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

• also evaluated, where it was observed that even after 8 cycles without any treatment the morphology of the nanotubes remained the same, without leaching of considerable amounts of ʟ-proline into the reaction mixture. The mechanism of action involves the activation of the aldehyde by the grafted ʟ

• nanocompounds, instead picking graphene oxide (GO), due to its unique morphology and high chemical stability (Scheme 20) [112]. The graphene oxide was decorated with CuBr nanoparticles, which had already shown great catalytic potential, forming the GO–CuBr complex that was utilized for the synthesis of BIMs

• research group [126]. Kaur et al. synthesized various CdS nanostructures with differences in their morphology and screened them for their catalytic potential, while avoiding the use of surfactants, which were too difficult to remove from the reaction mixture (Scheme 24). CdS_3a which was a porous and

Optimizing reaction conditions for the light-driven hydrogen evolution in a loop photoreactor

• Pengcheng Li,
• Daniel Kowalczyk,
• Johannes Liessem,
• Mohamed M. Elnagar,
• Dariusz Mitoraj,
• Radim Beranek and
• Dirk Ziegenbalg

Beilstein J. Org. Chem. 2024, 20, 74–91, doi:10.3762/bjoc.20.9

• activity of the hydrogen evolution. The efficiency of the loop photoreactor is also compared with results from literature obtained in a Schlenk tube system [30]. Results and Discussion Photocatalyst characterization The surface morphology of the Pt-PCN photocatalyst has been analyzed by scanning electron

• photocatalyst is referred to as Pt-PCN. The surface morphology, chemical composition, and elemental distribution of the Pt-PCN were analyzed using a ZEISS LEO 1550 VP scanning electron microscope (SEM) equipped with energy dispersive spectroscopy (EDS) from Ametek, USA. The SEM was operated at an acceleration

Charge carrier transport in perylene-based and pyrene-based columnar liquid crystals

• Alessandro L. Alves,
• Simone V. Bernardino,
• Carlos H. Stadtlober,
• Edivandro Girotto,
• Giliandro Farias,
• Rodney M. do Nascimento,
• Sergio F. Curcio,
• Thiago Cazati,
• Marta E. R. Dotto,
• Juliana Eccher,
• Leonardo N. Furini,
• Hugo Gallardo,
• Harald Bock and
• Ivan H. Bechtold

Beilstein J. Org. Chem. 2023, 19, 1755–1765, doi:10.3762/bjoc.19.128

• to address the thickness and the morphology of the films of 1 and 2 deposited on the hole-only and electron-only device structures. The thickness of the films in these structures was 40 nm. The films deposited on PEDOT:PSS for the hole-only devices indicate homogenous properties with low root mean

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• morphology on Qx26 and Qx27, employing indacenodithiophene, Qx and rhodanine as donor, acceptor and end group, respectively. The incorporation of specific side chains facilitated improved thermal stability, solubility, and broad absorption spectra (300–750 nm), narrow bandgaps (1.68–1.74 eV) and PCEs in the

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• to observe the morphology of CS-TPE aggregates. At pH 5.3, CS-TPE with Rf = 2, 10 and 20 mol % assembled into homogeneous spherical nanoparticles with average diameters of 131 nm, 166 nm and 236 nm, respectively (Figure 3a–c). This assembly behavior is supposed to be caused by the amphiphilic nature

• ratios for the formation of TBTQ-C6/CS-TPE-10% and TBTQ-C6/CS-TPE-20% supra-amphiphilic assemblies are 0.10 mM TBTQ-C6 + 68 µg/mL CS-TPE-10% (Figure 5c and 5d) and 0.10 mM TBTQ-C6 + 60 μg/mL CS-TPE-20% (Figure 5e and 5f), respectively. The morphology and size distribution of TBTQ-C6/CS-TPE aggregates

• measured on a high-sensitivity fluorescence spectrometer HORIBA Fluorolog-3. TEM experiments. The morphology and size of TBTQ-C6/CS-TPE nanoparticles were studied by use of a Talos F200X G2 field emission transmission electron microscope (TEM). The sample solution was dropped on a copper net and then dried

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• hexagonal columnar phases in their pure states and can form organogels in 1,4-dioxane with an unusual flower-like sphere morphology. Ol'shevskaya et al. [64] recently established a CuAAC-based synthesis of a novel series of meso-triazoloporphyrin-carborane conjugates, as shown in Scheme 33. First, the

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• the decrease in cell number and the change in cell morphology draw attention in the microscopic images. In particular, in the CT26 cell line incubated with poly-β-CD-C6 nanoparticles the presence of red-labeled dead cells was observed. Especially in HT29 cells, it is noteworthy that the cellular

Preparation of β-cyclodextrin/polysaccharide foams using saponin

• Max Petitjean and
• José Ramón Isasi

Beilstein J. Org. Chem. 2023, 19, 78–88, doi:10.3762/bjoc.19.7

• correlated to the foam stability. Morphology of the matrices studied by scanning electron microscopy (SEM) The different microstructures of the samples have been analysed for the three polysaccharide combinations. Those of β-cyclodextrin/LBG matrices will be shown here, since all the polysaccharides

• citrate crosslinker, changing the morphology of the internal structures. As can be seen in Figure 3 for sample β-csp (cyclodextrin/saponin without polysaccharides), the washing process causes a swelling of the walls, transforming an ordered porous structure into a random structure, composed of a mixture

Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• (refcode: DOCYID), and the γ-CD·PRO complex produced via co-precipitation (3:2). (a) The crystal morphology of β-CD·BES recorded with polarised light. (b) The crystal morphology of β-CD·PRO. (c) The highly magnified crystal morphology of γ-CD·BES. (d) The crystal morphology of γ-CD·PRO. (a) A

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• absorption band corresponding to the heptazine breathing mode at 800 cm−1, while also retaining the characteristic P–C vibration at 950 cm−1 (Supporting Information File 1, Figure S3, green). STEM-EELS analysis The composition and particle morphology were investigated further using scanning tunneling

• at 300 °C for 1 hour under argon, the phosphorus content is shown to increase, while still remaining partially localized, with the particles retaining their size and morphology (Supporting Information File 1, Figure S4b). 31P magic angle spinning (MAS) NMR Bulk solid-state analysis of the heptazine

Tetraphenylethylene-embedded pillar[5]arene-based orthogonal self-assembly for efficient photocatalysis in water

• Zhihang Bai,
• Krishnasamy Velmurugan,
• Xueqi Tian,
• Minzan Zuo,
• Kaiya Wang and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2022, 18, 429–437, doi:10.3762/bjoc.18.45

• binding interaction between m-TPEWP5 and G is strong enough to form a stable complex in an aqueous solution. The morphology of the supramolecular m-TPEWP5G and m-TPEWP5G-EsY systems was monitored by using transmission electron microscopy (TEM). As shown in Figure 3, m-TPEWP5G self-assembled to form a worm

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

• that the morphology of the catalyst did not change after six consecutive reaction cycles. Apfel et al. reported the first selective cross-coupling reaction between terminal phenylacetylene and iodobenzene derivatives using Fe(II) bisphosphine complexes, which serve as precatalyst (Scheme 17) [33]. In

• 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

• various features like structure, morphology, magnetic nature, and catalytic performance. One among the major attractions of this protocol is that the catalyst could be reused for at least 7 successive runs. Chu et al. developed an efficient and inexpensive procedure for the formation of carbon–carbon

Synthesis and bioactivity of pyrrole-conjugated phosphopeptides

• Qiuxin Zhang,
• Weiyi Tan and
• Bing Xu

Beilstein J. Org. Chem. 2022, 18, 159–166, doi:10.3762/bjoc.18.17

• peptides, resulting in hydrogelation (Figure 3A) [62]. In comparison with 1, 4a, forming networks of nanoparticles at 400 μM and 200 μM, exhibits little change in the morphology of the assemblies after being incubated with 1 U/mL of ALP for 24 h (Figure 3B), although LC–MS confirms the enzymatic

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

• [18]. This has led to concerns over producing cryogels with dimensions greater than 25 mm [19]. Although, a report by Macková et al. outlines the benefits of graduated pore size distribution in hydrogels used in tissue engineering, since many human body tissues also exhibit a heterogeneous morphology

• properties and/or morphology. Often it can be characterised in terms of swelling, as the solubility of a polymer within a solvent, or solvation state, changes with temperature in thermally responsive cryogels. This leads to variation in cryogel volume, as at differing temperatures the nature of intra- and

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

• the SW982 MCTS model. The spheroids were treated with the nano-objects at a drug concentration c = 11.25 µM and the size and morphology of the MCTS were traced after 3 and 6 days. The chosen concentration was based on IC50 values of various PENAO formulations measured in earlier works, which typically

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

• understanding of the polymer–solvent (–surface) interactions and the influence of the polymer morphology is essential for the generation of new polymer-equipped devices with tailored properties for specific applications. At the end of the review article all abbreviations are explained in a separate list. Review

• will be briefly introduced concerning the relationship between their morphology and the temperature-induced phase transition. These polymer arrangements of constrained mobility include star polymers, micelles and grafted linear polymers on flat surfaces as well as on nanoparticles. In general, these

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

• ), however, this morphology is highly irregular. A change in wetting behavior could be demonstrated, and toluidine blue staining indicates successful SIPGP of HEMA on PCL scaffolds. However, to prove that this material is indeed PHEMA, we performed confocal Raman microscopy on the samples, which allows a

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• the morphology of thin films of the photovoltaic cells. To date, the maximum efficiency of 12.05% has been shown by an OSC based on a composite of a donor polythiophene and an acceptor polymeric dicyanoindanone derivative [13]. Among the derivatives of isoindigo, the leading compounds are polymers 1–3

• % N-methylpyrrolidone (Scheme 7). As the authors believe [21], the addition of this viscous solvent made it possible to provide a better surface morphology of a thin-film layer since without it, the efficiency was almost two times lower (2.8%). Therein, the key role of the structure of the acceptor

• thermal cleavage of Boc groups [42]. Without studying the main characteristics of the OSCs, they showed that after annealing the mixtures of these polymers with PC61BM at 200 °C, the surface morphology becomes highly inhomogeneous, with the presence of a large number of crystalline domains. In contrast to

Antiviral therapy in shrimp through plant virus VLP containing VP28 dsRNA against WSSV

• Santiago Ramos-Carreño,
• Ivone Giffard-Mena,
• Jose N. Zamudio-Ocadiz,
• Alfredo Nuñez-Rivera,
• Ricardo Valencia-Yañez,
• Jaime Ruiz-Garcia,
• Maria Teresa Viana and
• Ruben D. Cadena-Nava

Beilstein J. Org. Chem. 2021, 17, 1360–1373, doi:10.3762/bjoc.17.95

• . The morphology of the VLPs is maintained after this last step of the assembly process. The VLPs synthesized had two types of morphologies: icosahedral capsids and large rods (Figure 2A, c to f). Also, aggregations of spherical capsid can be observed at the last VLP assembly step. The distribution of

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• analysis to evaluate the vTA incorporation, and microscopy techniques were employed to examine the impact on their morphology. In terms of applicability, water contact angle measurement, equilibrium swelling ratio analysis, and dye releasing efficiency experiment were also conducted. All hydrogel samples

• , Figure S1). Scanning electron microscopy was performed to investigate the morphology of freeze-dried HGCM and HGCM-vTA. As shown in Figure 2a, HGCM exhibits a significantly porous and uniform morphology. Formation of accessible pores for vTA was the key point to reach in order to activate g-CN nanosheets

• g-CN nanosheets to enhance the modification. Surface transformation has drastically changed the parental hydrogel morphology. Closure of pores (Figure 2) are the supportive evidences for a successful modification as they are not observed in parental hydrogel (Figure 2a). Besides, elemental mapping

Valorisation of plastic waste via metal-catalysed depolymerisation

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

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

• compared to 2D materials, thanks to a typical 8–16 nm outer diameter tubular morphology [215][216] and the potential for facile metal doping via ion-exchange of the solid support [217][218]. Lewis acid-type catalytic activity was also postulated for γ-Fe2O3 NPs, which provided BHET in 90% yield at 300 °C

Supramolecular polymerization of sulfated dendritic peptide amphiphiles into multivalent L-selectin binders

• David Straßburger,
• Svenja Herziger,
• Katharina Huth,
• Moritz Urschbach,
• Rainer Haag and
• Pol Besenius

Beilstein J. Org. Chem. 2021, 17, 97–104, doi:10.3762/bjoc.17.10

• we have assigned this characteristic CD band to a β-sheet-dominated short-range ordering of oligopeptide monomers, which is stable over a wide concentration range [30][39][40]. The application of transmission electron microscopy (TEM) gave further insight into the morphology of the assemblies induced

• molecules to form supramolecular polymers. The copresence of shorter, more flexible structures could be seen as well. Under higher magnification, a sheet like arrangement of densely packed and oriented rods could be revealed. Since the morphology of the aqueous supramolecular polymers observed in dry TEM

• sulfated dendrons and supports the application of the supramolecular polymers in biological applications. In order to compare the morphology of the self-assembled sulfated compound II with the TEG-decorated compound I, TEM and cryo-TEM experiments were performed (Figure 2B and 2C). Based on the outcome

Circularly polarized luminescent systems fabricated by Tröger's base derivatives through two different strategies

• Cheng Qian,
• Yuan Chen,
• Qian Zhao,
• Ming Cheng,
• Chen Lin,
• Juli Jiang and
• Leyong Wang

Beilstein J. Org. Chem. 2021, 17, 52–57, doi:10.3762/bjoc.17.6

• scanning electron microscope (SEM). At the molar ratio of rac-TBPP/DGG = 1:80, the co-gel shows belt-like nanofibers (Figure 3c), while the fibrous morphology could not be observed at the molar ratio of 1:16 (Figure 3d). It indicates that two different kinds of supramolecular assemblies were formed at the

• ratios of rac-TBPP/DGG 1:80 and 1:16, respectively, which is also coincident with the inversion of the CPL responses. However, more detailed studies are still needed to clarify the relations between the morphology and CPL handedness. Conclusion In conclusion, two strategies were demonstrated to obtain

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• upon drying, as was evidenced by TEM and atom force microscopy. Photophysical studies, including femtosecond transient absorption spectroscopy, revealed a distinct influence of the ONC morphology on their photonic properties (excitation energy transfer was observed only in the high-aspect ONCs

• - and morphology-dependent properties arising from confinement effects and strong interactions between neighboring atoms [1][2][3]. The correlation between nanoparticle size and the related electronic and optical properties has extensively been studied, leading to applications in novel technologies and

• mobility [20], but no control over the crystal size and morphology was demonstrated. Using self-assembled monolayers as templates for the seeding and growth of molecular crystals may offer control over structure and polymorphism [21]. However, in this method, the crystal formation is limited by the