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

Enhancing structural diversity of terpenoids by multisubstrate terpene synthases

• Min Li and
• Hui Tao

Beilstein J. Org. Chem. 2024, 20, 959–972, doi:10.3762/bjoc.20.86

• noncanonical prenyl substrates Most of the terpene biosynthesis is well defined by the ‘isoprene rule’ to form natural products by the polymerization of C5 isoprene. Although terpenes with irregular carbon atoms (C6, C7, C11, C12, C16, and C17) have been characterized, they are thought to be synthesized by

Switchable molecular tweezers: design and applications

• Pablo Msellem,
• Maksym Dekthiarenko,
• Nihal Hadj Seyd and
• Guillaume Vives

Beilstein J. Org. Chem. 2024, 20, 504–539, doi:10.3762/bjoc.20.45

• protecting arms to move away from the salen complex thereby exposing the catalytic site. This triple-layer catalyst was applied in the control of a ring-opening polymerization reaction. The open state achieved full monomer conversion, while the closed state exhibited minimal activity (7% conversion after 100

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• Polymerization, Stremayrgasse 9, 8010 Graz, Austria Institute of Physical and Theoretical Chemistry, Graz University of Technology, Stremayrgasse 9, 8010 Graz, Austria Institute of Chemistry, Inorganic Chemistry, University of Graz, Schubertstraße 1, 8010 Graz, Austria Institute of Inorganic Chemistry, Graz

Long oligodeoxynucleotides: chemical synthesis, isolation via catching-by-polymerization, verification via sequencing, and gene expression demonstration

• Yipeng Yin,
• Reed Arneson,
• Alexander Apostle,
• Adikari M. D. N. Eriyagama,
• Komal Chillar,
• Emma Burke,
• Martina Jahfetson,
• Yinan Yuan and
• Shiyue Fang

Beilstein J. Org. Chem. 2023, 19, 1957–1965, doi:10.3762/bjoc.19.146

• have difficulty to produce sequences containing stable secondary structures. Here, we report a direct de novo chemical synthesis of 400 nt ODNs, and their isolation from the complex reaction mixture using the catching-by-polymerization (CBP) method. To determine the authenticity of the ODNs, 399 and

• . Keywords: automated synthesis; catching-by-polymerization; gene assembly; long oligonucleotide; synthetic biology; Introduction Long oligodeoxynucleotides (ODNs) are segments of DNAs extending beyond one hundred nucleotides (nt). Emerging research areas such as synthetic biology [1][2], protein

• -polymerization (CBP) technique [19]. Using the method, long ODNs with 399 and 401 nt were directly synthesized on an automated synthesizer. The full-length sequences were extracted from the complex mixture generated from over a thousand reactions using CBP. The two ODNs were joined together to form the 800 nt

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• in the 1BFC [12] and 2AXM [13] complexes and chondroitin sulfate-4 in the case of 3C9E [36]/4N8W [37]), where the length is dp6 (dp stands for degree of polymerization) and 2. an additional part with different degree of sulfation or sulfation pattern (in case of ligands 1 and 2 for 1BFC and 2AXM dp6

Thienothiophene-based organic light-emitting diode: synthesis, photophysical properties and application

• Recep Isci and
• Turan Ozturk

Beilstein J. Org. Chem. 2023, 19, 1849–1857, doi:10.3762/bjoc.19.137

• adapted with permission of Institution of Chemical Engineers (IChemE) and The Royal Society of Chemistry from [38] (“Cationic and radical polymerization using a boron–thienothiophene–triphenylamine based D-π-A type photosensitizer under white LED irradiation”) by A. Suerkan et al., Mol. Syst. Des. Eng

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• past century, new knowledge on radical chemistry has both promoted and been generated from the emergence of polymer synthesis and modification techniques. In this review, we discuss radical chemistry in polymer science from four interconnected aspects. We begin with radical polymerization, the most

• employed technique for industrial production of polymeric materials, and other polymer synthesis involving a radical process. Post-polymerization modification, including polymer crosslinking and polymer surface modification, is the key process that introduces functionality and practicality to polymeric

• constantly acquire new inspirations from organic chemists. Dialogues on radical chemistry between the two communities will deepen the understanding of the two fields and benefit the humanity. Keywords: crosslinking; polymer surface modification; post-polymerization modification; radical chemistry; radical

Acetaldehyde in the Enders triple cascade reaction via acetaldehyde dimethyl acetal

• Alessandro Brusa,
• Debora Iapadre,
• Maria Edith Casacchia,
• Alessio Carioscia,
• Giuliana Giorgianni,
• Giandomenico Magagnano,
• Fabio Pesciaioli and
• Armando Carlone

Beilstein J. Org. Chem. 2023, 19, 1243–1250, doi:10.3762/bjoc.19.92

• self-aldol condensations, polymerization and Tishchenko-type processes) and stereoselectivity [20]; the activation of acetaldehyde via aminocatalysis, furthermore, suffers from a lack of proper steric hindrance for the enantio-discrimination process. However, some methodologies enabling the use of

Photoredox catalysis enabling decarboxylative radical cyclization of γ,γ-dimethylallyltryptophan (DMAT) derivatives: formal synthesis of 6,7-secoagroclavine

• Alessio Regni,
• Francesca Bartoccini and
• Giovanni Piersanti

Beilstein J. Org. Chem. 2023, 19, 918–927, doi:10.3762/bjoc.19.70

• compounds were obtained; this result was probably due to the competitive cycloaddition and polymerization reactions and decomposition of the diene moiety, which is unstable and very sensitive to acidic and basic conditions [106]. As shown in Figure 3 and anticipated above, our proposed mechanism begins with

Asymmetric synthesis of a stereopentade fragment toward latrunculins

• Benjamin Joyeux,
• Antoine Gamet,
• Nicolas Casaretto and
• Bastien Nay

Beilstein J. Org. Chem. 2023, 19, 428–433, doi:10.3762/bjoc.19.32

• , France 10.3762/bjoc.19.32 Abstract Latrunculins are marine toxins used in cell biology to block actin polymerization. The development of new synthetic strategies and methods for their synthesis is thus important in order to improve, modulate or control this biological value. The total syntheses found in

• ng/ mL [2]. It was rapidly demonstrated that the toxins target the cytoskeleton and inhibit the actin polymerization by specifically sequestering the G-actin monomers with a high affinity [4], unlike cytochalasin D that targets the actin filament [5]. Structure–activity relationships have also been

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• investigate the structure–activity relationship (SAR) of combretastatin D-2, Couladouros and co-workers [73] studied the effect of structural modifications in compound 28 on tubulin polymerization at different concentrations using the filtration-colorimetric method. Tubulin polymerization results in the

• formation of microtubules, which are important structures in the constitution of eukaryotic cells [74]. All tested compounds interfered with the polymerization of tubulin, and when compared to colchicine, classified as a destabilizing agent which prevents the microtubule assembly [55], the tested

• ) against cancer cell lines [18]. Effect of combretastatin D derivatives on tubulin polymerization (%) [73]. Solubility comparison of combretastatin D-2 (2) and prodrugs in water at 25 °C [55]. Inhibition of cancer cell growth by combretastatin D-2 (2) and prodrug salts [55]. Funding We gratefully

Investigation of cationic ring-opening polymerization of 2-oxazolines in the “green” solvent dihydrolevoglucosenone

• Solomiia Borova and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2023, 19, 217–230, doi:10.3762/bjoc.19.21

• biomedical applications in, e.g., drug delivery systems, tissue engineering and more. Commonly, the synthesis of poly(2-oxazoline)s involves problematic organic solvents that are not ideal from a safety and sustainability point of view. In this study, we investigated the cationic ring-opening polymerization

• of 2-ethyl-2-oxazoline and 2-butyl-2-oxazoline using a variety of initiators in the recently commercialized "green" solvent dihydrolevoglucosenone (DLG). Detailed 1H NMR spectroscopic analysis was performed to understand the influence of the temperature and concentration on the polymerization process

• polymerization, as evidenced by side products and limited control over the polymerization. However, we could establish that the use of the 2-ethyl-3-methyl-2-oxazolinium triflate salt as an initiator at 60 °C results in polymers with a relatively narrow molar mass distribution and a reasonable control over the

Sequential hydrozirconation/Pd-catalyzed cross coupling of acyl chlorides towards conjugated (2E,4E)-dienones

• Benedikt Kolb,
• Daniela Silva dos Santos,
• Sanja Krause,
• Anna Zens and
• Sabine Laschat

Beilstein J. Org. Chem. 2023, 19, 176–185, doi:10.3762/bjoc.19.17

• , which might be incompatible with existing functional groups and/or the stereochemical integrity [18][22]. Especially in natural product synthesis, dienone functional groups suffer from isomerization and polymerization [23]. Therefore, a late stage introduction of dienone units is advantageous [24

Total synthesis of insect sex pheromones: recent improvements based on iron-mediated cross-coupling chemistry

• Eric Gayon,
• Guillaume Lefèvre,
• Olivier Guerret,
• Adrien Tintar and
• Pablo Chourreu

Beilstein J. Org. Chem. 2023, 19, 158–166, doi:10.3762/bjoc.19.15

• . Dienyl halides indeed tend to polymerize at low temperatures, and drastic storage conditions must be applied. For example, chloroprene, a well-known precursor of isoprene polymers, must be transported under inert atmosphere below −10 °C, and an inhibitor must be added to prevent polymerization. Cross

• degradation, likely by polymerization. To circumvent this matter, we developed a workup procedure allowing to directly obtain THF solutions of 1-bromopenta-1,3-diene in the 0.4–0.7 M concentration range, and no further purification was required. Those solutions can be directly used in a subsequent iron

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• complexes of A2B-type pyrrole substituted corroles. We believe that the placement of the polymerizable pyrrole as a conjugated substituent to the macrocycle is an important contribution to the polymerization of corroles and the expansion of the usage areas of these compounds. Further studies on the

• production of mono pyrrole metal-free corrole compounds and the polymerization reactions of the obtained compounds are ongoing in our laboratory. Experimental General information All reactions were performed under N2 atmosphere. All reagents and solvents were of reagent grade. The NMR spectra were recorded