Advances in radical peroxidation with hydroperoxides

• Oleg V. Bityukov,
• Pavel Yu. Serdyuchenko,
• Andrey S. Kirillov,
• Gennady I. Nikishin,
• Vera A. Vil’ and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2024, 20, 2959–3006, doi:10.3762/bjoc.20.249

• in Kwon’s review [34]. Cu-catalyzed oxygen atom transfer with TBHP were discussed in the review [35]. The review by Xiao considered visible light-driven C–C bond cleavage enabled with organic peroxides [36]. This comprehensive review summarizes all ever published studies on radical peroxidation with

• photocatalytic system under visible light irradiation (443 nm) [56]. Peroxidation of β-ketoesters, cyanoacetic esters, and malonic esters 37 was performed using the TBAI/TBHP system (Scheme 15) [57]. The highest product yields in the TBAI-catalyzed peroxidation were achieved with malonic acid esters, in contrast

• in situ-generated Cu(I) complexes was developed (Scheme 23) [43]. 2-Phenylbutane (64) was converted into peroxide 65 in a 70% yield with 4% ee. A visible light-induced direct decarboxylative peroxidation of carboxylic acids 66 with the formation of peroxides 67 under metal-free conditions using Mes

Recent advances in transition-metal-free arylation reactions involving hypervalent iodine salts

• Ritu Mamgain,
• Kokila Sakthivel and
• Fateh V. Singh

Beilstein J. Org. Chem. 2024, 20, 2891–2920, doi:10.3762/bjoc.20.243

• position of quinoline N-oxides and pyridine N-oxides, utilizing hypervalent iodine salts as the arylation reagents. The reaction was facilitated by visible light in conjunction with a photocatalyst. The absence of either the photocatalyst or light resulted in only trace amounts of the product, underscoring

• mechanism by adding 2 equivalents of TEMPO to the reaction mixture. The absence of the desired product indicated the involvement of a radical pathway in the process. The proposed reaction mechanism begins with the activation of eosin Y by visible light from 5 W blue LEDs, transitioning it to its excited

N-Glycosides of indigo, indirubin, and isoindigo: blue, red, and yellow sugars and their cancerostatic activity

• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2840–2869, doi:10.3762/bjoc.20.240

• not visible, E/Z < 2:98). The configurations were determined by comparison of chemical shifts of our products with those of non-glycosylated indirubin, by the presence of an intramolecular hydrogen bond N–H···O and by crystal structure analysis. In fact, the chemical shifts of the H-4 proton signals

• very good yield. Likewise, glucoside β-33b, galactoside β-33c, and mannoside β-33d were prepared. All products were isolated as the pure Z-configured isomers (determination by NMR, the other isomer was not visible, E/Z < 2:98). The configurations were determined by comparison of chemical shifts of our

• pure Z-configured isomers (determination by NMR, the other isomer was not visible, E/Z > 98:2). Deprotection of E-β-43a,b under acidic conditions gave rhamnosides E-β-44a,b in good yields. However, deprotection of E-β-43c–e failed. Kornienko et al. reported the synthesis and antiproliferative activity

Interaction of a pyrene derivative with cationic [60]fullerene in phospholipid membranes and its effects on photodynamic actions

• Hayato Takagi,
• Çetin Çelik,
• Ryosuke Fukuda,
• Qi Guo,
• Tomohiro Higashino,
• Hiroshi Imahori,
• Yoko Yamakoshi and
• Tatsuya Murakami

Beilstein J. Org. Chem. 2024, 20, 2732–2738, doi:10.3762/bjoc.20.231

• Instutite for Liberal Arts and Sciences (ILAS), Kyoto University, Sakyo-ku, Kyoto 606-8501, Japan 10.3762/bjoc.20.231 Abstract We have reported that upon visible light irradiation, ferrocene-porphyrin-[60]fullerene triad molecules yield long-lived charge-separated states, enabling the control of the plasma

• from a difference in electric charge on the two sides of the plasma membrane (approximately 5 nm thickness), with a slight excess of the positive ions inside relative to the negative ions outside. Our ferrocene-porphyrin-C60 triad molecule exhibited long-lived charge-separated states under visible

Synthesis of spiroindolenines through a one-pot multistep process mediated by visible light

• Francesco Gambuti,
• Jacopo Pizzorno,
• Chiara Lambruschini,
• Renata Riva and
• Lisa Moni

Beilstein J. Org. Chem. 2024, 20, 2722–2731, doi:10.3762/bjoc.20.230

• indole alkaloids. Here, we develop a novel approach for the one-pot multistep synthesis of different spiro[indole-isoquinolines]. The protocol proposed involves the visible light mediated oxidation of N-aryl tertiary amines using bromochloroform with the generation of a reactive iminium species, which

• reacts with an isocyanide and an electron-rich aniline in a three-component Ugi-type reaction to give an α-aminoamidine. This compound might undergo an additional visible light-mediated oxidation to furnish a second iminium intermediate, which acts as electrophile in an intramolecular electrophilic

• : isocyanide; multicomponent reactions; one-pot reaction; oxidation; spiroindolenine; Ugi reaction; visible light; Introduction Diversity-oriented synthesis (DOS) is a successful approach to biologically active scaffolds directed to create an enormous exploratory space in pharmaceutical hit discovery [1][2

Photoluminescence color-tuning with polymer-dispersed fluorescent films containing two fluorinated diphenylacetylene-type fluorophores

• Kazuki Kobayashi,
• Shigeyuki Yamada,
• Motohiro Yasui and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2682–2690, doi:10.3762/bjoc.20.225

• especially indispensable for our affluent life, is more difficult than the development of the blue-, yellow-, and red-light-emitting molecules mentioned above [24][25][26]. Therefore, to achieve white luminescence covering the entire spectral range of the visible light region, two or more colors of

• fluorophore 1c. The absorption wavelengths and spectral shapes in the ultraviolet (UV)–visible absorption spectra of the PMMA films containing 1 wt % of 1a and 1c or 1f as representative examples (Figure S2 in Supporting Information File 1) were similar to those in the corresponding excitation spectra, which

The scent gland composition of the Mangshan pit viper, Protobothrops mangshanensis

• Jonas Holste,
• Paul Weldon,
• Donald Boyer and
• Stefan Schulz

Beilstein J. Org. Chem. 2024, 20, 2644–2654, doi:10.3762/bjoc.20.222

• the first methyl group was at C-4, due to a missing peak at m/z 178 in the corresponding ion series (Supporting Information File 1, Figure S6). The next visible ion in this series, m/z 232 results from cleavage adjacent to the double bond, and the ion m/z 246 results from allylic cleavage. The 40 Da

Deciphering the mechanism of γ-cyclodextrin’s hydrophobic cavity hydration: an integrated experimental and theoretical study

• Stiliyana Pereva,
• Stefan Dobrev,
• Tsveta Sarafska,
• Valya Nikolova,
• Silvia Angelova,
• Tony Spassov and
• Todor Dudev

Beilstein J. Org. Chem. 2024, 20, 2635–2643, doi:10.3762/bjoc.20.221

• cyclodextrin cavity and in the intermolecular space. Several overlapped steps are visible on the TG curve, which is associated with the release of water molecules in several stages, with the steepest lightening of the sample at 350–370 K. Consistent with this is the DSC endothermic peak, which is asymmetric

Anion-dependent ion-pairing assemblies of triazatriangulenium cation that interferes with stacking structures

• Yohei Haketa,
• Takuma Matsuda and
• Hiromitsu Maeda

Beilstein J. Org. Chem. 2024, 20, 2567–2576, doi:10.3762/bjoc.20.215

• +) cations, used as visible light fluorescent dyes, have been synthesized via a nucleophilic aromatic substitution (SNAr) reaction with primary alkylamines (e.g., 1a+; Figure 1) [15][16]. The highly planar geometry of the TATA+ core unit induces π–π stacking structures in single-crystal and film states, as

• spectra were referenced to residual solvent. UV–visible absorption spectra were recorded on a Hitachi U-4500 spectrometer. Fluorescence spectra were recorded on a Hitachi F-4500 fluorescence spectrometer. MALDI–TOF MS was recorded on a Shimadzu Axima-CFRplus. TLC analyses were carried out on aluminum

Visible-light-mediated flow protocol for Achmatowicz rearrangement

• Joachyutharayalu Oja,
• Sanjeev Kumar and
• Srihari Pabbaraja

Beilstein J. Org. Chem. 2024, 20, 2493–2499, doi:10.3762/bjoc.20.213

• and development of a visible light-assisted modular photo-flow reactor with a seamlessly integrated post-synthetic work-up procedure enabling the efficient synthesis of dihydropyranones from furfuryl alcohols. The reaction uses sun light as green energy source, and the novel photo-flow reactor

• a result, developing an alternative strategy would be an attractive solution to address the limitations described above. Flow chemistry was chosen as the most attractive alternative for the photo-induced (visible light) Achmatowicz rearrangement to convert furfuryl alcohol scaffolds into

• product synthesis. Scope of the integrated continuous photo-flow (visible light)-induced Achmatowicz rearrangement reaction. Reaction conditions: Stock solution (A) comprise of 2/K2S2O8/Ru(bpy)3Cl·6H2O/ACN/DMSO/H2O in a molar ratio of 1:1:0.005:70:54:408; yields are based on isolated yields. Proposed

Synthesis, electrochemical properties, and antioxidant activity of sterically hindered catechols with 1,3,4-oxadiazole, 1,2,4-triazole, thiazole or pyridine fragments

• Daria A. Burmistrova,
• Andrey Galustyan,
• Nadezhda P. Pomortseva,
• Kristina D. Pashaeva,
• Maxim V. Arsenyev,
• Oleg P. Demidov,
• Mikhail A. Kiskin,
• Andrey I. Poddel’sky,
• Nadezhda T. Berberova and
• Ivan V. Smolyaninov

Beilstein J. Org. Chem. 2024, 20, 2378–2391, doi:10.3762/bjoc.20.202

• changes. This is confirmed by the appearance of an absorption maximum in the UV–visible spectrum at λ = 490 nm, which is characteristic of thiolated o-benzoquinones. This absorption band corresponds to intramolecular charge transfer between the thioether group and the o-benzoquinone fragment [36][62][63

Cell-free protein synthesis with technical additives – expanding the parameter space of in vitro gene expression

• Tabea Bartsch,
• Stephan Lütz and
• Katrin Rosenthal

Beilstein J. Org. Chem. 2024, 20, 2242–2253, doi:10.3762/bjoc.20.192

• avoid evaporation of the solvent in the headspace of the reaction vessel due to the high vapor pressures. In contrast to the standard volumetric ratio of 20 µL in a 1.5 mL microreaction tube, a visible gradient in the concentration of sfGFP occurred under these conditions. Therefore, shaking at 700 rpm

Metal-free double azide addition to strained alkynes of an octadehydrodibenzo[12]annulene derivative with electron-withdrawing substituents

• Naoki Takeda,
• Shuichi Akasaka,
• Susumu Kawauchi and
• Tsuyoshi Michinobu

Beilstein J. Org. Chem. 2024, 20, 2234–2241, doi:10.3762/bjoc.20.191

• addition. Thus, compound 6a shows an ultraviolet absorption peak at 249 nm (λmax) and no absorption in the visible region was observed. When excited at 249 nm, an emission band at 513 nm (λem) appeared in the spectrum with a fluorescence quantum yield (Φ) of 7.0%. The absorption and fluorescence spectra

• previously reported electron-donating hexyloxy substituents. The addition pattern was experimentally investigated by 2D NMR, which was also supported by DFT calculations. The bistriazole product displayed fluorescence in the visible range with a fluorescence quantum yield of 7.0%. Finally, the developed

O,S,Se-containing Biginelli products based on cyclic β-ketosulfone and their postfunctionalization

• Kateryna V. Dil and
• Vitalii A. Palchykov

Beilstein J. Org. Chem. 2024, 20, 2143–2151, doi:10.3762/bjoc.20.184

• ][4][9] or even visible light-driven methods [25][26][27][28]. We started our study from the optimization of the reaction conditions using β-ketosulfone 1, benzaldehyde and thiourea as model reaction. According to the literature, the reaction has been shown to work best and most efficiently under

Efficacy of radical reactions of isocyanides with heteroatom radicals in organic synthesis

• Akiya Ogawa and
• Yuki Yamamoto

Beilstein J. Org. Chem. 2024, 20, 2114–2128, doi:10.3762/bjoc.20.182

• , when using sunlight, which is an inexhaustible natural energy, it is expected to be the most environmentally friendly method. The homolysis of E–E upon visible light irradiation is induced by exciting one electron of the isolated electron pair on E to the anti-bonding orbital of the E–E-bond (σ

• * orbital). Such an n–σ* transition usually indicates the maximum absorption in the near-UV region, and the absorption cutoff reaches the visible region, especially in the case of highly periodic E–E. Therefore, interelement compounds E–E with groups 15–17 heteroatoms have isolated electron pairs, and E

• %). Since it is known that the carbon radical capturing ability of (PhTe)2 is even four times higher than that of (PhSe)2 [31], we investigated the radical addition to isocyanides using a disulfide–ditelluride binary system under photoirradiation. The visible-light-irradiated thiotelluration reaction did

Cage-like microstructures via sequential Ugi reactions in aqueous emulsions

• Rita S. Alqubelat,
• Yaroslava A. Menzorova and
• Maxim A. Mironov

Beilstein J. Org. Chem. 2024, 20, 2078–2083, doi:10.3762/bjoc.20.179

• ) [17]. As before, depending on the CMC concentration, we obtained submicron particles with an average diameter from 200–600 nm, which were visible under an optical microscope in the form of luminous points. Next, Pickering emulsions were obtained by emulsifying toluene in an aqueous suspension of

Understanding X-ray-induced isomerisation in photoswitchable surfactant assemblies

• Beatrice E. Jones,
• Camille Blayo,
• Jake L. Greenfield,
• Matthew J. Fuchter,
• Nathan Cowieson and
• Rachel C. Evans

Beilstein J. Org. Chem. 2024, 20, 2005–2015, doi:10.3762/bjoc.20.176

• ]. In addition to this, AAPTAB has a high thermal half-life at room temperature (5.7 years [19]), meaning there is no significant contribution from thermal Z–E isomerisation over the course of these experiments. Using in-situ UV- and visible-light irradiation with SAXS, here we measure the intermediate

• change in the SAXS profile from the AzoTAB (Figure 1c), resulting in a steady decrease in the scattering intensity and a shift in the Guinier plateau to higher Q values. These changes are visible within 10 minutes of UV irradiation and stabilise with no further structural changes after around 20 minutes

• that Z–E isomerisation cannot be easily induced using gentle heating or visible light, as shown by the stability of the UV–vis absorbance spectra and SAXS patterns under these conditions (Figures S1 and S3, Supporting Information File 1). In contrast, irradiation with X-rays leads to significant

A new platform for the synthesis of diketopyrrolopyrrole derivatives via nucleophilic aromatic substitution reactions

• Vitor A. S. Almodovar and
• Augusto C. Tomé

Beilstein J. Org. Chem. 2024, 20, 1933–1939, doi:10.3762/bjoc.20.169

• aromatic substitution; phenol; thiol; Introduction Diketopyrrolopyrroles (DPPs) are a class of organic pigments discovered by serendipity in the 1970s [1][2]. Generally, N-unsubstituted DPP derivatives exhibit high melting points, low solubility in most solvents, and strong absorption in the visible

A facile three-component route to powerful 5-aryldeazaalloxazine photocatalysts

• Ivana Weisheitelová,
• Radek Cibulka,
• Marek Sikorski and
• Tetiana Pavlovska

Beilstein J. Org. Chem. 2024, 20, 1831–1838, doi:10.3762/bjoc.20.161

• /alloxazine photoredox catalysis [9][14][15][16][17][18][19], 7-methoxyderivatives should also be considered due to their absorption closer to the visible light region. This allows longer wavelength LEDs with lower energy photons to be applied, potentially contributing to avoiding undesired reactions [14][15

• potent, biologically active compounds. Interestingly, the introduction of a strong methoxy group at position 7 of the 5-aryldeazaalloxazine core led to a bathochromic shift in the absorption spectra of the synthesised molecules, making them more suitable for visible light photocatalysis. Experimental

Discovery of antimicrobial peptides clostrisin and cellulosin from Clostridium: insights into their structures, co-localized biosynthetic gene clusters, and antibiotic activity

• Moisés Alejandro Alejo Hernandez,
• Katia Pamela Villavicencio Sánchez,
• Rosendo Sánchez Morales,
• Karla Georgina Hernández-Magro Gil,
• David Silverio Moreno-Gutiérrez,
• Eddie Guillermo Sanchez-Rueda,
• Yanet Teresa-Cruz,
• Brian Choi,
• Armando Hernández Garcia,
• Alba Romero-Rodríguez,
• Oscar Juárez,
• Siseth Martínez-Caballero,
• Mario Figueroa and
• Corina-Diana Ceapă

Beilstein J. Org. Chem. 2024, 20, 1800–1816, doi:10.3762/bjoc.20.159

• , G, and H). The treatment with the mature peptides led to numerous blebs visible after 1 hour. Interestingly, no cocci structures were detected after 5 hours of treatment (see Figure 6). The precursor peptides, especially cellulosin, appear to elicit some effects on the membrane of S. epidermidis

Synthesis and characterization of 1,2,3,4-naphthalene and anthracene diimides

• Adam D. Bass,
• Daniela Castellanos,
• Xavier A. Calicdan and
• Dennis D. Cao

Beilstein J. Org. Chem. 2024, 20, 1767–1772, doi:10.3762/bjoc.20.155

• title compounds indicates that they are optically and electronically similar to previously reported naphthalene and anthracene diimides, absorbing/emitting light in the visible region and readily undergoing one-electron-reduction processes. As such, this work opens the possibility of incorporating the

New triazinephosphonate dopants for Nafion proton exchange membranes (PEM)

• Fátima C. Teixeira,
• António P. S. Teixeira and
• C. M. Rangel

Beilstein J. Org. Chem. 2024, 20, 1623–1634, doi:10.3762/bjoc.20.145

• phosphonate compounds also present their strongest bands in this region, but they are overlapped by the more intense Nafion bonds due to the small wt % loading of the dopants. As a result, despite the visible slight dark-brown color, observed by a visual inspection of the membranes, only discrete changes are

Supramolecular assemblies of amphiphilic donor–acceptor Stenhouse adducts as macroscopic soft scaffolds

• Ka-Lung Hung,
• Leong-Hung Cheung,
• Yikun Ren,
• Ming-Hin Chau,
• Yan-Yi Lam,
• Takashi Kajitani and
• Franco King-Chi Leung

Beilstein J. Org. Chem. 2024, 20, 1590–1603, doi:10.3762/bjoc.20.142

• moiety. The excellent photoswitchability in organic medium and the photoresponsiveness in aqueous medium, driven by visible light, were investigated by UV–vis absorption spectroscopy. The assembled supramolecular nanostructures were confirmed by electron microscopy, while the supramolecular packing was

• revealed by X-ray diffraction analysis. Upon visible-light irradiation, significant transformations of the DA geometry enabled transformations of the supramolecular assemblies on a microscopic scale, subsequently disassembling macroscopic soft scaffolds of DAs. The current work shows promising use for the

• fabrication of visible-light-controlled macroscopic scaffolds, offering the next generation of biomedical materials with visible-light-controlled microenvironments and future soft-robotic systems. Keywords: donor–acceptor Stenhouse adduct; photoresponsive molecular amphiphile; supramolecular transformation

Benzylic C(sp³)–H fluorination

• Alexander P. Atkins,
• Alice C. Dean and
• Alastair J. J. Lennox

Beilstein J. Org. Chem. 2024, 20, 1527–1547, doi:10.3762/bjoc.20.137

• pioneering report in 2013 that used photocatalyst 9-fluorenone under visible-light irradiation to generate a photoexcited aryl ketone, capable of HAT to promote benzylic fluorination with Selectfluor (Figure 23) [69]. The reaction tolerated an exceptional range of functional groups and enabled the

• disclosed the use of catalytic amounts of the organic dye Acr+-Mes under visible-light irradiation in combination with stoichiometric amounts of Selectfluor to achieve benzylic fluorination (Figure 29) [74]. It was proposed that a SET between Selectfluor and the photoexcited catalyst liberated fluoride and

Photoswitchable glycoligands targeting Pseudomonas aeruginosa LecA

• Yu Fan,
• Ahmed El Rhaz,
• Stéphane Maisonneuve,
• Emilie Gillon,
• Maha Fatthalla,
• Franck Le Bideau,
• Guillaume Laurent,
• Samir Messaoudi,
• Anne Imberty and
• Juan Xie

Beilstein J. Org. Chem. 2024, 20, 1486–1496, doi:10.3762/bjoc.20.132

• undergo reversible photoisomerization under UV–vis irradiation in aqueous solution. The O-galactosyl azobenzene 1 shows reversible photoisomerization under UV (370 nm) and visible (485 nm) irradiations in water, with a high fatigue resistance as no degradation has been observed after more than 10 UV–vis