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

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

• were recorded on Agilent Cary 8454 spectrophotometer at 25 °C in analytical-grade DMF. Absorption spectra were processed by using Microsoft Excel and Origin 2018 (OriginLab). Typical procedure for the synthesis of 5-aryldeazaalloxazines 2: An equimolar mixture (3.0 mmol) of the corresponding aniline 3

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

• cellulolyticum, and clostrubin, a polyphenolic polyketide antibiotic and the first reported polyketide from anaerobic bacteria [35][36][37]. Therefore, the discovery of a lantibiotic with a Clostridium origin, reported in this study, has significant implications for developing novel antibiotics. The unique

• because of the novelty that lanthipeptides from Clostridium could constitute, since no such BGCs with this taxonomic origin had been described before. The tree also indicates the presence of other yet unexplored LanM clades, such as from Bacilli, Cyanobacteria, and Actinobacteria, which could be

• function–structure relationships and how they impact biological activity. Since we have not found evidence of horizontal transfer of the cloA1 and cloA2 gene clusters, it is an interesting speculation that they could constitute the origin of this family and that, by duplicating one of these clusters, C

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

• /mL [107][108][109]. While originally thought to be of NRPS origin due to their extensive modifications, Freeman et al. discovered in 2012 that polytheonamides are actually of ribosomal origin [108]. Polytheonamides A and B contain eight methylated asparagine residues (Figure 4), all of which are

• Imani et al. Types I–III are of fungal origin, types IV–X are of bacterial origin [103]. Radical SAM C-methyltransferases. A) The different rSAM MT classes containing different functional domains. Class B includes a cobalamin binding domain (CBD) and class C a domain similar to HemN_C, which is an

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

• group in 25 is rare. Feeding [1-13C]acetate to the culture resulted the enrichment of C1, C3, C5, C7, and C9 carbons, which verified the origin of the carbon skeleton as being fatty acid-derived. Feeding experiments with ʟ-[methyl-13C]methionine yielded only enrichment of C11 methyl, indicating that

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

• were performed by repeating the same protocol, but injecting the ligand into buffer solution. The supplied software Origin 7 or MicroCal PEAQ-ITC was used to fit the experimental data to a theoretical titration curve allowing the determination of affinity (i.e., dissociation constant, Kd), binding

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

• characterized sequences. Conclusion In summary, we systematically assessed the stereoselectivity-associated sequence motifs from 1,762 KR sequences in bacterial modular cis-AT PKSs whose product structures were experimentally determined. Our analyses revealed that different KRs, by taxonomic origin or by module

• Figure 3. For full-length sequence logo, see Figure S5 in Supporting Information File 1. Summary of the updated fingerprints sorted by the taxonomic origin and the module type. Percentage numbers show KRs meeting the fingerprint description in our curated dataset. (a) Motifs useful for the stereochemical

Cofactor-independent C–C bond cleavage reactions catalyzed by the AlpJ family of oxygenases in atypical angucycline biosynthesis

• Jinmin Gao,
• Liyuan Li,
• Shijie Shen,
• Guomin Ai,
• Bin Wang,
• Fang Guo,
• Tongjian Yang,
• Hui Han,
• Zhengren Xu,
• Guohui Pan and
• Keqiang Fan

Beilstein J. Org. Chem. 2024, 20, 1198–1206, doi:10.3762/bjoc.20.102

• [25]. On the other hand, the origin of 1, spontaneously derived from 8 under aerobic conditions, raises uncertainties about the actual production in vivo. Furthermore, the significance of the C12 hydroxy group in the hydroquinone intermediate 11 is evident in subsequent reactions, including the

Stability trends in carbocation intermediates stemming from germacrene A and hedycaryol

• Naziha Tarannam,
• Prashant Kumar Gupta,
• Shani Zev and
• Dan Thomas Major

Beilstein J. Org. Chem. 2024, 20, 1189–1197, doi:10.3762/bjoc.20.101

• Naziha Tarannam Prashant Kumar Gupta Shani Zev Dan Thomas Major Department of Chemistry and Institute of Nanotechnology and Advanced Materials, Bar-Ilan University, Ramat-Gan 52900, Israel 10.3762/bjoc.20.101 Abstract In the current work, we analyzed the origin of difference in stabilities among

Novel analogues of a nonnucleoside SARS-CoV-2 RdRp inhibitor as potential antivirotics

• Luca Julianna Tóth,
• Kateřina Krejčová,
• Milan Dejmek,
• Eva Žilecká,
• Blanka Klepetářová,
• Lenka Poštová Slavětínská,
• Evžen Bouřa and
• Radim Nencka

Beilstein J. Org. Chem. 2024, 20, 1029–1036, doi:10.3762/bjoc.20.91

• the beginning of the pandemic, a variety of heterocyclic small molecules – either of natural or synthetic origin – was reported as promising inhibitors of the SARS-CoV-2 RdRp [13][14][15]. However, compounds with a sufficient combination of high potency and suitable pharmacokinetic properties are

Advancements in hydrochlorination of alkenes

• Daniel S. Müller

Beilstein J. Org. Chem. 2024, 20, 787–814, doi:10.3762/bjoc.20.72

• deuterium incorporation. However, when D2O-saturated nitromethane was used >95% D-incorporation took place. Hence the small (500–2000 ppm) content of water in commercially available nitromethane was at the origin of the hydrochlorination reaction (Scheme 16). As a result, the reaction of 104 with water

Possible bi-stable structures of pyrenebutanoic acid-linked protein molecules adsorbed on graphene: theoretical study

• Yasuhiro Oishi,
• Motoharu Kitatani and
• Koichi Kusakabe

Beilstein J. Org. Chem. 2024, 20, 570–577, doi:10.3762/bjoc.20.49

• pathway on the adiabatic potential energy surface that connects these conformations caused by the deformation of the PASE linker. The reaction pathway for the conformational change of the PASE itself was found to have a reaction activation barrier [9]. First, we identify that the origin of the barrier is

• , where conformation 1 corresponds to a 0 rotation, conformation 2 a 2π/3 rotation, and the conformation at the activation barrier top a π/3 rotation, respectively. To confirm the origin of the activation barrier that appears between conformation 1 and 2, we discuss the structural features of the

• how an activation barrier appears on the potential energy surface in PASE adsorbed on graphene. The conformational change between two bi-stable PASE structures can be regarded as rotational motion around a C–C bond in the alkyl chain. An origin of an activation barrier is the steric hindrance coming

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• seeds per pot depending on the plant species (10 seeds for corn and wheat spectrum). The harmful plants and crops used in greenhouse tests were the following species: Alopecurus myosuroides (ALOMY), resistant Alopecurus myosuroides (ALOMY_R, origin: Germany), Apera spica-venti (APESV), Brachiaria

• platyphylla (BRAPP), Bromus tectorum (BROTE), Echinochloa crus-galli (ECHCG), Digitaria sanguinalis (DIGSA), Eleusine indica (ELEIN), Glycine max (GLXMA), Lolium rigidum (LOLRI), Lolium sp. (LOLSS), resistant Lolium sp. (LOLSS_R, origin: France), Poa annua (POAAN), Setaria viridis (SETVI), Sorghum halepense

Enhanced host–guest interaction between [10]cycloparaphenylene ([10]CPP) and [5]CPP by cationic charges

• Eiichi Kayahara,
• Yoshiyuki Mizuhata and
• Shigeru Yamago

Beilstein J. Org. Chem. 2024, 20, 436–444, doi:10.3762/bjoc.20.38

• suggested the partial electron transfer from [10]CPP to [5]CPP2+ in the complex, and this charge-transfer (CT) interaction is most likely the origin of the higher association constant of the dicationic complex than the neutral one. Keywords: charge-transfer; cycloparaphenylene; dication; host–guest

• photophysical and electrochemical analyses and DFT calculations. Therefore, this CT is most likely the origin of the increased Ka value. We also discuss the charged double-layer structure, as determined by X-ray crystallographic analysis. Results and Discussion The size-complementary interaction between CPP2

Additive-controlled chemoselective inter-/intramolecular hydroamination via electrochemical PCET process

• Kazuhiro Okamoto,
• Naoki Shida and
• Mahito Atobe

Beilstein J. Org. Chem. 2024, 20, 264–271, doi:10.3762/bjoc.20.27

• radical acceptor moieties. Therefore, we investigated the origin of this selectivity under electrochemical conditions. Results and Discussion Anodic oxidation of uridine derivative 1 was performed in a CH2Cl2/Bu4NPF6 (0.1 M) electrolyte system using a carbon felt (CF) anode and a Pt cathode in the

Cycloaddition reactions of heterocyclic azides with 2-cyanoacetamidines as a new route to C,N-diheteroarylcarbamidines

• Pavel S. Silaichev,
• Tetyana V. Beryozkina,
• Vsevolod V. Melekhin,
• Valeriy O. Filimonov,
• Andrey N. Maslivets,
• Vladimir G. Ilkin,
• Wim Dehaen and
• Vasiliy A. Bakulev

Beilstein J. Org. Chem. 2024, 20, 17–24, doi:10.3762/bjoc.20.3

• cells within the concentration range. This indicates the low cytotoxicity of these compounds. Meanwhile, compounds 3m,l are characterized by a borderline inhibition of cell culture viability. Attention is drawn to the increased toxic effect of 3m on cells of tumor origin, in comparison with normal human

Studying specificity in protein–glycosaminoglycan recognition with umbrella sampling

• Mateusz Marcisz,
• Sebastian Anila,
• Margrethe Gaardløs,
• Martin Zacharias and
• Sergey A. Samsonov

Beilstein J. Org. Chem. 2023, 19, 1933–1946, doi:10.3762/bjoc.19.144

• , respectively), while on the way back, the still high correlation with the H-bond number (0.58) and an essentially decreased one with the native contact number (0.36) mean that hydrogen binding dominates the binding energetics of the system and is an origin of multipose binding. When correlating the values for

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• (Figure 1C). Elongation of the tether in fullerenes 10 and 11 reduced product ratios to still significant A/D10/9 ~ A/D11/9 = 2.1. The origin of this decrease in anion–π catalysis is likely to include increasing entropy losses in pseudo-macrocyclic transition states. Normalized against the fullerene-free

• . The origin of autocatalysis on π-acidic surfaces was clarified only this year because the involvement of two molecules of water in the decisive transition state XI complicated the situation [70]. This reaction was intriguing for reasons beyond autocatalysis. It is the only example so far where

• graphite might be relevant with regard to early steps in the origin of life [124][125]. Conclusion Anion–π catalysis on carbon allotropes originates from the observation that access to strong anion–π interactions by increasing the intrinsic π acidity of aromatic surfaces is not realistic. Any permanent

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• natural products of microbial origin such as HHQ and its C5-congener. Two compounds with high activity against S. aureus have been identified among the newly obtained quinolones, with MICs ≤ 3.12 and ≤ 6.25 µg/mL, respectively. Keywords: antibacterial; β-keto amides; enaminones; 4-quinolones; quorum

• most prominent examples in this regard are the fluoroquinolone antimicrobials [3] – a remarkably successful drug class, used to treat bacterial infections caused by both Gram-positive and Gram-negative bacteria [4]. Other notable 4-quinolones of synthetic origin are ivacaftor [5] and elvitegravir [6

• avicennae [18]. Inhibition of hepatitis C virus replication by 2-nonyl-4-quinolone, isolated from Ruta angustifolia leaves, has also been reported [19]. Another significant group of natural 4-quinolones are those of microbial origin. The function of these compounds in the microbial world is a matter of

Effects of the aldehyde-derived ring substituent on the properties of two new bioinspired trimethoxybenzoylhydrazones: methyl vs nitro groups

• Dayanne Martins,
• Roberta Lamosa,
• Talis Uelisson da Silva,
• Carolina B. P. Ligiero,
• Sérgio de Paula Machado,
• Daphne S. Cukierman and
• Nicolás A. Rey

Beilstein J. Org. Chem. 2023, 19, 1713–1727, doi:10.3762/bjoc.19.125

• /HEPES mixture (pH 7.4). Experimental conditions: l = 1.0 cm and T = (25.0 ± 0.1) °C. (A) Gaussian fitting of the bands in the spectrum at t0, along with the spectra of precursors TMP (dotted gray curve) and MBA (dotted purple). Deconvolution performed with Origin software. (B) Spectra measured at t0 and

• 10% DMSO/buffer mixtures (pH ranging from 3.8 to 8.2). Inset: A440 versus pH with sigmoidal fitting. Gaussian fitting of the bands in a solution of the hydrazone in (B) 10% DMSO/acetate buffer (pH 3.8) and (C) 10% DMSO/Tris-HCl buffer (pH 8.2). Deconvolution performed with Origin software. Spectra of

Sulfur-containing spiroketals from Breynia disticha and evaluations of their anti-inflammatory effect

• Ken-ichi Nakashima,
• Naohito Abe,
• Masayoshi Oyama,
• Hiroko Murata and
• Makoto Inoue

Beilstein J. Org. Chem. 2023, 19, 1604–1614, doi:10.3762/bjoc.19.117

• ), suggesting that breynin formation may involve the attachment of a mercaptoacetamide to 5, followed by cyclization. However, to the best of our knowledge, the origin of mercaptoacetamide has not been reported and further biosynthetic exploration is needed. We also isolated two new sulfur-containing

Radical chemistry in polymer science: an overview and recent advances

• Zixiao Wang,
• Feichen Cui,
• Yang Sui and
• Jiajun Yan

Beilstein J. Org. Chem. 2023, 19, 1580–1603, doi:10.3762/bjoc.19.116

• considered to have two mechanisms, degenerative transfer and reversible termination, which are comparable to RAFT and NMP, respectively (Scheme 7) [70]. Iodine transfer polymerization (ITP) is also a commonly used degenerate chain-transfer method. Its origin can be traced back to the 1970s [71] and it is

• gaseous [195]. While the depolymerization in both systems has a thermodynamic origin [196], the mechanism of poly(olefin sulfone) depolymerization is much more complex. Bowmer et al. proposed a simultaneous radical/cationic process (Scheme 20b) [197]. Meanwhile, an anionic process is also possible in the

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

Aromatic C–H bond functionalization through organocatalyzed asymmetric intermolecular aza-Friedel–Crafts reaction: a recent update

• Anup Biswas

Beilstein J. Org. Chem. 2023, 19, 956–981, doi:10.3762/bjoc.19.72

• groups into the aromatic ring. This reaction has a great scope of forming aza-stereocenters which can be tuned by different asymmetric catalysts. This review assembles recent advances in asymmetric aza-Friedel–Crafts reactions mediated by organocatalysts. The mechanistic interpretation with the origin of

• mechanistic approaches with explanation about the origin of stereoselectivities has also been elaborated. This reaction has been successfully utilized as the key step in the syntheses of different important natural products which have been included in this article as well. On searching the literature, it has

Intermediates and shunt products of massiliachelin biosynthesis in Massilia sp. NR 4-1

• Till Steinmetz,
• Blaise Kimbadi Lombe and
• Markus Nett

Beilstein J. Org. Chem. 2023, 19, 909–917, doi:10.3762/bjoc.19.69

• structures of compounds 1–6 isolated in this study and of the structurally related siderophores massiliachelin (7) and (S)-dihydroaeruginoic acid (8). 1H,1H-COSY and selected 1H,13C-HMBC correlations in 1. Proposed origin of the isolated compounds 1–6 as well as massiliachelin (7). Domain notation of the