Synthesis of tricarbonylated propargylamine and conversion to 2,5-disubstituted oxazole-4-carboxylates

• Kento Iwai,
• Akari Hikasa,
• Kotaro Yoshioka,
• Shinki Tani,
• Kazuto Umezu and
• Nagatoshi Nishiwaki

Beilstein J. Org. Chem. 2024, 20, 2827–2833, doi:10.3762/bjoc.20.238

• ), the mixture was concentrated under reduced pressure. The residue was purified by column chromatography on silica gel (eluent: hexane/ethyl acetate 70:30, Rf 0.55) to afford diethyl 2-[(4-methylbenzoyl)amino]-2-(phenylethynyl)propanedioate (4a, 122 mg, 0.31 mmol, 78% yield) as yellow oil. 1H NMR (400

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

• equation; LoD = yB + 3sB. yB is the signal associated with the blank and sB corresponds to the standard deviation of the blank [22][23]. LoD: [Tb.1·3Cu]3+ 0.63 μM, λem = 544 nm. Previously reported lanthanide complexes [12][16][17]. Absorption (red line), excitation (yellow line, λem = 615 nm), and

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

• °C at 451 nm (blue LEDs) under magnetic stirring for 24 h. The reaction mixture was treated with Et3N (3 equiv, 1.44 mmol, 200 µL), concentrated and the residue was purified by column chromatography on silica gel with PE/Et2O (from 85:15 to 75:25) to give 3a (121 mg, 61%), as yellow oil; IR (ATR) ν̃

Synthesis of fluoroalkenes and fluoroenynes via cross-coupling reactions using novel multihalogenated vinyl ethers

• Yukiko Karuo,
• Keita Hirata,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2024, 20, 2691–2703, doi:10.3762/bjoc.20.226

• purified by column chromatography and preparative TLC (hexane only), and obtained in 96% yield (122.0 mg) as a pale yellow oil; 1H NMR (400 MHz, CDCl3) δ 7.04–7.22 (m, 2H), 7.26–7.50 (m, 6H), 7.55–7.69 (m, 2H); 13C NMR (100 MHz, CDCl3) δ 101.4 (d, J = 30.9 Hz), 102.5 (d, J = 48.0 Hz), 116.5 (d, J = 3.8 Hz

• chromatography and preparative TLC to afford 3. (3-Chloro-4-fluoro-4-phenoxybut-3-en-1-yn-1-yl)trimethylsilane (3a): Reaction time was 19 h. 3a was purified by column chromatography (pentane only), and obtained in 80% yield (107.2 mg) as a yellow oil; 1H NMR (400 MHz, CDCl3) δ 0.13 (s) and 0.24 (s) (9H), 7.08 (d

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

• and effective luminescence color-tuning method is proposed to investigate the photoluminescence behavior of two-component polymer dispersion films blended with two types of fluorinated diphenylacetylenes, namely blue- and yellow- or red-fluorescent fluorinated diphenylacetylenes. It is confirmed that

• 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

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

• column chromatography [28]. Yellow oil: 1.95 g (45% over 2 steps); 1H NMR (CDCl3, 300 MHz) δ 9.64 (s, 1H), 3.68 (s, 3H), 2.40 (m, 3H), 2.07 (m, 1H), 1.70 (m, 1H), 1.13 (d, J = 7 Hz, 3H); 13C NMR (CDCl3, 75 MHz) δ 200.9, 173.4, 51.6, 45.5, 31.2, 25.3, 13.2; EIMS (70 eV) m/z (%): 116 (10), 113 (15), 112

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

Efficient modification of peroxydisulfate oxidation reactions of nitrogen-containing heterocycles 6-methyluracil and pyridine

• Alfiya R. Gimadieva,
• Yuliya Z. Khazimullina,
• Aigiza A. Gilimkhanova and
• Akhat G. Mustafin

Beilstein J. Org. Chem. 2024, 20, 2599–2607, doi:10.3762/bjoc.20.219

• brown color. After recrystallization from ethanol, 1.11 g (90%) of pyridine 9 were obtained as a light yellow powder. Mp 108–110 °С; 1H NMR (CDCl3) δ 6.16 (dd, 1H, С5H), 6.38 (d, 1H, С3H), 7.38 (d, 1H, С6H), 7.40 (dd, 1H, С4H), 11.5 (s, 1H, C1-OH); 13С NMR (CDCl3) δ 104.8 (С4), 119.7 (С3), 135.2 (С6

Synthesis and cytotoxicity studies of novel N-arylbenzo[h]quinazolin-2-amines

• Battini Veeraiah,
• Kishore Ramineni,
• Dabbugoddu Brahmaiah,
• Nangunoori Sampath Kumar,
• Hélène Solhi,
• Rémy Le Guevel,
• Chada Raji Reddy,
• Frédéric Justaud and
• René Grée

Beilstein J. Org. Chem. 2024, 20, 2592–2598, doi:10.3762/bjoc.20.218

• reduced pressure to afford crude compound 2 as pale-yellow solid (65% yield). Its NMR data are in agreement with literature [5]. 1H NMR (400 MHz, DMSO-d6, δ ppm) 10.49 (s, 1H), 8.26 (d, J = 8.4 Hz, 1H), 8.10 (d, J = 8.0 Hz, 1H), 7.90 (d, J = 8.8 Hz, 1H), 7.84–7.74 (m, 3H). Step 2: Synthesis of benzo[h

Base-promoted cascade recyclization of allomaltol derivatives containing an amide fragment into substituted 3-(1-hydroxyethylidene)tetronic acids

• Andrey N. Komogortsev,
• Constantine V. Milyutin and
• Boris V. Lichitsky

Beilstein J. Org. Chem. 2024, 20, 2585–2591, doi:10.3762/bjoc.20.217

• -ylidene)furan-2,4(3H,5H)-dione (4a). Pale yellow powder; yield 62% (0.25 g); mp 121–123 °C; 1H NMR (300 MHz, DMSO-d6) δ 7.31–7.13 (m, 5H), 4.34 (t, J = 7.5 Hz, 2H), 2.74 (t, J = 7.6 Hz, 2H), 2.56–2.48 (m, 2H in DMSO), 2.46 (s, 3H), 2.14 (t, J = 11.8 Hz, 2H), 1.64–1.54 (m, 3H), 1.41–1.09 (m, 5H); 13C NMR

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

Phenylseleno trifluoromethoxylation of alkenes

• Clément Delobel,
• Armen Panossian,
• Gilles Hanquet,
• Frédéric R. Leroux,
• Fabien Toulgoat and
• Thierry Billard

Beilstein J. Org. Chem. 2024, 20, 2434–2441, doi:10.3762/bjoc.20.207

• addition of DNTFB and quickly turns yellow). Then, the tube is opened and PhSeBr (118 mg, 0.5 mmol, 1 equiv) is added in one portion. The resulting reaction mixture is stirred in the same ice bath for 15 minutes. Then, the tube is opened and the alkene (1, 0.5 mmol, 1 equiv) is added. The reaction is

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

• ) highlighting molecules identified in the first 45 iterations for (A) AD-CP, (B) Chemprop (CP), and (C) random selection (Random). Top ten percentile most potent compounds are shown as stars and identified compounds are highlighted in yellow. The number of times a model ‘jumps’ from one cluster to another is

• receptor) highlighting molecules identified in the first 45 iterations for (A) AD-XGB, (B) XGBoost (XGB), and (C) Random Forest (RF). Top ten percentile most potent compounds are shown as stars and identified compounds are highlighted in yellow. The number of times a model ‘jumps’ from one cluster to

Allostreptopyrroles A–E, β-alkylpyrrole derivatives from an actinomycete Allostreptomyces sp. RD068384

• Marwa Elsbaey,
• Naoya Oku,
• Mohamed S. A. Abdel-Mottaleb and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2024, 20, 1981–1987, doi:10.3762/bjoc.20.174

• chromatography followed by ODS HPLC to yield compounds 1–5. Allostreptopyrrole A (1) was obtained as a greenish yellow amorphous solid. The molecular formula was determined to be C15H23NO4 based on a molecular ion peak at m/z 280.1550 [M − H]− (calcd for 280.1554) observed in a negative HRESITOF mass spectrum

• provided a methoxycarbonyl (–COOMe) fragment. Finally, this fragment was placed at C2 by an HMBC correlation from H5 to C6 to complete the gross structure of 1. Both compounds 2 and 3 were obtained as greenish yellow amorphous and their molecular formula were suggested to be the same as that of 1 from

• total 6.5 mg of 1, 3.1 mg of 2, 2.6 mg of 3, 7.2 mg of 4, and 5.6 mg of 5 from 12 L culture. Allostreptopyrrole A (1): greenish yellow amorphous solid; UV (MeOH) λmax nm (log ε) 234 (3.86), 273 sh (3.44); IR (ATR) νmax: 3275, 2964, 2928, 2855, 1658, 1554, 1418 cm−1; 1H and 13C NMR data, see Table 1

The Groebke–Blackburn–Bienaymé reaction in its maturity: innovation and improvements since its 21st birthday (2019–2023)

• Cristina Martini,
• Muhammad Idham Darussalam Mardjan and
• Andrea Basso

Beilstein J. Org. Chem. 2024, 20, 1839–1879, doi:10.3762/bjoc.20.162

Chemo-enzymatic total synthesis: current approaches toward the integration of chemical and enzymatic transformations

• Ryo Tanifuji and
• Hiroki Oguri

Beilstein J. Org. Chem. 2024, 20, 1693–1712, doi:10.3762/bjoc.20.151

• diversity-oriented synthesis. Targeted natural products and key enzymatic transformations in the chemo-enzymatic total syntheses featured in this review. Enzymatically formed bonds or units are highlighted in yellow. Biosynthetic pathway to brassicicenes in Pseudocercospora fijiensis [14]. (A) Cyclization

Methyltransferases from RiPP pathways: shaping the landscape of natural product chemistry

• Maria-Paula Schröder,
• Isabel P.-M. Pfeiffer and
• Silja Mordhorst

Beilstein J. Org. Chem. 2024, 20, 1652–1670, doi:10.3762/bjoc.20.147

• /aspartimide to isoaspartate. The methyl group is highlighted in blue. The reverse reaction with isoaspartate as substrate of PAMTs is also known. Structural organisation of the OphMA homodimer. A) Schematic representation. The MT domain is coloured in blue; the leader peptide is coloured in yellow, and the

Generation of multimillion chemical space based on the parallel Groebke–Blackburn–Bienaymé reaction

• Evgen V. Govor,
• Vasyl Naumchyk,
• Ihor Nestorak,
• Dmytro S. Radchenko,
• Dmytro Dudenko,
• Yurii S. Moroz,
• Olexiy D. Kachkovsky and
• Oleksandr O. Grygorenko

Beilstein J. Org. Chem. 2024, 20, 1604–1613, doi:10.3762/bjoc.20.143

• molecules to be similar. In this way, data visualization becomes possible since similar molecules will likely have close values of t-SNE1 and t-SNE2. As apparent from Figure 7, there is a small overlap between the GBB chemical space (yellow datapoints) with all four databases of comparison (blue data points

• yellow. Distribution of maximal values among pairwise-calculated Tanimoto similarities T (MFP2 fingerprints [46]) of extended Bemis–Murcko scaffolds for the generated chemical space members (5.60 Mln. scaffolds) to the extended Bemis–Murcko scaffolds of A) ChEMBL compounds (v. 33); B) PubChem compounds

Mining raw plant transcriptomic data for new cyclopeptide alkaloids

• Draco Kriger,
• Michael A. Pasquale,
• Brigitte G. Ampolini and
• Jonathan R. Chekan

Beilstein J. Org. Chem. 2024, 20, 1548–1559, doi:10.3762/bjoc.20.138

• lack an oxidative decarboxylation of the C-terminus (Figure 3, arabipeptin A). Our transcriptome mining results further support the prevalence of cyclopeptide alkaloids in the Rubiaceae family. Chiococca alba (Snowberry), Cinchona calisaya (Yellow Cinchona), Gardenia jasminoides (Cape Jasmine), C

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

• represents a ΔG value of −30 kJ/mol, corresponding to a Kd of approx 5 μM in the experimental conditions. (B) Manual docking of scaffold for compound 3 with selected low energy conformations of the E-isomer (yellow sticks) and Z-isomer (cyan sticks) superimposed on conserved position of galactose in all LecA

Bioinformatic prediction of the stereoselectivity of modular polyketide synthase: an update of the sequence motifs in ketoreductase domain

• Changjun Xiang,
• Shunyu Yao,
• Ruoyu Wang and
• Lihan Zhang

Beilstein J. Org. Chem. 2024, 20, 1476–1485, doi:10.3762/bjoc.20.131

• rings. The triangles indicate a product having α-substituents. (c) Crystal structure of DH-ER-KR tridomain (PDB ID 8G7W) [24]. DH, KRS, ER, KRC are colored in cyan, pink, yellow, and purple, respectively. The lid of KR catalytic pocket is colored in red. The co-crystallized cofactor is represented as

Rapid construction of tricyclic tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine via isocyanide-based multicomponent reaction

• Xiu-Yu Chen,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2024, 20, 1436–1443, doi:10.3762/bjoc.20.126

• -(2-methoxyphenyl)-2-methyl-4,4a,8,8a-tetrahydrocyclopenta[4,5]pyrrolo[2,3-b]pyridine-3,4b,5,6,7(1H)-pentacarboxylate (4a): yellow solid, 89%, mp 209–211 °C; 1H NMR (400 MHz, CDCl3) δ 7.49 (d, J = 8.0 Hz, 1H, ArH), 7.47–7.44 (m, 3H, ArH), 7.41–7.38 (m, 1H, ArH), 7.02–6.97 (m, 1H, ArH), 6.68–6.62 (m

A comparison of structure, bonding and non-covalent interactions of aryl halide and diarylhalonium halogen-bond donors

• Nicole Javaly,
• Theresa M. McCormick and
• David R. Stuart

Beilstein J. Org. Chem. 2024, 20, 1428–1435, doi:10.3762/bjoc.20.125

• that we studied here revealed an opposite trend (Scheme 4b, orange, yellow, blue, and green dots). The halogen-bond length decreased with increasing van der Waals radii of X and the trend was more pronounced for monovalent halogen-bond donors. This is exemplified by halogen-bond complexes of the

• halogen-bond donors are clustered into hypervalent 1–8 (Scheme 6b, green dots), monovalent aryl 26–28 and 30–32 (Scheme 6b, orange dots), perfluorophenyl 33–36 (Scheme 6b, yellow dots), and imidazolium 37–40 (Scheme 6b, blue dots) linear correlations with similar slopes are observed for p-orbital

• for compounds 1–24; data from prior work is represented by grey dots [21]. Correlation of ΔG for XB bond formation and X---Cl distance for compounds 9–24 (green dots), 41–48 (orange dots), 49–52 (yellow dots), and 53–56 (blue dots). Correlation of X---Cl distance with van der Waals radii of X

Diameter-selective extraction of single-walled carbon nanotubes by interlocking with Cu-tethered square nanobrackets

• Guoqing Cheng and
• Naoki Komatsu

Beilstein J. Org. Chem. 2024, 20, 1298–1307, doi:10.3762/bjoc.20.113

• -nanobrackets 1b. DFT-optimized structure of Cu-nanobrackets (a) 1a and (b) 1b. The yellow regions indicate their spherical cavities. (c) Experimental and calculated results of Raman spectra of 1b (λex = 488 nm). For calculation, Raman activity was transferred to Raman intensity (298.15 K, the full width at

Mechanistic investigations of polyaza[7]helicene in photoredox and energy transfer catalysis

• Johannes Rocker,
• Till J. B. Zähringer,
• Matthias Schmitz,
• Till Opatz and
• Christoph Kerzig

Beilstein J. Org. Chem. 2024, 20, 1236–1245, doi:10.3762/bjoc.20.106

• chloride. We believe that our findings pave the way for a broader usage of the inherently chiral polyazahelicene photocatalyst class, both in photoredox and energy transfer catalysis. A) Room-temperature absorption (black) and emission (yellow) spectra of Aza-H recorded in MeCN/H2O (9:1), and fluorescence

• from Ref [77], transient absorption spectrum of Aza-H with 0.3 mM MV2+ and the difference spectrum of both spectra (cyan). E) Emission lifetime of Aza-H in the presence (dark yellow) and absence (black) of 0.3 mM MV2+. Stilbene isomerization and additional energy transfer experiments. A) and B) Triplet