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

• reagents, organic solvents or chaotropic agents must be avoided to preserve protein stability, preventing folding heterogeneity and supporting sustainability. Scalability. For therapeutic and industrial applications, modification methods should minimise waste and curtail costs, reflected in low process

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

• Manfred Bochmann School of Chemistry, University of East Anglia, Norwich Research Park, NR4 7TJ, Norwich, United Kingdom 10.3762/bjoc.22.66 Abstract Gold catalysis has developed into an increasingly important method in organic synthesis. Especially the potential of gold(I,III) redox systems and

• 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

• − or Cl− to −15 ppm for BH2− [46]. Whereas in organic compounds 1H NMR chemical shifts tend to be interpreted in terms of the acidic or hydridic character of the H atom concerned, the shifts in metal hydrides permit no such interpretations and are the result of spin–orbit and paramagnetic contributions

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

• states provides a powerful way to control organic molecules. Through the controlled conversion of thioethers to sulfoxides and sulfones [21], it is possible to tune their reactivity and biological properties. Indeed, compounds of this type possess pronounced neuroprotective properties [12][13][14

• chemoselective oxidation of the thioether group to the sulfoxide, without overoxidation to the sulfone, remains a current challenge in organic chemistry. Peroxide compounds – such as hydrogen peroxide [33], organic hydroperoxides [34][35], peracids [36], ozone, and the peroxymonosulfate anion (the active

Total synthesis of the capsular polysaccharide repeating unit towards the development of a glycoconjugate vaccine against Klebsiella pneumoniae ST512

• Shuo Zhang,
• Ondřej Daněk and
• Peter H. Seeberger

Beilstein J. Org. Chem. 2026, 22, 821–827, doi:10.3762/bjoc.22.64

• : Department of Chemistry, Dalian University of Technology, No. 2 Linggong Road, 116024 Dalian, China Institute of Organic Chemistry and Biochemistry of the Czech Academy of Sciences, Flemingovo náměstí 542/2, 160 00 Praha 6, Czech Republic 10.3762/bjoc.22.64 Abstract Klebsiella pneumoniae ST512 is an

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

• Irene Moreno-Gutierrez Josefa L. Lopez-Martinez Sonia Berenguel-Gomez Irene Torres-Garcia Duane Choquesillo-Lazarte Manuel Munoz-Dorado Miriam Alvarez-Corral Ignacio Rodriguez-Garcia Organic Chemistry, University of Almería, CIAIMBITAL, 04120 Almería, Spain Laboratorio de Estudios Cristalográficos

Knoevenagel condensation of 4,5- and 1,8-diazafluorenes

• Darya S. Cheshkina,
• Christina S. Becker,
• Alina A. Sonina and
• Maxim S. Kazantsev

Beilstein J. Org. Chem. 2026, 22, 803–812, doi:10.3762/bjoc.22.62

• Darya S. Cheshkina Christina S. Becker Alina A. Sonina Maxim S. Kazantsev N.N. Vorozhtsov Novosibirsk Institute of Organic Chemistry SB RAS, Lavrentieva 9, 630090 Novosibirsk, Russia 10.3762/bjoc.22.62 Abstract Diazafluorenylidenes are potential antitumor agents, ligands, and functional materials

• materials [14]. Furthermore, diazafluorenylidenes may exhibit polymorphism, high solid-state emission, and decent charge carrier mobility which makes these molecules promising for use in organic optoelectronics [5][15][16]. Current synthetic approaches to diazafluorenylidenes are limited. The typical method

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

• was stirred at room temperature for 2 hours. A 10% aqueous solution of Na2S2O3 (20 mL) was added to stop the reaction. The mixture was extracted with CH2Cl2 (20 mL × 1), and separated. The aqueous phase was extracted with CH2Cl2 (20 mL × 2). The combined organic phase was washed with H2O (20 mL) and

• brine (20 mL), and dried over Na2SO4. After this, filtration and concentration were performed; the organic phase was passed through a short column of silica gel using CH2Cl2 (100 mL) to remove inorganic materials and others; then it was concentrated under reduced pressure to give the crude product. This

Halogenated azobenzene acrylates: from efficient solution photoswitching to stable solid-state photochromic materials

• Martina Vachtlová,
• Michaela Fecková,
• Vítězslav Zima,
• Jan Podlesný,
• Milan Klikar,
• Oldřich Pytela,
• Patrik Pařík,
• Jakub Opršal,
• Eliška Juhaňáková,
• Veronika Chrtová and
• Filip Bureš

Beilstein J. Org. Chem. 2026, 22, 782–794, doi:10.3762/bjoc.22.60

• . Neumanna 1316, Pardubice, 53002, Czech Republic Institute of Organic Chemistry and Technology, Faculty of Chemical Technology, University of Pardubice, Studentská 573, Pardubice, 53210, Czech Republic 10.3762/bjoc.22.60 Abstract The design, synthesis, and comprehensive characterization of six novel

Preparation of 3-(alkylamino)imidazo[1,2-a]pyridine-2-carbaldehydes via Kornblum oxidation and unexpected ring-opening reactions of the corresponding alcohols under oxidative conditions

• Sandile J. Mkhize,
• Memory Zimuwandeyi,
• Manuel A. Fernandes,
• Amanda L. Rousseau and
• Moira L. Bode

Beilstein J. Org. Chem. 2026, 22, 763–770, doi:10.3762/bjoc.22.58

• derivatives have been found to be of interest in the development of organic materials with interesting properties [11][12]. The importance of imidazo[1,2-a]pyridines is evidenced by the plethora of recent review articles covering methods for their preparation [13][14][15][16] and functionalisation reactions

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

• the reactivity of other readily available sulfinate nucleophiles using competition and exchange experiments. Keywords: diastereoselectivity; Rongalite; sulfones; Introduction Sulfonyl groups are widespread in licensed drugs [1]. New methods for the incorporation of sulfonyl groups into organic

• used as a bleaching agent in the dyeing industry for more than a century [5][6]. Over the last 10 years particularly, it has begun to join the toolbox of reagents in organic synthesis, and shows diverse reactivity. It has been employed in reductions, radical processes and as a reagent for C1 transfer

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

• compounds; catalysis; (3 + 2) cycloaddition; decarboxylation; dipolarophiles; iminoesters; polycyclic compounds; spirocyclic compounds; stereoselectivity; Introduction The 1,3-dipolar cycloaddition is one of the most popular pericyclic reactions in organic synthesis, in which a dipole molecule interacts

• reactions. Due to their unique chemical properties and high versatility, fullerenes are finding increasing application in organic synthesis. In this work, the authors focused on the functionalization of C60 with a helicene component via Cu(II)/L13-catalyzed enantioselective 1,3-dipolar cycloaddition of

Harnessing light energy with molecules

• Grace G. D. Han,
• Mogens Brøndsted Nielsen and
• Hermann A. Wegner

Beilstein J. Org. Chem. 2026, 22, 680–682, doi:10.3762/bjoc.22.52

• Grace G. D. Han Mogens Brondsted Nielsen Hermann A. Wegner Department of Chemistry and Biochemistry, University of California, Santa Barbara, CA 93016, USA Department of Chemistry, University of Copenhagen, Universitetsparken 5, 2100 Copenhagen, Denmark Institute of Organic Chemistry, Justus

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

• Egor N. Boronin Svetlana E. Kaurkina Milena M. Svetlakova Anton S. Bolshakov Maxim V. Arsenyev Vasilii F. Otvagin Alexey Yu. Fedorov Timothy Noel Alexander V. Nyuchev Department of Organic Chemistry, N.I. Lobachevsky State University of Nizhny Novgorod, Gagarina Av. 23, 603950 Nizhny Novgorod

• conditions using an inexpensive and atom-efficient CF3 source, trifluoroacetic anhydride, in ethyl acetate as a green solvent. An organic cyanoarene photocatalyst enables efficient CF3 radical generation under blue-light irradiation, providing a broad range of trifluoromethylated arenes and heteroarenes. The

• -based complexes to other transition metals and organic photocatalysts, as well as diverse CF3 sources. The major limitations of these methodologies include the high cost of catalysts and trifluoromethylating reagents, along with the use of toxic species such as transition-metal complexes and hazardous

Towards the targeted protein degradation of CK2: design and synthesis of CAM4066-based PROTACs

• Sophie Day-Riley,
• Sona Krajcovicova,
• Aryaman Raj Sokhal,
• Jan L. Venne,
• Paul Brear,
• Marko Hyvönen,
• Benjamin C. Whitehurst,
• Jason S. Carroll and
• David R. Spring

Beilstein J. Org. Chem. 2026, 22, 611–619, doi:10.3762/bjoc.22.47

• Sophie Day-Riley Sona Krajcovicova Aryaman Raj Sokhal Jan L. Venne Paul Brear Marko Hyvonen Benjamin C. Whitehurst Jason S. Carroll David R. Spring Yusuf Hamied Department of Chemistry, University of Cambridge, Lensfield Road, CB2 1EW, Cambridge, United Kingdom Department of Organic Chemistry

Continuous-flow carbonyl hydrogenation under subatmospheric to atmospheric hydrogen pressure enabled by robust heterogeneous Pt–Fe catalysts

• Hiroyuki Miyamura,
• Ryosuke Kajiyama,
• Shun-ya Onozawa,
• Yoshihiro Kon and
• Shū Kobayashi

Beilstein J. Org. Chem. 2026, 22, 575–582, doi:10.3762/bjoc.22.43

• , including ketones and aldehydes, to alcohols is a fundamental and important reaction in organic synthesis. One of the most ideal methods is catalytic hydrogenation, however, the hydrogenation of ketones generally requires harsh reaction conditions, such as high temperature and high pressure. We developed a

• : bimetallic nanostructure; carbonyl reduction; continuous-flow reaction; heterogeneous catalyst; subatmospheric hydrogen; Introduction The reduction of carbonyl compounds, ketones and aldehydes to alcohols is a fundamental and important reaction in organic synthesis that can provide valuable chemicals such

• ]. Recently, continuous-flow organic synthesis has attracted much attention from both academia and industry, because it offers numerous advantages, such as not only a high productivity with limited space but also realizing green sustainable syntheses minimizing required energy and resources. When

Kinetic resolution of racemic planar-chiral vinylcymantrenes by molybdenum-catalyzed asymmetric metathesis dimerization

• Haruna Imazu,
• Hitoshi Izu,
• Yasuhiro Ohki and
• Masamichi Ogasawara

Beilstein J. Org. Chem. 2026, 22, 568–574, doi:10.3762/bjoc.22.42

• resolution; molybdenum; olefin metathesis; planar chirality; Introduction The development of the well-defined molybdenum- [1][2] or ruthenium-alkylidene [3][4][5] catalysts has proven the olefin metathesis reaction to be a powerful tool in organic synthesis. Asymmetric extension is a recent trend in

Molecular tweezer–peptide conjugates disrupt the protein–protein interaction between survivin and histone H3 essential in mitosis

• Catherine Gsell,
• Philipp Rebmann,
• Karina Opara,
• Christine Beuck,
• Peter Bayer,
• David Bier,
• Ingrid R. Vetter and
• Thomas Schrader

Beilstein J. Org. Chem. 2026, 22, 557–567, doi:10.3762/bjoc.22.41

• + ions that were surprisingly observed in the center of the aromatic ring structure, perhaps due to their weaker binding of the hydrate shell. However, this early crystal structure was obtained with the diacetoxytweezer in organic solution [18]. Interestingly, a similar unexpected inclusion of a

Experimental and DFT studies on the regioselective methanolysis of 5-azido-9-oxabicyclo[6.1.0]nonan-4-yl 4-nitrobenzoate isomers

• İlknur Polat,
• Selçuk Eşsiz and
• Emine Salamci

Beilstein J. Org. Chem. 2026, 22, 547–556, doi:10.3762/bjoc.22.40

• process, highlighting its precision and efficiency. Keywords: azides; 8-azidocyclooct-4-en-1-yl 4-nitrobenzoate; DFT; epoxycyclooctane azide; methanolysis; Introduction Organic azides are very important precursors for the preparation and synthesis of various nitrogen-containing compounds, as well as

• NaHCO3 (0.78 g, 9.29 mmol) were added to the solution and stirred for 1.5 hours. Subsequently, 50 mL of 1.5 M NaOH solution was added and the reaction mixture was stirred for 15 min at 0 °C, then extracted with dichloromethane (4 × 30 mL). The organic layer was dried over Na2SO4, filtered, and evaporated

• . The progress was monitored by TLC and the reaction was completed in 36 hours. The solvent was removed by rotary evaporation, 30 mL water was added to the residue and the mixture was extracted with ethyl acetate (4 × 25 mL). The combined organic phases were dried over Na2SO4 and concentrated in vacuo

Melifoliox B, a novel phloroglucin derivative isolated from Melicope barbigera (Rutaceae) and synthesis of new oxidation products from melifoliones A and B

• Horst Weber,
• Kim-Thao Tran-Cong,
• Bernhard Mayer,
• Guido J. Reiss,
• Iryna S. Konovalova,
• Marc S. Appelhans,
• Kenneth R. Wood and
• Claus M. Passreiter

Beilstein J. Org. Chem. 2026, 22, 535–546, doi:10.3762/bjoc.22.39

• Biotechnology, Heinrich-Heine-University Duesseldorf, 40225 Duesseldorf, Germany Institute of Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University Duesseldorf, 40225, Duesseldorf, Germany Institute of Inorganic Chemistry and Structural Chemistry, Heinrich-Heine-University Duesseldorf, 40225

• . Successive extraction with 0.1 N NaOH (5 × 20 mL) afforded a clear alkaline water phase that was acidified with dilute sulfuric acid and extracted with diethyl ether (5 × 20 mL). The organic phase was washed with water, dried over MgSO4, filtered and evaporated under reduced pressure to give 3,1 g (51.2%) of

• ) and extracted with diethyl ether (3 × 20 mL). The remaining aqueous layer was acidified using 0.1 N H2SO4 and extracted with diethyl ether (3 × 30 mL). The organic phase was washed with NaHCO3 solution (1%) and water, dried with MgSO4, filtered and evaporated to give 520 mg (57%) of 6 (CAS: 66050-33-7

Get a better glimpse on sequential photoreactions of trisnorbornadienes with ¹⁹F NMR spectroscopy

• Julian Felix Maria Hebborn,
• Ben Eric Merten,
• Thomas Paululat and
• Heiko Ihmels

Beilstein J. Org. Chem. 2026, 22, 527–534, doi:10.3762/bjoc.22.38

• ]heptadien-2-yl)-1,3,2-dioxaborolane (1e, 501 mg, 2.30 mmol), Pd(PPh3)4 (66.5 mg, 57.5 µmol, 5 mol %), THF (5.0 mL), and aq. NaOH (5.7 mmol, 2.7 M, 2.1 mL) was stirred at 80 °C for 16 h under anaerobic conditions [22]. After cooling the emulsion to room temperature, EtOAc (15 mL) was added and the organic

Synthesis and uranyl(VI) extraction performance of a calix[4]pyrrole–tetrahydroxamic acid receptor

• Sara Karnib,
• Rana Baydoun,
• Wissam Zaidan,
• Nancy AlHaddad,
• Omar El Samad,
• Bilal Nsouli,
• Francine Cazier-Dennin and
• Pierre-Edouard Danjou

Beilstein J. Org. Chem. 2026, 22, 486–494, doi:10.3762/bjoc.22.36

• receptors bearing both anion- and cation-binding sites, as well as systems capable of promoting ion-pair formation [23][24]. As effective chelating agents for a broad range of transition metals, hydroxamic acids constitute an important class of organic compounds that have attracted considerable attention

• corresponding hydroxamic acid, with no detectable acid-derived by-products. Solubility tests revealed that PCP HA is soluble exclusively in highly polar aprotic solvents (DMSO, DMF) and remains completely insoluble in other common organic solvents (chloroform, ether, etc.) and water. The absence of ligand

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

• chiral scaffolds, which arise from hindered rotation between two planes connected by a single bond, have attracted increasing attention due to their widespread applications in chiral ligands, organocatalysts [1], and functional materials [2], making them highly valuable molecular frameworks in organic

• prospects in the field of chiral organic material design. In 2025, Hong and co-workers successfully predicted a series of novel Sadphos (sulfinamide phosphine) ligands and accomplished the first enantioselective Ni-catalyzed Suzuki–Miyaura cross-coupling reaction (Scheme 24) [63]. Their work validated the

Structural reassignment of compound 968, an allosteric glutaminase inhibitor

• Lindsey A. Albertelli,
• Sainabou Jallow,
• Chun Li and
• Scott M. Ulrich

Beilstein J. Org. Chem. 2026, 22, 455–460, doi:10.3762/bjoc.22.33

• EtOAc (70 mL), which was separated and washed with water (3 × 50 mL). The organic layer was dried with anhydrous MgSO4, filtered, and the solvent removed by rotary evaporation to yield 3-bromo-4-dimethylaminobenzaldehyde as a thick gold oil (5.49 g, 89%). 1H NMR (400 MHz, CDCl3) δ 9.78 (s, 1H), 8.01 (m

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

• National Institute of Biological Sciences, 7 Science Park Road ZGC Life Science Park, Beijing,102206, China School of Pharmaceutical Sciences, Tsinghua University, 100084 Beijing, China 10.3762/bjoc.22.32 Humankind’s fascination with organic molecules and their functions holds a special place in the

• history of science. Indeed, organic compounds have an unparalleled track record in elucidating the mysteries behind a wide range of physical, chemical, and biological phenomena, and advances in chemical synthesis have been instrumental in these explorations. Specifically, target-oriented syntheses of

• complex organic architectures have witnessed remarkable achievements in recent years, continuously redefining the boundaries of creativity, efficiency, and practicality. On the other hand, it has been suggested that the field of complex molecular assembly is transitioning (or ought to transition) from an

A facile and practical method for the synthesis of trans-(±)-taxifolin and its derivatives via Darzens reaction

• Bo Peng,
• Panpan Yang,
• Maaz Khan,
• Xiaotong Lin,
• Jiang Wu,
• Peng Fu and
• Qingqing Wu

Beilstein J. Org. Chem. 2026, 22, 443–450, doi:10.3762/bjoc.22.31

• in the synthetic route. Therefore, the reaction conditions of 2 and a selected benzaldehyde 3a with two MOM-protected OH groups were optimized. Firstly, various organic and inorganic bases were screened (Table 1). The commonly used organic bases, such as Et3N, DBU, and pyridine, seemed not effective

• compounds. Although HCl is the commonly used acid for this step [19][20][21][22][23][24][25][26][27][28][29][30], we also screened some other acids and the results are collected in Table 2. As can be seen from the table, inorganic acids (Table 2, entries 1 and 2) generally gave better results than organic