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

• ) [51]. The corresponding peroxides 30 are enough stable under the reaction conditions and were isolated in high yields (Scheme 12). Flow-modification of the 2-oxoindole peroxidation method using nanoparticles of iron oxide as the catalyst was proposed [52]. The summarized proposed reaction pathway is

• . Then the alkene interacts with the C-centered radical C leads to the formation of radical species D. Finally, recombination of D and B results in the formation of the target difunctionalization product 98. Related methods were subsequently proposed for the modification of coumarins 99 [92] in the

• -coupling between cyclohexyl radical B and C-center radical D provides the difunctionalized product 103. Related methods were subsequently proposed for the modification of indene 104 [42] (Scheme 37). The target peroxides 106 were synthesized in good yields. In the case of indenes 104 a different

Synthesis of fluorinated acid-functionalized, electron-rich nickel porphyrins

• Mike Brockmann,
• Jonas Lobbel,
• Lara Unterriker and
• Rainer Herges

Beilstein J. Org. Chem. 2024, 20, 2954–2958, doi:10.3762/bjoc.20.248

• -synthetic modification of this porphyrin proved to be difficult. Therefore, we have integrated the acid group into the aldehyde component of the Rothemund reaction to prepare the target porphyrin. In initial tests, we have established that trifluoroacetic acid can be replaced by perfluorinated alkyl

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

• potential chiral dopants. Our long-term goal would be to provide a structure–property relationship of this class of molecules by i) modification of the aryl and ii) and/or acetal moieties (Scheme 1) and to elucidate the possible role of fluorine on their physical properties, with comparison to their non

The charge transport properties of dicyanomethylene-functionalised violanthrone derivatives

• Sondos A. J. Almahmoud,
• Joseph Cameron,
• Dylan Wilkinson,
• Michele Cariello,
• Claire Wilson,
• Alan A. Wiles,
• Peter J. Skabara and
• Graeme Cooke

Beilstein J. Org. Chem. 2024, 20, 2921–2930, doi:10.3762/bjoc.20.244

• properties of violanthrone is traced back to 1950, when Akamatu and Inokuchi measured its electrical conductivity (σ), which was found to be 3.4 × 10−4 Ω−1 cm−1 [27][28]. The chemical structure of violanthrone allows for its modification and hence the synthesis of materials with interesting spectral

• properties. Due to the low solubility of violanthrone in the majority of organic solvents, special attention has been drawn to its dihydroxy derivative (Figure 1), which allows further modification to the materials via etherification or esterification [29][30]. There has been a report on the structural

• modification of dihydroxyviolanthrone where the effect of three alkoxy substituents on the 16,17-bis(2-ethylhexyloxy)anthra[9,1,2-cde]benzo[rst]pentaphene-5,10-dione, on aggregation and photovoltaic properties was studied [30]. It was found that derivatives with the shortest linear alkyl chain (n-hexyl

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

• the combination with TRAIL. In conclusion, indirubin-N-glycosides and their analogues exhibit the highest anticancer activity observed so far for indirubin derivatives. Future studies are directed to a modification of the isatin moiety of the products

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

• biologically active compounds [27][28][29][30][31] and their synthetic intermediates [32][33][34][35][36]. Thus, this method, which enables modification at the 2- and 5-positions of oxazole-4-carboxylates, is a valuable tool for the study of these compounds. Experimental General All reagents except for DEMO

C–C Coupling in sterically demanding porphyrin environments

• Liam Cribbin,
• Brendan Twamley,
• Nicolae Buga,
• John E. O’ Brien,
• Raphael Bühler,
• Roland A. Fischer and
• Mathias O. Senge

Beilstein J. Org. Chem. 2024, 20, 2784–2798, doi:10.3762/bjoc.20.234

• literature. In light of the promise of appropriately designed nonplanar porphyrins as receptors and catalysts we report here on our efforts to use the Suzuki–Miyaura reaction for the modification of the o,m,p-phenyl positions in 5,10,15,20-tetraryl-2,3,7,8,12,13,17,18-octaethylporphyrins. Results and

• porphyrins synthesized via modification of the meso-para-phenyl position of porphyrin 13. Scope of arm-extended dodecasubstituted porphyrins synthesized via reaction at the meso-meta-phenyl position of porphyrin 12. Attempts of arm-extension of dodecasubstituted porphyrins at the meso-ortho-phenyl position

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

• in Vm was caused by some modification – most likely oxidation – of the plasma membrane by the photoexcited triad molecule. Taken together, for the realization of rapid control of Vm using such C60-based molecules in the membrane, the suppression of ROS generation is an important consideration. In

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

• plot analysis reveals that the best candidate is F3_NB_C5_CF3, which is the catalyst based on the 2-borylbenzenamine scaffold, with a pyrrolidine substituent on the nitrogen atom and CF3 substituents on the boron. Through strategic modification of the Lewis base substituents, a stereoselective catalyst

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

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

A review of recent advances in electrochemical and photoelectrochemical late-stage functionalization classified by anodic oxidation, cathodic reduction, and paired electrolysis

• Nian Li,
• Ruzal Sitdikov,
• Ajit Prabhakar Kale,
• Joost Steverlynck,
• Bo Li and
• Magnus Rueping

Beilstein J. Org. Chem. 2024, 20, 2500–2566, doi:10.3762/bjoc.20.214

• C–H hydroxylation process by combining continuous flow chemistry and electrochemistry (Scheme 8) [16]. The surface modification of electrodes can lead to improved reactivity and selectivity. In this regard, Li and coworkers developed electron-deficient W2C nanocrystal-based electrodes to enhance the

HFIP as a versatile solvent in resorcin[n]arene synthesis

• Hormoz Khosravi,
• Valeria Stevens and
• Raúl Hernández Sánchez

Beilstein J. Org. Chem. 2024, 20, 2469–2475, doi:10.3762/bjoc.20.211

• described herein exemplifies that even when protocols are well-established, a simple, yet critical modification may improve access to known species in shorter reaction times, and most importantly unveil new scaffolds that were previously inaccessible. We encourage scientists starting their careers in this

Tandem diazotization/cyclization approach for the synthesis of a fused 1,2,3-triazinone-furazan/furoxan heterocyclic system

• Yuri A. Sidunets,
• Valeriya G. Melekhina and
• Leonid L. Fershtat

Beilstein J. Org. Chem. 2024, 20, 2342–2348, doi:10.3762/bjoc.20.200

• agents contain a 1,2,3-triazine ring [37][38][39]. The structures of some bioactive 1,2,3-triazin-4-one derivatives are shown in Figure 1. Hence, one can assume that molecular hybridization of the 1,2,3-triazin-4-one moiety with the 1,2,5-oxadiazole core can lead to a significant modification of the

Improved deconvolution of natural products’ protein targets using diagnostic ions from chemical proteomics linkers

• Andreas Wiest and
• Pavel Kielkowski

Beilstein J. Org. Chem. 2024, 20, 2323–2341, doi:10.3762/bjoc.20.199

• -crosslinker, is attached synthetically to the basic scaffold (Figure 2A) [28][29][30][31][32]. However, this requires a structure–activity relationship (SAR) screening to ensure that the selected NP retains biological activity after modification. The term probe is further used to unite such NPs and active

• that does not necessitate for NP modification might be desirable. This may include hydrogen–deuterium exchange mass spectrometry (HDX-MS), limited proteolysis-coupled mass spectrometry (LiP–MS), thermal proteome profiling (TPP), cellular thermal shift assay (CETSA), affinity selection-mass spectrometry

• using orthogonal fragmentation techniques [75][76]. Because of the often low number of identified peptides bearing a desired modification, it is difficult to control the false-discovery rate (FDR) of the hits, and thus, the introduction of proper negative controls is of the upmost importance. Thus far

Deuterated reagents in multicomponent reactions to afford deuterium-labeled products

• Kevin Schofield,
• Shayna Maddern,
• Yueteng Zhang,
• Grace E. Mastin,
• Rachel Knight,
• Wei Wang,
• James Galligan and
• Christopher Hulme

Beilstein J. Org. Chem. 2024, 20, 2270–2279, doi:10.3762/bjoc.20.195

• modification of 1d, representative of the large swath of chemical space accessible by Ugi-deprotect-cyclize (UDC) methodology, gave the dihydroquinoxaline 1g in good yield with high deuterium retention [29][30][31][32]. The catalytic three-component Ugi reaction was first reported by List in 2008 [33][34] and

Factors influencing the performance of organocatalysts immobilised on solid supports: A review

• Zsuzsanna Fehér,
• Dóra Richter,
• Gyula Dargó and
• József Kupai

Beilstein J. Org. Chem. 2024, 20, 2129–2142, doi:10.3762/bjoc.20.183

• fine chemical and pharmaceutical industries [9]. The limitation of homogeneous catalysts, however, is their complex, time-consuming and energy-intensive recovery and subsequent recycling. Therefore, synthetic modification of catalysts is a commonly used method to aid their recovery. Obstacles to the

• influence on the properties and thus performance of the resulting heterogeneous catalyst. However, immobilisation and structural modification introduce additional steps in the synthesis of the catalyst. Moreover, the catalytic activity and selectivity of immobilised catalysts are often lower than those of

• spaces. The confinement of the heterogeneous version of cinchona amine and thiourea catalysts was reported, leading to improved enantioselectivity values in the Michael addition of nitromethane (5) to chalcone (6) through modification of the pore size of mesoporous silica 8 or 9 (Scheme 2) [63]. Thus

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

• . Specifically, it is possible to check the H atoms, the quality of the structure, evaluate some steric clashes and visualise in a friendly manner the full structure (http://molprobity.biochem.duke.edu/). 2. PDBtools [101]: It is a freely accessible software that allows the manipulation and modification of a PDB

Multicomponent syntheses of pyrazoles via (3 + 2)-cyclocondensation and (3 + 2)-cycloaddition key steps

• Ignaz Betcke,
• Alissa C. Götzinger,
• Maryna M. Kornet and
• Thomas J. J. Müller

Beilstein J. Org. Chem. 2024, 20, 2024–2077, doi:10.3762/bjoc.20.178

• intermediary ketenimine 162. The latter undergoes cyclization with elimination to form the corresponding pyrazoles 160 in a one-pot fashion (Scheme 54) [160]. The reaction can be extended by synthesizing hydrazone carboxamides in situ from hydrazine and isocyanates [161]. An unusual modification of alkynones

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

• spectra are very similar. These results indicate that substituents with different functional groups can be attached to DPP 2 without significant modification of their optical properties. The observed Stokes shifts for dyes 3 and 4 averaged in the range of 60–70 nm. All compounds exhibited high

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

• use of triflic acid (TfOH) resulted also in the cleavage of the alkyl group derived from the isocyanide, with formation of 47 (Scheme 18). Kanizsai et al. [51] have reported the synthesis of 4,5-disubstituted 2-amino-1H-imidazoles and their further modification through the GBB-3CR. The 2

• precursors which can be involved in further modifications. In addition, the GBB-like reactions can also be used to deliver other heterocyclic motifs. 3.1 One-pot synthesis As an efficient approach in organic synthesis, one-pot synthesis has been exploited in the post-modification of GBB products. This

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

• is recognized by post-translational enzymes and a core peptide where these enzymes produce the formation of Dha-Cys or Dhb-Cys residues. The post-translational modification enzymes involved span different functional domains (a cyclase and a dehydratase), and their activity is tightly controlled at

• -translational modification enzymes The selected supercluster is predicted to be formed by two adjacent, biosynthetically complete transcriptional units, each with specific promoter and terminator sites (Figure 2) containing two LanM enzymes (CloM1 and CloM2), the precursor peptides CloA1 and CloA2, as well as

• predictions suggesting that this should be a functional system. This lack of modification could be due to the amino acid sequence of the precursor, which differs from those described in the literature, or to mutations in the CloM1 enzyme. These mutations may require additional co-factors or specific

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

• well as their analogs, is outlined with an emphasis on comparing these chemo-enzymatic syntheses with the corresponding natural biosynthetic pathways. Keywords: chemo-enzymatic synthesis; late-stage modification; reactive biosynthetic intermediate; regio- and stereoselective (macro)cyclization; total

• pentacyclic scaffolds. The designed and chemically synthesized substrate analog 96 was tolerated by the key NRPS module SfmC despite the structural modification (Scheme 10A). In vitro enzymatic conversion of 96 with tyrosine derivative 86 [103] followed by the addition of KCN concisely furnished the

• relies heavily on enzyme selection and substrate design. The first strategy, "site- and stereoselective late-stage modification", was highlighted by demonstrating the systematic total synthesis of cotylenol (1) and its related natural products, brassicicenes (Scheme 2 and Scheme 3). Natural and

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

• encoded in the same BGC as the precursor peptide install post-translational modifications in the core peptide. Finally, a protease releases the modified core peptide, creating the mature natural product [2]. The transfer of a methyl group is a common post-translational modification in RiPP biosynthesis

• ]. Further O-MTs can be classified based on a common acceptor group of modification, namely C-terminal carboxy-MTs and peptide/protein ʟ-aspartyl O-MTs (PAMTs). C-terminal carboxymethyltransferases Carboxy-MTs catalyse the formation of a methyl ester by methylating the oxygen atom within the hydroxy group of

• aspartimide intermediates (Figure 6). The activity of most PAMTs depends on a cyclised precursor peptide. Modification of the aspartate/isoaspartate residue was found only in a hairpin-like or the macrocyclic region [71][78]. The underlying purpose of this structural requirement of PAMTs has not yet been