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

• . Polylactic acid (PLA) and polyglycolic acid (PGA) are most important examples of biopolymers exhibiting interesting biodegradability properties [41]. The co-polymerization of PLA with glycolic acid was reported by Ayyoob and Kim [42]. High molecular weight poly-lactic-co-glycolic acid (PLGA) was obtained by

• the direct condensation and co-polymerization of both monomers promoted by a bicatalytic system including stannous chloride (SnCl2·2H2O) and methane sulfonic acid (MSA). PLGA films were prepared by the solvent casting technique, for which the presence of glycolic acid was found to increase their

• ). The obtained hydrocarbons exhibited higher density (0.78–0.88 g/cm3) and higher net heat of combustion (44.0–46.0 MJ/kg) than some commonly commercial fuels [194]. Multicomponent reactions involving the reactivity of furfural are also noteworthy. A Ugi four-component polymerization was developed to

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

• [47], where the azobenzene moieties undergo reversible photoisomerization and thermally induced reverse isomerization, enabling "energy charging–discharging" cycles (Figure 4a). Under ultraviolet (UV) irradiation (254 nm), the closely packed diacetylene polymers undergo polymerization to form π

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

• supramolecular polymers. Introducing α-CD onto DiCh effectively adjusts the flexibility of the spacer group, which in turn enhances supramolecular polymerization. Despite DiCh being captured by both α-CD and bisSC4A, the resultant assembly retains enzyme responsiveness, attributed to the dynamic equilibrium

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

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

• N2 adsorption and desorption. Molecular design for uniform microporosity and efficient polymerization is a next challenge. Conclusion In this work, we developed formylation on a naphthalene ring in [3.3.3]- and [4.3.3]-type fully π-fused propellanes. High selectivity was achieved for monoformylation

• -branched linear polymers, macrocyclic compounds, and molecular assemblies that incorporate propellanes as key 3D components. As a proof of concept, the formylated products were reduced to the corresponding alcohols and polymerized in acidic conditions. Although the degrees of polymerization were not high

Biobased carbon dots as photoreductants – an investigation by using triarylsulfonium salts

• Valentina Benazzi,
• Arianna Bini,
• Ilaria Bertuol,
• Mariangela Novello,
• Federica Baldi,
• Matteo Hoch,
• Alvise Perosa and
• Stefano Protti

Beilstein J. Org. Chem. 2025, 21, 1024–1030, doi:10.3762/bjoc.21.84

• photoreductants, and we considered triarylsulfonium salts Ar3S+X− as suitable probes. Such derivatives are photoreactive molecules characterized by a positively charged sulfur atom bonded to three aromatic moieties [20][21][22][23], mainly employed as photoacid generators in cationic polymerization [19]. Apart

On the photoluminescence in triarylmethyl-centered mono-, di-, and multiradicals

• Daniel Straub,
• Markus Gross,
• Mona E. Arnold,
• Julia Zolg and
• Alexander J. C. Kuehne

Beilstein J. Org. Chem. 2025, 21, 964–998, doi:10.3762/bjoc.21.80

Study of tribenzo[b,d,f]azepine as donor in D–A photocatalysts

• Katy Medrano-Uribe,
• Jorge Humbrías-Martín and
• Luca Dell’Amico

Beilstein J. Org. Chem. 2025, 21, 935–944, doi:10.3762/bjoc.21.76

• computational study to design new PCs to be employed in atom transfer radical polymerization (O-ATRP) [17]. Notably, the sulfur-based structure 2 showed excellent performance for this transformation. One year later, the same research group reported its use in a reversible addition-fragmentation chain-transfer

• (RAFT) polymerization [18]. Moreover, in 2022, Zysman-Colman and collaborators showed that molecule 3, initially synthesized as a TADF (thermally activated delayed fluorescence) emitter [14], can be used as a PC under electron-transfer (ET) and energy-transfer (EnT) processes (Figure 1a) [19]. All the

Formaldehyde surrogates in multicomponent reactions

• Cecilia I. Attorresi,
• Javier A. Ramírez and
• Bernhard Westermann

Beilstein J. Org. Chem. 2025, 21, 564–595, doi:10.3762/bjoc.21.45

• difficult to separate [86][87][88]. Probably, the high reactivity of the imines generated by formaldehyde leads to their polymerization [84] or even to the incorporation of other nucleophiles present in the reaction mixture, such as the solvent or a second molecule of the amidine component (Scheme 32) [84

Unprecedented visible light-initiated topochemical [2 + 2] cycloaddition in a functionalized bimane dye

• Metodej Dvoracek,
• Brendan Twamley,
• Mathias O. Senge and
• Mikhail A. Filatov

Beilstein J. Org. Chem. 2025, 21, 500–509, doi:10.3762/bjoc.21.37

• promising strategy for synthesizing substituted cyclobutanes without the need for ultraviolet irradiation. Keywords: bimane; [2 + 2] cycloaddition; fluorescence; topochemical polymerization; X-ray crystallography; Introduction Topochemical polymerizations refer to polymerization reactions occurring in the

• primarily focused on [2 + 2] photocycloaddition in the solid state, making it one of the earliest known examples of topochemical polymerization and a valuable method for synthesizing substituted cyclobutanes [5]. These solid-state reactions are highly influenced by the arrangement of monomers within the

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• states. In this section, the document highlights applications of these complexes in reactions like ring-closing metathesis and polymerization, where red light’s deeper penetration enhances yields and efficiency, particularly for large-scale reactions. The second section broadens the focus to explore

• the ruthenium(I) complex 2. In this study, T. Rovis et al. demonstrated a third advantage of working with red light: its penetrating power. To this end, a polymerization reaction of dicyclopentadiene 4 was investigated through various materials such as amber glass, white paper, a solution of

• hemoglobin, and silicon by selectively irradiating a specific area of the reaction medium with red light (660 nm) or blue light (456 nm), respectively (Scheme 2). The authors have demonstrated that this polymerization reaction proceeded much more efficiently under red light irradiation. Indeed, red light can

Three-component reactions of conjugated dienes, CH acids and formaldehyde under diffusion mixing conditions

• Dmitry E. Shybanov,
• Maxim E. Kukushkin,
• Eugene V. Babaev,
• Nikolai V. Zyk and
• Elena K. Beloglazkina

Beilstein J. Org. Chem. 2025, 21, 262–269, doi:10.3762/bjoc.21.18

• [4][5][6] and polymerization processes of unstable methylidene adducts [7][8][9], instead of the desired formation of a monocrotonic product. Therefore, heating [6][10][11][12][13][14] or Lewis acid activation [15][16][17][18] have often been used in the literature for successful multicomponent

• , which should significantly reduce undesirable polycondensations involving CH2O as well as polymerization of the intermediately formed methylidene derivatives. In this work, we generated methylidene adducts by formaldehyde condensation under diffusion mixing conditions in three-component reactions with

Hydrogen-bonded macrocycle-mediated dimerization for orthogonal supramolecular polymerization

• Wentao Yu,
• Zhiyao Yang,
• Chengkan Yu,
• Xiaowei Li and
• Lihua Yuan

Beilstein J. Org. Chem. 2025, 21, 179–188, doi:10.3762/bjoc.21.10

• cooperative intermolecular forces. Zinc ion-induced coordination with the macrocycle and a terpyridinium derivative enabled orthogonal polymerization, as revealed by 1H NMR, DLS, and TEM techniques. In addition, viscosity measurements showed a transition from oligomers to polymers at the critical

• polymerization concentration of 17 μM. These polymers were highly concentration-dependent. Establishing this new dimerization motif with shape-persistent H-bonded macrocycles widens the scope of noncovalent building blocks for supramolecular polymers and augurs well for the future development of functional

• photoluminescent materials [16]. In this regard, macrocycles emerged a decade ago as a “sticking” end for homo- and heterodifunctional monomers, enabling supramolecular polymerization [17]. So far, macrocycles that are applied to orthogonal self-assembly have been limited to three-dimensional rings, such as

Hot shape transformation: the role of PSar dehydration in stomatocyte morphogenesis

• Remi Peters,
• Levy A. Charleston,
• Karinan van Eck,
• Teun van Berlo and
• Daniela A. Wilson

Beilstein J. Org. Chem. 2025, 21, 47–54, doi:10.3762/bjoc.21.5

• ring-opening polymerization of N-carboxyanhydrides (NCAs), following a protocol adapted from Tian et al. [28]. High-purity monomers were obtained using this method, ensuring the subsequentially polymer synthesis proceeded with minimal impurities. Sequential polymerization commenced with poly(benzyl

• glutamate) (PBLG) as the hydrophobic block, which was done to prevent ending on a primary amine in the final product which could disrupt self-assembly due to its ionizable nature. Subsequently, PBLG served as a macroinitiator for the polymerization of sarcosine NCA, yielding the final polymer with high

• the vesicles at higher temperatures. d–f) Vesicles after shape transformation: illustrated at 60 °C, 70 °C, and 80 °C, respectively. i) Synthesis of benzyl glutamate NCA using phosgene and propylene oxide as a scavenger. ii) Ring-opening polymerization of BnGluNCA using benzylamine as initiator. iii

Emerging trends in the optimization of organic synthesis through high-throughput tools and machine learning

• Pablo Quijano Velasco,
• Kedar Hippalgaonkar and
• Balamurugan Ramalingam

Beilstein J. Org. Chem. 2025, 21, 10–38, doi:10.3762/bjoc.21.3

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• comonomers (Scheme 4D) [67]. In this polyaddition reaction, various combinations of comonomers, e.g., di-isocyanate macro comonomers, bulky comonomers, or bulky diamine comonomers, enabled the fine-tuning of the resulting polymer properties. In addition to one-shot polymerization, chain extension and the

• , [3]rotaxane diol 10 was used as the initiator of the controlled ring-opening polymerization (ROP) of ε-caprolactone in the presence of a diphenyl phosphate catalyst to introduce the polyester main chain into the rotaxane framework; the successive end-capping reactions yielded macromolecular [3

• units are easily modified by acylation, the hydrophilicity of the rotaxane crosslinker (RC) could be tuned in this manner. This [3]rotaxane crosslinker RC was added 0.5 mol % on the standard free radical polymerization of vinyl monomers to afford rotaxane-crosslinked polymer (RCP) (Figure 15B). Similar

Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• . Keywords: C–H functionalization; oxidation; peroxidation; radical reactions; TBHP; Introduction Organic peroxides are used in many different areas of human activities. The traditional and most developed field is the use of peroxides as initiators in the polymerization process for the production of a wide

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• of double twist cylinders [10][11]. A prototype of a polymer-stabilized Blue Phase LCD with ultra-fast switching times has been presented in 2008 by Samsung [12]. Another class of materials including high HTP chiral dopants are cholesteric films prepared by the polymerization of reactive mesogens

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• introduced into octadehydrodibenzo[12]annulene. In this report, the synthesis of new octadehydrodibenzo[12]annulene derivatives, regioselective double addition of organic azides, and an application to crosslinking polymers are described. Keywords: annulene; click chemistry; polymerization; strain-promoted

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• heteroatom radicals When reacting a heteroatom radical with an isocyanide, the first thing to consider is the method of generating the heteroatom radicals [13][14][15]. As mentioned above, isocyanides are readily polymerizable molecules, so to suppress the polymerization of isocyanides, it is necessary to

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• (hetero)aryl iodides gives rise to 3-arylalkynyl acetals 142. Since 3-arylpropynals are sensitive to oligo- and polymerization, it proved useful to perform acetal deprotection and cyclization with hydrazine hydrate in a one-pot procedure to give 3-substituted pyrazoles 141 (Scheme 48) [151]. Given that

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

• (41–67%). Multicomponent polymerizations are simple and efficient methods to construct a library of polymers with great structural complexity and diversity, including fused-heterocyclic polymers[64]. Tang et al. [65] reported the transition-metal-free multicomponent polymerization of dialdehydes 96a–c

• and diisocyanides 97a,b in the presence of 2-aminopyridine (1, Scheme 30). The polymerization was carried out under mild conditions (in ethanol as the solvent and p-TsOH as the catalyst) and delivered six polymers featured with high yields (up to 98%), molecular weight (up to 41,700 g/mol), atom

Synthesis of cyclic β-1,6-oligosaccharides from glucosamine monomers by electrochemical polyglycosylation

• Md Azadur Rahman,
• Hirofumi Endo,
• Takashi Yamamoto,
• Shoma Okushiba,
• Norihiko Sasaki and
• Toshiki Nokami

Beilstein J. Org. Chem. 2024, 20, 1421–1427, doi:10.3762/bjoc.20.124

• polymerization of organic molecules is an important strategy for the preparation of functional materials, such as conducting polymers [1][2][3][4][5]. Electrochemical reactions can be controlled by electric potential or current, electrodes, and electrolytes, which are not available in conventional chemical

• oligoglucosamines via electrochemical polymerization of thioglycoside monomers that are derived from glucosamine hydrochloride. Results and Discussion Electrochemical polyglycosylation of 2-deoxy-2-phthalimido-substituted thioglycoside monomers We initiated our research with the electrochemical polyglycosylation of

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• polymerization, and solvent oxidation. For aniline and o-anisidine, predominant oxidative polymerization occurred, leading to the formation of the respective polyaniline polymers as major products. For methyl anthranilate, the oxidative polymerization was suppressed due to the delocalization of amine lone pair

• calculations suggest that the highest occupied molecular orbital of methyl anthranilate was deeply buried, which suppressed the oxidative polymerization pathway. Due to solvent oxidation, oxamide formation was also noticed to a considerable extent. This study provides that utmost care must be exercised while

• using SeO2 as an electrophile source in aromatic electrophilic substitution reactions. Keywords: arylamines; electrophilic substitution; oxamides: polymerization; selenium dioxide; Introduction Organoselenium compounds have received considerable attention due to interesting medicinal properties, such

Carbonylative synthesis and functionalization of indoles

• Alex De Salvo,
• Raffaella Mancuso and
• Xiao-Feng Wu

Beilstein J. Org. Chem. 2024, 20, 973–1000, doi:10.3762/bjoc.20.87

• carbonylation reaction [81]. Initially it was assumed that the presence of the halide and the NH group could lead to an oligomerization or polymerization reaction, but carrying out the reaction with Pd(CH3CN)2Cl2/dppf as catalyst system and Et3N as the base at 130 °C under 25 bar of CO, they succeeded in the