Advances in the use of metal-free tetrapyrrolic macrocycles as catalysts

• Mandeep K. Chahal

Beilstein J. Org. Chem. 2024, 20, 3085–3112, doi:10.3762/bjoc.20.257

• Metal-free tetrapyrrolic macrocycles as supramolecular organocatalysts Supramolecular organocatalysis has recently attracted emerging attention as a green alternative to metal-based catalysis [24][25][26]. Organocatalysis using macrocyclic scaffolds such as crown ethers, cyclodextrins, cucurbiturils

• macrocycles, both synthetic and found in nature, and their ability to act as organocatalysts, metal-free porphyrin macrocycles have a potential to be excellent candidates for green, cost-effective catalysts of various organic transformations including asymmetric synthesis. 2 Metal-free tetrapyrrolic

Extension of the π-system of monoaryl-substituted norbornadienes with acetylene bridges: influence on the photochemical conversion and storage of light energy

• Robin Schulte,
• Dustin Schade,
• Thomas Paululat,
• Till J. B. Zähringer,
• Christoph Kerzig and
• Heiko Ihmels

Beilstein J. Org. Chem. 2024, 20, 3061–3068, doi:10.3762/bjoc.20.254

• up to 8 h at room temperature. Furthermore, the norbornadienes were transformed quantitatively into their quadricyclane photoproducts by irradiation with green light (520 nm) in the presence of a photosensitizer. Keywords: light energy conversion; photochemistry; photochromism; quadricyclanes

• converted quantitatively into quadricyclanes by irradiation with green light. Thus, it was shown with the latter results that the photosensitization with suitable triplet sensitizers enables mild conversion of visible light in chemical energy in quantitative photoreactions of norbornadienes, even in cases

Chemical structure metagenomics of microbial natural products: surveying nonribosomal peptides and beyond

• Thomas Ma and
• John Chu

Beilstein J. Org. Chem. 2024, 20, 3050–3060, doi:10.3762/bjoc.20.253

• based on a dataset of known pairs of nonribosomal code/substrate BB. c) An analysis that compared the known vs predicted NRP BBs grouped based on their chemical structures found both oversampled (green)/underexplored (blue) niches in the NRP chemical space; the analysis was performed across all bacteria

Cyclodextrin-based rotaxanes for polymer materials: challenge on simultaneous realization of inexpensive production and defined structures

• Yosuke Akae

Beilstein J. Org. Chem. 2024, 20, 3026–3049, doi:10.3762/bjoc.20.252

• fluorescence (Figure 15C,D). Namely, the fluorescence of the initial RCP in DMF was observed as a blue emission by the naked eye, while according to the degradation, the dumbbell species spread throughout the solution and the [3]rotaxane structure disappeared, resulting in the light green color fluorescence of

Tunable full-color dual-state (solution and solid) emission of push–pull molecules containing the 1-pyrindane moiety

• Anastasia I. Ershova,
• Sergey V. Fedoseev,
• Konstantin V. Lipin,
• Mikhail Yu. Ievlev,
• Oleg E. Nasakin and
• Oleg V. Ershov

Beilstein J. Org. Chem. 2024, 20, 3016–3025, doi:10.3762/bjoc.20.251

• Table S1 and Figure S1, Supporting Information File 1). The electronic absorption spectra were characterized by a pronounced maximum in the visible region centered at 431–448 nm. Emission maxima of compound 1c were more significantly affected by the change of polarity and ranged from 475 nm (blue-green

• 1 in toluene were characterized by a high fluorescence quantum yield, reaching 87.5% for the para-methoxy-substituted derivative 1c. Emission maxima in DMSO were found to be in the range of 506–721 nm (Figure 6, right), associated with a fluorescence color from green to red (Figure 7, bottom). The

• contrast to related compounds A (Figure 1), were characterized by solid-state emission (Table 4 and Figure 8). This was apparently caused by the presence of the dimethylene bridge, preventing intermolecular interactions. Emission maxima of compounds 1 ranged from 540–767 nm, namely from the green to the

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

Investigation of a bimetallic terbium(III)/copper(II) chemosensor for the detection of aqueous hydrogen sulfide

• Parvathy Mini,
• Michael R. Grace,
• Genevieve H. Dennison and
• Kellie L. Tuck

Beilstein J. Org. Chem. 2024, 20, 2818–2826, doi:10.3762/bjoc.20.237

• emission (green line, λex = 250 nm) spectra of 5 µM Tb.1 in 10 mM Tris-HCl buffer, pH 7.4, containing 5% DMSO. (a) Changes in the luminescence emission spectrum of 5 µM [Tb.1·3Cu]3+ upon the addition of Na2S (0–15 µM); spectra measured in 10 mM HEPES buffer (pH 7.4) with λex = 250 nm. (b) Change in

• the presence of various anions/sulfur compounds; spectra measured in 10 mM Tris HCl buffer (pH 7.4) with λex = 250 nm. Green bar: [Tb.1·3Cu]3+ alone (5 µM). Blue bar: [Tb.1·3Cu]3+ (5 µM) and Na2S (15 µM). Grey bars: [Tb.1·3Cu]3+ (5 µM) and anion/sulfur compound (50 µM). Black bars: [Tb.1·3Cu]3+ (5 µM

Synthesis and antimycotic activity of new derivatives of imidazo[1,2-a]pyrimidines

• Dmitriy Yu. Vandyshev,
• Daria A. Mangusheva,
• Khidmet S. Shikhaliev,
• Kirill A. Scherbakov,
• Oleg N. Burov,
• Alexander D. Zagrebaev,
• Tatiana N. Khmelevskaya,
• Alexey S. Trenin and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2024, 20, 2806–2817, doi:10.3762/bjoc.20.236

• ) Superposition of docked compounds 4a–e and 5e in a CYP51 ACb. aThe amino acid residues of the protein are colored green, compound 4e is colored gold and the haem is colored grey. The heterocyclic nitrogen of compound 5e appears to be orientated towards iron and is located 2.8 Å away from it, which may indicate

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

• (–) and DMSO under irradiation for 30 min by blue LED lamp. In the ESR spectra, signals corresponding to the adducts are indicated with red (4-oxo-TEMPO in a), blue (DMPO-OH in b), and green (DEPMPO-CH3 in c) arrows. Acknowledgements The authors thank Dr. Ebert from ETH Zurich for his support on ESR

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

• if blue and green–yellow or yellow fluorophores are blended in appropriate ratios, a binary blend with color coordinates (0.20, 0.32) can be achieved, which approaches the white point of pure white emission. These findings contribute to the development of effective lighting and display devices as new

• has been severely delayed [4][5][6]. However, since Tang et al. first reported the aggregation-induced emission phenomenon in 2001 [7], the development of solid-state light-emitting materials has accelerated significantly [8][9][10]. Many photoluminescent materials that emit blue, green, and yellow

• yellow-fluorescent molecules from the viewpoint of their ΦPL. Therefore, we investigated the PL behavior of PMMA dispersion films containing blue-fluorescent 1a, green–yellow fluorescent 1c, and yellow-fluorescent 1f. Photoluminescence behavior of PMMA dispersion films containing a mixture of blue

Computational design for enantioselective CO₂ capture: asymmetric frustrated Lewis pairs in epoxide transformations

• Maxime Ferrer,
• Iñigo Iribarren,
• Tim Renningholtz,
• Ibon Alkorta and
• Cristina Trujillo

Beilstein J. Org. Chem. 2024, 20, 2668–2681, doi:10.3762/bjoc.20.224

• than the catalysts at the top show lower catalytic activity due to insufficient activation of the substrate (Figure 1A, green points). Conversely, catalysts that bind too strongly impede the detachment of the catalyst–reactant complex, thereby reducing the catalyst turnover (Figure 1A, pink points) [26

• remarkable 96%ee yielded by the catalyst. Schematic representation of an (A) 2D and a (B) 3D volcano plot. The abbreviation “cat.” stands for catalyst. (A) Structure of PO annotated with the C–O bond distances and electron densities at the BCPs. BCPs are indicated by green spheres and the ring critical point

Applications of microscopy and small angle scattering techniques for the characterisation of supramolecular gels

• Connor R. M. MacDonald and
• Emily R. Draper

Beilstein J. Org. Chem. 2024, 20, 2608–2634, doi:10.3762/bjoc.20.220

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

• ) packing structures and (ii) enlarged views for the columnar structures. In (i), cation and anion are represented in cyan and magenta colors, respectively. In (ii), brown, pink, yellow, blue, yellow green, orange, and green (spherical) refer to carbon, hydrogen, boron, nitrogen, fluorine, phosphorus, and

• +-Cl−, (b) 2+-BF4−, and (c) 2+-PF6−. Atom color code: yellow, green, orange, and green (spherical) refer to boron, fluorine, phosphorus, and chlorine, respectively. (i) Single-crystal X-ray structures and (ii) interaction energies for the pairs (a) 2+-Cl−, (b) 2+-BF4−, and (c) 2+-PF6−. In (i), the

• cation and the anion are represented in cyan and magenta colors, respectively. Hirshfeld surface analysis mapped with dnorm of closely contacted ion pairs: (a) 2+-B(C6F5)4− and (b) 2+-PCCp−. Atom color code: brown, yellow, blue, and green refer to carbon, boron, nitrogen, and fluorine, respectively. (i

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

• ], spirulina [16], Ti(OiPr)4/t-BuOOH [17], VO(acac)2)/t-BuOOH [18], and enzymatic oxidation [19] etc., which may compromise the environmental benefits (Scheme 1a,b) and take longer reaction times. Alternatively, a new green pathway is necessary for the Achmatowicz reaction to be performed in a faster and safer

• manner. Towards this direction, few research groups have already reported the Achmatowicz reaction utilizing greener approaches, yet they suffered due to some limitations. Sun et al. [20] have successfully demonstrated an Achmatowicz rearrangement using electricity as a green oxidant (Scheme 1c) in a

Synthesis and conformational analysis of pyran inter-halide analogues of ᴅ-talose

• Olivier Lessard,
• Mathilde Grosset-Magagne,
• Paul A. Johnson and
• Denis Giguère

Beilstein J. Org. Chem. 2024, 20, 2442–2454, doi:10.3762/bjoc.20.208

• , 17, and α-ᴅ-talose 18. ORTEP diagram showing 50% thermal ellipsoid probability (except for 18): carbon (gray), oxygen (red), fluorine (green), chlorine (orange), bromine (dark red), iodine (purple), and hydrogen (white). Packing arrangement of compound compound 15; a) View down the b axis; b

• ) proposed intermolecular interactions involving halogens. ORTEP diagram showing 50% thermal ellipsoid probability: carbon (gray), oxygen (red), fluorine (green), iodine (purple), and hydrogen (white). Synthesis of halogenated talopyranose analogues 13–15, and 17 that include a 2,3-cis, 3,4-cis relationship

Homogeneous continuous flow nitration of O-methylisouronium sulfate and its optimization by kinetic modeling

• Jiapeng Guo,
• Weike Su and
• An Su

Beilstein J. Org. Chem. 2024, 20, 2408–2420, doi:10.3762/bjoc.20.205

• Jiapeng Guo Weike Su An Su Key Laboratory of Pharmaceutical Engineering of Zhejiang Province, Key Laboratory for Green Pharmaceutical Technologies and Related Equipment of Ministry of Education, Collaborative Innovation Center of Yangtze River Delta Region Green Pharmaceuticals, Zhejiang

• University of Technology, Hangzhou, 310014, P. R. China State Key Laboratory Breeding Base of Green Chemistry-Synthesis Technology, Key Laboratory of Green Chemistry-Synthesis Technology of Zhejiang Province, College of Chemical Engineering, Zhejiang University of Technology, Hangzhou, Zhejiang 310014, China

Efficient one-step synthesis of diarylacetic acids by electrochemical direct carboxylation of diarylmethanol compounds in DMSO

• Hisanori Senboku and
• Mizuki Hayama

Beilstein J. Org. Chem. 2024, 20, 2392–2400, doi:10.3762/bjoc.20.203

• a novel, efficient, facile, and green organic method. Experimental General information 1H (400 MHz) and 13C (100 MHz) NMR spectra were recorded in CDCl3 or DMSO-d6 with a JEOL JNM-ECS400 FT NMR spectrometer. The chemical shifts δ are given in ppm with tetramethylsilane (δ 0 ppm) or DMSO (δ 2.50 ppm

Hydrogen-bond activation enables aziridination of unactivated olefins with simple iminoiodinanes

• Phong Thai,
• Lauv Patel,
• Diyasha Manna and
• David C. Powers

Beilstein J. Org. Chem. 2024, 20, 2305–2312, doi:10.3762/bjoc.20.197

• (denoted by asterisk *) of HFIP in the presence of iminoiodinane 2c suggesting hydrogen bonding observed in 1H NMR spectra (CD3CN) of: 8.0 mM 2c with no HFIP (blue line), 8.0 mM 2c with 32 mM HFIP (green line), 4.0 mM of 4-(trifluoromethyl)benzenesulfonamide with 32 mM HFIP (purple line), only 32 mM HFIP

Selective hydrolysis of α-oxo ketene N,S-acetals in water: switchable aqueous synthesis of β-keto thioesters and β-keto amides

• Haifeng Yu,
• Wanting Zhang,
• Xuejing Cui,
• Zida Liu,
• Xifu Zhang and
• Xiaobo Zhao

Beilstein J. Org. Chem. 2024, 20, 2225–2233, doi:10.3762/bjoc.20.190

• hydrolysis reactions were carried out in the presence of 3.0 equiv of NaOH. The green approach to β-keto thioesters and β-keto amides avoids the use of harmful organic solvents, thiols and thiolacetates as well as amines, which could result in serious environmental and safety issues. Keywords: α-oxo ketene

• synthetic method for the preparation of β-keto thioesters and β-keto amides remains imperative. Organic reactions in water are an important and exciting research topic of green chemistry because water as a solvent exhibits fascinating features, such as low cost, good environmental compatibility, nontoxicity

• , such as nontoxicity, inexpensiveness, nonflammability, low volatility and good water solubility, which are consistent with the concept of green chemistry [74][75]. Therefore, we tested the reaction in the presence of PEG-400 (Table 1, entries 7–9). It was found that the reaction uniquely produced 3a in

Finding the most potent compounds using active learning on molecular pairs

• Zachary Fralish and
• Daniel Reker

Beilstein J. Org. Chem. 2024, 20, 2152–2162, doi:10.3762/bjoc.20.185

• shown in the inlet with a green bar while the times it ‘stays’ in the same cluster is shown with a light blue bar. Arrow gradient towards darker grey indicates increasing iteration number. Tree-based model navigation of chemical space. T-SNE of a representative dataset (CHEMBL232-1, Alpha-1b adrenergic

• another is shown in the inlet with a green bar while the times it ‘stays’ in the same cluster is shown with a light blue bar. Arrow gradient towards darker grey indicates increasing iteration number. Supporting Information Supporting Information File 54: Supplementary figures and tables

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

• gossypii, Tripomastigote Chagas, Tcruzi amastigota, Tcruzi epimastigota, Leishmania amazonensis, and Dengue larvicida. Keywords: dihydropyrimidinone/thione/selenone; green chemistry; in silico biological profile; multicomponent reaction (MCR); thiopyrandioxide; Introduction Multicomponent reactions (MCRs

• of other sulfones of both synthetic and biological importance can be obtained by using the in this work reported efficient, multicomponent and green protocol. We postfunctionalized the typical Biginelli product using Hantzsch-type thiazole chemistry and desulfurization. Assessing drug-likeness, we

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

• understand the conditions for the generation of heteroatom radicals. In addition, from the perspective of recent green chemistry, the development of environmentally friendly synthetic methods is strongly demanded. In other words, a new synthetic method should have excellent atom economy, produce no waste, be

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

• , Oxfordshire, OX11 0DE, United Kingdom School of Chemistry, Trinity College Dublin, University of Dublin, College Green, Dublin 2, Ireland Department of Chemistry, Molecular Sciences Research Hub, White City Campus, Imperial College London, 82 Wood Lane, London, W12 7SL, United Kingdom Institut für Organische

• (365 nm, irradiance = 6.00 mW⋅cm−2), blue (455 nm, 5.16 mW⋅cm−2) or green (525 nm, 0.06 mW⋅cm−2) light. For the SAXS studies at high concentration, samples were irradiated in a custom-build LED light box with UV (365 nm) light at an irradiance of 1.24 mW⋅cm−2 for 3.5 h. This resulted in 98 ± 2 and 71

Harnessing the versatility of hydrazones through electrosynthetic oxidative transformations

• Aurélie Claraz

Beilstein J. Org. Chem. 2024, 20, 1988–2004, doi:10.3762/bjoc.20.175

• -diphenylethylene proceeded with similar efficiency, thereby excluding any radical pathway. As such, it was proposed that the catalytic electrooxidation of iodide (ENH4I = 0.41 V and 0.75 V vs Ag/AgCl in dimethylacetamide for I−/I3− and I3−/I2 redox couples) into iodine provided a green and mild tool to in situ

Development of a flow photochemical process for a π-Lewis acidic metal-catalyzed cyclization/radical addition sequence: in situ-generated 2-benzopyrylium as photoredox catalyst and reactive intermediate

• Masahiro Terada,
• Zen Iwasaki,
• Ryohei Yazaki,
• Shigenobu Umemiya and
• Jun Kikuchi

Beilstein J. Org. Chem. 2024, 20, 1973–1980, doi:10.3762/bjoc.20.173

• Transformative Research Areas (A) “Green Catalysis Science for Renovating Transformation of Carbon-Based Resources” (JP23H04908) from MEXT, Japan and a Grant-in-Aid for Young Scientists (JP19K15552) from JSPS.