Synthesis and properties of 6-alkynyl-5-aryluracils

• Ruben Manuel Figueira de Abreu,
• Till Brockmann,
• Alexander Villinger,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 898–911, doi:10.3762/bjoc.20.80

• was performed on Merck Silica gel 60 (particle size 63–200 μm). Solvents for extraction and column chromatography were distilled prior employment. Representative method for the preparation of starting materials 5-Bromo-6-chloro-1,3-dimethyluracil (2). Uracil 1 (22.9 mmol; 4.00 g) was dissolved in

Synthesis and characterization of water-soluble C₆₀–peptide conjugates

• Yue Ma,
• Lorenzo Persi and
• Yoko Yamakoshi

Beilstein J. Org. Chem. 2024, 20, 777–786, doi:10.3762/bjoc.20.71

• -Arg (5c) and images of dissolved or dispensed compounds in Milli-Q® water (pH 7.0). aCrude yield. DLS diagrams of C60–peptide conjugates 5a (1 mM, in Milli-Q® water), 5b (1 mM, in Milli-Q® water or in pH 9.0 TRIS buffer), and 5c (1 mM, in Milli-Q® water). Particle size: mean, nm (polydispersity index

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• carried out using silica (Merck; 40–63 μm particle size). General procedures General procedure for the hydration of alkynes catalysed by BF3·Et2O in ILs In a 10 mL vial, 1 mL of the IL, a magnetic stirring bar and the amount of alkyne, water and BF3·Et2O reported in Tables 1, 3, and 4 were added. The vial

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• about 8% compared to DMSO and also decreases with increasing amine size. Exchange interactions between the components of the complex are generally greater in CHCl3 than in DMSO and slightly increase with the increasing amine particle size: ranging from 12.1% to 14% in CHCl3 and from 7.1% to 12.3% in

Non-peptide compounds from Kronopolites svenhedini (Verhoeff) and their antitumor and iNOS inhibitory activities

• Yuan-Nan Yuan,
• Jin-Qiang Li,
• Hong-Bin Fang,
• Shao-Jun Xing,
• Yong-Ming Yan and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 789–799, doi:10.3762/bjoc.19.59

• chromatography (CC) was performed using macroporous adsorbent resin Amberlite TM XAD 16N (particle size 20–60 mesh, Rohm and Haas Company), MCI gel CHP 20P (particle size 75–150 μm, Mitsubishi Chemical Industries, Japan), RP-18 (particle size 40–60 μm; Daiso Co.), C-18 silica gel (particle size 40–60 μm; Daiso

• Co., Japan), Sephadex LH-20 (Amersham Biosciences), and YMC gel ODS-A-HG (particle size 40–60 μm; YMC Co. Japan). A Saipuruisi chromatograph with a semi-preparative high-pressure infusion pump (SP-5030) and a semi-preparative UV–vis dual wavelength detector (UV200) were utilized for RP–HPLC. A YMC

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

• under an infrared lamp to prepare a sample for TEM measurement. The morphology of nanoparticles was observed at an accelerating voltage of 200 kV, and high-resolution TEM images were obtained. DLS and Zeta potential measurements. The measured samples were examined by a laser particle size analyzer

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

• (Mestrelab Research, Santiago de Compostela, Spain). Size exclusion chromatography (SEC) measurements were performed on a Polymer Standard Service SECurity (PSS, Mainz, Germany); precolumn: 50 × 8 mm PSS PFG linear M; 2 columns: 300 × 8 mm PSS PFG linear M (particle size 7 µm; pore size 0.1–1,000 kDa) at 313

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

• from the dosage system may be controlled by altering the physicochemical parameters (particle size, zeta potential, hydrophobicity) of the self-assembling units utilized to design nanoparticles [9][10][11][12]. However, oral nano drug delivery systems capable of providing all the necessary features

• particle size, very low polydispersity index, and a zeta potential of + 40 mV. In vitro release experiments showed that amphiphilic CD NPs have properties suitable for colon targeting, but the most promising were poly-β-CD-C6 NPs with 52% of encapsulated CPT successfully delivered all the way to the

• positive change in 6-O-capro-β-CD nanoparticles. It is known that the same nanoparticles may have different effects on cancer cells of different species. In addition to the surface charges, particle size and distribution also play a very important role in the cellular interactions of nanoparticles. For

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

First example of organocatalysis by cathodic N-heterocyclic carbene generation and accumulation using a divided electrochemical flow cell

• Daniele Rocco,
• Ana A. Folgueiras-Amador,
• Richard C. D. Brown and
• Marta Feroci

Beilstein J. Org. Chem. 2022, 18, 979–990, doi:10.3762/bjoc.18.98

• by staining with potassium permanganate. Flash column chromatography was performed using high purity silica gel, pore size 60 Å, 230–400 mesh particle size, purchased from Merck. 1H NMR and 13C NMR spectra were recorded in CDCl3 (purchased from Cambridge Isotope Laboratories) at 298 K using a Bruker

Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• ) of zero; therefore, they lack the hysteresis contribution in the heating process (Figure 2). Their mechanism of electromagnetic energy dissipation is described by the Néel relaxation mechanism [18]. This phenomenon is called superparamagnetism (SPM) and occurs with decreasing particle size when

• particle size of 110 µm. Conventionally heated trickle bed reactors using externally located heating devices suffer from uneven temperature distribution in the reactor bed and the formation of hot spots that can lead to rapid deactivation of the catalyst. The authors selected the synthesis of isopulegol (2

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• chromatography was performed on silica gel 60 (230–400 mesh, particle size 0.040–0.063 mm, Merck). Bromopropargylic alcohols 1a–c and chloropropargylic alcohol were prepared according to published methods [22][23][59]. Phenol (2a), naphthalen-1-ol (2b), naphthalen-2-ol (2c), 4-nitrophenol (2d), 2-nitrophenol (2e

Glycosylated coumarins, flavonoids, lignans and phenylpropanoids from Wikstroemia nutans and their biological activities

• Meifang Wu,
• Xiangdong Su,
• Yichuang Wu,
• Yuanjing Luo,
• Ying Guo and
• Yongbo Xue

Beilstein J. Org. Chem. 2022, 18, 200–207, doi:10.3762/bjoc.18.23

• (10 × 250 mm, 5 µm particle size); mobile phase methanol/water (65:35) to yield compound 10 (20.0 mg). The fraction EE8 (13.3 g) was subjected to a HP20 gel eluting with a solvent mixture of methanol/H2O (20% to 100%, v/v) to produce six sub-fractions (EE8.1–8.6). The sub-fraction EE8.3 (250 mg) was

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

• the reason why the proton signals and absorbance of TBT in the 1H NMR and UV–vis spectra greatly declines. Then SEM and dynamic light scattering (DLS) are used for in-depth research of Q[8]-TBT complex. As shown in Figure 4b, compared with TBT (5.35 nm), the particle size of Q[8]-TBT is greatly

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

• (degasser), LC-20AD (pump), SIL-20AHT (auto sampler), CTO-10AC vp (oven), SPD-20A (UV detector), RID-10A (RI detector), PSS SDV guard/1000 Å/1,000,000 Å (5 μm particle size) chloroform/isopropanol/triethylamine [94/2/4] with 1 mL/ min at 40 °C, poly(ethylene glycol) (standard). Differential scanning

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

• subject to CC BY 4.0. Summary of the pPEGMA and pMPC block copolymers prepared by PISA at 70 °C including the hydrodynamic diameter Dh and particle size distribution PdI obtained by DLS and the drug loading content (DLC) calculated using DLC = m(PENAO)/[m(PENAO) + m(polymer)]. The table here contains the

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

• nanoparticle core directly affects the thermal response. Thus, it was found that with increasing particle size, the LCST decreases [140]. The reason for this is the strong dependence of the free space per polymer chain at the same grafting density on the degree of curvature [115]. Responsive polymers with LCST

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Enhanced target cell specificity and uptake of lipid nanoparticles using RNA aptamers and peptides

• Roslyn M. Ray,
• Anders Højgaard Hansen,
• Maria Taskova,
• Bernhard Jandl,
• Jonas Hansen,
• Citra Soemardy,
• Kevin V. Morris and
• Kira Astakhova

Beilstein J. Org. Chem. 2021, 17, 891–907, doi:10.3762/bjoc.17.75

• , 31.8 µL Tat) were added to the LNPs (90 µL). Samples were incubated on a thermomixer for 30 minutes (25 °C at 250 rpm) for postinsertion addition. Thereafter, samples were stored at 4 °C until further use. DLS and ZP Particle size, polydispersity, and ZP were analyzed by DLS instrument model Zetasizer

• ) was determined. Histograms are representative of the mean ± SEM. Data representative of two independent experiments performed in quadruplicates. Formulations used in the present study.a DLS data listing particle size, PDI

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

• examined, showing the critical operational parameters to be temperature and catalyst concentration, whereas the process was not significantly affected by particle size or stirring speed. Thus, up to 100% Me-La yield was obtained using the six-coordinated Zn(ligand)2 complex sketched in Scheme 9a, either at

A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• , operated at an acceleration voltage of 100 kV. Approximately one hundred metal particles were measured to perform the particle size distribution. The cobalt content in the supported catalyst was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), on a Spectro Arcos instrument

1,2,3-Triazoles as leaving groups in S_NAr–Arbuzov reactions: synthesis of C6-phosphonated purine derivatives

• Kārlis-Ēriks Kriķis,
• Irina Novosjolova,
• Anatoly Mishnev and
• Māris Turks

Beilstein J. Org. Chem. 2021, 17, 193–202, doi:10.3762/bjoc.17.19

• an Agilent Technologies 1200 Series system equipped with an XBridge C18 column, 4.6 × 150 mm, particle size 3.5 μm, with a flow rate of 1 mL/min, using eluent A–0.1% TFA/H2O with 5 vol % MeCN and eluent B–MeCN as the mobile phase. The wavelength of detection was 260 nm. Gradient: 30–95% B 5 min, 95

Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

• Alexander Zika and
• Franziska Gröhn

Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17

• photodimerization [55][56][57], photocleavage [58][59], and cis–trans photoisomerization [60][61][62][63][64][65]. While it had been well-established to access oligomer formation and gelation, a light-switchable particle size has remained a challenge until realized through the mentioned electrostatic self-assembly

• -potential by RH. Previously we have reported that the effective surface charge density significantly controls the supramolecular particle size in electrostatic self-assembly [4][86][87]. (The effective surface charge density considers the effect of all particle charges at the shear plane.) For cycle I, the

• from the B form to AH+, which creates a cationic charge on the Flavy molecule. A decreased electrostatic driving force due to the repulsion of the positive charges of Flavy and the polyelectrolyte lead to the decrease in particle size. In other words, again the increased effective surface charge

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• of a reaction in the solid state. As such, we recently investigated the influence of the particle size of β-CD in the synthesis of β-CD mesitylene sulfonate (β-CDMts) in the solid state using a vibrating ball-mill. We were particularly interested in the role of the particle size on the kinetics of

• highlighting the advantages of the mechanically assisted synthesis. Results and Discussion Analysis of ground CDs Scanning electron microscopy (SEM) SEM enables particle size evolution upon grinding to be monitored. The SEM images in Figure 1 show the surface topography changes of polycrystalline β-CD for six

• the ImageJ software, we also calculated the granulometric composition of the β-CD particles against the grinding time (Figure 2). While a rapid decrease in size was observed over the first 10 min of grinding, a slight variation on the particle size was noticed when the grinding of β-CD was left to

NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• increase in particle size. Interestingly, a >2-fold excess of calix[8]arene over Cyt c results in a breaking up of the ligand-induced tetramers, which also results in a resharpening of the NMR signals at higher ligand concentrations [24]. This tendency to bridge protein molecules and assemble them into