Chiral cyclopropenimine-catalyzed enantioselective Michael reactions of phenol and benzofuran-derived α,β-unsaturated pyrazolamides with benzophenone-imine of glycine esters

• Ya Bai,
• Xue-Ying Wang,
• Si-Kai Zhu,
• Yan-Ting Shen,
• Sheng-Yong Zhang and
• Ping-An Wang

Beilstein J. Org. Chem. 2026, 22, 888–896, doi:10.3762/bjoc.22.69

• synthesis, neurotransmitter function, and regulation of acid-base balance, metabolic intermediates, and promotion of nutrient absorption [4]. Therefore, the synthesis of substituted glutamic and pyroglutamic acid derivatives is vital to medicinal chemistry. In our previous reports, we have synthesized a

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

• exhibit uncertain and incompletely characterised stability. Moreover, depending on the conjugated epitope, modifications can cause loss of function or aggregation, underscoring the need for further innovation. Post-translational modification (PTM) chemical labelling Post-translational modifications (PTMs

• called (GlycoConnect®) used in ADC manufacturing [138][139]. In summary, glycan-directed labelling excels by omitting engineering or denaturation of the protein substrates. Often, the protein function is mostly preserved, for example, the antigen-binding (Fab) region of antibodies is free of glycan

• sortase A-protein Z system has limited site specificity; it also requires equimolar enzyme-to-antibody ratios and additional purification steps. MTG, similarly, requires near-stoichiometric enzyme to function, restricting scalability; this enzyme is also produced as a zymogen and requires activation post

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

• -planar geometries there is always also the influence of two cis-ligands. Melpolder and Burmeister used solution infrared spectroscopy to determine the ratio of N-bonded and S-bonded thiocyanate ligands in LAuSCN/NCS as a function of L. As expected, ligands L with a strong trans-influence, such as

• -examine the dependence of the 1H NMR chemical shift as a function of ligand trans-influence and extend the theoretical work on gold(I) hydrides [46] to gold(III). Gratifyingly, the same rules were found to apply. The calculated and experimental 1H NMR values were in excellent agreement. Plotting the

• of increasing cis influence, but generally the above series applies [50]. Au–H insertion reactions The different nature of the Au–H bond as a function of the trans-ligand has consequences in terms of chemical reactivity. Experiments have shown that gold hydrides can be grouped into two classes: those

Synthesis and biological evaluation of new brassinosteroid analogs with C-22 benzoate function

• María Núñez,
• Camila Escobar,
• Mario Párraga,
• Mauricio Soto,
• Luis Espinoza-Catalán,
• Katy Díaz and
• Andrés F. Olea

Beilstein J. Org. Chem. 2026, 22, 753–762, doi:10.3762/bjoc.22.57

• characterization of new brassinosteroid (BR) analogs, in which substituents with different electronegativities and molecular sizes have been attached to a C-22 benzoate function, are described. The biological activities of all new compounds were evaluated by using the rice lamina inclination test (RLIT) and

• -carbonyl or 3β-hydroxy function in this ring. Additionally, the accumulation of the dephosphorylated form of the BES1 protein, which is part of the BRs signaling pathway and control their activity, has been evaluated as well. The results are analyzed in terms of BR analog’s structure and compared with

• matter of current interest. For example, derivatives of teasterone (3), compounds 4–11, and castasterone, compounds 12–14, with benzoyl function at C-22 (Figure 2) have been synthesized, and their bioactivities have been evaluated by BSIB, RLIT, and inhibition of root and hypocotyl elongation in A

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

• and a phenyl spacer were introduced to modulate donor strength and spatial separation. The work underscores the crucial role of excited-state structural relaxation in tuning photoinduced charge separation. In another study, Kerzig and co-workers [20] show how polyaza[7]helicene can function as a

Using generative AI to transform peptide hits into small molecule leads

• Joshua Mills and
• Yu Heng Lau

Beilstein J. Org. Chem. 2026, 22, 672–679, doi:10.3762/bjoc.22.51

• molecules that recapitulate key components of a peptide pharmacophore. In general, diffusion models function by progressively adding Gaussian noise to training data over a series of timesteps (forward diffusion). A neural network is then trained to reverse this process, iteratively reconstructing the

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

• conditions. Since the photocatalyst can function as both an oxidizing and a reducing agent, we examined the literature data to evaluate the possible reaction pathway. Based on the experimentally determined oxidation and reduction potentials of the excited state of 3DPAFIPN (E1/2(PC·+/PC*) = −1.38 V, E1/2 (PC

Advantages of PROTACs in achieving selective degradation of homologous protein families

• Luxi Yang,
• Xinfei Mao,
• Jingyi Zhang,
• Jing Shu,
• Wenhai Huang,
• Xiaowu Dong,
• Yinqiao Chen and
• Mingfei Wu

Beilstein J. Org. Chem. 2026, 22, 628–661, doi:10.3762/bjoc.22.49

• ; PROTAC; protein–protein interaction; selectivity; ubiquitination; Introduction The cell is the fundamental unit of structure and function in the human body [1][2]. More than 20,000 proteins act in concert to regulate the entire cellular life process [1]. To date, dysregulated protein function has been

• sufficient to trigger rapid ubiquitination [15][16]. Consequently, a PROTAC operates through an event-driven pharmacological paradigm, distinguishing itself from the traditional occupancy-driven model of small-molecule inhibitors [17]. Furthermore, PROTACs function catalytically, requiring only

• ) proteins are epigenetic readers. They comprise the ubiquitously expressed BRD2, BRD3, and BRD4 and the testicular-specific expressed BRDT [101]. The function of the BET protein family is mainly to regulate gene transcription by recognizing acetylated lysine residues on histones [102][103]. The imbalance of

Hydrogen production from formic acid catalyzed by NHC–Cu complexes

• Orlando Santoro and
• Catherine S. J. Cazin

Beilstein J. Org. Chem. 2026, 22, 620–627, doi:10.3762/bjoc.22.48

• produced, the pressure change was measured as a function of time (see Supporting Information File 1, Table S1). By heating formic acid in toluene in the presence of 1 and 10 mol % of 1a, no evolution of gas was observed neither at 25 nor at 110 °C (see Supporting Information File 1, Table S1, entries 1–4

Regioselective approach to 5-arylsulfonylisoxazoles and their antimicrobial activity

• Artem S. Sazonov,
• Dmitry A. Vasilenko,
• Denis V. Porfiriev,
• Yuri K. Grishin,
• Rimma A. Gazzaeva,
• Alisa P. Chernyshova,
• Maxim A. Kryakvin,
• Anna A. Baranova,
• Vera A. Alferova and
• Elena B. Averina

Beilstein J. Org. Chem. 2026, 22, 592–602, doi:10.3762/bjoc.22.45

• passage of the strands through the break and subsequent ligation, leading to DNA relaxation. DNA gyrase performs a similar function but without the requirement for ATP hydrolysis. The antibiotic ciprofloxacin (Cip), which inhibits DNA gyrase, was used as the positive control. In this test, all tested

Design and synthesis of an erdafitinib-based selective FGFR2 degrader

• Yumeng Jin,
• Shidong Wang,
• Sihan Pan,
• Shuqi Huang,
• Weichen Zhou,
• Xiaohao Huang,
• Lei Zheng and
• Lingfeng Chen

Beilstein J. Org. Chem. 2026, 22, 583–591, doi:10.3762/bjoc.22.44

• subtype selectivity and the ability to degrade membrane-bound FGFR2. This molecule successfully repurposed erdafitinib, a broad-spectrum FGFR inhibitor, into a highly selective degrader. It not only provides a new chemical tool for investigating FGFR2 function but also lays a crucial foundation for the

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

• inhibitor of the survivin–histone H3 tail interaction would be a very valuable chemical tool because it could allow to deliberately shut down the recruitment of the CPC to the nucleosomes and to study its effect on CPC function. Results and Discussion In 2005, our group discovered molecular tweezers with

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

• Duesseldorf, Germany Integrative Taxonomy of Plants, Friedrich-Schiller-University Jena, 07743 Jena, Germany Senckenberg Institute for Plant Form and Function (SIP) Jena, 07743 Jena, Germany National Tropical Botanical Garden, 3530 Papalina Road, Kalaheo, HI 96741, USA 10.3762/bjoc.22.39 Abstract In addition

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

• spectroscopy. The extraction performance was systematically evaluated as a function of pH and ligand-to-metal molar ratio to study the effect of these two key parameters on the extraction process. In doing so, this work aligns with current research dedicated to the design of functional supramolecular materials

Synthesis of a HDAC inhibitor–nanogold probe for cryo-EM visualization in class I HDAC co-repressor complexes

• Wiktoria A. Pytel,
• John W. R. Schwabe and
• James T. Hodgkinson

Beilstein J. Org. Chem. 2026, 22, 480–485, doi:10.3762/bjoc.22.35

• complex and diminishing its deacetylase function. However, the maximal HDAC inhibition by Au–NH2 was considerably less compared to Au–(CI-994) and CI-994, suggesting Au–(CI-994), is inhibiting HDAC enzymatic activity by direct competition for the HDAC active site. We next determined the IC50 of Au–(CI-994

Synthesis and anti-cancer activity of naphthalimide–organylselanyl conjugates

• Rajkumar Ravi and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2026, 22, 416–435, doi:10.3762/bjoc.22.29

• optimisation. In this study, we report the in-silico modelling and anticancer activity of two 1,8-napthalimide (NAP) derivatives containing organyl selanyl groups. The organylselanyl function n-octylselanyl (n-OctSe) or phenylselanyl (PhSe) was introduced at the 6-position of a naphthalimide structure having a

• conserved 3-(4-(tert-butyl)phenoxy)propyl function at the imide nitrogen. The resultant naphthalimide–organylselanyl conjugates, NAP-SePh and NAP-Se(n-Oct), were characterised using various spectroscopic techniques, including FTIR, ¹H, ¹³C, ⁷⁷Se NMR and high-resolution mass spectrometry (HRMS). NAP-SePh was

• secondary amino functions strongly suppress acetylation and the embedded sulfur function contributes to the apoptosis induction [40][41].The third modification route centres on functional group engineering, in which small amine substituents are replaced with polyamines or long aliphatic chains, thereby

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

• the pKa of [3]·+ radical cation and spin density of neutral radical intermediate Int-I (optimized at the UB3LYP/6-31G+(d,p) level of theory with IEPCM model as solvation of DCM. Grimme’s dispersion with the original D3 damping function was applied as empirical dispersion correction to the optimized

Non-central chirality in organic chemistry

• Ken Tanaka and
• Naohiko Yoshikai

Beilstein J. Org. Chem. 2026, 22, 370–371, doi:10.3762/bjoc.22.24

• . Collectively, the articles in this Thematic Issue should not be viewed as an exhaustive account of non-central chirality but rather as representative snapshots of an evolving landscape. They capture the current state of the field, where structure, reactivity, dynamics, and function increasingly intersect under

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

• substrate scope, mechanistic features, and unique advantages or limitations, with the goal of providing a comprehensive overview of current strategies and future opportunities for amide-bond manipulation. Review Transition-metal catalysis Various transition metals that function as Lewis acids have been

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

• crokonoid B (67) by oxidation, carbocation formation and 1,2-alkyl shift in a semi-pinacol rearrangement [127]. The authors of the isolation report proposed an epoxide 67a as initiating species, but a diol could also serve in this function (see Scheme 21B). Upon formation of the secondary carbocation 67b, a

Screwing the helical chirality through terminal peri-functionalization

• Devesh Chandra,
• Sachin and
• Upendra Sharma

Beilstein J. Org. Chem. 2026, 22, 205–212, doi:10.3762/bjoc.22.14

• asymmetric synthesis, where they serve as chiral ligands and organocatalysts, delivering high enantioselectivities [17][18]. Their tunable HOMO–LUMO gaps and controlled π–π interactions, is key to the use of helicenes in molecular electronics and organic semiconductors as well. Helicenes function as active

Improved synthesis and physicochemical characterization of the selective serotonin 2A receptor agonist 25CN-NBOH

• Adrian G. Rossebø,
• Hannah G. Kolberg,
• Anders E. Tønder,
• Louise Kjaerulff,
• Poul Erik Hansen,
• Karla A. Frydenvang,
• Jesper Østergaard and
• Jesper L. Kristensen

Beilstein J. Org. Chem. 2026, 22, 175–184, doi:10.3762/bjoc.22.11

• coefficients (absorbance), as a function of the wavelength (185–750 nm) and pH in the interval 2.0–12.0, were determined at 30.8 °C. A stock solution (5.0 mM) of 1·HCl in N-methyl-2-pyrrolidone (NMP) was added to 36 mL of an ionic strength-adjusted buffer solution (I = 0.172 M) containing acetate, phosphate

Design and synthesis of an axially chiral platinum(II) complex and its CPL properties in PMMA matrix

• Daiki Tauchi,
• Sota Ogura,
• Misa Sakura,
• Kazunori Tsubaki and
• Masashi Hasegawa

Beilstein J. Org. Chem. 2026, 22, 143–150, doi:10.3762/bjoc.22.7

• ), revealing two emission bands centered at approximately 427 nm and 596 nm (Figure 2). The corresponding emission decays were well fitted by a three-exponential function, yielding fluorescence components of 3.6 ns (62%), 8.0 ns (20%), and 0.39 ns (18%) at 427 nm, and phosphorescence components of 0.11 μs (64

Highly electrophilic, gem- and spiro-activated trichloromethylnitrocyclopropanes: synthesis and structure

• Ilia A. Pilipenko,
• Mikhail V. Grigoriev,
• Olga Yu. Ozerova,
• Igor A. Litvinov,
• Darya V. Spiridonova,
• Aleksander V. Vasilyev and
• Sergey V. Makarenko

Beilstein J. Org. Chem. 2026, 22, 123–130, doi:10.3762/bjoc.22.5

• carboxylic acids [4]. The trichloromethyl group is a convenient precursor of the carboxylic function, which determines their use in the synthesis of α-amino acids [5]. A number of natural trichloromethyl-containing compounds are metabolites of symbionts of marine sponges – cyanobacteria [6][7][8] – and have

Reactivity umpolung of the cycloheptatriene core in hexa(methoxycarbonyl)cycloheptatriene

• Dmitry N. Platonov,
• Alexander Yu. Belyy,
• Rinat F. Salikov,
• Kirill S. Erokhin and
• Yury V. Tomilov

Beilstein J. Org. Chem. 2026, 22, 64–70, doi:10.3762/bjoc.22.2

• isomer of anion 2 we analyzed the structure of its highest occupied molecular orbital (HOMO) and the distribution of the electrophilic Fukui function (f–) [28] – the difference in electron density between the anion and the derived radical by abstraction of one electron (Figure 2). Both approaches

• revealed that the α-position is most nucleophilic. Notably, anion 1 demonstrated similar HOMO and Fukui function distribution (see Supporting Information File 1), however, all positions would lead to the very same products. The potassium salt of anion 2 was generated in an acetonitrile solution from hexa

• -hydroxyisoquinolones [36][37]. Additionally, the analyses of both HOMO and Fukui f– function shows little or no nucleophilicity at this position (Figure 2). Therefore, the formation of products 4a,b and 10k could proceed through the intermediary formation of the corresponding compounds 5 and their subsequent