efficient access to structurally diverse S-alkyl dithiocarbamates demonstrate the synthetic utility of this approach. Considering the well-documented biological relevance of dithiocarbamate scaffolds, the synthesized compounds may

Synthesis of novel 1,2,4-oxadiazole-isoxazoline hybrids and their in silico potential with adenosine receptors

• Pshtiwan S. Mohammed,
• Mohammed K. S. Dalo,
• Onur C. Yazıcı,
• Muhammet Yildirim and
• Akın Sağırlı

Beilstein J. Org. Chem. 2026, 22, 1033–1047, doi:10.3762/bjoc.22.82

• , palladium-catalyzed reactions, anodic oxidations, transformations from other heterocycles or 1,3-dipolar cycloaddition [29][30][31][32][33][34][35][36][37][38][39][40][41][42][43][44]. For isoxazoline derivatives, the 1,3-dipolar cycloaddition (1,3-DC) of nitrile oxides serves as a fundamental synthetic

Synthesis and optical resolution of 4,5-diaminohomoadamantane: a promising scaffold for chiral ligands and bioactive compounds

• Polina A. Man’kova,
• Vadim A. Shiryaev,
• Olga S. Podlipnova,
• Marat M. Khisyamov,
• Dmitry S. Nikerov,
• Alexander N. Reznikov and
• Yuri N. Klimochkin

Beilstein J. Org. Chem. 2026, 22, 1013–1022, doi:10.3762/bjoc.22.80

• been extensively studied [8][9][10][11][12][13][14][15][16], while the properties of homoadamantane, its closest homologue, have not been studied so thoroughly. Chemical transformations of homoadamantane both at the bridgehead [17][18][19][20][21][22][23] and at the C-4 positions [24][25][26][27][28

• in clinical practice [64][65][66], as well as auxiliaries and ligands in important asymmetric transformations [67][68][69][70]. Bi- and polycyclic vicinal diamines can also be considered as potential ligands for asymmetric catalysis [71][72][73][74], but little attention has been paid to methods for

Z-Selective semihydrogenation of alkynes via Ni/Lewis acid synergistic catalyzed system using DMF as hydrogen source and solvent

• Lei Kang,
• Haifeng Gao and
• Luo Yang

Beilstein J. Org. Chem. 2026, 22, 1004–1012, doi:10.3762/bjoc.22.79

• , as outlined in Scheme 5. The cycle likely begins with the reduction of the Ni(II) precursor to an active Ni(0) species A – a common initiation step in nickel-catalyzed transformations, and the in-situ-generated formic acid functions as the reducing agent for this Ni(II)-to-Ni(0) conversion

• . Overall, this work provides a practical and cost-effective alternative to existing semihydrogenation methods and highlights the potential of base metal synergistic catalysis in stereocontrolled synthetic transformations. Experimental All experiments were performed under air. An oven-dried reaction vessel

Novel macrocycles: from synthesis to supramolecular function

• Veronica Iuliano,
• Carmen Talotta,
• Margherita De Rosa,
• Paolo Della Sala,
• Konrad Tiefenbacher,
• Pablo Ballester and
• Carmine Gaeta

Beilstein J. Org. Chem. 2026, 22, 982–985, doi:10.3762/bjoc.22.76

• designed protection and functionalization sequences, the authors introduced orthogonal reactive groups at opposite rims of the macrocycle. The synthetic versatility of these systems was demonstrated by copper-catalyzed “click” reactions and amine-based transformations, yielding highly functionalized

Electrochemical reduction of unsaturated carbon–carbon bonds via 3d transition-metal catalysis

• Geon Kang,
• Minki Jeon,
• Pooja Kumari Jat,
• Cheoljae Kim and
• Isaac Choi

Beilstein J. Org. Chem. 2026, 22, 955–981, doi:10.3762/bjoc.22.75

• achievable reactivity and selectivity [29]. A design for electroorganic synthesis Chemical transformations are inherently governed by the movement of electrons. Consequently, electrochemistry offers a platform in which an applied potential directly controls the electron flow, enable redox processes without

• . As this review primarily addresses reductive electroorganic transformations, the anodic process is often not directly involved in product formation. In such cases, sacrificial anodes, most commonly zinc or magnesium, are employed, wherein the electrode material undergoes dissolution to maintain

• protonation to furnish the final product (Scheme 2D). Cobalt Alkynes to alkenes Cobalt readily operates within open-shell and radical manifolds [92][93], rendering it particularly effective for HAT-based reductive transformations. In 2022, the Baran group reported a ligand-controlled E- or Z-selective alkyne

Recent advances in copper-catalyzed direct hydroamination of alkenes with (hetero)aromatic amines

• Hyejeong Lee and
• Yunmi Lee

Beilstein J. Org. Chem. 2026, 22, 925–947, doi:10.3762/bjoc.22.73

• coordination behavior of these substrates render such transformations inherently challenging. Recently, copper catalysis has emerged as a versatile and practical platform for addressing these limitations. Owing to its redox flexibility and ligand tunability, copper facilitates multiple activation modes

• yields under mild conditions. Furthermore, the heterogeneous catalyst could be readily recovered and reused without significant loss of activity, demonstrating the practical utility of NP-based copper catalysts for sustainable aza-Michael transformations. Under conditions B, Rahman et al. developed a bio

• crystallinity and well-defined lattice features, characteristic of the polycrystalline spinel phase of CuCo2O4. These sheet-like structures provide a large surface area and abundant exposed catalytic sites, which are advantageous for heterogeneous catalytic transformations. Under optimized conditions using 6

Diastereodivergent electrophilic trapping of α-boryl lithium derivatives

• Tereza Pavlíčková,
• Noam Orbach and
• Ilan Marek

Beilstein J. Org. Chem. 2026, 22, 882–887, doi:10.3762/bjoc.22.68

• diverse catalytic and stereoselective transformations [28][29][30][31][32][33]. In this context, we have recently demonstrated that a broad range of arylated (iodomethyl)cyclopropylboronic ester 2 [34] undergo ring-opening reactions, followed by electrophilic trapping of the resulting α-boryl carbanion

• , this work establishes α-boryl lithium intermediates as valuable stereogenic platforms for conducting highly diastereoselective nucleophilic transformations. The combination of the anion-stabilizing capability of boron with strain-release-driven ring fragmentation provides exceptional chemo- and

Site-specific labelling of native peptides and proteins: chemical and enzymatic strategies

• Antonio Angelastro,
• Jonathan Bargh,
• Subhajit Guria,
• Victor Laserna and
• Louis Luk

Beilstein J. Org. Chem. 2026, 22, 857–881, doi:10.3762/bjoc.22.67

• transformations [3][4]. However, the limited abundance of free cysteine residues in proteins has driven the development of alternative approaches targeting other chemical motifs. This review summarizes current strategies for site-specific modifications of these alternative sites, followed by a comparative

• ) refer to chemical changes to a protein in-cell after it is synthesised by the ribosome, encompassing over 650 types of transformations, including phosphorylation, methylation, acylation, ubiquitination and glycosylation [110]. While numerous naturally occurring PTMs have been repurposed for

The trans-influence in gold chemistry from a catalytic perspective

• Manfred Bochmann

Beilstein J. Org. Chem. 2026, 22, 838–856, doi:10.3762/bjoc.22.66

• recent mechanistic insights. Keywords: catalysis; gold; ligands; reaction mechanism; trans-influence; Introduction Gold catalysts have emerged as catalysts of choice in a multitude of organic transformations, not least due to their high functional group tolerance. Their applications have been widely

Unsymmetrical sulfoxides with sterically hindered catechol fragment: synthesis, structure, electrochemical properties, and antiradical activity

• Daria A. Burmistrova,
• Vasiliy A. Fokin,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Maxim V. Arsenyev,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2026, 22, 828–837, doi:10.3762/bjoc.22.65

• on the sulfoxide group. Keywords: antioxidant activity; catechol thioethers; redox-transformations; sulfoxides; X-ray analysis; Introduction Polyphenolic compounds can participate in redox processes and undergo a wide range of chemical modifications. As a result, they possess diverse biological

• 1.82–1.91 V. The value of Epox2 for the above-mentioned compounds is shifted anodically by 0.26–0.31 V relative to the corresponding thioethers, reflecting an increase in the Gibbs free energy (ΔG) of the electrooxidation process by 12–15 kcal/mol. Redox transformations at the sulfur atom occur in

• either one or two stages, depending on the degree of branching of the hydrocarbon substituent. A possible mechanism for the anodic transformations of sulfoxides is the two-electron oxidation of the substituted o-benzoquinone formed in the first stage to a dication (Scheme 2, path a). Further

Synthesis and structural elucidation of a novel bis-spirooxindole from isatin and ethylenediamine

• Irene Moreno-Gutiérrez,
• Josefa L. López-Martínez,
• Sonia Berenguel-Gómez,
• Irene Torres-García,
• Duane Choquesillo-Lazarte,
• Manuel Muñoz-Dorado,
• Miriam Álvarez-Corral and
• Ignacio Rodríguez-García

Beilstein J. Org. Chem. 2026, 22, 813–820, doi:10.3762/bjoc.22.63

• conditions. Keywords: ethylenediamine; isatin; spirooxindole; Introduction Isatin (1) is a highly versatile platform for heterocycle construction, particularly through skeletal editing, ring expansion, and related transformations that enable rapid access to complex molecular architectures [1]. In parallel

Synthetic study of vic-bromination of diarylacetylenes, easy purification and separation

• Akane Togo,
• Hiyono Suzuki,
• Yuto Akai,
• Makoto Matsumoto,
• Yoshinori Suzuma,
• Hidehiko Kodama and
• Kouichi Matsumoto

Beilstein J. Org. Chem. 2026, 22, 795–802, doi:10.3762/bjoc.22.61

• ; Introduction The addition reaction of bromine to diphenylacetylene is one of basic reactions and is recognized as important, because resulting 1,2-dibromo-1,2-diphenylethylene can serve as a precursor for various molecular transformations in organic synthesis [1][2]. This reaction seems to be simple, but some

• interested in the selective synthesis of the E isomer of 1,2-dibromo-1,2-diphenylethylene, together with simple purification and separation toward process chemistry, because the compound is an attractive synthetic intermediate for further transformations. During the course of our studies, we have found that

Rongalite addition to dienones: diastereoselectivity in cyclic sulfone synthesis; stereochemical rationalization and prospects as a general conjugate nucleophile

• Melina Goga,
• Hao Zong,
• James Franco,
• Jazmine Prana,
• Rudolph Michel,
• Antonia Muro,
• Elana Rubin,
• Janet Brenya,
• Henk Eshuis and
• Magnus W. P. Bebbington

Beilstein J. Org. Chem. 2026, 22, 742–752, doi:10.3762/bjoc.22.56

• heterocycles and also those looking to use Rongalite as a source of nucleophilic sulfur in other transformations. We are currently examining extensions of this method and other sulfinate reaction development and catalysis. Rongalite as an equivalent of the unstable hyposulfite ion. Sulfone diastereomers 1a and

Synthesis of heterocycles based on azomethine ylides from α-amino acids (or amines) and carbonyl compounds

• Ekaterina V. Berezhnaya,
• Alexander I. Ponyaev,
• Vitali M. Boitsov and
• Alexander V. Stepakov

Beilstein J. Org. Chem. 2026, 22, 705–741, doi:10.3762/bjoc.22.55

• , the importance of the formation of azomethine ylides from amino esters, amino acids, imine derivatives, aziridines or other substrates was emphasized. A review [26] demonstrates metal-catalyzed as well as metal-free asymmetric and racemic transformations of imino ethers upon interaction with various

Photoorganocatalytic trifluoromethylation of (het)arenes in green conditions

• Egor N. Boronin,
• Svetlana E. Kaurkina,
• Milena M. Svetlakova,
• Anton S. Bolshakov,
• Maxim V. Arsenyev,
• Vasilii F. Otvagin,
• Alexey Yu. Fedorov,
• Timothy Noël and
• Alexander V. Nyuchev

Beilstein J. Org. Chem. 2026, 22, 662–671, doi:10.3762/bjoc.22.50

• trifluoromethyl-substituted compounds. Over the past decade, numerous photocatalytic protocols for the trifluoromethylation of arenes and heteroarenes have been developed, including approaches employing microflow techniques [6]. These transformations utilize a broad spectrum of catalysts, ranging from Ru- and Ir

• -catalyzed [8], organic photocatalyst-mediated, or electrochemical transformations [9], and also include continuous-flow processes [6][10][11][12][13]. Given that photocatalytic reactions align with the principles of green chemistry, particularly energy efficiency and the use of catalytic pathways, such

• transformations were performed in acetonitrile, which reduces their ecological compatibility, particularly for large-scale applications. Tlili and co-workers have described the use of an organic photocatalyst for the CF3-functionalization of styrenes with the Langlois reagent (sodium trifluoromethanesulfinate

Computational prediction of C–H hydricities and their use in predicting the regioselectivity of electron-rich C–H functionalisation reactions

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

Beilstein J. Org. Chem. 2026, 22, 603–610, doi:10.3762/bjoc.22.46

• –N, C–C, and C–X bond formations, carbene insertions, and oxidative transformations. Comparative analysis with ALFABET, a bond dissociation energy (BDE)-based ML model, reveals that hydricity predictions, when combined with steric accessibility, correctly identify the reactive site in eight out of

• one of the most common C–H functionalisation approaches for sp3 C–H bonds [6]. Despite the prevalence of these transformations, predicting which of several electron-rich C–H sites will react remains challenging, especially when electronic and steric effects compete. As Cernak et al. [6] have pointed

• ). Many of these transformations are not formal hydride transfers; however, they commonly involve buildup of positive charge (e.g., via metal–carbene/nitrene insertion transition states, radical cations, or polar hydrogen atom transfer). Hydricity could therefore serve here as an empirical reactivity

Modern synthetic pathways towards eribulin and its subunits

• Sebastian Dominik Graf

Beilstein J. Org. Chem. 2026, 22, 495–526, doi:10.3762/bjoc.22.37

• cyclization proved to be suitable, but only moderately yielding, procedures. Further, this pathway, with the exception of the coupling reaction between 167 and 171, involves only simple and mild transformations using standard reagents. As mentioned above, 186 served as an intermediate for the total synthesis

• thereafter, Nasam and co-workers developed a novel synthesis of 1`s fragment 272 using multiple asymmetric catalytic transformations (Schemes 29–31) [102]. 256 was synthesized from trans-crotonic acid and served as a starting material for the first building block (261, Scheme 29). Hosomi–Sakurai allylation

• sequence of 12 steps, which only included the use of cheap materials and preparatively simple transformations. Therefore, if the overall yield can be increased even further, this synthesis represents a useful alternative to existing pathways. Conclusion In summary, numerous advancements were made in the

Recent advances in the stereoselective synthesis of distal biaxially chiral molecules

• Fanxing Zhou,
• Chen Zhang,
• Lingyu Sun,
• Yiyun Fang,
• Siming Zheng,
• Lina Hu,
• Mengyang Shen,
• Zhen Zhao,
• Wei Xu,
• Yunqiang Sun and
• Zi-Qiang Rong

Beilstein J. Org. Chem. 2026, 22, 461–479, doi:10.3762/bjoc.22.34

• induce axial chirality. In this approach, the initial formation of one or more stereogenic centers establishes a defined three-dimensional framework, which subsequently guides the generation of one or more chiral axes through cyclization, oxidative aromatization, or related transformations. This central

Concept-driven strategies in target-oriented synthesis

• David Yu-Kai Chen,
• Chao Li and
• Yefeng Tang

Beilstein J. Org. Chem. 2026, 22, 451–454, doi:10.3762/bjoc.22.32

• (vibralactone, Zhi-Yun Liu, Hong-Dong Hao et al.), interrupted [2 + 2]/retro-Mannich (aspidosperma alkaloids, Zhen Yang, Zhong-Chao Zhang et al.), dipolar cycloaddition (malayamycin A, Sha-Hua Huang, Jian Jin, Ran Hong, et al.), Zr-mediated radical transformations (review, Hugh Nakamura and co-worker)]. The

Cone p-aminocalix[4]arenes enriched with ‘clickable’ alkyne or azide functionalities

• Ilia Korniltsev,
• Vasily Bazhenov,
• Alexander Gorbunov,
• Dmitry Cheshkov,
• Stanislav Bezzubov,
• Vladimir Kovalev and
• Ivan Vatsouro

Beilstein J. Org. Chem. 2026, 22, 399–415, doi:10.3762/bjoc.22.28

• tetraureacalix[4]arenes was obtained. Examination of the 1H NMR spectra of the tetraureas in CDCl3 showed that in most cases triazole heterocycles do not intervene the formation of homo- and heterodimeric capsules by these compounds. Thus, considering the synthetic value of CuAAC and amine transformations, p

• herein report on the synthesis approaches to a series of cone p-aminocalix[4]arenes having propargyl or 2-azidoethyl groups at the narrow rims (Figure 1). The newly synthesized compounds may be thus treated as novel building blocks in calixarene chemistry capable of step-wise orthogonal transformations

• compatible with propargyl or 2-azidoethyl functionalities residing at the calixarene narrow rims, these ‘simple’ transformations are not applicable to the available propargylated/2-azidoethylated p-tert-butyl- or p-H-calix[4]arenes. Therefore, the multistep reaction sequences presented below have been

Electrosynthetic access to unsymmetrical oxaza[8]helicenes with high chiral stability and strong circularly polarized luminescence (CPL)

• Tin Zar Aye,
• Rubal Sharma,
• Muthu Karuppasamy,
• Daiya Suzuki,
• Haruka Nakajima,
• Yoshitane Imai,
• Mitsuhiro Arisawa,
• Mohamed S. H. Salem and
• Shinobu Takizawa

Beilstein J. Org. Chem. 2026, 22, 372–382, doi:10.3762/bjoc.22.25

• characteristic transformations of the organosulfur functionality [32][33]. In 2024, Badani, Karnik, and co-workers accessed one member of this class, 7,12-dioxa[8]helicene I, through a sequence featuring photochemical E–Z isomerization, electrocyclization, and oxidative aromatization [34]. In parallel, Liu and

Recent advances in the cleavage of non-activated amides

• Eun-Sol Choi and
• Hyo-Jun Lee

Beilstein J. Org. Chem. 2026, 22, 352–369, doi:10.3762/bjoc.22.23

• ]. Such activation has enabled a wide array of transformations, including metal-catalyzed cross-couplings via oxidative addition into the amide C–N bond (Scheme 1c) [32][33][34][35][36], and transition-metal-free acyl substitutions facilitated by improved leaving-group ability [37][38][39][40]. Although

• -promoted transformations enhanced by alkali-metal counter-cation effects, and (iii) installation of activating groups on the nitrogen to enable chemoselective cleavage under tailored conditions. These approaches collectively offer promising avenues for the efficient transformation of non-activated amides

• activation assisted by alkali metal counter cations Although strong bases can promote nucleophilic transformations of amides, such reactions have traditionally required harsh conditions [69][70]. Recently, however, the role of alkali metal counter cations in facilitating acyl substitution has been recognized

Ring contraction and ring expansion reactions in terpenoid biosynthesis and their application to total synthesis

• Nicolas Kratena,
• Nicolas Heinzig and
• Peter Gärtner

Beilstein J. Org. Chem. 2026, 22, 289–343, doi:10.3762/bjoc.22.21

• secured. Organic synthetic chemistry can help to fill gaps or evaluate, support or revise initially implausible proposed biogenesis routes by attempting to mimic these transformations (= bioinspired or biomimetic synthesis) [11][12][13][14][15][16][17][18]. In general, the biogenesis of unique carbon

• Moving on from these carefully characterised biosynthetic transformations, where often single steps were carried out with specific enzymes or isotope-labelled substrates to prove origin, we now move to the much larger body of speculative biosynthetic relationships. From macrocyclic lathyrane frameworks

• previous studies, no detailed studies on the transformations connecting all these families have been performed thus far [133][134][135][136]. Novel Euphorbia diterpenoids recently isolated by Wang, Zheng and Yu in 2024 (see Scheme 23A) could be considered “missing links” offering an explanation as to how