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

• blending compatibilizers [211]. Radical depolymerization capability can be incorporated at synthesis. Wang et al. introduced photodegradability to polyolefins by copolymerization of carbon monoxide [212]. Nevertheless, radical depolymerization is an essential tool to tackle the problem of polymer wastes

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

• product or process to have the least environmental impact throughout its life cycle [28][29]. Generally, DMF, NMP, and MeCN, or, more recently benzonitrile are solvents of choice for the 2-oxazoline polymerization and copolymerization. However, none of these are benign from a safety or environmental point

• distribution (Figure S13 in Supporting Information File 1). Polymerization and copolymerization of 2-butyl-2-oxazoline As mentioned, POx are desirable polymers for biomedicine. Under the right conditions, the living nature of CROP makes it possible to produce polymers, copolymers, and block copolymers with

• attempt a block copolymerization of BuOx and EtOx to investigate the living nature of the reaction (Figure S14 in Supporting Information File 1). It is well established that 2-oxazolines with a longer substituent polymerize more slowly than those with a shorter alkyl group. The polymerization of BuOx was

Exfoliated black phosphorous-mediated CuAAC chemistry for organic and macromolecular synthesis under white LED and near-IR irradiation

• Azra Kocaarslan,
• Zafer Eroglu,
• Önder Metin and
• Yusuf Yagci

Beilstein J. Org. Chem. 2021, 17, 2477–2487, doi:10.3762/bjoc.17.164

• cooling fan and the reaction temperature was kept constant at room temperature (24−25 °C). 1H NMR spectra were recorded 4 h later. Synthesis of anthracene functional poly(ε-caprolactone) (PCL-Anth) The same process as in the block copolymerization was applied. Az-2 (19.27 mg, 1 equiv), PCL-Alk (1 equiv

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• solvents. In order to obtain polymers containing a varying degree of pendant azulene units, such as 154, 155, 157, and 158, the authors performed the free radical copolymerization of the monomers 146 and 150 with methyl methacrylate (153) (Scheme 27A and B) and sulfobetaine methacrylate (156) (Scheme 27C

Constrained thermoresponsive polymers – new insights into fundamentals and applications

• Patricia Flemming,
• Alexander S. Münch,
• Andreas Fery and
• Petra Uhlmann

Beilstein J. Org. Chem. 2021, 17, 2123–2163, doi:10.3762/bjoc.17.138

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

• provides the living nature of the process as well as control over the control of functionality as confirmed by the spectroscopic analyses, and chain extension and block copolymerization experiments [138]. The same strategies were also performed in NIR region using NIR sensitizers comprising cationic

• . Furthermore, chain extension and block copolymerization experiments confirmed the chain end fidelity and therefore the living character of polymerization (Table 3, Figure 4). On/Off experiments demonstrated the light dependency of polymerization [81]. The proposed mechanism (Figure 5) involves the excited

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• found to be effective [10][11]. We have also engaged in the design of the side chain of polythiophenes, and several functionalities have been successfully introduced [12][13][14]. We further focused on the copolymerization of thiophene, employing differently substituted thiophene monomers, with which

Ugi reaction-derived prolyl peptide catalysts grafted on the renewable polymer polyfurfuryl alcohol for applications in heterogeneous enamine catalysis

• Alexander F. de la Torre,
• Gabriel S. Scatena,
• Oscar Valdés,
• Daniel G. Rivera and
• Márcio W. Paixão

Beilstein J. Org. Chem. 2019, 15, 1210–1216, doi:10.3762/bjoc.15.118

• polymerizable handle suitable for subsequent copolymerization with a monomeric counterpart. In this regard, multicomponent reactions (MCRs) provide a great opportunity for the simultaneous assembly of the catalyst along with the functionalization polymerizable handle. Orru and co-workers were the first to

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• silsesquioxanes (POSS) and POSS-containing polymeric materials. Three types of processes, i.e., cross metathesis (CM) of vinyl-substituted POSS with terminal olefins, acyclic diene metathesis (ADMET) copolymerization of divinyl-substituted POSS with α,ω-dienes and ring-opening metathesis polymerization (ROMP) of

• metathesis in chemistry of unsaturated derivatives of POSS is limited to three types of processes, i.e., cross metathesis (CM) of vinyl-substituted POSS with terminal olefins, acyclic diene metathesis (ADMET) copolymerization of divinyl-substituted POSS with α,ω-dienes and ring-opening metathesis

• the application of ADMET in the synthesis of oligomers or polymers containing a POSS unit in the main chain. Marciniec disclosed ADMET copolymerization of DDSQ-2SiVi with dienes in the stereoselective synthesis of a new class of vinylene–arylene copolymers containing double-decker silsesquioxanes in

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• (cyclohexene carbonate)s was carried out by the β-diiminate (BDI) zinc-catalyzed block copolymerization of functionalized epoxides and CO2 with a norbornenyl-containing initiator (Scheme 5) [68]. The subsequent “grafting through” by ROMP of norbornene resulted in the synthesis of multiblock copolymer brushes

• -substituted NB with poly(ethylene glycol) (PEG) [69]. Ring-opening metathesis copolymerization of the rather strained cyclooctene (COE) and a strainless 27-membered macrocyclic olefin (MCO) led to the multiblock copolymer consisting of octenylene blocks linked with ring-opened MCO segments (Scheme 6) [70

• excess of COE, the ring-opening metathesis copolymerization of NB and COE results in the formation of a mixture of the homopolymers and copolymers enriched with NB units [94][95]. The substantial difference in the monomer strain energy (NB: 100 kJ mol−1, −ΔG° ROMP = 47 kJ mol−1; COE: 16 kJ mol−1, −ΔG

Gold-catalyzed ethylene cyclopropanation

• Silvia G. Rull,
• Andrea Olmos and
• Pedro J. Pérez

Beilstein J. Org. Chem. 2019, 15, 67–71, doi:10.3762/bjoc.15.7

• copolymerization of ethylene and ethyl diazoacetate with rhodium-based catalysts (Scheme 2a). Ethyl cyclopropanecarboxylate has been prepared in several ways, alternative to the direct carbene addition to ethylene (Scheme 2b): ring contraction of 2-halocyclobutanone [5], cyclization of alkyl 4-halobutanoates [6

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• loading of 0.125 mol %. In 2008, Blechert and Buchmeiser et al. introduced a ruthenium complex featuring an unsymmetrical, chiral NHC ligand 44 and its pyridine derivative 45 (Figure 12) [26]. Both complexes revealed as efficient systems to promote the alternating copolymerization of norbornene (NBE, 46

• alternating diads ([poly(NBE-alt-CPE)n]), representing the highest value found until then. The selectivity in the copolymerization was mainly ascribed to the steric interaction between the 2-phenylethyl substituent at the nitrogen and the growing polymer chain. This study was then extended to a series of

• obtained as a mixture of mono- and bis(pyridine) adducts. In terms of initiation efficiency, the pyridine-derivatives turned out to be more efficient than the corresponding phosphine-containing complexes. In the copolymerization of NBE (46) and COE (47), complexes 49–52 afforded the corresponding

Copolymerization of epoxides with cyclic anhydrides catalyzed by dinuclear cobalt complexes

• Yo Hiranoi and
• Koji Nakano

Beilstein J. Org. Chem. 2018, 14, 2779–2788, doi:10.3762/bjoc.14.255

• Yo Hiranoi Koji Nakano Department of Organic and Polymer Materials Chemistry, Tokyo University of Agriculture and Technology, 2-24-16 Naka-cho, Koganei, Tokyo 184-8588, Japan 10.3762/bjoc.14.255 Abstract The alternating copolymerization of epoxides with cyclic anhydrides (CAs) is a highly diverse

• benzene ring as a linker and their activities in copolymerization reactions. The dinuclear cobalt complexes showed a higher catalytic activity for the copolymerization of propylene oxide with phthalic anhydride than the corresponding mononuclear cobalt–salen complex and achieved one of the highest

• turnover frequencies ever reported. A variety of epoxides and CAs were also found to be copolymerized successfully by the dinuclear cobalt complex with a high catalytic activity. Keywords: cobalt; copolymerization; cyclic anhydrides; epoxides; polyesters; Introduction Aliphatic polyesters have received

Domino ring-opening–ring-closing enyne metathesis vs enyne metathesis of norbornene derivatives with alkynyl side chains. Construction of condensed polycarbocycles

• Ritabrata Datta and
• Subrata Ghosh

Beilstein J. Org. Chem. 2018, 14, 2708–2714, doi:10.3762/bjoc.14.248

• diene. Thus unlike metathesis of 7a, metathesis of its acetate analogue 7b occurred through a domino ROM–RCEYM process. Addition of the Ru-carbene 10 arising from ring opening of norbornene unit in 7b could add to the acetylenic unit of another molecule of 7b leading to copolymerization. However, this

• process generally does not take place under such low molar concentration of the substrate [38][39][40][41][42][43]. We also did not isolate any copolymerization product. This may be attributed to the much faster rate of addition of the Ru-carbene 10 to the yne unit intramolecularly resulting in ring

Superstructures with cyclodextrins: Chemistry and applications IV

• Gerhard Wenz

Beilstein J. Org. Chem. 2017, 13, 2157–2159, doi:10.3762/bjoc.13.215

• magnetic resonance imaging (MRI) [22]. Well-defined fluorescent polyrotaxanes with alternating, threaded cucurbit[6]uril and CD rings were assembled by Fraser Stoddart’s group via an alkyne–azide click reaction exploiting supramolecular catalysis [23][24]. The concurrent radical copolymerization of 1,3

Block copolymers from ionic liquids for the preparation of thin carbonaceous shells

• Sadaf Hanif,
• Bernd Oschmann,
• Dmitri Spetter,
• Muhammad Nawaz Tahir,
• Wolfgang Tremel and
• Rudolf Zentel

Beilstein J. Org. Chem. 2017, 13, 1693–1701, doi:10.3762/bjoc.13.163

• . This excludes a mixture of homopolymers and demonstrates that block copolymers are obtained. The anchor block was thereby introduced in two synthetic steps. First, a block copolymerization using a reactive ester monomer was performed. Subsequently, the reactive ester block was aminolyzed to introduce

• block copolymerization as a polar solvent to solubilize the PIL macro-CTA. Optimized reaction conditions using 2,2-azobis(4-methoxy-2,4-dimethylvaleronitrile) (AMDVN) as an initiator, resulted in the successful block copolymerization. This was confirmed by 1H NMR spectroscopy after stirring for 20 hours

One-pot synthesis of block-copolyrotaxanes through controlled rotaxa-polymerization

• Jessica Hilschmann,
• Gerhard Wenz and
• Gergely Kali

Beilstein J. Org. Chem. 2017, 13, 1310–1315, doi:10.3762/bjoc.13.127

• Jessica Hilschmann Gerhard Wenz Gergely Kali Organic Macromolecular Chemistry, Saarland University, Campus C4.2, 66123 Saarbrücken, Germany 10.3762/bjoc.13.127 Abstract The aqueous reversible addition fragmentation chain-transfer (RAFT) copolymerization of isoprene and bulky comonomers, an

• , free radical copolymerization of a hydrophobic monomer, complexed in a host, with a stopper comonomer [24][25]. This latter has to be large enough to prevent the dissociation of the growing axis and the host, as it happens in the case of aqueous CD assisted homopolymerizations of hydrophobic monomers

• polyrotaxane synthesis since it is highly water-soluble and provides a sufficiently high binding constant for isoprene [24][25]. Results and Discussion In a first trial, statistical RAFT copolymerization of isoprene complexed in RAMEB was performed with water-soluble bulky comonomers, namely N-[tris

Continuous-flow processes for the catalytic partial hydrogenation reaction of alkynes

• Carmen Moreno-Marrodan,
• Francesca Liguori and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2017, 13, 734–754, doi:10.3762/bjoc.13.73

• ) produces 1-hexene (1a), one of the most commercially important linear α-olefins used in copolymerization processes [116][117]. High density polyethylene (HDPE) and linear low density polyethylene (LLDPE) contain approximately 2–4% and 8–10% of 1a, respectively [118]. 1-Hexene can be produced in ca. 91

Highly reactive, liquid diacrylamides via synergistic combination of spatially arranged curing moieties

• Maximilian Maier,
• Magnus S. Schmidt,
• Markus Ringwald and
• Christoph P. Fik

Beilstein J. Org. Chem. 2017, 13, 372–383, doi:10.3762/bjoc.13.40

• copolymerization of acrylamido and allyl moieties heavily favors acrylamide homopolymerization [28][32] and b) the allyl group is known for its chain-transfer behavior, but still c) reaction is fastest for the highest (intramolecular) occurrence of acryl/allyl groups, a dominant, non-classical polymerization

Formose reaction controlled by boronic acid compounds

• Toru Imai,
• Tomohiro Michitaka and
• Akihito Hashidzume

Beilstein J. Org. Chem. 2016, 12, 2668–2672, doi:10.3762/bjoc.12.263

• polymer, respectively (Scheme 1). The copolymer was prepared by radical copolymerization at a molar ratio of 1:10 in monomer feed. The formose reaction was carried out using a solution containing 200 mM formaldehyde and 20 mM calcium hydroxide at 60 °C. Fructose or glyceraldehyde was employed as a

Methylenelactide: vinyl polymerization and spatial reactivity effects

• Judita Britner and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 2378–2389, doi:10.3762/bjoc.12.232

• Judita Britner Helmut Ritter Institute of Organic Chemistry and Macromolecular Chemistry, Heinrich-Heine-University, Universitätsstraße 1, 40225 Düsseldorf, Germany 10.3762/bjoc.12.232 Abstract The first detailed study on free-radical polymerization, copolymerization and controlled radical

• polymerization of the cyclic push–pull-type monomer methylenelactide in comparison to the non-cyclic monomer α-acetoxyacrylate is described. The experimental results revealed that methylenelactide undergoes a self-initiated polymerization. The copolymerization parameters of methylenelactide and styrene as well

• as methyl methacrylate were determined. To predict the copolymerization behavior with other classes of monomers, Q and e values were calculated. Further, reversible addition fragmentation chain transfer (RAFT)-controlled homopolymerization of methylenelactide and copolymerization with N,N

Ionic liquids as transesterification catalysts: applications for the synthesis of linear and cyclic organic carbonates

• Maurizio Selva,
• Alvise Perosa,
• Sandro Guidi and
• Lisa Cattelan

Beilstein J. Org. Chem. 2016, 12, 1911–1924, doi:10.3762/bjoc.12.181

• acidic polyionic liquid by the copolymerization of a zwitterionic liquid based on vinylpyridinium, styrene and ethyleneglycol dimethacrylate (Scheme 4) [44]. The resulting PIL with particle sizes of about 0.5–3 mm, was an efficient catalyst for a series of esterification reactions of different acids

3,6-Carbazole vs 2,7-carbazole: A comparative study of hole-transporting polymeric materials for inorganic–organic hybrid perovskite solar cells

• Wei Li,
• Munechika Otsuka,
• Takehito Kato,
• Yang Wang,
• Takehiko Mori and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2016, 12, 1401–1409, doi:10.3762/bjoc.12.134

• , respectively, suggesting the successful copolymerization. Both polymers showed an explicit difference in their chemical shift values ascribed to the carbazole units due to the different connectivity patterns. In contrast, the IR spectra of the polymers were almost the same. Optical and electrochemical

From N-vinylpyrrolidone anions to modified paraffin-like oligomers via double alkylation with 1,8-dibromooctane: access to covalent networks and oligomeric amines for dye attachment

• Daniela Obels,
• Melanie Lievenbrück and
• Helmut Ritter

Beilstein J. Org. Chem. 2016, 12, 1395–1400, doi:10.3762/bjoc.12.133

• -dibromooctane can easily be conducted through a one-pot synthesis. Swellable networks can be obtained by radical copolymerization of 2a with N-VP. Furthermore, the conversion of the double bonds through thiol–ene click reaction with 2-aminoethanethiol hydrochloride leads to paraffinic oligomers 4 bearing

Superstructures with cyclodextrins: chemistry and applications III

• Gerhard Wenz and
• Eric Monflier

Beilstein J. Org. Chem. 2016, 12, 937–938, doi:10.3762/bjoc.12.91

• has been achieved in the synthesis of CD polyrotaxanes. The one-pot and one-step polyrotaxane synthesis of β-CDs was performed in aqueous solution by employing a click reaction [7] as well as by radical copolymerization [8]. Slide-ring gels, synthesized by the group of K. Ito through the crosslinking