Development of a chemical scaffold for inhibiting nonribosomal peptide synthetases in live bacterial cells

• Fumihiro Ishikawa,
• Sho Konno,
• Hideaki Kakeya and
• Genzoh Tanabe

Beilstein J. Org. Chem. 2024, 20, 445–451, doi:10.3762/bjoc.20.39

• -domains could attenuate the virulence of pathogens. 5’-O-N-(Aminoacyl or arylacyl)sulfamoyladenosine (AA-AMS) is a bisubstrate small-molecule inhibitor of the A-domains of NRPSs. However, the bacterial cell permeability of AA-AMS is typically a problem owing to its high hydrophilicity. In this study, we

Spatial arrangements of cyclodextrin host–guest complexes in solution studied by ¹³C NMR and molecular modelling

• Konstantin Lebedinskiy,
• Ivan Barvík,
• Zdeněk Tošner,
• Ivana Císařová,
• Jindřich Jindřich and
• Radim Hrdina

Beilstein J. Org. Chem. 2024, 20, 331–335, doi:10.3762/bjoc.20.33

• delivery [2][3][4], in analytical and preparative chemistry for compound separation [5] and in materials science for small molecule detection [6][7]. Association (binding) constants between the host and guest molecules [8][9][10] are typically measured by 1H NMR titration [11][12] or isothermal titration

Unveiling the regioselectivity of rhodium(I)-catalyzed [2 + 2 + 2] cycloaddition reactions for open-cage C₇₀ production

• Cristina Castanyer,
• Anna Pla-Quintana,
• Anna Roglans,
• Albert Artigas and
• Miquel Solà

Beilstein J. Org. Chem. 2024, 20, 272–279, doi:10.3762/bjoc.20.28

• open-cage C60 derivatives have been reported. These open-cage fullerenes can act as molecular containers. Of special interest is the procedure called molecular surgery designed by Murata et al. [22][23][24][25] in which a hole in the fullerene is opened, an atom or small molecule is introduced and then

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

• preserved, also with this mildly mismatched tether. The π-acidic NDI 61 with a Leonard-turned tertiary amine is a privileged small-molecule anion–π catalyst that catalyzes the enolate addition of malonate 4 with an activity that, however, does not reach that of the best carbon allotropes [95]. In the

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• small molecule inhibitors into PROTACs. The RAS proteins, once seen as drug-resistant, became susceptible and a series of covalent inhibitors [5][6][7] were synthesized to bind to KRASG12C. The application of the PROTAC principle has demonstrated the feasibility of endogenous degradation of KRAS [8][9

Quinoxaline derivatives as attractive electron-transporting materials

• Zeeshan Abid,
• Liaqat Ali,
• Sughra Gulzar,
• Faiza Wahad,
• Raja Shahid Ashraf and
• Christian B. Nielsen

Beilstein J. Org. Chem. 2023, 19, 1694–1712, doi:10.3762/bjoc.19.124

• aggregation of fullerene molecules within the polymer matrix [25]. Small molecule NFAs have significantly advanced the field of OSCs. Notably, the fused-ring electron acceptors (FREAs) have exhibited exceptional promise, heralding a new era of possibilities for OSC technology. In 2019, Yuan et al. reported on

• vital role in shaping the next generation of electronic devices and renewable energy systems. Structures of some of the most versatile Qx scaffolds; dashed lines indicate the substitution sites for core expansion. Qx-derived polymer acceptors. Qx-derived small molecule NFAs. Qx-derived small molecule

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

• initiation step includes Equation 1 and Equation 2, when the thermal initiator decomposes into two small-molecule radical species and the first monomer adds to the growing chain to form the first repeating unit. The propagation step is depicted in Equation 3 when monomers take turns to undergo radical

• . Radicals can be generated by a broader selection of homogeneous and heterogeneous approaches, including hydrogen atom abstraction, decomposition of immobilized initiators, electrochemical redox reaction, or irradiation because the reactions only need to take place at the surface. Small-molecule oxidants

Complexes of resorcin[4]arene with secondary amines: synthesis, solvent influence on “in-out” structure, and theoretical calculations of non-covalent interactions

• Waldemar Iwanek

Beilstein J. Org. Chem. 2023, 19, 1525–1536, doi:10.3762/bjoc.19.109

• substituents with R[4]A in ethanol were synthesized. The composition of the complexes was determined based on the integration of amine proton signals in the 1H NMR spectra. For small molecule sec-amines such as N,N-dimethylamine, N,N-diethylamine, and cyclic amines (pyrrolidine, piperidine, morpholine, N

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

CO₂ complexation with cyclodextrins

• Cecilie Høgfeldt Jessen,
• Jesper Bendix,
• Theis Brock Nannestad,
• Heloisa Bordallo,
• Martin Jæger Pedersen,
• Christian Marcus Pedersen and
• Mikael Bols

Beilstein J. Org. Chem. 2023, 19, 1021–1027, doi:10.3762/bjoc.19.78

• small value, which means that even at a partial pressure of 5 bar less than 1/2 the CD cavity is filled. The rationale for the poor binding is probably the large discrepancy between the size of CO2 and the CD cavity. 1 has a cavity of 174 Å3 while CO2 is a very small molecule with kinetic diameter of

Phenanthridine–pyrene conjugates as fluorescent probes for DNA/RNA and an inactive mutant of dipeptidyl peptidase enzyme

• Josipa Matić,
• Tana Tandarić,
• Marijana Radić Stojković,
• Filip Šupljika,
• Zrinka Karačić,
• Ana Tomašić Paić,
• Lucija Horvat,
• Robert Vianello and
• Lidija-Marija Tumir

Beilstein J. Org. Chem. 2023, 19, 550–565, doi:10.3762/bjoc.19.40

• polynucleotide–small molecule complex [36]. Thermal melting experiments showed that conjugates Phen-Py-1 and Phen-Py-2 had only a negligible effect on the double helix stability (below 0.5 °C), both for DNA and RNA (Table S1, Figures S6–S8, Supporting Information File 1). Spectrophotometric titrations The

• and probability of contact, including steric shielding and charge–charge interactions [41]. Circular dichroism (CD) experiments CD spectroscopy was chosen to monitor conformational changes of polynucleotide's secondary structure induced by small molecule binding [42]. Compounds Phen-Py-1 and Phen-Py-2

Group 13 exchange and transborylation in catalysis

• Dominic R. Willcox and
• Stephen P. Thomas

Beilstein J. Org. Chem. 2023, 19, 325–348, doi:10.3762/bjoc.19.28

• functionalisation of unsaturated bonds [1][2][3][4][5], and, more recently, frustrated Lewis pair (FLP) chemistries including small molecule activations and C–H insertion reactions [6][7][8][9][10]. Group 13 exchange is the transfer of one or more substituents from one group 13 element to another group 13 element

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• also had better release, physical stability, and cytotoxicity [13]. CPT is an anticancer small molecule drug that inhibits the topoisomerase I enzyme, which has a critical role in cellular DNA functions [14], and is effective in a wide spectrum of cancers such as metastatic colon cancer, breast cancer

• the ability to self-assemble into NPs amenable for encapsulation of an array of therapeutics (from small molecule drugs to nucleic acids) [19]. Moreover, their dense ammonium functional display furnishes their NPs with an overall positive charge and large buffering capabilities [19] at physiological

Microelectrode arrays, electrosynthesis, and the optimization of signaling on an inert, stable surface

• Kendra Drayton-White,
• Siyue Liu,
• Yu-Chia Chang,
• Sakashi Uppal and
• Kevin D. Moeller

Beilstein J. Org. Chem. 2022, 18, 1488–1498, doi:10.3762/bjoc.18.156

• lead to analogous drops in current to methods involving molecules bound directly to an electrode surface or increases in current if a binding event helps to swell a polymer. The utility of this approach for a polymer-coated electrode was verified by looking at several small molecule–protein

• than enough electrodes in any one region of the array for an extensive study. With that information in place, attention was turned back to the initial small molecule/G-protein interaction that lies at the heart of guiding the synthetic study proposed in connection with Figure 1. Initially, the same

• surface and a 1:1 R6A/cysteine methyl ester surface. Calibrating the array-based signaling experiment for monitoring small molecule G-protein interactions. A Cu(I)-catalyzed cross-coupling reaction on an array. An array-based Chan–Lam coupling reaction. A new method for decreasing the concentration of R6A

Mechanochemical synthesis of unsymmetrical salens for the preparation of Co–salen complexes and their evaluation as catalysts for the synthesis of α-aryloxy alcohols via asymmetric phenolic kinetic resolution of terminal epoxides

• Shengli Zuo,
• Shuxiang Zheng,
• Jianjun Liu and
• Ang Zuo

Beilstein J. Org. Chem. 2022, 18, 1416–1423, doi:10.3762/bjoc.18.147

• ; mechanochemistry; phenolic KR; Introduction In the past decade, more than twenty chiral small molecule drugs were approved by the FDA, including ruxolitinib, afatinib, sonidegib, encorafenib, lorlatinib, darolutamide, alpelisib, artesunate, maribavir, ponesimod, daridorexant and others [1][2][3]. The

Ionic multiresonant thermally activated delayed fluorescence emitters for light emitting electrochemical cells

• Merve Karaman,
• Abhishek Kumar Gupta,
• Subeesh Madayanad Suresh,
• Tomas Matulaitis,
• Lorenzo Mardegan,
• Daniel Tordera,
• Henk J. Bolink,
• Sen Wu,
• Stuart Warriner,
• Ifor D. Samuel and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2022, 18, 1311–1321, doi:10.3762/bjoc.18.136

• in organic light-emitting diodes (OLEDs), relatively little attention has been devoted to the design of ionic small molecule (SM) [13] organic emitters for LEECs. The majority of the reported SM emitters for LEECs are fluorescent in nature and so the internal quantum efficiency (IQE) of the device is

• film [5][41]. However, despite these efforts, still no emission was observed when the devices were biased. Next, neat films of DiKTa-OBuIm and DiKTa-DPA-OBuIm were directly used as active layers. Non-doped small molecule films have shown recently promising results in LEEC devices [42]. As both emitters

Polymer and small molecule mechanochemistry: closer than ever

• José G. Hernández

Beilstein J. Org. Chem. 2022, 18, 1225–1235, doi:10.3762/bjoc.18.128

• (mechanochemistry) can be accomplished through various experimental strategies. Among them, ultrasonication of polymeric matrices and ball milling of reaction partners have become the two leading approaches to carry out polymer and small molecule mechanochemistry, respectively. Often, the methodological differences

• differences between polymer and small molecule mechanochemistry has become an important subject of academic investigation and constructive discussion in review articles [13][14]. Additionally, questioning the relationship between polymer mechanochemistry and small molecule mechanochemistry has been a

• reference [15]). The question was initially rephrased as to what was the connection between polymer mechanochemistry and small molecule mechanochemistry. On second thoughts, Prof. Moore paraphrased the question further, ending asking if the speakers considered there was a way to use the mechanical energy in

Radical cation Diels–Alder reactions of arylidene cycloalkanes

• Kaii Nakayama,
• Hidehiro Kamiya and
• Yohei Okada

Beilstein J. Org. Chem. 2022, 18, 1100–1106, doi:10.3762/bjoc.18.112

• ; spiro ring system; Introduction Single-electron transfer is one of the simplest modes for small molecule activation, employing a polarity inversion to generate radical ions which have proven to be unique reactive intermediates in the field of synthetic organic chemistry. A radical cation Diels–Alder

Post-synthesis from Lewis acid–base interaction: an alternative way to generate light and harvest triplet excitons

• Hengjia Liu and
• Guohua Xie

Beilstein J. Org. Chem. 2022, 18, 825–836, doi:10.3762/bjoc.18.83

• reaction. In order to clarify the coordination reaction of nitrogen atoms, Bazan’s group designed a conjugated polymer containing pyridine and thiazole groups and small molecule 15 (Figure 8) and compared the 1H NMR spectra and 19F NMR spectra after the addition of 1 equivalent B(C6F5)3 at various

• small molecule 15 containing pyridine and thiazole groups reported by Bazan et al. and pyridine groups-containing diketopyrrolopyrroles (DPP) 16–18 investigated by Huang et al. (a) 1H NMR spectra in the aromatic region and (b) 19F NMR spectra of compound 15 (top) and the mixture with 1 equivalent B(C6F5

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• ; 3,4,5-trisubstituted isoxazoles; Introduction Isoxazoles are a privileged class of five-membered heterocycles, which are found in numerous bioactive natural products [1][2] and synthetic small molecule drugs [3][4], and are used as important precursors for the synthesis of β-hydroxycarbonyl compounds

Mechanistic studies of the solvolysis of alkanesulfonyl and arenesulfonyl halides

• Malcolm J. D’Souza and
• Dennis N. Kevill

Beilstein J. Org. Chem. 2022, 18, 120–132, doi:10.3762/bjoc.18.13

• methanol lead to the simple two molecule formulation of the SN2 process for the hydrolysis being an oversimplification. The observation that the small molecule H2O is in bulk a liquid at room temperature requires a dynamic situation where water molecules are to a large extent associated by hydrogen-bonding

Regioselective synthesis of methyl 5-(N-Boc-cycloaminyl)-1,2-oxazole-4-carboxylates as new amino acid-like building blocks

• Jolita Bruzgulienė,
• Greta Račkauskienė,
• Aurimas Bieliauskas,
• Vaida Milišiūnaitė,
• Miglė Dagilienė,
• Gita Matulevičiūtė,
• Vytas Martynaitis,
• Sonata Krikštolaitytė,
• Frank A. Sløk and
• Algirdas Šačkus

Beilstein J. Org. Chem. 2022, 18, 102–109, doi:10.3762/bjoc.18.11

• peptide-like structure. Heterocyclic amino acids and related compounds have been used to prepare synthetic DNA-encoded compound libraries for the discovery of small molecule protein ligands [23][24][25]. Recently, a highly specific and potent p38α kinase inhibitor containing a 3-amino-1-phenyl-1H-pyrazole

• -4-carboxylic acid residue was identified directly from the 12.6-million-member DNA-encoded small molecule library using yoctoReactor technology [26]. We have developed efficient protocols that provide easy access to highly functional heterocyclic compounds as novel amino acid-like building blocks by

A photochemical C=C cleavage process: toward access to backbone N-formyl peptides

• Haopei Wang and
• Zachary T. Ball

Beilstein J. Org. Chem. 2021, 17, 2932–2938, doi:10.3762/bjoc.17.202

• , byproducts or transiently stable intermediates were sometimes indicated by HPLC and/or NMR of these photocleavage reactions [16][17]. These observations prompted a more detailed study of the components present during photocleavage reactions of small-molecule models, leading to the identification of the N

Effect of a twin-emitter design strategy on a previously reported thermally activated delayed fluorescence organic light-emitting diode

• Ettore Crovini,
• Zhen Zhang,
• Yu Kusakabe,
• Yongxia Ren,
• Yoshimasa Wada,
• Bilal A. Naqvi,
• Prakhar Sahay,
• Tomas Matulaitis,
• Stefan Diesing,
• Ifor D. W. Samuel,
• Wolfgang Brütting,
• Katsuaki Suzuki,
• Hironori Kaji,
• Stefan Bräse and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 2894–2905, doi:10.3762/bjoc.17.197

• lifetimes are of a similar magnitude to that of ICzTRZ (τp = 11.5 ns) [14] while the average delayed fluorescence decays much faster for DICzTRZ (τd = 252.8 µs for ICzTRZ) [14]. We next focused on the photophysical study in a suitably high triplet energy small molecule host material, CzSi (9-(4-tert

Cryogels: recent applications in 3D-bioprinting, injectable cryogels, drug delivery, and wound healing

• Luke O. Jones,
• Leah Williams,
• Tasmin Boam,
• Martin Kalmet,
• Chidubem Oguike and
• Fiona L. Hatton

Beilstein J. Org. Chem. 2021, 17, 2553–2569, doi:10.3762/bjoc.17.171

• chemically or physically crosslinked cryogels [11][12][13]. Firstly, a reaction mixture is prepared consisting of monomers/small molecule precursors, polymeric precursors, or a combination of the two (Figure 1) and solvent (e.g., water). ). It is worth noting that while we refer to water as the solvent here

• and in Figure 1, other solvents can be used, providing they have an appropriate melting/freezing temperature. Typically, the reagents will comprise only 5–20% of the reaction mixture. Often an initiator may also be required to initiate the polymerisation of the monomers/small molecule precursors. The