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

• clear bimodality, but the molar mass distribution was slightly lower (Ð = 1.45) compared to PBuOx obtained from EtOxMeOTf (Figure S14, Supporting Information File 1). POx-based block copolymers are well known to formulate poorly water soluble drugs and Haider et al. recently compared the drug loading

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

• ingredients (APIs) is necessary to render them bioavailable. This study addresses the poor solubility of two potent steroid hormones, 17β-estradiol (BES) and progesterone (PRO), via their complexation with two water-soluble native cyclodextrins (CDs) namely β-CD and γ-CD. The hydrated inclusion complexes β

• results of comprehensive thermal characterization of these complexes, with emphasis on the determination of their water contents. While it is widely known that the solubility of poorly water-soluble steroidal compounds such as BES and PRO may be very significantly enhanced by various derivatised CDs, it

• relatively low cost of these CDs and in particular the low toxicity of γ-CD are advantageous for potential drug delivery. Furthermore, the amorphous nature of highly water-soluble CD derivatives (e.g., hydroxypropyl-CD and sulfobutyl ether CD) precludes their formation of crystalline inclusion complexes

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• concentration of less than 1% within four hours, and water-soluble monomers. In addition, the integration of this setup into an inline synthesis step starting from block copolymer solutions, and rhodamine encapsulation produced micelles without affecting the particle size is also demonstrated. The growing

Automated grindstone chemistry: a simple and facile way for PEG-assisted stoichiometry-controlled halogenation of phenols and anilines using N-halosuccinimides

• Dharmendra Das,
• Akhil A. Bhosle,
• Amrita Chatterjee and
• Mainak Banerjee

Beilstein J. Org. Chem. 2022, 18, 999–1008, doi:10.3762/bjoc.18.100

• not proceed to completion (Table S1, entry 8 in Supporting Information File 1). Further, during aqueous work-up at least 10% loss of the water-soluble crude product 2a was observed in the conventional solution-phase reactions leading to a drop in the isolated yields. Based on the above observations

On Reuben G. Jones synthesis of 2-hydroxypyrazines

• Pierre Legrand and
• Yves L. Janin

Beilstein J. Org. Chem. 2022, 18, 935–943, doi:10.3762/bjoc.18.93

• glyoxals, would lead to the corresponding α-hydroxyacids. Such transformation has been studied in the past, especially from phenylglyoxal (1{1}) [35][36] and since the resulting mandelic acid is water-soluble it would explain why such compounds were not isolated in our experiments. The second side reaction

• would be the hydrolysis of the α-aminoamides and the resulting α-amino acids would also be water-soluble. For these reasons, a low temperature as well as a plausibly softer base (i.e., tetraalkylammonium hydroxides) would be key parameters to alleviate the impact of these side reactions. These would

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• water-soluble hexacarboxylated tribenzotriquinacene derivative (TBTQ-CB6) was synthesized and used as a supramolecular drug carrier to load the model anticancer drugs dimethyl viologen (MV) and doxorubicin (DOX) via host–guest interactions. The drugs could be effectively released by spermine (SM), a

• novel TBTQ-based host–guest drug delivery system may have potential use in supramolecular chemotherapy. Keywords: competitive substitution; drug delivery; host–guest chemistry; tribenzotriquinacene; water soluble; Introduction Chemotherapy is considered to be one of the most effective strategies in

• derivatives in organic media have been well established [22][23][24][25][26][27]. Recently, the host–guest chemistry of TBTQ derivatives in aqueous phase was also investigated by us [28][29]. In particular, a water-soluble TBTQ-based hexacarboxylate (TBTQ-C6) was prepared and bound with an azobenzene

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

• supramolecular self-assembled nanosystem based on host–guest interactions between water-soluble tetraphenylethylene-embedded pillar[5]arene (m-TPEWP5) and ammonium benzoyl-ʟ-alaninate (G) in an aqueous medium. The obtained assembly of m-TPEWP5 and G showed aggregation-induced emission (AIE) via the blocking of

• photochemical catalytic reaction in aqueous medium. In addition, our group [30] reported the construction of a supramolecular photocatalytic system with a two-step FRET process through the supramolecular assembly of water-soluble pillar[5]arene and TPE derivatives as donor and EsY and Nile Red (NiR) as

• dehalogenation reaction with high yields within shorter reaction time is vastly essential and of industrial importance. Herein, we have fabricated a supramolecular AIE-emissive photocatalytic system (m-TPEWP5G–EsY) based on the host–guest interactions between meso-TPE embedded water-soluble pillar[5]arene (m

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

• ]. Moreover, in adult humans, vitamin K1 can be converted into vitamin K2, a process that requires menadione as intermediate [12]. Menadione sodium bisulfite complex (MSB, 13) [13] and menadiol (vitamin K4, 14) [14], in turn, are two water-soluble derivatives converted in the body, to menadione. The MSB

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• , and even emergence of new reaction pathways [19][20][21][22][23][24]. To simulate the aqueous environment of enzyme-catalyzed physiological transformations, researchers seek to design and synthesize supramolecular hosts in a water-soluble way. The ionic and polyol forms of them would provide good

• water solubility, and, on the other hand, these kinds of water-soluble moieties could also be introduced into the structures of other hosts to help them gain some extent of water solubility. In aqueous solution, the molecular containers provide hydrophobic pockets capable of binding a wide range of

• ) [60]. The host in here was a water-soluble deep cavitand D with methylated urea groups on the rim, which had already been used to mediate other organic reactions [61]. The feet of the host were transformed to pyridinium cationic moieties to make it soluble in water, and in other examples, similar

Flow synthesis of oxadiazoles coupled with sequential in-line extraction and chromatography

• Kian Donnelly and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 232–239, doi:10.3762/bjoc.18.27

• and an additional organic solvent could be introduced. As the reaction is carried out in DMSO, which is water soluble, an additional organic solvent was required to isolate the desired product from the aqueous phase. There are various examples of in-line separations published in the literature [37

Peptide stapling by late-stage Suzuki–Miyaura cross-coupling

• Hendrik Gruß,
• Rebecca C. Feiner,
• Ridhiwan Mseya,
• David C. Schröder,
• Michał Jewgiński,
• Kristian M. Müller,
• Rafał Latajka,
• Antoine Marion and
• Norbert Sewald

Beilstein J. Org. Chem. 2022, 18, 1–12, doi:10.3762/bjoc.18.1

• Pd source together with the water-soluble Buchwald ligand sulfonated SPhos (sSPhos) and potassium fluoride as a base. The reaction was performed in a solvent mixture of dimethoxyethane, ethanol and water (DME/EtOH/H2O 9:9:2) at 120 °C under microwave irradiation for 30 min (Scheme 1) [78]. The

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

• water-soluble branched polysaccharide, isolated from kefir grains. Scaffolds were prepared by cryogelation of a 2% w/v aqueous solution of the kefiran, without the need for any crosslinking agents. Release of diclofenac, a non-steroidal anti-inflammatory drug, was low with 15% of the drug released after

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

• content (DLC, Table 1). These nanoparticles were already described in [42], but they are included in this publication for convenience of the reader. Modification with TPP The PISA particles with excess hydroxy groups on the surface were subsequently modified with the water-soluble TPP derivate, TPP-COOH

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

• resembling phase separation with UCST. Unlike this classical polymer brush, the χ-parameter for water-soluble polymers depends on both temperature and concentration as well as on φ [71][72][73][74][129][130]. This dependency results in a shift of the critical point and a change of the shape of the

• coexistence curve enveloping the two-phase region. Because of the specific interactions between water and polymer chains, water-soluble polymers can have a critical point at any concentration, which often corresponds to a miscibility gap with a LCST [74], in contrast to nonpolar brushes in an organic solvent

• , the developed GA-polyHMPA initially exhibits UCST responsiveness, but can subsequently be slowly biodegraded to a fully water-soluble polymer (polyHMPA) via hydrolysis. Initial in vivo studies of a sustained release of either a hydrophilic model protein or a hydrophobic dye entrapped within the

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

• non-conductive polymers like water-soluble poly(2-ethyl-2-oxazoline) (PEtOx) [35], polypropylene (PP) [36][37] photo-cross-linkable and biodegradable poly(ʟ-lactide-co-ε-caprolactone-co-acryloyl carbonate) [38], or thermoplastic elastomers [39] have successfully been processed via MEW [40

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

• (between 5 and 14) could be obtained tuning the concentration of glucose (2a) or cellobiose (2b) primer acceptor [65]. Polymerization conducted under macromolecular crowding conditions using water-soluble polymers produced hydrogels consisting of cellulose and gelatin networks [54][66][67][68][69]. A study

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

• [143][144][145]. Three types of melanins are known to be produced by fungi of which A. fumigatus is able to produce two – pyomelanin and dihydroxynaphthalene melanin (DHN-melanin). While the water-soluble pyomelanin is synthesized via the tyrosine degradation pathway, the DHN-melanin synthesis relies

Substituted nitrogen-bridged diazocines

• Pascal Lentes,
• Jeremy Rudtke,
• Thomas Griebenow and
• Rainer Herges

Beilstein J. Org. Chem. 2021, 17, 1503–1508, doi:10.3762/bjoc.17.107

• approach starting from the corresponding aniline precursors. The Z→E photoconversion yields in acetonitrile are 80–85% and the thermal half-lives of the metastable E configurations are 31–74 min. Particularly, the high photoconversion yields (≈70%) of the water-soluble diazocines are noteworthy, which

• makes them promising candidates for applications in photopharmacology. The halogen substituents allow further functionalization via cross-coupling reactions. Keywords: bridged azobenzene; diazocine; photopharmacology; photoswitch; triazocine; visible light switch; water-soluble switch; Introduction

• -diazocine 10a were also investigated in pure water since they are water-soluble (11c: ≈250 µM, 10a: ≈150 µM). The highest Z→E conversion yields are observed by irradiation with 400 nm in water and the back-isomerization E→Z can be accomplished by irradiation with light in the range of 525 and 600 nm (Figure

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

• similarity to natural tissues, meaning that they are stable networks with high water content [1][2][3]. The simplest synthesis of hydrogels can be conducted in an aqueous solution of a water-soluble monomer and crosslinker (bi- or more functional) in the presence of an initiator (generally radical initiation

• yellow powder was ultrasonicated in water to obtain a g-CN aqueous colloidal dispersion. The freshly prepared CM/water colloidal dispersion was mixed with water-soluble monomer (N,N-dimethylacrylamide, DMA) and crosslinker (N,N’-methylenebisacrylamide, MBA) followed by the addition of the redox couple

Metal-free glycosylation with glycosyl fluorides in liquid SO₂

• Krista Gulbe,
• Jevgeņija Lugiņina,
• Edijs Jansons,
• Artis Kinens and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 964–976, doi:10.3762/bjoc.17.78

• of an ammonium salt. The 19F NMR spectra of the water-soluble components was than compared to the standard obtained from the reaction between TBAF and SO2. The peak that corresponds to the FSO2− anion was observed at 38.34 ppm (TFA as an external standard, −76.55 ppm) [77]. Also DFT calculations were

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

A chromatography-free and aqueous waste-free process for thioamide preparation with Lawesson’s reagent

• Ke Wu,
• Yichen Ling,
• An Ding,
• Liqun Jin,
• Nan Sun,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2021, 17, 805–812, doi:10.3762/bjoc.17.69

• in the work-up process and it was believed that the compound A was converted to a water-soluble thiophosphonate (Figure 2) [14][15][16]. Although this operation simplified the work-up procedure and allowed a scaled up chromatography-free purification, it generated quite large amounts of P-containing

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• itself (depending on the nature of the attached fragment) to exhibit inherent bioactive properties in a living organism. The efforts of chemists in the design and synthesis of organofunctionalized C60 derivatives for medicine are primarily focused on the creation of water-soluble compounds [18][26][27

• , conversion to water-soluble biologically active fullerene–peptide derivative 27 occurs (Scheme 12). Reactions of monophenyldiazomethanes with C60 were used in the syntheses of adducts 28, 29 [90], and 30 (Figure 2) [91]. Moreover, diphenyldiazomethanes were used for synthesizing 31 [79], 32, 33 [90], and 34

• .) Synthesis of fullerenylpeptides 23 and 24. The synthetic route to the water-soluble biologically active fullerene–peptide derivative 27. Serial synthesis of monophenylmethanofullerenes. Four-step synthesis of the [6,6]-tert-butyl phenyl-C61-butyrate 47. Synthesis of aminophenylfullerenes 49 and 51 based on

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

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

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• reported a light-harvesting system for photocatalysis based on the water-soluble pillar[5]arene WP5 [56]. The large cavity volume of the formed nanoparticles enabled two guest β-carotene (β-CAR) and chlorophyll-b (Chl-b) molecules to be encapsulated within the cavity (Figure 18). The β-CAR and Chl-b

• photocatalysis [57]. Yang and co-workers reported the photocyclodimerization of AC with the water-soluble pillar[6]arene WP6 (Figure 19). The HH/HT yield ratio of the HH- and HT-photodimers is 0.75 in the presence of WP6, which is greatly improved compared to that without WP6 (HH/HT 0.30). This phenomenon may be

Chemical constituents of Chaenomeles sinensis twigs and their biological activity

• Joon Min Cha,
• Dong Hyun Kim,
• Lalita Subedi,
• Zahra Khan,
• Sang Un Choi,
• Sun Yeou Kim and
• Chung Sub Kim

Beilstein J. Org. Chem. 2020, 16, 3078–3085, doi:10.3762/bjoc.16.257

• 1a (1 mg). To the dried water-soluble phase were added pyridine (0.5 mL) and ʟ-cysteine methyl ester hydrochloride (0.5 mg), and the reaction mixture was stirred at 60 °C for 1 h. Then, o-tolyl isothiocyanate (0.1 mL) was added and the mixture stirred at 60 °C for another 1 h. The reaction mixture