NMR Spectroscopy of supramolecular chemistry on protein surfaces

• Peter Bayer,
• Anja Matena and
• Christine Beuck

Beilstein J. Org. Chem. 2020, 16, 2505–2522, doi:10.3762/bjoc.16.203

• Survivin – Histone H3 interaction by a GCP ligand has been shown to inhibit tumor proliferation in cell culture [46]. Porphyrins, either with or without a complexed metal ion in the center, have been used as planar hydrophobic scaffolds where either negatively charged carboxylate or positively charged

• they have been used to serve as scaffolds for the assembly of protein arrays and crystallization aids [23][24][25][26][27][28]. In addition, a terbiumIII complex termed crystallophore has been developed as a crystallographic nucleation and phasing tool for protein crystallography that can also easily

• multivalent ligands, like multi-armed GCP ligands with flexible scaffolds or nanoparticles, have been published yet. NMR spectroscopy is the ideal method to gain structural information and identify residues involved in ligand binding because it delivers single-residue resolution. It is also suitable to

Dawn of a new era in industrial photochemistry: the scale-up of micro- and mesostructured photoreactors

• Emine Kayahan,
• Mathias Jacobs,
• Leen Braeken,
• Leen C.J. Thomassen,
• Simon Kuhn,
• Tom van Gerven and
• M. Enis Leblebici

Beilstein J. Org. Chem. 2020, 16, 2484–2504, doi:10.3762/bjoc.16.202

• an ene reaction of β-citronellol and Diels–Alder reactions of α-terpinene and (5-methylfuran-2-yl)methanol [46] as well as the synthesis of cyclopent-2-enones from furans [47] and the synthesis of diverse γ-lactam scaffolds [48]. Conversions larger than 90% were achieved for all reactions [46][47][48

Chan–Evans–Lam N1-(het)arylation and N1-alkеnylation of 4-fluoroalkylpyrimidin-2(1H)-ones

• Viktor M. Tkachuk,
• Oleh O. Lukianov,
• Mykhailo V. Vovk,
• Isabelle Gillaizeau and
• Volodymyr A. Sukach

Beilstein J. Org. Chem. 2020, 16, 2304–2313, doi:10.3762/bjoc.16.191

• , heterocyclic analogues of activated ketimines (Figure 1), thus offering potential applications in the design of new heterocyclic chemotypes [21][22][23][24][25]. Compounds I are precursors of trifluoromethyl-substituted dihydropyrimidine derivatives which appear as original and potent scaffolds in medicinal

Synthetic approaches to bowl-shaped π-conjugated sumanene and its congeners

• Shakeel Alvi and
• Rashid Ali

Beilstein J. Org. Chem. 2020, 16, 2212–2259, doi:10.3762/bjoc.16.186

• they are the most trustworthy strategies for direct functionalization of aromatic scaffolds [50]. As can be inspected from Scheme 18, monoiodosumanene 79 was obtained by gold-catalyzed iodination in the presence of N-iodosuccinimide (NIS). The mononitrosumanene 80 was achieved through the nitration

Lipophilicity trends upon fluorination of isopropyl, cyclopropyl and 3-oxetanyl groups

• Benjamin Jeffries,
• Zhong Wang,
• Robert I. Troup,
• Anaïs Goupille,
• Jean-Yves Le Questel,
• Charlene Fallan,
• James S. Scott,
• Elisabetta Chiarparin,
• Jérôme Graton and
• Bruno Linclau

Beilstein J. Org. Chem. 2020, 16, 2141–2150, doi:10.3762/bjoc.16.182

• (Figure 4), using the directly comparable isobutanol, cyclopropylmethanol and 3-oxetanylmethanol scaffolds. All compounds are either commercially available or are easily synthesized from available fluorinated building blocks. In addition, comparison of lipophilicities of relevant linear butanol

Access to highly substituted oxazoles by the reaction of α-azidochalcone with potassium thiocyanate

• Mysore Bhyrappa Harisha,
• Pandi Dhanalakshmi,
• Rajendran Suresh,
• Raju Ranjith Kumar and
• Shanmugam Muthusubramanian

Beilstein J. Org. Chem. 2020, 16, 2108–2118, doi:10.3762/bjoc.16.178

• ) using ethyl acetate/petroleum ether mixture to afford product 4. Examples of biologically active oxazole and aminothiazole scaffolds. Large-scale synthesis of 3i. a) At the start of the reaction, b) after the reaction. ORTEP diagram of compound 5. X-ray crystal structure of 4h. Strategies for the

How and why plants and human N-glycans are different: Insight from molecular dynamics into the “glycoblocks” architecture of complex carbohydrates

• Carl A. Fogarty,
• Aoife M. Harbison,
• Amy R. Dugdale and
• Elisa Fadda

Beilstein J. Org. Chem. 2020, 16, 2046–2056, doi:10.3762/bjoc.16.171

• invoked when discussing other biopolymers or complex carbohydrates. In the specific case of glycans, the structural complexity, in terms of the diversity of monosaccharides, the linkages’ stereochemistry and the branched scaffolds, makes the already difficult case even more intricate. Nevertheless, the

• of the addition of β(1-2)-Xyl and α(1-3)-Fuc to (F)A2G2 N-glycans scaffolds in terms of potential alteration of the (1-6) arm dynamics. β(1-2)-xylosylated mammalian N-glycans. Unlike the case of plants N-glycans, the presence of β(1-2)-Xyl hinders but does not completely prevent the (1-6) arm from

The biomimetic synthesis of balsaminone A and ellagic acid via oxidative dimerization

• Sharna-kay Daley and
• Nadale Downer-Riley

Beilstein J. Org. Chem. 2020, 16, 2026–2031, doi:10.3762/bjoc.16.169

• ]. There are many important applications of oxidative dimerization reactions, one of which is the direct synthesis of natural product scaffolds [1][7][16][17][18]. Examples of this application include the biomimetic synthesis of the bioactive natural products bismurrayaquinone A (1) [16], parvistemin A (2

Regiodivergent synthesis of functionalized pyrimidines and imidazoles through phenacyl azides in deep eutectic solvents

• Paola Vitale,
• Luciana Cicco,
• Ilaria Cellamare,
• Filippo M. Perna,
• Antonio Salomone and
• Vito Capriati

Beilstein J. Org. Chem. 2020, 16, 1915–1923, doi:10.3762/bjoc.16.158

• is an ongoing synthetic endeavor as these scaffolds are ubiquitous motifs in many biologically active compounds and pharmaceuticals. In this context, in the last decades, the so-called deep eutectic solvents (DESs) have received an increasing attention due to their biodegradability, high thermal

• place smoothly using such neoteric solvents (Scheme 1, path a) [16]. Among nitrogen-containing heterocyles, imidazoles and pyrimidines are important structural scaffolds commonly found in natural products [17][18], light-emitting devices [19][20], and pharmacologically active compounds as anticancer

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• : benzimidazoles; dihydropyrimidinones; highly substituted pyridines; natural dolomitic limestone; ultrasound irradiation; Introduction Nitrogen heterocycles are recognized as “privileged medicinal scaffolds” because these compounds are found in a wide variety of bioactive natural products and pharmaceuticals [1

Synthesis, docking study and biological evaluation of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones as potential inhibitors of the mycobacterial galactan synthesis targeting the galactofuranosyltransferase GlfT2

• Marek Baráth,
• Jana Jakubčinová,
• Zuzana Konyariková,
• Stanislav Kozmon,
• Katarína Mikušová and
• Maroš Bella

Beilstein J. Org. Chem. 2020, 16, 1853–1862, doi:10.3762/bjoc.16.152

• , Ilkovičova 6, SK-842 15 Bratislava, Slovakia 10.3762/bjoc.16.152 Abstract A series of ten novel ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones bearing a 1-O-phosphono moiety and three different substituents at C-2 has been prepared. Due to the structural similarities of these scaffolds to the native

When metal-catalyzed C–H functionalization meets visible-light photocatalysis

• Lucas Guillemard and
• Joanna Wencel-Delord

Beilstein J. Org. Chem. 2020, 16, 1754–1804, doi:10.3762/bjoc.16.147

Microwave-assisted efficient one-pot synthesis of N²-(tetrazol-5-yl)-6-aryl/heteroaryl-5,6-dihydro-1,3,5-triazine-2,4-diamines

• Moustafa Sherief Moustafa,
• Ramadan Ahmed Mekheimer,
• Saleh Mohammed Al-Mousawi,
• Mohamed Abd-Elmonem,
• Hesham El-Zorba,
• Afaf Mohamed Abdel Hameed,
• Tahany Mahmoud Mohamed and
• Kamal Usef Sadek

Beilstein J. Org. Chem. 2020, 16, 1706–1712, doi:10.3762/bjoc.16.142

• -2,4-diamines; one-pot synthesis; X-ray crystallography; Introduction The family of triazines is of considerable interest in fields related to organic and medicinal chemistry. 2,4-Diaminotriazines are privileged scaffolds exhibiting diverse biological activities such as antibacterial [1], anti-HSV-1

• specific biological target such as a receptor or an enzyme. A promising strategy that overcomes the classical one-target, one-molecule approach is the design of stable chemical hybrid molecules which are a combination of two biologically active scaffolds acting at different targets [20][21][22][23][24

Fluorohydration of alkynes via I(I)/I(III) catalysis

• Jessica Neufeld,
• Constantin G. Daniliuc and
• Ryan Gilmour

Beilstein J. Org. Chem. 2020, 16, 1627–1635, doi:10.3762/bjoc.16.135

• Selectfluor® and amine/HF mixtures, the formation of protected α-fluoroketones from simple alkynes was realised. Whilst the transient p-TolIF2 species generated in situ productively engaged with pentynyl benzoate scaffolds to generate the desired α-fluoroketone motif, augmentation or contraction of the linker

Azidophosphonium salt-directed chemoselective synthesis of (E)/(Z)-cinnamyl-1H-triazoles and regiospecific access to bromomethylcoumarins from Morita–Baylis–Hillman adducts

• Soundararajan Karthikeyan,
• Radha Krishnan Shobana,
• Kamarajapurathu Raju Subimol,
• J. Helen Ratna Monica and
• Ayyanoth Karthik Krishna Kumar

Beilstein J. Org. Chem. 2020, 16, 1579–1587, doi:10.3762/bjoc.16.130

• powerful synthetic tools. Keywords: halomethylcoumarin; Morita–Baylis–Hillman adducts; organocatalyst; phosphonium salt; triazolation; Introduction The presence of versatile functional groups in close proximity classifies Morita–Baylis–Hillman adducts as privileged key scaffolds for synthetic organic

Photocatalyzed syntheses of phenanthrenes and their aza-analogues. A review

• Alessandra Del Tito,
• Havall Othman Abdulla,
• Davide Ravelli,
• Stefano Protti and
• Maurizio Fagnoni

Beilstein J. Org. Chem. 2020, 16, 1476–1488, doi:10.3762/bjoc.16.123

• photocatalyst, have revolutionized the way chemists can arrive to important chemical scaffolds [24][25][26]. Indeed, the photocatalytic approach combines unparalleled mild conditions, due to the use of photons as traceless reagents that leave no residue behind [27][28], with the exploitation of rather

• ) finally yields the desired phenanthridine 4.4. Different radical sources R–X have been adopted to generate carbon or heteroatom-based radicals according to the general photocatalytic strategy gathered in Scheme 4, for their use in the construction of phenanthridine scaffolds. As an example, unsubstituted

• ., the 2-thienyl derivative 13.2) afforded vinyl radical 13.5·. The final intramolecular cyclization of 13.5· and re-aromatization smoothly yielded the desired polyheteroaromatic derivative (see the case of 13.6; 84% yield). Interestingly, all the obtained scaffolds bear two heteroatoms in close

One-pot synthesis of 1,3,5-triazine-2,4-dithione derivatives via three-component reactions

• Gui-Feng Kang and
• Gang Zhang

Beilstein J. Org. Chem. 2020, 16, 1447–1455, doi:10.3762/bjoc.16.120

• molecules. They are quite flexible as possible starting substrates, and through cyclization reactions, can lead to a variety of complex molecules, allowing a wide exploration of scaffolds and substituents diversity [24][25][26][27][28]. In this regard, the use of simple thiourea as an inexpensive

Synthesis of new fluorescent molecules having an aggregation-induced emission property derived from 4-fluoroisoxazoles

• Kazuyuki Sato,
• Akira Kawasaki,
• Yukiko Karuo,
• Atsushi Tarui,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2020, 16, 1411–1417, doi:10.3762/bjoc.16.117

• light ray and the structures often include fluorescein, rhodamine, or 7-amino-4-methylcoumarin (7-AMC) scaffolds as fluorophores. These fluorophores usually exhibit strong fluorescence in dilute solutions, but most of their emissions are partially or completely quenched in the solid state or in highly

Highly selective Diels–Alder and Heck arylation reactions in a divergent synthesis of isoindolo- and pyrrolo-fused polycyclic indoles from 2-formylpyrrole

• Carlos H. Escalante,
• Eder I. Martínez-Mora,
• Carlos Espinoza-Hicks,
• Alejandro A. Camacho-Dávila,
• Fernando R. Ramos-Morales,
• Francisco Delgado and
• Joaquín Tamariz

Beilstein J. Org. Chem. 2020, 16, 1320–1334, doi:10.3762/bjoc.16.113

• activity [15][16] and great diversity as building block [17][18]. Among the tetracyclic scaffolds, isoindolo[2,1-a]indoles have attracted a particular interest from the synthetic point of view, either as the target or the motif for designing novel annulation methodologies [19][20][21]. Indeed, isoindole

Synthesis of pyrrolidinedione-fused hexahydropyrrolo[2,1-a]isoquinolines via three-component [3 + 2] cycloaddition followed by one-pot N-allylation and intramolecular Heck reactions

• Xiaoming Ma,
• Suzhi Meng,
• Xiaofeng Zhang,
• Qiang Zhang,
• Shenghu Yan,
• Yue Zhang and
• Wei Zhang

Beilstein J. Org. Chem. 2020, 16, 1225–1233, doi:10.3762/bjoc.16.106

• ]isoquinolines and related ring systems [11][12][13][14][15], while medicinal chemists have also been interested in making related compounds for biological screening and drug development [16][17]. Multicomponent reactions (MCRs) have been developed as highly efficient tools for assembling heterocyclic scaffolds

• , triazolobenzodiazepines and tetrahydrochromeno[3,4-b]pyrrolizine (Scheme 2) [30][31][32][33][34][35][36][37][38][39]. Many of these scaffolds were synthesized through the combination of MCR and one-pot synthesis. A literature search indicated that a [3 + 2] cycloaddition-initiated method has also been used for the

• achieved by the combination of a three-component reaction with one-pot reactions. This synthetic sequence is a new addition of our [3 + 2] cycloaddition-initiated reactions for making diverse cyclic scaffolds. Experimental General procedure for the synthesis of pyrrolidine adducts 5 A solution of amino

Anthelmintic drug discovery: target identification, screening methods and the role of open science

• Frederick A. Partridge,
• Ruth Forman,
• Carole J. R. Bataille,
• Graham M. Wynne,
• Marina Nick,
• Angela J. Russell,
• Kathryn J. Else and
• David B. Sattelle

Beilstein J. Org. Chem. 2020, 16, 1203–1224, doi:10.3762/bjoc.16.105

• the motility and a range of other phenotype scores, leading to the identification of 2 new small molecules with distinct chemical scaffolds 17 and 18 with activity against schistosomula and adult worms at low micromolar concentrations (Figure 4). Another CellProfiler toolbox enables the quantitation

Activated carbon as catalyst support: precursors, preparation, modification and characterization

• Melanie Iwanow,
• Tobias Gärtner,
• Volker Sieber and
• Burkhard König

Beilstein J. Org. Chem. 2020, 16, 1188–1202, doi:10.3762/bjoc.16.104

• , controllable particle sizes and large uniform pores received much attention [97][98]. One possibility to prepare such carbon spheres with defined particle sizes and pore structures is the nanocasting strategy using silica scaffolds as shown by Fuertes [99]. Nevertheless, due to the complex and high-cost

• preparation of these carbon materials (preparation of the solid scaffolds, pyrolysis of the carbon precursors in these templates and finally, the selective removal of the silica template) and the risk of structure and morphology defects by the harsh carbonization and template removal processes, this method is

Photocatalysis with organic dyes: facile access to reactive intermediates for synthesis

• Stephanie G. E. Amos,
• Marion Garreau,
• Luca Buzzetti and
• Jerome Waser

Beilstein J. Org. Chem. 2020, 16, 1163–1187, doi:10.3762/bjoc.16.103

• either oxidative or reductive SET with an excited photoredox catalyst. The most used scaffolds consist of electron-poor O-acyl and O-aryl hydroxylamines, which are prone to reduction, and α-N-oxy acids, which undergo oxidations followed by β-scission [128][136][139]. Leonori first described how O-aryl

Copper-based fluorinated reagents for the synthesis of CF₂R-containing molecules (R ≠ F)

• Louise Ruyet and
• Tatiana Besset

Beilstein J. Org. Chem. 2020, 16, 1051–1065, doi:10.3762/bjoc.16.92

• fluorine atom or a fluorinated moiety of unique properties [15]. Despite the tremendous advances made in that field, key synthetic challenges remain to synthesize fluorinated scaffolds. Among the different developed strategies to ravel synthetic issues, the use of inexpensive and readily available copper

Fluorinated phenylalanines: synthesis and pharmaceutical applications

• Laila F. Awad and
• Mohammed Salah Ayoup

Beilstein J. Org. Chem. 2020, 16, 1022–1050, doi:10.3762/bjoc.16.91

• are nowadays incorporated into drug scaffolds of compounds either licensed or currently being studied in clinical trials. Categories I–V of fluorinated phenylalanines. Structures of PET radiotracers of 18FPhe derivatives. Structures of melfufen (179) and melphalan (180) anticancer drugs. Structure of