From amines to (form)amides: a simple and successful mechanochemical approach

• Federico Casti,
• Rita Mocci and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 1210–1216, doi:10.3762/bjoc.18.126

• assistance with the generation of the 1H, 13C NMR, and GC–MS spectroscopic data. Funding This research was funded by MIUR Italy, PRIN 2017 project (grant number: 2017B7MMJ5_001) “MultIFunctional poLymer cOmposites based on groWn matERials (MIFLOWER) and Fondazione di Sardegna (FdS, F72F20000230007).

Heterogeneous metallaphotoredox catalysis in a continuous-flow packed-bed reactor

• Wei-Hsin Hsu,
• Susanne Reischauer,
• Peter H. Seeberger,
• Bartholomäus Pieber and
• Dario Cambié

Beilstein J. Org. Chem. 2022, 18, 1123–1130, doi:10.3762/bjoc.18.115

• colour of the polymer in the packed bed turned rapidly black (see Supporting Information File 1, Figure S4), and lower yields were observed (Table 1, entries 6 and 7). The catalyst deactivation could be due to the formation of nickel-black [28], or via (photo-)thermal degradation of the polymer. Packed

Introducing a new 7-ring fused diindenone-dithieno[3,2-b:2',3'-d]thiophene unit as a promising component for organic semiconductor materials

• Valentin H. K. Fell,
• Joseph Cameron,
• Alexander L. Kanibolotsky,
• Eman J. Hussien and
• Peter J. Skabara

Beilstein J. Org. Chem. 2022, 18, 944–955, doi:10.3762/bjoc.18.94

• example, ITIC (10), is shown in Figure 4. ITIC [17], in combination with polymer 11, achieved a power conversion efficiency (PCE) of 6.8%, which was the best value for NFA organic solar cells at the time of publication. Fluorination of ITIC, obtaining IT-4F (12), shown in Figure 5, reduced ELUMO. Combined

• with the donor polymer 13, PCEs up to 17% were achieved [8]. More recently, another fused-thiophene containing NFA was published, Y6 (14), shown in Figure 6 [30]. Y6 held the record for the highest value of an OPV with PCEs up to 18% upon blending with polymer 15 [31]. This has now been surpassed; in

• 2021, Hou et al. reported a ternary OPV, using a mixture of the novel PBQx-TF (16) donor polymer and the non-fullerene acceptor eC9-2Cl (17), shown in Figure 7. In addition, a third material, F-BTA3 (18) was blended in [32]; all three materials are fused thiophene systems. The resulting OPV achieved a

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• . In 2002, Monkman reported the addition of camphor sulfonic acid (CSA) to the fluorescent polymer poly{2,5-pyridylene-co-1,4-[2,5-bis(2-ethylhexyloxy)]phenylene} (compound 1 in Figure 2) containing pyridine groups led to the protonation effect [26]. CSA has strong acidity and low volatility, which is

• (C6F5)3 (BCF) to bind to nitrogen atoms at the basic site a of π-conjugated polymer, providing a simple strategy to regulate the optical properties of the A–D–A chromophore with charge transfer excited state properties [28]. In 2019, Wang et al. constructed a novel exciplex system by using the Lewis

• substituents on the benzene rings of B(C6F5)3 is responsible for its stronger Lewis acidity compared to B(C6H5)3, and reacted efficiently with the basic fluorescent materials. In 2011, Hayashi investigated the modification of pyridyl-conjugated polymer films with the Lewis acid BF3 [31]. Through repeated acid

A trustworthy mechanochemical route to isocyanides

• Francesco Basoccu,
• Federico Cuccu,
• Federico Casti,
• Rita Mocci,
• Claudia Fattuoni and
• Andrea Porcheddu

Beilstein J. Org. Chem. 2022, 18, 732–737, doi:10.3762/bjoc.18.73

• Ricerca d'Ateneo) core facility of the University of Cagliari and Dr. Sandrina Lampis for assistance with the generation of the 1H and 13C NMR spectroscopic data. Funding This research was funded by MIUR Italy, PRIN 2017 project (grant number: 2017B7MMJ5_001) “MultIFunctional poLymer cOmposites based on

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• the axle, placing it away from the polymer backbone. By N-acylation of the ammonium group, a shuttling of the macrocycle towards the ester moiety is achieved, placing the chiral information of the macrocycle in closer proximity to the polymer backbone (polymers 33). The influence of the chiral BINOL

• unit on the helicity of the polyacetylene was investigated by CD spectroscopy. Here, no chiral induction was observed for the ammonium species 32, while the N-acylated polymers 33 showed clear Cotton effects in the absorption range of the polymer main chain (490 nm), demonstrating an effective

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• toluene solutions as well as 1 wt % PMMA (poly(methyl methacrylate)) films. The solid-state samples were prepared by dissolving the compounds and polymer or host material at appropriate ratios in toluene solution and then wet-casting the solutions on quartz substrates. The absorption spectra were recorded

Recent developments and trends in the iron- and cobalt-catalyzed Sonogashira reactions

• Surendran Amrutha,
• Sankaran Radhika and
• Gopinathan Anilkumar

Beilstein J. Org. Chem. 2022, 18, 262–285, doi:10.3762/bjoc.18.31

• polymer) (Co@imine-POP) has been synthesized by immobilizing cobalt onto a nitrogen-rich porous organic polymer (Scheme 20) [35]. Using scanning electron microscopy, the surface morphology of the catalyst was evaluated. Nowadays, covalent organic frameworks (COF) were found to be a suitable support in

• reaction (Scheme 31). Non-nanoparticle-based protocols Nanoparticles are materials with sizes around nanometer scales. The used nanoparticles are environmentally friendly magnetic cross-linked chitosan fibers which is a natural polysaccharide polymer. In this regard the use of such polymers is promising

Green synthesis of C5–C6-unsubstituted 1,4-DHP scaffolds using an efficient Ni–chitosan nanocatalyst under ultrasonic conditions

• Soumyadip Basu,
• Sauvik Chatterjee,
• Suman Ray,
• Suvendu Maity,
• Prasanta Ghosh,
• Asim Bhaumik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 133–142, doi:10.3762/bjoc.18.14

• . Chitosan is one of the most abundant bio-based polymers in nature [9]. It is the N-deacetylated form of chitin found in industrial waste [10]. Chitosan is a broadly used natural polymer because of properties such as biocompatibility, low cost, and nontoxicity. It has diverse applications, such as drug

Study on the interactions between melamine-cored Schiff bases with cucurbit[n]urils of different sizes and its application in detecting silver ions

• Jun-Xian Gou,
• Yang Luo,
• Xi-Nan Yang,
• Wei Zhang,
• Ji-Hong Lu,
• Zhu Tao and
• Xin Xiao

Beilstein J. Org. Chem. 2021, 17, 2950–2958, doi:10.3762/bjoc.17.204

• supermolecule polymer with TBT due to its larger cavity. Since Q[7] and TBT form a host–guest complex, the carboxyl group at the end of TBT and the carbonyl group of the Q[7] still have a strong ability to coordinate with metals. Therefore, Q[7]-TBT is selected for the detection of silver ions (Ag+) [32][33

Polymer chemistry: fundamentals and applications

• Bernhard V. K. J. Schmidt

Beilstein J. Org. Chem. 2021, 17, 2922–2923, doi:10.3762/bjoc.17.200

• Bernhard V. K. J. Schmidt School of Chemistry, University of Glasgow, G12 8QQ Glasgow, UK 10.3762/bjoc.17.200 Keywords: polymer chemistry; Ever since the introduction of the term macromolecule and the early days of polymer science [1], organic chemistry and polymer chemistry have been closely

• related [2]. It only seems to be a logical step to give room for a thematic issue on polymer chemistry in the Beilstein Journal of Organic Chemistry. The connection between organic and polymer chemistry has been highlighted frequently [3][4], up to the point where one can talk about macroorganic chemistry

• , where oligomers bring molecular precision from organic chemistry together with materials properties from polymer chemistry [5]. Especially in the challenge of transformation to a more sustainable polymer science, organic chemistry can give significant support in the development of greener polymer

A two-phase bromination process using tetraalkylammonium hydroxide for the practical synthesis of α-bromolactones from lactones

• Yuki Yamamoto,
• Akihiro Tabuchi,
• Kazumi Hosono,
• Takanori Ochi,
• Kento Yamazaki,
• Shintaro Kodama,
• Akihiro Nomoto and
• Akiya Ogawa

Beilstein J. Org. Chem. 2021, 17, 2906–2914, doi:10.3762/bjoc.17.198

• polymerization (ATRP) reactions and functional polymer synthesis [29][30][31][32][33][34]. Although α-bromo-γ-butyrolactone, which is a five-membered lactone, is easily accessible from the five-membered lactone by some bromination methods [35][36], the bromination method for the six-membered lactone, δ

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• other high molecular weight emitters can show at least some degree of orientation in solution-processed films. For instance, Senes et al. [23][24]. showed that the OPVn series of polymers exhibited higher horizontal orientation by increasing the length of the polymer chain, and by extension the molecule

Adjusting the length of supramolecular polymer bottlebrushes by top-down approaches

• Tobias Klein,
• Franka V. Gruschwitz,
• Maren T. Kuchenbrod,
• Ivo Nischang,
• Stephanie Hoeppener and
• Johannes C. Brendel

Beilstein J. Org. Chem. 2021, 17, 2621–2628, doi:10.3762/bjoc.17.175

• University Jena, Philosophenweg 7, 07743 Jena, Germany 10.3762/bjoc.17.175 Abstract Controlling the length of one-dimensional (1D) polymer nanostructures remains a key challenge on the way toward the applications of these structures. Here, we demonstrate that top-down processing facilitates a

• straightforward adjustment of the length of polyethylene oxide (PEO)-based supramolecular polymer bottlebrushes (SPBs) in aqueous solutions. These cylindrical structures self-assemble via directional hydrogen bonds formed by benzenetrisurea (BTU) or benzenetrispeptide (BTP) motifs located within the hydrophobic

• methods represent an easily implementable technique toward 1D polymer nanostructures with an adjustable length in the range of interest for perspective biomedical applications. Keywords: distribution; dual centrifugation; filomicelles; self-assembly; ultrasonication; Introduction Cylindrical polymer

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• ; Introduction Gels can be defined as polymer networks that are expanded throughout their whole volume by a fluid. In the case of hydrogels, the network component is a hydrophilic polymer, and the swelling agent is water [1]. However, their lack of interconnected macropores and elasticity, required properties

• solution is then cooled to below the freezing point of water, whereby ice crystals form. Importantly, here the solvent (water) solidifies (freezes) and forms solid solvent porogens within the structure allowing the polymer network to form around these crystals, templating the porous structure of the final

• properties Cryogels are macroporous hydrogels with interconnected porosity, with high swelling capacities and large surface areas. Ultimately, many of the final cryogel properties are dependent on the choice of polymer/monomer composition used. However, other factors such as crosslinking, pore size, wall

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• Robin Klintworth Garreth L. Morgans Stefania M. Scalzullo Charles B. de Koning Willem A. L. van Otterlo Joseph P. Michael Molecular Sciences Institute, School of Chemistry, University of the Witwatersrand, PO Wits 2050, Johannesburg, South Africa Department of Chemistry and Polymer Science

In-depth characterization of self-healing polymers based on π–π interactions

• Josefine Meurer,
• Julian Hniopek,
• Johannes Ahner,
• Michael Schmitt,
• Jürgen Popp,
• Stefan Zechel,
• Kalina Peneva and
• Martin D. Hager

Beilstein J. Org. Chem. 2021, 17, 2496–2504, doi:10.3762/bjoc.17.166

• of Photonic Technology (IPHT), e. V. Jena, Albert-Einstein-Straße 9, 07745 Jena, Germany 10.3762/bjoc.17.166 Abstract The self-healing behavior of two supramolecular polymers based on π–π-interactions featuring different polymer backbones is presented. For this purpose, these polymers were

• behavior as well as the in-depth characterization of the molecular behavior and the macroscopic properties, which reveals new insights into the self-healing materials based on π–π interactions. Results and Discussion Polymer synthesis For the synthesis of supramolecular polymers based on π-π interactions a

• molar mass of approximately 2000 g/mol resulting in polymer P1. In order to study the influence of the polymer backbone on the material’s properties, the diamine containing polymer was exchanged to a triblock copolymer of poly(propylene glycol)-block-poly(ethylene glycol)-block-poly(propylene glycol

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

• , Turkey King Abdulaziz University, Faculty of Science, Chemistry Department, 21589 Jeddah, Saudi Arabia 10.3762/bjoc.17.164 Abstract The development of long-wavelength photoinduced copper-catalyzed azide–alkyne click (CuAAC) reaction routes is attractive for organic and polymer chemistry. In this study

• has set a milestone as a new and effective method for the synthesis of macromolecules [11]. Initiation of this reaction photocatalytically provides many advantages for the synthetic methodologies including bioconjugation, labeling, surface functionalization, dendrimer synthesis, polymer synthesis, and

• polymer modification by adding spatial and temporal control [12][13]. In recent years, heterogeneous photocatalysts have been performed in many photosynthetic reactions since they provide a more reasonable and easy way to synthesize the targeted products compared to the classical homogenous photocatalysts

Post-functionalization of drug-loaded nanoparticles prepared by polymerization-induced self-assembly (PISA) with mitochondria targeting ligands

• Janina-Miriam Noy,
• Fan Chen and
• Martina Stenzel

Beilstein J. Org. Chem. 2021, 17, 2302–2314, doi:10.3762/bjoc.17.148

• -((phenylcarbonothioyl)thio)pentanoic acid, but it was modified with ethylene glycol. During the polymerization of the water-soluble polymers, fluorescein O-methacrylate was added at a ratio of CTA to fluorescent monomer of 1:0.3. This means more that three out of ten polymer chains will be labelled, which is sufficient

• for cell work. The water-soluble polymer was then chain-extended via PISA using MMA at a various feed ratio of MMA and RAFT agent using earlier procedures [42], resulting in nanoparticles with hydroxy functionalities located on the surface. In earlier studies it was observed that shorter MPC blocks

• ppm was used. As the polymer has 63 PEGMEMA repeating units, the intensity of this peak is 189, which should be equivalent to the 15 aromatic peaks of TPP. This signal overlaps with 7 × 4 aromatic peaks belonging to PENAO. Care needs to be taken here as this is also the region of the aromatic group of

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

• photovoltaic (PV) cells. Since azulene has a fused five and seven-membered ring structure, it can be incorporated onto the polymer backbone through either of these rings or by involving both the rings. These azulene-connection patterns can influence the properties of the resulting polymers and the chemical

• chemical and electrochemical means. Through electrochemical methods, only the five-membered rings can be incorporated onto the polymer backbone, and often the polymers produced are insoluble [17]. On the other hand, chemical synthesis provides an avenue to synthesize soluble polymers where azulene can be

• incorporated into the backbone through either of the rings or by involving both the rings. These substitution patterns can influence the property of the resulting polymer. However, to achieve the synthesis of such homo- and copolymers, suitably tailor-made azulene monomers with specific substitution patterns

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

• , have been intensively studied in solution. For the application of such polymers in novel sensors, drug delivery systems or as multifunctional coatings, they typically have to be transferred into specific arrangements, such as micelles, polymer films or grafted nanoparticles. However, it turns out that

• the thermodynamic concept for the phase transition of free polymer chains fails, when thermoresponsive polymers are assembled into such sterically confined architectures. Whereas many published studies focus on synthetic aspects as well as individual applications of thermoresponsive polymers, the

• representative. In contrast, for polymer arrangements with an upper critical solution temperature (UCST), there is only limited knowledge about preparation, application and precise physical understanding of the phase transition. This review article provides an overview about the current knowledge of

An initiator- and catalyst-free hydrogel coating process for 3D printed medical-grade poly(ε-caprolactone)

• Jochen Löblein,
• Thomas Lorson,
• Miriam Komma,
• Tobias Kielholz,
• Maike Windbergs,
• Paul D. Dalton and
• Robert Luxenhofer

Beilstein J. Org. Chem. 2021, 17, 2095–2101, doi:10.3762/bjoc.17.136

• Jochen Loblein Thomas Lorson Miriam Komma Tobias Kielholz Maike Windbergs Paul D. Dalton Robert Luxenhofer Polymer Functional Materials, Chair for Advanced Materials Synthesis, Institute for Functional Materials and Biofabrication, Department of Chemistry and Pharmacy, Julius-Maximilians

• nm to 10 µm) and micro-scale filaments onto a collector with repeat fiber deposition to build up a micro-scale 3D object, with build heights in the range of several millimeters [9][10][11]. In MEW, the polymer jet is electrostatically drawn from a nozzle, resulting in a considerable reduction of the

• mechanical properties, cytocompatibility, biodegradability, and good printing properties [8][14][15], it is a hydrophobic polymer and immersion into fluids can result in air bubble capture within the scaffold structure, biofouling and non-specific cell interactions [16]. Protein adsorption and denaturation

Towards new NIR dyes for free radical photopolymerization processes

• Haifaa Mokbel,
• Guillaume Noirbent,
• Didier Gigmes,
• Frédéric Dumur and
• Jacques Lalevée

Beilstein J. Org. Chem. 2021, 17, 2067–2076, doi:10.3762/bjoc.17.133

• abilities were found for some reported dyes when used in combination with iodonium salt and amine. Markedly, photothermal effects with a huge heater behavior were also observed for different NIR dye structures. Interestingly, the synthesis of interpenetrating polymer networks (IPNs, e.g., for the

• filled samples can be potentially used for composite materials and/or adhesives. Both photochemical and photothermal NIR approaches were proposed to initiate polymerization, e.g., for free-radical processes, interpenetrating polymer network (IPN) synthesis, or photopolyaddition reactions [3][4][6][7][8

• -component systems can also be used for the preparation of IPNs through the polymerization of acrylate/epoxy monomer blends (3,4-epoxycyclohexylmethyl-3,4-epoxycyclohexane carboxylate from Allnex was used as benchmark epoxy monomer) [20]. The formation of IPNs can be highly worthwhile to reach better polymer

Progress and challenges in the synthesis of sequence controlled polysaccharides

• Giulio Fittolani,
• Theodore Tyrikos-Ergas,
• Denisa Vargová,
• Manishkumar A. Chaube and
• Martina Delbianco

Beilstein J. Org. Chem. 2021, 17, 1981–2025, doi:10.3762/bjoc.17.129

• be quite challenging to prepare. Moreover, problems can occur during the removal of the PGs, since partially deprotected compounds can generate insoluble aggregates [24]. Incomplete deprotection and residual PGs can largely affect the properties of the obtained polymer. Chemical synthesis provides

• methodologies or post-extraction modifications are not discussed. Review Glucose-based polysaccharides Cellulose Cellulose is a polymer consisting of glucose units connected by β(1–4) glycosidic bonds. It is mainly found in two allomorphs – Cellulose I (natural) and Cellulose II (synthetic) – that differ in the

• achieved by ROP of 3,6-dibenzyl-protected 4 catalyzed by Ph3CBF4 [83]. The protected polymer 5 was obtained in 2 h in 62% yield and an average DP of 19.3. The benzyl (Bn) group seems to be essential for the selective transformation [84]. Several derivatives were prepared in a similar fashion (Scheme 1B

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• -melanin synthesis completely which leads to white spores [45]. DHN-melanin is a heterogeneous polymer, as such it does not have a unique structure. Its insolubility aggravates any structural analyses of the deciphering of repetitive motives. However, there were studies doing either computational