Light-enabled intramolecular [2 + 2] cycloaddition via photoactivation of simple alkenylboronic esters

• Lewis McGhie,
• Hannah M. Kortman,
• Jenna Rumpf,
• Peter H. Seeberger and
• John J. Molloy

Beilstein J. Org. Chem. 2025, 21, 854–863, doi:10.3762/bjoc.21.69

• excitation [66][67], product derivatization was explored (Scheme 2A). While initial efforts for oxidation proved challenging, due to a competing retro-aldol ring-opening reaction, employing a buffered system enabled access to β-alcohol 5. Given the previous power of trifluoroborates in cross-coupling

• cyclobutyldiol. A) Product derivatization and B) transition-metal EnT catalysis. Reaction conditions A): 4d (1 equiv), H2O2 (30 wt % in H2O), aq NaH2PO4, THF, 0 °C; B) 4 (1 equiv), KF (4 equiv), ʟ-tartaric acid (2.1 equiv), MeOH, MeCN, H2O, rt. Probing EnT catalysis of alkenylboronic ester 1a via alkene

Synthesis of HBC fluorophores with an electrophilic handle for covalent attachment to Pepper RNA

• Raphael Bereiter and
• Ronald Micura

Beilstein J. Org. Chem. 2025, 21, 727–735, doi:10.3762/bjoc.21.56

• bromoalkyl HBC derivatives 7, 8, and 9. Synthesis of the HBC ether derivative 11. Derivatization of the HBC fluorophore 5 to generate handles with distinct electrophilic groups. Synthesis of mesylated HBC fluorophores 16, 17, and 18. Synthesis of the bifunctional HBC fluorophore 22. For an application of 22

Study of the interaction of 2H-furo[3,2-b]pyran-2-ones with nitrogen-containing nucleophiles

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

Beilstein J. Org. Chem. 2025, 21, 556–563, doi:10.3762/bjoc.21.44

• subsequent opening of the furanone ring and proton transfer results in final compounds 8, 10 and 11. The synthetic application of obtained pyrazolones 8 was demonstrated by its further derivatization. The interaction with electrophilic agents is determined by the presence of several nucleophilic centers in

Synthesis of N-acetyl diazocine derivatives via cross-coupling reaction

• Thomas Brandt,
• Pascal Lentes,
• Jeremy Rudtke,
• Michael Hösgen,
• Christian Näther and
• Rainer Herges

Beilstein J. Org. Chem. 2025, 21, 490–499, doi:10.3762/bjoc.21.36

• [17]. As a starting point for further derivatization, the synthesis and characterization of monohalogenated N-acetyl diazocines 2 and 3 (Figure 1) have been performed [22]. Unfortunately, diazocines in general, and N-acetyl diazocines in particular cannot be derivatized by electrophilic aromatic

• substitution. Substituents such as halogen atoms must be introduced into the N-acetyl diazocine structure during the synthesis of the building blocks. In the present work we start from mono- and dihalogenated N-acetyl diazocine 2–4 (Figure 2) and focus on the further derivatization via cross-coupling reactions

• diazocine attached to glutamate to form a photoswitchable neurotransmitter [10]. The halogen-substituted N-acetyl diazocines 2–4 were used as the starting compounds for further derivatization via Pd-catalyzed cross-coupling reactions. Solutions of the Z isomers are yellow. The E isomers are red. Synthesis

Non-covalent organocatalyzed enantioselective cyclization reactions of α,β-unsaturated imines

• Sergio Torres-Oya and
• Mercedes Zurro

Beilstein J. Org. Chem. 2024, 20, 3221–3255, doi:10.3762/bjoc.20.268

• further investigate the potential utility of this methodology, a gram scale experiment was conducted affording product 16f in a good yield and a slight decrease of the enantioselectivity. Additionally, a derivatization of product 16f by hydrogenation was carried out to yield the tricyclic piperidine 17

Direct trifluoroethylation of carbonyl sulfoxonium ylides using hypervalent iodine compounds

• Radell Echemendía,
• Carlee A. Montgomery,
• Fabio Cuzzucoli,
• Antonio C. B. Burtoloso and
• Graham K. Murphy

Beilstein J. Org. Chem. 2024, 20, 3182–3190, doi:10.3762/bjoc.20.263

• successful derivatization of sulfoxonium ylides with trifluoroethyl or tetrafluoropropyl groups, and provides valuable insights into the scope and limitations of this approach. Nineteen examples have been prepared (45–92% yields), with structural diversity modified at two key sites on the sulfoxonium ylide

• discovered by Umemoto has proven an effective electrophilic trifluoroethyl transfer reagent [34][35], and to further explore the potential of fluoroalkyliodonium salts we evaluated the reactivity of such compounds in the context of sulfoxonium ylide derivatization. As depicted in Table 1, we began our

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

• accepting a wide variety of protective and functional groups, the method creates products with an iodine substituent that is easily accessible for product derivatization. Moreover, it is a convenient methodology for both N-arylation and O-arylation. The arylation of amines 38 was achieved in acetonitrile as

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

• readily available and cheap. Since then, indigo was produced in large scale. The synthesis, derivatization, and application of indigo derivatives have been widely studied [1][2][3]. Besides their application as dyes, indigo derivatives represent versatile tools for the development of innovative

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

• a tetrafluoroethylene group on an asymmetric carbon center. Synthetic strategy for preparing fluorine-containing amines via [1,3]-proton shift reactions. Preparation of the substrates used in this study. Derivatization of (S)-20b to (S)-23b for determining the optical purity of (S)-20b. Substrate

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

• GC–HRMS. Additional chemical derivatization of the extracts and final synthesis of the proposed structure candidates led to the structures of compounds A–F. Unknown compounds A–F Compounds A–F showed closely related mass spectra (Figure 2) and mostly occurred as pairs of diastereomers, labeled, e.g

• ion at m/z 141 showed a composition of C8H13O2 (m/z 141.0898, calcd. 141.0910). Derivatization with N-methyl-N-(trimethylsilyl)trifluoroacetamide (MSTFA) or trimethylsulfonium hydroxide (TMSH) converted A–F into the corresponding trimethylsilyl or methyl esters (Am–Fm) (Supporting Information File 1

• derivatization products by GC–MS. Failure of DMDS derivatization on unsaturated isoprenoids has been reported [21]. It has been suggested that steric hindrance of trisubstituted double bonds results in little or no adduct formation [21]. Another method for elucidating double bond positions is the formation of

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

• : 3a (1 mmol), CDI (0.49 g, 3 mmol), DBU (0.17 g, 1.1 mmol), MeCN (7 mL). Proposed reaction mechanism for the formation of products 4. Synthesis of derivatization products 7 and 9. Optimization of the reaction conditionsa. Supporting Information Supporting Information File 141: General information

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

• three different reactions (Figure 11A). Mechanistic model transferability for CPA-catalysed Minisci reactions [125] was utilised for the derivatization of quinolines and pyridines. Models trained on these compound classes show good generalisation towards other nitrogen-containing heteroaromatics

Natural resorcylic lactones derived from alternariol

• Joachim Podlech

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

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

• structures were elucidated by 1D and 2D NMR spectroscopic analyses, HRESIMS, and chemical derivatization. The absolute configurations of compounds 2 and 3 were predicted by comparison of experimental and calculated specific rotation data. Compounds 1–5 are the first examples of natural pyrroles substituted

• -configurations were proposed for compounds 2 and 3. However, this prediction was not confirmed by chemical derivatization due to their limited availability. 1H and 13C NMR spectra of compounds 4 and 5 were superimposable to those of 1 except for methylene resonances, supporting that both 4 and 5 possess the same

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

• derivatization, allowed the obtainment of 18 in high yield under relatively mild conditions, and was extended to the synthesis of 23 analogues, all in high yields (>86%). The catalyst could be recovered from the reaction medium by precipitation and reused up to five times without loss in activity. In 2020, Tyagi

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

• derivatization assay with iodoacetamide followed by trypsin digestion was performed for cellulosin, revealing a pattern of multicharged ions with the most intense peak at [M − 6H2O+AcNH2 + 5H]5+ with an m/z of 1,345.16 associated with the fragment from N23 to C64, six times dehydrated, and exhibiting an increase

• the iodoacetamide derivatization assay, where 5 out of 6 cysteines are involved in the formation of Dha and Dhb along the core peptide, preventing trypsin digestion. We were unable to detect any modifications of the CloA1 precursor peptide by the CloM1 biosynthetic enzyme, despite previous in silico

• -modified cellulosin tryptic fragment, featuring 5 and 6 net dehydrations, followed by the analysis of the sixth dehydrated fragment post-iodoacetamide derivatization to detect possible cross-links and dehydrated residues (Figure 4 and Supporting Information File 1, Figure S1, associated with ion lists in

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

• -) derivatization of aromatic scaffolds because it can be exploited to stabilize the longer (hetero)acenes. In contrast to cata-benzannulation, cata-imide-annulation does not perturb aromaticity patterns and further introduces inductive stabilization of frontier MO levels, which has enabled the production of n-type

• physical properties. Results and Discussion Synthesis The synthesis of the title compounds is shown in Scheme 1. To obtain a naphthalene core with the requisite 1,2,3,4-tetracarbonyl derivatization pattern, we leveraged the cycloaddition of 1 equiv of aryne percursor 1 with 2 equiv of dimethyl

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

• [11]. Different strategies have been developed to avoid these competitive reactions, the most common ones being the use of protecting groups (Ugi/deprotection/cyclization strategy) [12][13][14] or of surrogates of amines [15]. However, direct incorporation of the second amine without derivatization is

Polymer degrading marine Microbulbifer bacteria: an un(der)utilized source of chemical and biocatalytic novelty

• Weimao Zhong and
• Vinayak Agarwal

Beilstein J. Org. Chem. 2024, 20, 1635–1651, doi:10.3762/bjoc.20.146

• determined using a combination of NMR spectroscopy and chemical derivatization experiments, adding new members to this class of imidazole-containing natural products such as the nocarimidazoles A and B reported from a marine-derived actinomycete Nocardiopsis sp. before [126]. Compound 21 was determined to be

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

• collected polyketide products were manually checked by literature searches. Absolute configurations determined entirely by chemical methods, such as crystal structures, NMR, chemical degradation and derivatization, were considered reliable. Alternatively, relative configurations determined by NMR methods

Selectfluor and alcohol-mediated synthesis of bicyclic oxyfluorination compounds by Wagner–Meerwein rearrangement

• Ziya Dağalan,
• Muhammed Hanifi Çelikoğlu,
• Saffet Çelik,
• Ramazan Koçak and
• Bilal Nişancı

Beilstein J. Org. Chem. 2024, 20, 1462–1467, doi:10.3762/bjoc.20.129

• distinct advantageous such as (i) the methodology does not require the presence of any metal moities, (ii) enables the synthesis of corresponding oxyfluorinated analogues with high yields and selectivity, (iii) allows derivatization of natural chiral molecules, (iv) uses a safe solvent in mild reaction

Synthesis of 4-functionalized pyrazoles via oxidative thio- or selenocyanation mediated by PhICl₂ and NH₄SCN/KSeCN

• Jialiang Wu,
• Haofeng Shi,
• Xuemin Li,
• Jiaxin He,
• Chen Zhang,
• Fengxia Sun and
• Yunfei Du

Beilstein J. Org. Chem. 2024, 20, 1453–1461, doi:10.3762/bjoc.20.128

• 3a and their derivatization. Plausible reaction mechanism. Optimization of oxidative thiocyanation of pyrazole.a Supporting Information Supporting Information File 28: Synthetic details and compound characterization data. Funding We acknowledge the National Key Research and Development Program of

Synthesis of substituted triazole–pyrazole hybrids using triazenylpyrazole precursors

• Simone Gräßle,
• Laura Holzhauer,
• Nicolai Wippert,
• Olaf Fuhr,
• Martin Nieger,
• Nicole Jung and
• Stefan Bräse

Beilstein J. Org. Chem. 2024, 20, 1396–1404, doi:10.3762/bjoc.20.121

• . It offers the additional benefits of chemistry on solid support: straightforward purification of the resin-bound intermediates by washing steps and a high throughput that allows for faster derivatization. Further research is necessary to establish a protocol for the cleavage of 4-substituted

Generation of alkyl and acyl radicals by visible-light photoredox catalysis: direct activation of C–O bonds in organic transformations

• Mithu Roy,
• Bitan Sardar,
• Itu Mallick and
• Dipankar Srimani

Beilstein J. Org. Chem. 2024, 20, 1348–1375, doi:10.3762/bjoc.20.119

• irradiation to harness the reactivity of alcohols and acids both upon derivatization and through direct use. By exploring recent advancements in deoxygenation reactions and the design of potential reactants, we aim to give an overview of the diverse strategies that highlight the unique reaction design and

Synthesis of 1,2,3-triazoles containing an allomaltol moiety from substituted pyrano[2,3-d]isoxazolones via base-promoted Boulton–Katritzky rearrangement

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

Beilstein J. Org. Chem. 2024, 20, 1334–1340, doi:10.3762/bjoc.20.117

• cyclization with participation of hydrazine and carbonyl functions leads to pyrazolylisoxazole D. Finally, condensation with second equivalent of hydrazine results in the target hydrazone 6. The synthetic utility of obtained 1,2,3-triazoles is demonstrated by its further derivatization. So, alkylation by MeI