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

• distilled before use. All other chemicals were used without purification unless otherwise stated. Air- and H2O-sensitive reactions were performed under N2. ASAP-APCI-MS was performed on an Expression MS (Advion) mass spectrometer equipped with an APCI ionization source operated in positive mode. The

• freshly distilled propanal (1, 2.1 mL, 30 mmol) were added to a 50 mL flask. The mixture was stirred at 0 °C for 1 h. The residue was filtered and washed twice with diethyl ether, and the solvent was removed in vacuo. The crude product was used without further purification. EIMS (70 eV) m/z (%): 125 (40

• room temperature. The solvent was removed and the residue was washed twice with pentane and dried under vacuum. The product was used without further purification. Analytical data were identical to those reported earlier. 1-Methylheptyltriphenylphosphonium iodide (5): In a manner similar to [31

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

• , whereas in β-CD it is a one-step process. Experimental Materials γ-CD was used as received (without further purification or modification) from Wacker Chemie AG (CAVAMAX FOOD) with a purity of ≥98%. Experimental measurements The thermal behavior of γ-CD was investigated with a Perkin Elmer DSC7

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

• purification. The synthetic utility of the prepared tetronic acids was demonstrated by further transformations at the hydroxyethylidene fragment. The structures of one obtained tetronic acid and one product of derivatization were confirmed by X-ray analysis. Keywords: allomaltol; base-promoted recyclization

• purification procedure are the advantages of the considered method. The synthetic utility of obtained tetronic acids was demonstrated by preparation of enamine and enehydrazine derivatives. The structures of one target tetronic acid and synthesized enehydrazine were established by X-ray analysis. Experimental

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• without further purification. All solvents were used without distillation. Triarylbismuthines 1 were synthesized according to the previously reported procedures [62]. 1H, 13C{1H}, and 11B NMR spectra were recorded in CDCl3 using a Bruker AVANCE III HD 500 spectrometer at 500, 126, and 160 MHz

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

• further purification unless otherwise stated. According to the previous procedure [30], 4,8,12-tris(2,6-dimethylphenyl)-4,8,12-triazatriangulenium as a Cl− ion pair, 2+-Cl−, was prepared. NMR spectra used in the characterization of products were recorded on a JEOL ECA-600 600 MHz spectrometer. All NMR

Machine learning-guided strategies for reaction conditions design and optimization

• Lung-Yi Chen and
• Yi-Pei Li

Beilstein J. Org. Chem. 2024, 20, 2476–2492, doi:10.3762/bjoc.20.212

• interdependencies between different reaction sequences, such as additional separation and purification steps, could reduce the overall yield [202]. This indicates that the suboptimal combination of each reaction does not necessarily represent the global optimum for multistep synthesis [203][204][205]. In contrast

• , telescoped flow sequences [206][207][208] or one-pot batch synthesis [209] emphasize the use of chemically compatible reagents and solvents in each reaction step to minimize intermediate purification steps. Volk et al. [210] developed AlphaFlow, which utilizes reinforcement learning as an optimization

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

• nucleophilic than chloride in an aprotic solvent such as acetonitrile. Gratifyingly, an excellent yield was obtained (Table 1, entry 6) without detection of the brominated by-product. To facilitate purification, the amount of DNTFB was reduced to 2 equiv without significantly changing the result (Table 1

• derivative 2k, and the estrone derivative 2l were also successfully bis-functionalized. Some products appeared to be sensitive during purification by chromatography on silica gel. Suspecting acid sensitivity, compound 2a was treated with trifluoroacetic acid to confirm this hypothesis (Scheme 3). The product

• separatory funnel and 10 mL of water are added. The aqueous layer is extracted three times with 10 mL of diethyl ether. The organic layers are combined and washed with 10 mL of water. The organic layer is dried with MgSO4, filtered, and concentrated under vacuum. Compounds 2 are obtained after purification

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• of compound 1b [42] (0.23 g, 1.00 mmol) in 3.0 mL of CH3CN was added NaClO aq. (5% in H2O, 1.50 g, 1.00 mmol) and the solution was stirred for 4.5 h at room temperature. This mixture was extracted with CH2Cl2 and the usual workup and purification afforded 0.15 g (0.60 mmol) of the pure title compound

• in 60% yield. GP-1B (by use of NaClO·5H2O): To a solution of compound 1b [42] (0.2302 g, 1.00 mmol) in 3.0 mL of CH3CN was added NaClO·5H2O (0.3290 g, 2.00 mmol) at 0 °C, and the solution was stirred for 6 h at the same temperature. After the same workup process and purification with silica gel

• room temperature. Then, 0.1477 g (0.60 mmol) of 2b in 0.8 mL of DMSO was introduced to the resultant solution and the stirring was continued for 0.5 h. The same workup process and purification furnished 0.1717 g of an inseparable mixture of anti,syn-7a (dr = 99:1) and anti,syn-7b (7a:7b = 83:17). Anti

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

• , 98.0%) was purchased from Sinopharm Chemical Reagent Co., Ltd.; pure water from AR, Hangzhou Wahaha Group Co., Ltd.; all reagents were used without further purification. Sulfuric acid solutions of different mass fractions were prepared with pure water and 98% concentrated sulfuric acid in an ice bath

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

• were used as received without further purification. Electrochemical reactions were carried out using a constant current power supply (model 5944), Metronix Corp., Tokyo. Diphenylmethanol (1a) [21], bis(4-chlorophenyl)methanol (1b) [22], (2-fluorophenyl)phenylmethanol (1c) [23], (4-methylphenyl

Asymmetric organocatalytic synthesis of chiral homoallylic amines

• Nikolay S. Kondratyev and
• Andrei V. Malkov

Beilstein J. Org. Chem. 2024, 20, 2349–2377, doi:10.3762/bjoc.20.201

• employing a bulkier allyl-transfer reagent 116. They used a novel pre-formed chiral triborate catalyst 115 in tandem with a non-chiral Brønsted acid and expanded the scope to aliphatic homoallylic amines (Scheme 24). The new method established a scalable, chromatography-free purification protocol for the

• purification. The bulky aryl groups in 116 were synthesized in a one-pot procedure, starting from 3,5-dimethylbenzonitrile, by the addition of 3,5-dimethylphenylmagnesium bromide and allylmagnesium chloride (24% combined yield on a 1 g scale). The authors also optimised the protocol for a large-scale synthesis

• scale (Scheme 27). Thus, the hydrolysis of the N=CPh2 group in the N-morpholinyl product 129 with hydroxylamine hydrochloride afforded the deprotected homoallylic amine 133 in a 99% yield without need for chromatographical purification. In a separate experiment, the sequential reduction of the N

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

• unprotected alcohol is tolerated in our procedure, with product 3l delivered at 50% NMR yield; 3l is sensitive to column chromatography, and thus aziridine-opening to a cyclic ether was observed (31% isolated yield) during purification. Aziridination of cis- or trans-4-octene afforded aziridine 3m as a 1.3

Catalysing (organo-)catalysis: Trends in the application of machine learning to enantioselective organocatalysis

• Stefan P. Schmid,
• Leon Schlosser,
• Frank Glorius and
• Kjell Jorner

Beilstein J. Org. Chem. 2024, 20, 2280–2304, doi:10.3762/bjoc.20.196

Synthesis and reactivity of the di(9-anthryl)methyl radical

• Tomohiko Nishiuchi,
• Kazuma Takahashi,
• Yuta Makihara and
• Takashi Kubo

Beilstein J. Org. Chem. 2024, 20, 2254–2260, doi:10.3762/bjoc.20.193

• product. After silica gel column purification, the isolated yield of these compounds were 64% and 13%, respectively. Additionally, a radical species, showing an ESR peak pattern distinct from that of the DAntM radical and mainly splitting into five peaks with g = 2.0037, was confirmed (Figure 4, Figure S7

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Novel truxene-based dipyrromethanes (DPMs): synthesis, spectroscopic characterization and photophysical properties

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2024, 20, 2163–2170, doi:10.3762/bjoc.20.186

• General: All the reagents/solvents were purchased from commercial suppliers (Sigma-Aldrich, Alfa Aesar, TCI, GLR innovation, Avera, Spectrochem and Across), and used without further purification. Solvents were dried according to standard reported procedures. Pyrrole was used after a fresh distillation

Computational toolbox for the analysis of protein–glycan interactions

• Ferran Nieto-Fabregat,
• Maria Pia Lenza,
• Angela Marseglia,
• Cristina Di Carluccio,
• Antonio Molinaro,
• Alba Silipo and
• Roberta Marchetti

Beilstein J. Org. Chem. 2024, 20, 2084–2107, doi:10.3762/bjoc.20.180

• , providing practical guidelines for carbohydrate structural analysis, spanning from the purification to the structural analysis of polysaccharides. MD simulations: Once the 3D glycan structure is built, taking into account the energetically favourable conformations of each constituent disaccharide unit, and

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

• purification system. Hydrobromic acid (48%) and deuterium oxide (99.9 atom %) were supplied by Merck. Sample preparation To produce micellar samples, light-responsive PS were shaken with the solvent (50 mM in either H2O or D2O) until homogenous. For samples of higher concentration, AAPTAB was added to water

Regioselective alkylation of a versatile indazole: Electrophile scope and mechanistic insights from density functional theory calculations

• Pengcheng Lu,
• Luis Juarez,
• Paul A. Wiget,
• Weihe Zhang,
• Krishnan Raman and
• Pravin L. Kotian

Beilstein J. Org. Chem. 2024, 20, 1940–1954, doi:10.3762/bjoc.20.170

• yields from the same carbon sources through reagent control. Experimental General methods All materials were obtained from commercial suppliers and used without further purification unless otherwise noted. Anhydrous solvents were obtained from Sigma-Aldrich and used directly. Reactions involving air- or

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

• purification. Thus, it significantly improves existing approaches. Keywords: catalysis; deazaalloxazine; flavin; multicomponent approach; one-pot reaction; Introduction Heterocyclic compounds containing pyrimidine and quinoline motifs in their structure, both of natural and synthetic origin, find a wide set

• vary from low to moderate, the reaction starts from commercially available substances and leads to valuable compounds. The procedure is low cost and operationally easy with no need for further purification and opens a new route to the synthesis of powerful, phoredox, flavin-like catalysts, as well as

• Reagents and analytics: Starting materials were purchased from Sigma-Aldrich and Fluorochem. The solvents were purified and dried using standard procedures. Commercially obtained reagents were used as received without further purification unless otherwise stated. The compound structures were drawn and

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

• biosynthetic enzymes hold promise as novel entities with untapped bioactive potential. Expression and purification of the CloA1 precursor peptide, CloA2 precursor peptide, and C39 peptidase domain We could not access the producing microorganisms, so the gene sequences reported in public databases (Supporting

• was co-expressed with the corresponding precursor peptide in the same E. coli strain (expected size 150 kDa). The precursor peptides and the peptidase domain of CloPt1 were fused with a 6xHis tag at their N-terminal end for purification purposes (Figure S7 in Supporting Information File 1). After

• purification, we estimated mature peptide and peptidase yields based on SDS-PAGE densitometry between 0.8 and 1.5 g/L of culture for all products. The heat liability of the peptide products challenged the purification, and when trying to perform several purification cycles to increase their purity, we obtained

Ugi bisamides based on pyrrolyl-β-chlorovinylaldehyde and their unusual transformations

• Alexander V. Tsygankov,
• Vladyslav O. Vereshchak,
• Tetiana O. Savluk,
• Serhiy M. Desenko,
• Valeriia V. Ananieva,
• Oleksandr V. Buravov,
• Yana I. Sakhno,
• Svitlana V. Shishkina and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2024, 20, 1773–1784, doi:10.3762/bjoc.20.156

• reaction step for the synthesis and purification of the starting azomethines 9, we cannot propose the Ugi-3CR approach as more suitable compared to the Ugi-4CR approach. The structure of the Ugi bisamides 5–8 were proved by X-ray diffraction study on the example of substance 8c (Figure 2), according to

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

• sodium hydroxide, followed by acidification with HCl, yielded a mixture of carboxylic acids and anhydrides 5, as evidenced by 1H NMR spectroscopy (Figure S13 in Supporting Information File 1). Gratifyingly, purification of these mixtures was not necessary as they could be used directly for imidization

Harnessing unprotected deactivated amines and arylglyoxals in the Ugi reaction for the synthesis of fused complex nitrogen heterocycles

• Javier Gómez-Ayuso,
• Pablo Pertejo,
• Tomás Hermosilla,
• Israel Carreira-Barral,
• Roberto Quesada and
• María García-Valverde

Beilstein J. Org. Chem. 2024, 20, 1758–1766, doi:10.3762/bjoc.20.154

• corresponding pyrrolopiperazinoquinazolines 13 with high yields. Interestingly, despite the acidic medium and high temperatures, the hemiaminal group was conserved, showing the high stability of these systems. On the other hand, the reduction of the N-phenylglycine derivative 10c, used without purification

• dipyrrolopiperazinone 12 quantitatively. In view of the interest of these structures and the poor global yield obtained because of the purification in the first step, we tried the synthesis of these polycyclic systems in a one-pot sequence. In this way, after performing the Ugi reaction for 24 h, the reaction mixture

• , without purification, was treated with caesium carbonate (1 equiv) and heated to reflux for an hour. Gratefully, the dipyrrolopiperazinone derivatives 12 were obtained with high yields and complete diastereoselectivity in an efficient and simple way (Scheme 11, Table 6). The structure of these systems was

Synthesis of polycyclic aromatic quinones by continuous flow electrochemical oxidation: anodic methoxylation of polycyclic aromatic phenols (PAPs)

• Hiwot M. Tiruye,
• Solon Economopoulos and
• Kåre B. Jørgensen

Beilstein J. Org. Chem. 2024, 20, 1746–1757, doi:10.3762/bjoc.20.153

• purification. Further experimental details are given in Supporting Information File 1. The best result was obtained at 6 F/mol equivalents, giving 47% of quinone 4b (Table 2, entry 4). These experiments, where the reaction mixture was passed through the cell a single time, gave rather low yields. This may be

• acetals. However, the methoxylated products from electrochemical oxidation of chrysen-1-ol (3b) and chrysen-6-ol (3d) rapidly hydrolysed to quinones during purification and could not be isolated. The attempted electrochemical oxidation of naphthalene-1-ol (1b) was unsuccessful; only small traces of