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

• free-base) macrocycles have not been explored as much in terms of catalysis, even though they are starting compounds for the preparation of their metallated analogues that are commonly used as catalysts. In contrast with a calix[4]pyrrole macrocycle with four NHs (from four pyrrole units), a metal-free

• , Ballester and co-workers reported on the preparation of an octapyridinium-based water-soluble superaryl-extended calix[4]pyrrole molecular container and used it as a capsule for desymmetrization reactions [41], where the reported compound acts both as sequestering and supramolecular protecting group. All of

Enantioselective regiospecific addition of propargyltrichlorosilane to aldehydes catalyzed by biisoquinoline N,N’-dioxide

• Noble Brako,
• Sreerag Moorkkannur Narayanan,
• Amber Burns,
• Layla Auter,
• Valentino Cesiliano,
• Rajeev Prabhakar and
• Norito Takenaka

Beilstein J. Org. Chem. 2024, 20, 3069–3076, doi:10.3762/bjoc.20.255

• propargyltrichlorosilane without N,N-diisopropylethylamine and (b) with N,N-diisopropylethylamine. It includes Gibbs free energies (kcal/mol) and Mulliken charges (in parentheses). Metallotropic rearrangement and regioselectivity issues. Asymmetric catalytic allenylation of aldehydes. Selective preparation of

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

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

• the facile preparation of molecular libraries with an emphasis on skeletal diversity for the development of new push–pull molecules. Results and Discussion Synthesis and structure determination A two-step procedure was used to obtain the target compounds (Scheme 1). Cyclopenta[b]pyridine derivative 2

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

• -scale syntheses demonstrated that the protocol is practical and useful for preparation of the γ-carbonyl peroxides. The authors propose the following reaction mechanism: initially Co(II) is oxidized by TBHP to form Co(III)OH and the tert-butoxy radical. In result of ligand exchange with TBHP or acetic

4,6-Diaryl-5,5-difluoro-1,3-dioxanes as chiral dopants for liquid crystal compositions

• Maurice Médebielle,
• Peer Kirsch,
• Jérémy Merad,
• Carolina von Essen,
• Clemens Kühn and
• Andreas Ruhl

Beilstein J. Org. Chem. 2024, 20, 2940–2945, doi:10.3762/bjoc.20.246

• still remain elusive and are not well understood [29]. Recently we have become interested in the preparation of racemic [30] anti- and highly enantioenriched 2,2-difluoro-1,3-diols [30][31][32] through an acylative double catalytic kinetic resolution (DoCKR) process [33]. While the 1,3-diol motif is

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

C–H Trifluoromethylthiolation of aldehyde hydrazones

• Victor Levet,
• Balu Ramesh,
• Congyang Wang and
• Tatiana Besset

Beilstein J. Org. Chem. 2024, 20, 2883–2890, doi:10.3762/bjoc.20.242

• using the synthetic potential of hydrazones in organic synthesis. Experimental General procedure for the preparation of trifluoromethylthiolated products 2–6: An oven-dried 10 mL reaction tube equipped with a stirring bar was charged with the hydrazone derivative (0.3 mmol, 1.0 equiv) and CH3CN (0.7 mL

Synthesis of pyrrole-fused dibenzoxazepine/dibenzothiazepine/triazolobenzodiazepine derivatives via isocyanide-based multicomponent reactions

• Marzieh Norouzi,
• Mohammad Taghi Nazeri,
• Ahmad Shaabani and
• Behrouz Notash

Beilstein J. Org. Chem. 2024, 20, 2870–2882, doi:10.3762/bjoc.20.241

• ), respectively. Preventive education for synthesizing triazolobenzodiazepine 6a–h Azides are highly reactive, toxic, explosive, and shock-sensitive chemicals that can be used under certain conditions. Special safety procedures must be followed during preparation, storage, handling, and disposal. TMSN3 is an

Multicomponent synthesis of α-branched amines using organozinc reagents generated from alkyl bromides

• Baptiste Leroux,
• Alexis Beaufils,
• Federico Banchini,
• Olivier Jackowski,
• Alejandro Perez-Luna,
• Fabrice Chemla,
• Marc Presset and
• Erwan Le Gall

Beilstein J. Org. Chem. 2024, 20, 2834–2839, doi:10.3762/bjoc.20.239

• stoichiometric amount of LiCl was essential for the efficiency of the subsequent three-component coupling with aldehydes and amines. A variety of primary, secondary, and tertiary organozinc reagents as well as secondary amines and aromatic aldehydes could be used for the straightforward preparation of α-branched

• amines. Interestingly, whereas previously reported work describing the preparation and reaction of organozinc iodides in acetonitrile showed higher reactivity of secondary organozinc reagents over primary ones, reactions in THF in the presence of LiCl led to opposite results, with higher reactivity of

• presence of LiCl in THF for the metalation of alkyl bromides at room temperature [19]. Besides, Huo described the insertion of zinc dust into alkyl bromides at 80 °C in DMA or DMF [20]. Despite the high synthetic interest in mixed organozinc compounds, their use in the preparation of α-branched amines

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

• (NAIs) [13][14][19][20][21][22]. To apply the latter method to the preparation of N,1,1-tricarbonylated propargylamines, the corresponding NAIs are necessary. However, the poor structural diversity of available NAIs limits the use of this method. For example, N,1-dicarbonylated NAIs derived from α-keto

• -4200 spectrometer equipped with an ATM detector. High-resolution mass spectra (HRMS) were obtained with a Bruker compact mass spectrometer APCI–TOF set at positive mode. The melting point was measured on an SRS-OptiMelt automated melting point system. Preparation of N,O-acetal 1 In a manner analogous

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

• each addition. In situ preparation of the [Tb.1·3Cu]3+ sensor. Solutions of 5 μM [Tb.1·3Cu]3+ were prepared by combining a DMSO stock solution of Tb.1 (100 μM) with 1 mM Cu(NO3)2·5H2O(aq). Solutions were then diluted with the appropriate amount of buffer (final concentration 10 mM Tris–HCl or 10 mM

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

• in Table 1). The optimal conditions found for product 4a also proved to be efficient for the preparation of its analogs 5 from N-arylitaconimides 3 (Scheme 1). Therefore, a broad range of variously substituted imidazo[1,2-a]pyrimidines was synthesized (Table 2). For the interaction of the

• candidates for further in vitro and in vivo testing as antifungal prodrugs. Experimental General procedure for preparation of N-R-7-oxo-5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine-5-carboxamides 4a–i: A mixture of 2-aminoimidazole hemisulfate (1, 0.66 g, 5 mmol), N-substituted maleimides 2a–i (5 mmol), sodium

• -aminoimidazole (1). Results of MEP calculations for the reaction of N-phenylithaconimide (3a) with 2-aminoimidazole (1). Screening of reaction conditions for the preparation of 7-oxo-N-phenyl-5,6,7,8-tetrahydroimidazo[1,2-a]pyrimidine-5-carboxamide (4a). Yields of the products 4 and 5. Characterization of ligand

Access to optically active tetrafluoroethylenated amines based on [1,3]-proton shift reaction

• Yuta Kabumoto,
• Eiichiro Yoshimoto,
• Bing Xiaohuan,
• Masato Morita,
• Motohiro Yasui,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2024, 20, 2776–2783, doi:10.3762/bjoc.20.233

• reports on the preparation of chiral molecules possessing a tetrafluoroethylene unit on an asymmetric carbon center in a high optical purity, and to the best of our knowledge, only the following have been published so far (Scheme 1). As a highly enantioselective synthesis, there has been a pioneering work

• diastereomers 12 and 13 are often easily separable, and each diastereomer of optically active alcohols or amines can be obtained with an excellent optical purity (reactions 3 and 4 in Scheme 1). To the best of our knowledge, these are the only four works for the preparation of optically active substances having

• ]-proton shift reaction of various tetrafluoroethylenated imines. Results and Discussion The preparation of substrates used in this study was as outlined in Scheme 3. Namely, the zinc reagent was prepared from commercially available 3,3,4,4-tetrafluoro-1-butene (18) [33] and reacted with various acid

Copper-catalyzed yne-allylic substitutions: concept and recent developments

• Shuang Yang and
• Xinqiang Fang

Beilstein J. Org. Chem. 2024, 20, 2739–2775, doi:10.3762/bjoc.20.232

• , which further limits the preparation of the related compounds. He et al. [65] used tetramethyldiaminomethane as a suitable surrogate of dimethylamine to achieve the asymmetric dimethylamination of yne-allylic esters, providing an efficient and convenient pathway for the synthesis of enantioenriched 1,4

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

• the photocontrol of the plasma membrane potential (Vm) using fullerene-containing triad molecules on a millisecond scale. Experimental Preparation of liposomes with catC60 (catC60-lip) or C60 (C60-lip) Liposomes were prepared using a thin-film hydration method. DMPC (NOF AMERICA Corporation, White

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

• -catalyzed protocol to obtain spiro[benzo[e][1,3]oxazine-2,3’-indoles] starting from 2-alkynylphenyl azides and 1,2-benzisoxazoles [12] (Scheme 1b). However, all these processes generally involve the preparation of starting materials, often not trivial. On the other hand, in 2018 Aksenov and Rubin reported

• –N bond oxidation to generate α-iminoamidines and then a final cyclization takes place (Scheme 2a). Although the synthetic procedure allowed the preparation of highly substituted complex structures under mild reaction conditions and on gram scale, it suffers from a limited structural diversity. Since

• the preparation of complex structures without using catalysts, and purification of intermediates. Remarkably, the reaction can be performed even on gram scale without loss of efficiency. Studies directed toward evaluating the biological activities of the spiroindolenines are currently underway in our

Synthesis of benzo[f]quinazoline-1,3(2H,4H)-diones

• Ruben Manuel Figueira de Abreu,
• Peter Ehlers and
• Peter Langer

Beilstein J. Org. Chem. 2024, 20, 2708–2719, doi:10.3762/bjoc.20.228

• (51), 271 (18), 268 (26); HRESIMS-TOF (m/z): [M + H]+ calcd for C23H19N2O2S, 387.1167; found, 387.1171. General procedure for the preparation of 5 A mixture of the corresponding starting material 4 (0.145 mmol) and p-TsOH·H2O (20 equiv; 2.94 mmol; 559 mg) was dissolved in dry toluene (2 mL) and

5th International Symposium on Synthesis and Catalysis (ISySyCat2023)

• Anthony J. Burke and
• Elisabete P. Carreiro

Beilstein J. Org. Chem. 2024, 20, 2704–2707, doi:10.3762/bjoc.20.227

• easily recovered by precipitation using polar solvents. This catalyst proved to be excellent for the preparation of (S)-baclofen on a gram scale, furnishing the main chiral intermediate in high yield and enantioselectivity. Furthermore, the catalyst was recycled over five cycles while maintaining its

• preparation of biologically active compounds [15]. The synthesis was achieved via a sulfonyl group rearrangement driven by the azide–tetrazole equilibrium in quinazolines. The researchers utilized two synthetic pathways to prepare the target compounds. The first pathway involved a nucleophilic aromatic

• values in the range of 1–10 μM. Teixeira et al. reported the preparation of new triazinephosphonate-based dopants and their application in the production of Nafion proton exchange membranes, which exhibited higher conductivity with only 1 wt % loading [19]. These new triazinephosphonate dopants could

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

• occurring DKPs usually consist only of the ʟ,ʟ-diastereomer, here both syn- and anti-diastereomers were observed. This may be due to slow epimerization due to enolization within the gland or during sample preparation and storage, as the ᴅ,ʟ-diastereomers of proline DKPs are more stable than the ʟ,ʟ

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

• be feasibly analysed [15]. A recent review by Kubota et al. summarised both the spatiotemporal advantages and disadvantages, as well as the artefacts arising from sample preparation and imaging conditions in the microscopy of molecular self-assemblies [16]. When imaging supramolecular gels, atomic

• number of structural features, but the sample preparation required can lead to significant changes in the materials morphology. EM requires many preparative steps to allow structures to be imaged including the application of an ultrathin coating of carbon, gold, or platinum. These are applied to conduct

• number of reviews discussing its pivotal nature in supramolecular material characterisation [32]. One of the most common methods of vitrification involves plunging the hydrogel into a liquid propane/ethane mixture, transferred under vacuum to a preparation chamber where it is fractured, sublimed, and

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

• was 88% and for compound 5 70%. Preparation of compounds 6-Methyluracil-5-ammonium sulfate (2). The spectral characteristics are given in [13]. 1,3,6-Trimethyluracil-5-ammonium sulfate (5). The spectral characteristics are given in [13]. General procedure for the hydrolysis of uracils 2 and 5. As

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

• describe a short and efficient synthesis for this type of novel skeleton and to prepare a focused library for these targets C. Further, we will report results on their cytotoxic activities. Results and Discussion Chemical synthesis For the preparation of our targets, we selected a flexible strategy which

• tested (25 μM). For these more potent molecules, further studies will be required to rationalize their activities and selectivities and explore their mechanism(s) of action. Conclusion In conclusion, we have designed a short and versatile strategy for the preparation of new N-arylbenzo[h]quinazoline-2

• -amines and it was exemplified through the preparation of a focused chemical library with 19 members. In addition, the cytotoxicity assays afforded interesting results demonstrating that the substitution on the anilino part can have significant effects on their bioactivity. Two molecules (4a and 4i

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 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

• variety of transition-metal-catalyzed reactions and photoredox reactions using arylboronates as aryl sources have been energetically investigated for the construction of carbon–carbon or carbon–heteroatom bonds [12][13][14][15]. The preparation of arylboronates often requires pre-functionalized substrates