Incorporation of a metal-mediated base pair into an ATP aptamer – using silver(I) ions to modulate aptamer function

• Marius H. Heddinga and
• Jens Müller

Beilstein J. Org. Chem. 2020, 16, 2870–2879, doi:10.3762/bjoc.16.236

• washing with buffer. The elution was quantified by UV–vis spectroscopy. In the absence of Ag(I), the aptamer derivatives bearing imidazole residues show a lower affinity to ATP than the unmodified aptamer (Figure 9). While only 17% of the DNA is eluted in the five washing fractions of 1af, the amount of

Selective recognition of ATP by multivalent nano-assemblies of bisimidazolium amphiphiles through “turn-on” fluorescence response

• Rakesh Biswas,
• Surya Ghosh,
• Shubhra Kanti Bhaumik and
• Supratim Banerjee

Beilstein J. Org. Chem. 2020, 16, 2728–2738, doi:10.3762/bjoc.16.223

• . Sodium chloride, 28% ammonia solution and all the solvents were purchased from Merck. Milli-Q water was used for all the experiments. UV–vis spectroscopic measurements were carried out in Agilent Cary 8454 spectrophotometer. Emission spectroscopic measurements were carried out in a Horiba Fluoromax 4

A heterobimetallic tetrahedron from a linear platinum(II)-bis(acetylide) metalloligand

• Matthias Hardy,
• Marianne Engeser and
• Arne Lützen

Beilstein J. Org. Chem. 2020, 16, 2701–2708, doi:10.3762/bjoc.16.220

• diastereomers. The new complexes were characterized by NMR and UV–vis spectroscopy and ESI mass spectrometry. Using GFN2-xTB we generated energy-minimized models of the diastereomers of this cage that further corroborated the results from analytical findings. Keywords: cage compounds; heterobimetallic

• UV–vis spectroscopy. The spectrum of tetrahedron 4 in acetonitrile solution revealed multiple absorption maxima. The most prominent maxima are located at 200 and 294 nm with a shoulder at 360 nm, probably corresponding to π–π* transitions from the aromatic systems and the triple bonds. Finally, a

• , correlation of the proton. Low- and high-resolution electrospray ionization mass spectrometry (ESIMS) spectra were recorded on a Bruker Daltonic LTQ Orbitrap XL. The UV–vis spectrum was recorded on a Specord 200 spectrometer (Analytik Jena AG) at ambient temperature. 4-Ethynylaniline (1) [50], trans-[Pt(PBu3

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• signals of the immobilized ligand molecules but no sharp signals, showing that the nanoparticles were not contaminated with unbound ligands or residual citrate. According to transmission electron microscopy (TEM), NPrac-1 had an average diameter of 9.1 ± 2.4 nm and a maximum of the SPR band in the UV–vis

• sensing, even when simultaneously present at concentrations significantly higher than the actual analyte. The effects of the phosphate salts on the solutions of all four nanoparticles were then followed in a more precise fashion by using UV–vis spectroscopy. To this end, the solutions of the four

• nanoparticles NP4-Zn, NP10-Zn, NP25-Zn, and NP35-Zn (0.25 mg/mL) in water/methanol 1:2 (v/v) were treated with increasing amounts of either Na2HPO4, Na4P2O7, or Na5P3O10, and the UV–vis spectra of the resulting solutions were recorded between 350 and 800 nm to assess the effects of the salts on the position and

Synthesis and characterization of S,N-heterotetracenes

• Astrid Vogt,
• Florian Henne,
• Christoph Wetzel,
• Elena Mena-Osteritz and
• Peter Bäuerle

Beilstein J. Org. Chem. 2020, 16, 2636–2644, doi:10.3762/bjoc.16.214

• ). Optical spectroscopy of the various SN4-heteroacenes was performed in THF solutions. UV–vis absorption spectra of TTA, SN4 9, and SN4'' 33 are shown in Figure 2, left, those of heteroacenes 13, 19, and 22 in Figure S6 (Supporting Information File 1) and data is listed in Table 1. In general, the

• ', and SN4''. UV–vis absorption spectra of TTA, Hex-SN4 9, Pr-SN4'' 33 and fluorescence spectrum of 33 in THF at rt (left) and corresponding cyclic voltammograms in dichloromethane/tetrabutylammonium hexafluorophosphate (0.1 M), 100 mV/s (right). Energy diagram of the frontier molecular orbitals of

• benzofused S,N-heteroacenes 19 and 22. Supporting Information Supporting Information File 561: Synthetic procedures, 1H, 13C NMR, HRMS, and UV–vis spectra as well as cyclic voltammograms. Supporting Information File 562: Crystallographic data. Acknowledgements We gratefully acknowledge B. Müller, Institute

Anion exchange resins in phosphate form as versatile carriers for the reactions catalyzed by nucleoside phosphorylases

• Julia N. Artsemyeva,
• Ekaterina A. Remeeva,
• Tatiana N. Buravskaya,
• Irina D. Konstantinova,
• Roman S. Esipov,
• Anatoly I. Miroshnikov,
• Natalia M. Litvinko and
• Igor A. Mikhailopulo

Beilstein J. Org. Chem. 2020, 16, 2607–2622, doi:10.3762/bjoc.16.212

• ), except where otherwise indicated. TLC was performed on TLC glass plates covered with silica gel 60 F254 (Merck, Germany). The TLC control of the PF-1Pis synthesis and conversions was tested first by UV light then by heating of the plates. UV–vis spectra were recorded with a Shimadzu UV-Mini 1240

Synthesis of 4-substituted azopyridine-functionalized Ni(II)-porphyrins as molecular spin switches

• Jannis Ludwig,
• Tobias Moje,
• Fynn Röhricht and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2589–2597, doi:10.3762/bjoc.16.210

• and 1j because of paramagnetic line broadening and overlapping signals. To circumvent these problems, UV–vis spectroscopy was performed at very low concentrations (Table 1). The porphyrin Soret bands are different for the diamagnetic (λmax ≈ 406 nm) and the paramagnetic species (λmax ≈ 423 nm). The

• File 1. “Record player” approach for molecular spin switching. a) General principle b) Variation of the substituent R in 4-position of the pyridine unit. Record player molecules synthesized in this work (1f–j) are highlighted. Hammett plot of the investigated pyridine substituents [36]. UV–vis spectra

Thermodynamic and electrochemical study of tailor-made crown ethers for redox-switchable (pseudo)rotaxanes

• Henrik Hupatz,
• Marius Gaedke,
• Hendrik V. Schröder,
• Julia Beerhues,
• Arto Valkonen,
• Fabian Klautzsch,
• Sebastian Müller,
• Felix Witte,
• Kari Rissanen,
• Biprajit Sarkar and
• Christoph A. Schalley

Beilstein J. Org. Chem. 2020, 16, 2576–2588, doi:10.3762/bjoc.16.209

• properties of the rotaxane NDIRot were investigated by UV–vis–NIR spectroelectrochemistry in a CH2Cl2/CH3CN 1:1 mixture and compared to NDIC8 and NDIC7 (Figure 4 and Table S3 in Supporting Information File 1). In the neutral state, the rotaxane displays the typical absorption pattern of an N,N’-disubstituted

• clarity), b) NDIC7 (CH3CN molecule omitted for clarity) and c) NDIC8. a) Synthesis of the [2]rotaxane NDIRot. b) Stacked 1H NMR spectra (700 MHz, CDCl3, 298 K) of NDIC8 (top), NDIRot (middle), and A1·BArF24 (bottom). The signal assignment was done by 2D NMR spectroscopy. UV–vis–NIR spectra obtained by

Water-soluble host–guest complexes between fullerenes and a sugar-functionalized tribenzotriquinacene assembling to microspheres

• Si-Yuan Liu,
• Xin-Rui Wang,
• Man-Ping Li,
• Wen-Rong Xu and
• Dietmar Kuck

Beilstein J. Org. Chem. 2020, 16, 2551–2561, doi:10.3762/bjoc.16.207

• with fullerenes (Figure 1). All these TBTQ-based hosts were found to bind fullerenes in organic solvents with different strengths, as indicated by UV–vis or 1H NMR titration experiments. Moreover, easily accessible C3v-symmetrical sixfold hydroxy-functionalized TBTQ derivatives gain increasing

• affinity of C70-fullerene may be attributed to its larger size and surface area as compared to C60-fullerene [50]. The complexation between TBTQ-(OG)6 and fullerenes was also examined by UV–vis spectroscopy in both toluene/DMSO 1:1 (v/v) and water. Figure 3a shows the UV–vis spectra of TBTQ-(OG)6, C60 and

• NMR spectra were recorded on a 400 MHz Bruker NMR spectrometer and chemical shifts were reported in ppm (δ). The fluorescence spectra were measured on a F97Pro fluorescence spectrophotometer (LengGuang Tech, Shanghai, China) and UV–vis spectra were measured on a UV-3300PC spectrometer (Mapada

Host–guest interaction of cucurbit[8]uril with oroxin A and its effect on the properties of oroxin A

• Zhishu Zeng,
• Jun Xie,
• Guangyan Luo,
• Zhu Tao and
• Qianjun Zhang

Beilstein J. Org. Chem. 2020, 16, 2332–2337, doi:10.3762/bjoc.16.194

• –guest interactions between oroxin A (OA) and cucurbit[8]uril (Q[8]) using 1H NMR, MS, UV–vis and IR spectroscopy. The results showed that OA and Q[8] formed an inclusion compound (OA@Q[8]) with a molar ratio of 1:1 and a binding constant of 1.299 × 107 L·mol−1. In addition, the effect of Q[8] on the

• containing 10% DMSO by volume, OA (500 μmol·L−1) upon the addition of different molar equivalents of Q[8]: (a) 0, ( b ) 0.35, (c) 0.44, (d) 1.03, (e) 1.60 and (f) neat Q[8]. (A) The UV–vis absorption spectra recorded for OA in the presence of Q[8] (c(Q[8]), labeled a–k: 0, 0.2, 0.4, 0.6, ..., 2.0 × 10–5

Styryl-based new organic chromophores bearing free amino and azomethine groups: synthesis, photophysical, NLO, and thermal properties

• Anka Utama Putra,
• Deniz Çakmaz,
• Nurgül Seferoğlu,
• Alberto Barsella and
• Zeynel Seferoğlu

Beilstein J. Org. Chem. 2020, 16, 2282–2296, doi:10.3762/bjoc.16.189

• all dyes 3–7 and 8–12 were recorded in the same solvents of various polarities that were used in the UV–vis studies, and the results are summarized in Table 1 and Table S1 (Supporting Information File 1). All dyes showed fluorescence properties and there was no direct correlation of the increase of

• maximum absorption wavelengths of these dyes were in the range of 374–386 nm and 377–385 nm. Moreover, almost the same trends which were obtained from the UV–vis absorption spectra were also observed in the emission maxima. The photophysical properties of dyes 3–7 were similar to those of the

• . An interaction between the dyes and hydroxide anion was investigated in DMSO as the solvent. The presence of hydroxide led to small changes in the UV–vis absorption spectra of the dyes. As presented in Figure 5, the interaction of dye 12 with the hydroxide anion, led to a small hyperchromic effect in

The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

• Patrizia Andreozzi,
• Lorenza Tamberi,
• Elisamaria Tasca,
• Gina Elena Giacomazzo,
• Marta Martinez,
• Mirko Severi,
• Marco Marradi,
• Stefano Cicchi,
• Sergio Moya,
• Giacomo Biagiotti and
• Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

• by UV–vis spectroscopy (λmax = 508–511 nm). The DMSO/ethanol mixtures and ethanol solutions were dried under vacuum, the recovered dye was solubilized in DMSO, and the UV–vis spectra were recorded. The amount of recovered PBA-BODIPY (1) was estimated (Figure 2A), using the molar extinction

• by means of UV–vis spectroscopy, Fourier-transform infrared spectroscopy (FTIR), dynamic light scattering (DLS), and transmission electron microscopy (TEM) analysis (see Supporting Information File 1). Concerning the chemical structure of the conjugate, the data reported in the literature were

• -BODIPY-dextran conjugate Dex-1b were studied in water. The UV–vis spectra of Dex-1b reported in Figure 3A shows the same absorption pattern of the PBA-BODIPY (1, see Supporting Information File 1) [26]. The main absorption band corresponding to the transition S0 → S1, is observed at λabs = 508 nm. The

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• palladium(II) was carried out in the presence of PdCl2(MeCN)2 in a stepwise manner, confirmed by UV–vis spectroscopic technique. The cyclopentadienyl (Cp) ligand has its own identity in the field of organometallic chemistry as a plethora of transition metal complexes contain this moiety in their structures

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

• Poulami Jana,
• Filip Šupljika,
• Carsten Schmuck and
• Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

• charges, while at pH 5 both GCP moieties are also protonated, yielding 4 with four positive charges [18]. The concentration dependence of 4 according to its UV–vis spectrum at both, pH 5 and 7, was linear up to 2 × 10−5 M (Supporting Information File 1), supporting the presence of single, non-aggregated 4

• molecules in water. The absorption maxima and corresponding molar extinction coefficients (ε) are given in Table S1 (Supporting Information File 1). Heating of the aqueous solution of 4 up to 90 °C did not yield any significant changes in its UV–vis spectrum, suggesting that the chromophores are not

• involved in intra- or intermolecular stacking interactions. The excellent reproducibility of the UV–vis spectrum upon cooling back to room temperature (Figure S2, Supporting Information File 1) verified the chemical stability of the compound. The aqueous solution of the studied compound 4 was non

Synthesis of 6,13-difluoropentacene

• Matthias W. Tripp and
• Ulrich Koert

Beilstein J. Org. Chem. 2020, 16, 2136–2140, doi:10.3762/bjoc.16.181

• HOMO–LUMO gap of 6,13-difluoropentacene was determined via UV–vis spectroscopy and compared to other fluorinated pentacenes. Keywords: fluorinated acenes; Friedel–Crafts reaction; ortho-lithiation; synthesis; Introduction Pentacenes are a prototype in the field of organic semiconductors due to their

• degradation in degassed C6D6 was slow enough to obtain a clean 1H NMR spectrum (see Supporing Information File 1) [17]. Next, the HOMO–LUMO gap of 5 was investigated via UV–vis spectroscopy in solution (Figure 2). The λmax was determined to be at 597 nm, which corresponds to a HOMO–LUMO gap of ΔE = 2.08 eV

• -difluoroanthracene. This strategy could be applicable for the synthesis of differently substituted 6,13-difluoropentacenes as well. Structures of pentacene and fluorinated pentacenes. UV–vis spectrum of F2PEN 5 in CH2Cl2. Retrosynthetic analysis of F2PEN 5. Synthesis of F2PEN 5. Decomposition of diol 13 in solution

Azo-dimethylaminopyridine-functionalized Ni(II)-porphyrin as a photoswitchable nucleophilic catalyst

• Jannis Ludwig,
• Julian Helberg,
• Hendrik Zipse and
• Rainer Herges

Beilstein J. Org. Chem. 2020, 16, 2119–2126, doi:10.3762/bjoc.16.179

• influence of the solvent on the switching efficiency was evaluated by UV–vis (Figure S2, Supporting Information File 1) and NMR experiments (Figure 2). It is important to note that there are two ways to define the switching efficiency of record player molecules: 1. the cis–trans isomerization of the

• ) in the PSS at 530 nm and 435 nm, determined by 1H NMR spectroscopy (600 MHz; for details, see Supporting Information File 1). a) UV–vis cuvette with a solution of porphyrin 1 (13.1 µM in THF) and the corresponding UV–vis spectra at 25 °C in the PSS at 530 nm (green) and 435 nm (blue). b) Signals of

Naphthalene diimide–amino acid conjugates as novel fluorimetric and CD probes for differentiation between ds-DNA and ds-RNA

• Annike Weißenstein,
• Myroslav O. Vysotsky,
• Ivo Piantanida and
• Frank Würthner

Beilstein J. Org. Chem. 2020, 16, 2032–2045, doi:10.3762/bjoc.16.170

• molecular ground-state electrical dipole (µ = 7.04 D), which is an evidence for an intramolecular charge transfer (CT) character of the chromophore [34]. The predicted UV–vis spectra by TD-DFT are in excellent agreement with the experimental one (Figure 3, Table 1, the vibrational coupling is neglected

• ) with a UV–vis detector (UV 3702). The melting points (mp) of compounds were determined with an Olympus BX-41 polarization microscope equipped with a Linkam THMS 600 hot stage and a temperature controller unit. 1H and 13C NMR spectra were recorded in CD3OD, CDCl3, D2O or DMSO-d6 at 298 K on a Bruker

• , 18H), 2.14 (m, 4H); 13C NMR (DMSO-d6, 101 MHz) 161.1, 160.7, 137.6, 134.1, 127.0, 126.3, 122.5, 63.2, 52.2, 37.7, 21.4; HRMS-ESI+ (methanol, m/z): [M]2+ calcd for C26H32Cl2N4O4, 267.0900; found, 267.0900; UV–vis (MeOH) λ [nm] (ε [M−1 cm−1]) 397 (10300), 377 (10900), 357 (16000). Synthesis of (S)-N,N

Design, synthesis and application of carbazole macrocycles in anion sensors

• Alo Rüütel,
• Ville Yrjänä,
• Sandip A. Kadam,
• Indrek Saar,
• Mihkel Ilisson,
• Astrid Darnell,
• Kristjan Haav,
• Tõiv Haljasorg,
• Lauri Toom,
• Johan Bobacka and
• Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

• for MC002 with lactate and pivalate were obtained by UV–vis measurements as absolute values [31]. Five carboxylates were studied in the form of their tetrabutylammonium salts: pivalate, acetate, benzoate, lactate, and formate. The anions were titrated in DMSO-d6/H2O solvent systems of two proportions

Et₃N/DMSO-supported one-pot synthesis of highly fluorescent β-carboline-linked benzothiophenones via sulfur insertion and estimation of the photophysical properties

• Dharmender Singh,
• Vipin Kumar and
• Virender Singh

Beilstein J. Org. Chem. 2020, 16, 1740–1753, doi:10.3762/bjoc.16.146

• measurement of UV–vis absorption and fluorescence emission of the samples, stock solutions of 1.0 mM concentration were prepared using analytical grade CHCl3 as the solvent, and diluted to the final concentration of 4.0 μM. Next, we carefully measured the photophysical properties at room temperature including

Clickable azide-functionalized bromoarylaldehydes – synthesis and photophysical characterization

• Dominik Göbel,
• Marius Friedrich,
• Enno Lork and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2020, 16, 1683–1692, doi:10.3762/bjoc.16.139

• triazole 45 in 83% yield. Photophysical properties Finally, we examined the photophysical properties of both the azides and the triazoles. UV–vis absorption measurements of para-bromobenzaldehyde 3 and ortho-bromobenzaldehyde 4 as well as the corresponding triazoles 33–40 were conducted in chloroform

• fluorescence. This may be owing to the azide moiety, either as a functional group or as part of the triazole heterocycle. Similar observations were already made for luminescent materials [74][75]. Fluorene derivatives were subjected to photophysical measurements as well. UV–vis absorption spectra of

• of the alkyl bridge between the arene and the azide are underway in our laboratories. Top: literature examples of organic compounds showing RTP in the crystalline state (a) and in solution (b). Bottom: azide-linked derivatives presented in this work. a) Normalized UV–vis absorption spectra of 3 (blue

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• monitored with in-line and on-line spectroscopies, such as UV–vis, FTIR, mass spectrometry, and NMR [63][64][65][66][67][68]. These systems can be automated to ensure consistency and to remove the need for laborious manual sampling. In-line and on-line monitoring is well aligned with automated synthesis and

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• properties of BKIs and F-BKIs, we measured the optical properties of compounds 6 and 9 (Table 2). As shown in Figure 2, the UV–vis absorptions of 6b and 9b in THF decreased upon the addition of H2O, and white precipitates formed in samples exceeding 80% of water content. Concurrently, the fluorescent

• parent BKI. Further structural modifications of compounds 3 or 9 and applications to fluorescent bioprobes are currently under investigation. UV–vis and fluorescence (FL) spectra of compounds 3b and 3c. Photochemical properties comparisons of BKIs and F-BKIs. (a–c) BKI 6b: photograph (a), UV–vis (b), and

• FL (c) spectra at different solvent compositions of THF/H2O upon excitation at 365 nm (1.0 × 10−5 M); (d–f) F-BKI 9b: photograph (d), UV–vis (e), and FL (f) spectra at different solvent compositions of THF/H2O upon excitation at 380 nm (1.0 × 10−5 M). Selective fluorination of isoxazoles and one-pot

Oxime radicals: generation, properties and application in organic synthesis

• Igor B. Krylov,
• Stanislav A. Paveliev,
• Alexander S. Budnikov and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2020, 16, 1234–1276, doi:10.3762/bjoc.16.107

• oxime 1g (Scheme 5). Oxime radical 16 is a pale blue crystalline compound that is stable at room temperature [35][62], whereas liquid neat di-tert-butyliminoxyl radical (8) decomposed within a week [59]. The di(1-adamantyl)iminoxyl radical (16) was characterized by IR, UV–vis, EPR, and NMR spectroscopy

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• . The theoretical UV–vis spectra of the derivatives had single absorption bands. The band at ca. 310 nm was characterized by a combination of various transitions towards several excited states. The theoretical UV spectrum of derivative 1 had a shoulder at 390 nm. In general, the experimental UV spectra

• the derivatives 1–3 correlated with electrochemically estimated ones and with the ionization potential values discussed above. The photophysical characteristics determined from the UV–vis absorption and photoluminescence spectra are collected in Table 2. The emission spectra of diluted toluene

• -based compounds 1–3, calculated at the B3LYP/6-31G (d, p) level of theory. Cyclic voltammograms of quinazoline-based compounds 1–3. UV–vis absorption spectra of compounds 1–3. a) Theoretical and b) experimental spectra of compounds 1–3 in THF solution. Fluorescence spectra (a) of dilute solutions and

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• components of F-1 were catalytically active, and hence that the reaction was partly catalyzed heterogeneously and partly promoted by the leached catalyst under the experimental conditions. To investigate this in more detail, studies on the solubility of F-1 in MeOH were conducted by UV–vis spectroscopy at

• ) ranging from 5.0 to 3.8. The solubility of F-1 in water was determined by UV–vis spectroscopy to be 0.9 g/L. This corresponded to approximately 50% of the catalyst F-1 being dissolved in the water phase of the reactions reported in Table 1, runs 12–14. The concentration of the ammonium groups was then 4.0