The role of spacer length and flexibility in peptide self-assembly

• Julian Link,
• Albin Lahu,
• Manfred Wagner,
• Tanja Weil and
• David Y. W. Ng

Beilstein J. Org. Chem. 2026, 22, 986–996, doi:10.3762/bjoc.22.77

• Julian Link Albin Lahu Manfred Wagner Tanja Weil David Y. W. Ng Max Planck Institute for Polymer Research, Ackermannweg 10, D-55128 Mainz, Germany 10.3762/bjoc.22.77 Abstract Spacer length is a key molecular parameter governing the self-assembly of short peptides. Here, we investigate isoleucine

Synthesis of sterically shielded piperidine nitroxides via acid-catalyzed heterocyclization of β-aminoketone derivatives with ketones

• Mark M. Gulman,
• Yurii I. Glazachev and
• Sergey A. Dobrynin

Beilstein J. Org. Chem. 2026, 22, 948–954, doi:10.3762/bjoc.22.74

• nitroxide-mediated polymerization (NMP), because shielding with ethyl or bulkier alkyl groups decreases accessibility of the nitroxide moiety and improves the equilibrium parameters in the reversible trapping of alkyl radical of the growing polymer chain [11]. This shielding also alters the redox properties

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

• , and antibacterial agents [6][7][8]. However, the practical utility of such type of compounds extends beyond biomedical applications. For instance, Michael addition reactions between dithiols and phenolic compounds yield cross-linked, colorless polymer films with universal adhesion and high stability

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

• ; photoswitch; polymer; thin film; Introduction The azobenzene photoinduced E/Z isomerization represents a well-investigated switching process that found various utilizations [1][2][3][4]. In contrast to the state-of-the-art achieved in solution and despite its perhaps even greater application potential, a

• to the viscoelastic state of (Z)-azobenzene. Hence, the azobenzene-doped polymer can be photo-welded going from the viscoelastic to the glassy state after reverse Z→E isomerization. Laser-induced surface relief grating (SRG) on azobenzene-containing polymers is another prominent application of the

• has also been used within the frame of a microgripper constructed from an azobenzene liquid crystal polymer (LCP) [12]. Violet (E → Z) or green (Z → E) light can power shapeshifting of this miniature device made of two LCP strips. The photoinduced transition between the heterosmectic and isotropic

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

• the remediation of uranium-contaminated environmental samples. Future work will focus on the covalent anchoring of this macrocycle onto solid matrixes (polymer or silica). The development of such functionalized material is intended to allow for implementation in continuous flow filtration systems for

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

• valuable features, amide derivatives are ubiquitous across the pharmaceutical, agrochemical, dye, polymer, and renewable-energy industries [6][7][8][9][10][11]. Accordingly, the development of efficient methods for both amide-bond formation and the selective transformation of amide functionalities remains

• -mediated transamidation of an acrylamide polymer. Zn-catalyzed chemoselective cleavage of amides directed by tert-butyl nicotinate. Chemoselective cleavage of N-PMB anilide for transamidation via acyl fluoride 194 generation. a) Cu(II) bromide/Selectfluor hybrid system for cleavage of N-PMB anilide. b

Configuration–packing synergy enabling integrated crystalline-state RTP and amorphous-state TADF

• Ruiyan Wang and
• Yunan Wu

Beilstein J. Org. Chem. 2026, 22, 224–236, doi:10.3762/bjoc.22.16

• polymer hosts. In contrast, TADF relies on the reduction of the singlet–triplet energy gap (ΔEST), facilitating thermally activated reverse intersystem crossing (RISC) from the triplet state to the singlet excited state, where the excitation energy is released via delayed fluorescence [29]. Common

• /PEDOT:PSS (40 nm)/mCP (20 nm)/CBP:1 (15 nm, 12% doping)/TPBi (40 nm)/LiF (1 nm)/Al (120 nm). In this structure, PEDOT:PSS, a conductive polymer serves as the hole-injection layer, LiF acts as the electron-injection layer; mCP – 9,9'-(1,3-phenyl)-2-9H-carbazole, is the hole-transport material, TPBi – 1,3,5

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

• exciton coupling in both the ground and excited states. While no CPL was observed in solution, distinct CPL properties observed in the PMMA matrices. This behavior is attributed to the effect of the axial chirality, which becomes more effective upon suppression of molecular motion within the polymer

• ethynyl-linked coordination sites. Therefore, we prepared a PMMA polymer matrix containing 1 wt % of S/R-Pt to investigate the emission behavior under conditions where molecular motion was suppressed. The PMMA matrix was obtained by dissolving S/R-Pt and PMMA in chloroform under heating at 40 °C, casting

Synthesis and applications of alkenyl chlorides (vinyl chlorides): a review

• Daniel S. Müller

Beilstein J. Org. Chem. 2026, 22, 1–63, doi:10.3762/bjoc.22.1

• significantly influenced the overall yield. The decline in yield over time can potentially be attributed to polymerization side reactions of product 9 under the reaction conditions. Visual evidence of polymerization included difficulty in cleaning the reaction flask and the formation of solid polymer deposits

• that were irreversibly adhered (Figure 6, oval stirring bar left a mark in the solid polymer). Various catalyst loadings of CuCl (5–20 mol %) were evaluated, with 15–20 mol % required to achieve useful yields of 9 within several hours (Figure 7). Mechanistic analysis proved challenging, as the catalyst

Silica gel with covalently attached bambusuril macrocycle for dicyanoaurate sorption from water

• Michaela Šusterová and
• Vladimír Šindelář

Beilstein J. Org. Chem. 2025, 21, 2604–2611, doi:10.3762/bjoc.21.201

• example, an amphiphilic poly(methyl methacrylate)-based polymer modified with calix[4]pyrrole was found to form micelles in water that capture anions from caesium salts and can be precipitated from solution upon heating [11]. Similarly, a hydrogel composed of poly(vinyl alcohol) cross-linked by a “Texas

Rotaxanes with integrated photoswitches: design principles, functional behavior, and emerging applications

• Jullyane Emi Matsushima,
• Khushbu,
• Zuliah Abdulsalam,
• Udyogi Navodya Kulathilaka Conthagamage and
• Víctor García-López

Beilstein J. Org. Chem. 2025, 21, 2345–2366, doi:10.3762/bjoc.21.179

• -driven shuttling of the cyclodextrin macrocycle was accompanied by alternations in fluorescence between two fluorescent stoppers [49]. Takashima and co-workers developed a photoresponsive polymeric actuator utilizing [2]rotaxane units as topological cross-links in a polymer network, in which the

Insoluble methylene-bridged glycoluril dimers as sequestrants for dyes

• Suvenika Perera,
• Peter Y. Zavalij and
• Lyle Isaacs

Beilstein J. Org. Chem. 2025, 21, 2302–2314, doi:10.3762/bjoc.21.176

• that β-cyclodextrin (Figure 1)-based polymers could remove organic micropollutants from water [15][16]. For example, in 2021, Sessler and co-workers reported the synthesis of a calix[4]pyrrole (Figure 1)-based porous organic polymer, which exhibits the rapid uptake of dyes from water [17]. In addition

• , graphene functionalized with β-cyclodextrins [18], a starch-based β-cyclodextrin polymer [19], and pillar[5]arene-based crosslinked polymers have also been investigated as sequestrants for dyes [20]. The Isaacs group has a longstanding interest in the synthesis and mechanism of formation of macrocyclic

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

• toward useful biobased functional compounds or intermediates with applications in fuels, polymer chemistry and fine organic synthesis (CH activation, Piancatelli rearrangement, etc.). Conversion of furfural to alcohols, aldehydes and ketones: One of the most important transformations of furfural is its

Solar thermal fuels: azobenzene as a cyclic photon–heat transduction platform

• Jie Yan,
• Shaodong Sun,
• Minghao Wang and
• Si Wu

Beilstein J. Org. Chem. 2025, 21, 2036–2047, doi:10.3762/bjoc.21.159

• Jie Yan Shaodong Sun Minghao Wang Si Wu Hefei National Research Center for Physical Sciences at the Microscale, Anhui Key Laboratory of Optoelectronic Science and Technology, Department of Polymer Science and Engineering, University of Science and Technology of China, Hefei 230026, China Research

• perspective, we systematically analyze four representative azobenzene-based solar thermal fuel systems including nanocarbon-hybrid, conjugated polymer, linear polymer, and small-molecule derivative formulations to trace their developmental trajectories and identify key limitations. Through this comparative

• applications, highlighting key contributions in the field. Discussion Nanocarbon-based azobenzene polymer solar thermal fuels Nanocarbon-based azobenzene polymer solar thermal fuels are constructed by grafting azobenzene moieties onto carbon nanotube [43][44][45] or reduced graphene oxide (RGO) templates

Photoswitches beyond azobenzene: a beginner’s guide

• Michela Marcon,
• Christoph Haag and
• Burkhard König

Beilstein J. Org. Chem. 2025, 21, 1808–1853, doi:10.3762/bjoc.21.143

Research progress on calixarene/pillararene-based controlled drug release systems

• Liu-Huan Yi,
• Jian Qin,
• Si-Ran Lu,
• Liu-Pan Yang,
• Li-Li Wang and
• Huan Yao

Beilstein J. Org. Chem. 2025, 21, 1757–1785, doi:10.3762/bjoc.21.139

• 2023, Zhang and colleagues [109] constructed a tumor microenvironment (TME)-activated supramolecular nanoplatform (Figure 8) which was consisted of a pillar[5]arene-based amphiphilic polymer (POPD), a phototherapeutic agent (Cy7-CN), an antimalarial drug with respiratory function (atovaquone, ATO), and

• various stimuli used to control responsive assemblies, enzymatic methods offer several benefits, including biocompatibility, high efficiency, specificity, and mild reaction conditions. Liu and colleagues reported an enzyme-responsive supramolecular ternary polymer (DiCh@a-CD-bisSC4A) (Figure 12) [95]. The

• supramolecular polymer with suberyl dicholine (DiCh) as the axle, with α-CD as the thread wheel and bisSC4A macrocycles as the iterative end cap units. Due to the hydrolysis of DiCh by cholinesterase, the formed supramolecular polymer assembly can be dispersed through enzymatic reactions. They successfully

Unique halogen–π association detected in single crystals of C–N atropisomeric N-(2-halophenyl)quinolin-2-one derivatives and the thione analogue

• Mai Uchibori,
• Nanami Murate,
• Kanako Shima,
• Tatsunori Sakagami,
• Ko Kanehisa,
• Gary James Richards,
• Akiko Hori and
• Osamu Kitagawa

Beilstein J. Org. Chem. 2025, 21, 1748–1756, doi:10.3762/bjoc.21.138

• -electron on the quinolinone benzene ring, while that in optically pure forms is caused by an n–π* interaction between a lone electron pair on the halogen atom and a π* orbital of the quinolinone. In contrast to the formation of the homochiral layered polymer in quinolinones, in racemic N-(2-bromophenyl

• the single crystals of racemates significantly differs from that of optically pure forms (chirality-dependent halogen bonding, Figure 1) [20][21]. That is, in crystals of racemic mebroqualone rac-I, heterochiral zig-zag polymer chains, in which (P)-I and (M)-I were alternately connected, were formed

• optically pure mebroqualone (P)-I, the homochiral layered polymer was formed through a bromine–π association. The association is due to an n–π* interaction between a lone electron pair on the bromine atom and a π* orbital of the quinazolinone ring. In the optically pure thio-analogue (P)-II, the formation

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

• latent failure modes (e.g., reactor fouling due to precipitation of polynitro by-products or acid-catalyzed polymer formation) that conventional short-term experiments often overlook but are especially prevalent in continuous nitration systems. This systematic validation approach enables predictive

Ambident reactivity of enolizable 5-mercapto-1H-tetrazoles in trapping reactions with in situ-generated thiocarbonyl S-methanides derived from sterically crowded cycloaliphatic thioketones

• Grzegorz Mlostoń,
• Małgorzata Celeda,
• Marcin Palusiak,
• Heinz Heimgartner,
• Marta Denel-Bobrowska and
• Agnieszka B. Olejniczak

Beilstein J. Org. Chem. 2025, 21, 1508–1519, doi:10.3762/bjoc.21.113

• polymer chemistry [36] and the crop protection industry [37] as well. Therefore, in extension of a typically synthetic work, a preliminary study on biological activity of the hitherto unreported 1H-tetrazole derivatives such as thioaminals 9 and dithioacetals 10 was carried out and it demonstrated that

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

• thia-bridged triarylamine[4]helicene-functionalized polynorbornenes 63a–c via ring-opening metathesis polymerization (ROMP), introducing helicene chirality into polymer backbones with tunable electrochromic behavior [78]. These polymers exhibit reversible pH-responsive color changes. For instance, 63a

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

• range of functionalized polyolefins, showcasing the applicability of this xanthylated polyolefin in various reactions, including trifluoromethylthiolation, polymer grafting, Michael addition, and epoxide opening. Amidyl radical from N–X bond cleavage Direct halogenation of C–H bonds is of significant

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

• , new OFET-based acid vapor sensors were developed from 150 by synergistically utilizing its charge transport and protonation−deprotonation properties. The solution-phase synthesis of a non-benzenoid nanoribbon from an azulene-containing polymer via alkyne benzannulation was reported by Morin and co

• -workers (Scheme 20) [98]. The starting polymer 152 was synthesized using Suzuki cross coupling and is regiorandom, meaning the orientation of the azulene units within the main chain is not defined. Polymer 152 was annulated using MsOH (methanesulfonic acid) yielding the non-alternant graphene nanoribbon

Selective monoformylation of naphthalene-fused propellanes for methylene-alternating copolymers

• Kenichi Kato,
• Tatsuki Hiroi,
• Seina Okada,
• Shunsuke Ohtani and
• Tomoki Ogoshi

Beilstein J. Org. Chem. 2025, 21, 1183–1191, doi:10.3762/bjoc.21.95

• , each product was separated into oligomer and linear polymer by preparative GPC using CHCl3 as eluent. According to analytical GPC in THF (Figures S501–504 in Supporting Information File 1), oligomer fractions were mainly composed of tetramer for [3.3.3]_oligo and dimer and trimer for [4.3.3]_oligo

Gold extraction at the molecular level using α- and β-cyclodextrins

• Susana Santos Braga

Beilstein J. Org. Chem. 2025, 21, 1116–1125, doi:10.3762/bjoc.21.89

• sections of this review. The combination of interactions linking cyclodextrin channels with infinite polymer chains of tetrahaloaurate ions and their counterions affords a highly specific and stable superstructure that is the working pillar for the efficient and selective process of gold recovery from

Supramolecular assembly of hypervalent iodine macrocycles and alkali metals

• Krishna Pandey,
• Lucas X. Orton,
• Grayson Venus,
• Waseem A. Hussain,
• Toby Woods,
• Lichang Wang and
• Kyle N. Plunkett

Beilstein J. Org. Chem. 2025, 21, 1095–1103, doi:10.3762/bjoc.21.87

• pattern of assembly between HIM and metal cation in 2:1 ratio. While association with sodium leads to a polymer-like network, the lithium crystal structure was limited to dimeric assemblies of HIM. In the lithium-coordinating complex, the oxygen–lithium–oxygen bond angle is approximately 98.83

• 2.548 Å while the O12–Na is 2.323 Å. The average difference in bond lengths between Li+ and Na+ is ≈0.5 Å. Unlike the Li+ complex, the Na+ complex grows into a polymer-like network. While the overall structure forms a polymer, the molecular repeating unit consists of two HIM 1 for every NaBArF24. Though