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

• heating to 473 K until blue spots appeared. Column chromatography was conducted by using silica gel 60 with a particle size distribution of 40–63 μm and 230–400 ASTM, using hexane/EtOAc mixtures as the eluent. High-resolution mass spectrometry (HRMS) analyses were performed using a Bruker microTOF QII

Design, synthesis and application of carbazole macrocycles in anion sensors

• Alo Rüütel,
• Ville Yrjänä,
• Sandip A. Kadam,
• Indrek Saar,
• Mihkel Ilisson,
• Astrid Darnell,
• Kristjan Haav,
• Tõiv Haljasorg,
• Lauri Toom,
• Johan Bobacka and
• Ivo Leito

Beilstein J. Org. Chem. 2020, 16, 1901–1914, doi:10.3762/bjoc.16.157

• hydrogen bonding. The primary site of interaction is the X-COO− group. The geometry of the carboxylate group (and to a large extent also its charge distribution) is the same for all carboxylate anions. Therefore, high affinity towards carboxylates is easily achievable, but selectivity towards a specific

Three new O-isocrotonyl-3-hydroxybutyric acid congeners produced by a sea anemone-derived marine bacterium of the genus Vibrio

• Dandan Li,
• Enjuro Harunari,
• Tao Zhou,
• Naoya Oku and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1869–1874, doi:10.3762/bjoc.16.154

• (Figure 3a). Note that the sign distribution of the Δδ(S − R) values in β,β-substituted carboxylic acids is inverted from that observed in the α,α-substituted counterparts (Figure 3b) because the PGME anisotropy group is flipped upside down due to the insertion of an extra methylene group between the

• test compounds. Structures of the compounds 1–5. COSY (bold lines) and selected HMBC correlations (arrows) for 1–4. a) Distribution of positive (red) and negative (blue) Δδ(S − R) values (in ppm) calculated from the 1H NMR chemical shifts of the (S)- and (R)-PGME amides of 1–4. b) Comparison of the

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

• complex structure and also mimic its partial charges and charge distribution. Herein, the molecular docking, synthesis and inhibitory activity of ᴅ-fructofuranosyl and ᴅ-tagatofuranosyl sulfones 1–3 against GlfT2 are discussed. Moreover, we extended the scope of the simultaneous phosphorylation and

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

• size distribution of the deposited nanoparticles [158]. Colmenares and co-workers have reported these methodologies for the synthesis of TiO2 HPCats doped with various transition metals, such as Fe, Pd, Pt, and Au [159][160][161]. For more information, we recommend a recent review published by

In silico rationalisation of selectivity and reactivity in Pd-catalysed C–H activation reactions

• Liwei Cao,
• Mikhail Kabeshov,
• Steven V. Ley and
• Alexei A. Lapkin

Beilstein J. Org. Chem. 2020, 16, 1465–1475, doi:10.3762/bjoc.16.122

• reaction intermediates, the ratio of products was calculated from the relative energies of these intermediates using the Boltzmann distribution equation. Establishing the threshold between the two mechanisms Although both, the proton-abstraction and the electrophilic aromatic-substitution, mechanisms are

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

• distribution of boron ketoiminate scaffold induced by the strong electronegative fluorine atom [39]. The FL intensities were lower than that of the corresponding BKIs, a similar tendency to what was also observed in other F-BKIs 9a and 9c. In summary, we found that the F-BKIs described in this report exhibited

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

• -ray data from CSD about the distance of the Cethynyl–H···π interaction [76], an average distance value (ca. 3.0 Å) above the benzene ring centroid can be considered for the statistical distribution of the Cethenyl–H···π interaction [76], which is longer than present calculated value. On the other hand

[3 + 2] Cycloaddition with photogenerated azomethine ylides in β-cyclodextrin

• Margareta Sohora,
• Leo Mandić and
• Nikola Basarić

Beilstein J. Org. Chem. 2020, 16, 1296–1304, doi:10.3762/bjoc.16.110

• inclusion complexes 2@β-CD and 3@β-CD was investigated, and we found out that β-CD does not affect the decarboxylation efficiency, while it affects the subsequent photochemical H-abstraction, resulting in different product distribution upon irradiation in the presence of β-CD. The formation of ternary

• in the presence and absence of β-CD. However, for the adamantane derivative in the presence of β-CD, the secondary photochemical H-abstraction became more efficient, resulting in a different product distribution. More efficient H-abstraction reaction in the presence of β-CD have been reported [16]. β

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

• schistosomiasis treatment is the effect which climate change may have on aquatic environments (and the intermediate freshwater snail host Biomphalaria glabrata) and therefore on the distribution of water-borne diseases like schistosomiasis [47]. Similarly to the STHs, the WHO 2020 target for schistosomiasis is

• drug development and the approval of tafenoquine (11) and fexinadole (10) [68][69]. With increasing concerns over the potential emergence of resistance to currently deployed anthelmintics, the possibility of climate change altering the distribution of these parasites, coupled with the inability of the

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

• basic conditions, the pore size distribution and the chemical properties on the surface can be adjusted (polarity and hydrophobicity) according to the envisaged application. In addition, metal particles can be recovered simply by burning the carbon support [1][2]. Thus, porous carbon materials represent

• ) activation methods for the modification of the porosity of anthracite-based activated carbons. The final pore size distribution (mainly microporous or mainly mesoporous) depends on the choice of the activation agent, the treatment time and temperature and the initial textural properties of anthracite as

• the surface of the treated carbons in form of carboxyl groups, ketones, ether groups and carboxyl-carbonate structures is higher using nitric acid compared to hydrogen peroxide [116]. Nitrogen adsorption–desorption isotherms: The surface area and pore size distribution of solid catalyst materials can

Development of fluorinated benzils and bisbenzils as room-temperature phosphorescent molecules

• Shigeyuki Yamada,
• Takuya Higashida,
• Yizhou Wang,
• Masato Morita,
• Takuya Hosokai,
• Kaveendra Maduwantha,
• Kaveenga Rasika Koswattage and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 1154–1162, doi:10.3762/bjoc.16.102

• (HOMO)→lowest unoccupied molecular orbital (LUMO) transition. Focusing on the orbital distribution, the HOMO lobe of 2a covers the entire molecule, while the LUMO lobe is localized at the tolane moiety. In the case of 3a, the HOMO lobe is localized at the methoxy-substituted benzene ring, while the LUMO

• corresponding bis-oxidized bisbenzil derivatives. Based on theoretical calculations, the selective formation of the fluorinated analogues stemmed from the slight modulation of the charge distribution at the alkyne moiety of the reactant induced by the electron-withdrawing fluorine atoms. Evaluation of the

The charge-assisted hydrogen-bonded organic framework (CAHOF) self-assembled from the conjugated acid of tetrakis(4-aminophenyl)methane and 2,6-naphthalenedisulfonate as a new class of recyclable Brønsted acid catalysts

• Svetlana A. Kuznetsova,
• Alexander S. Gak,
• Yulia V. Nelyubina,
• Vladimir A. Larionov,
• Han Li,
• Michael North,
• Vladimir P. Zhereb,
• Alexander F. Smol'yakov,
• Artem O. Dmitrienko,
• Michael G. Medvedev,
• Igor S. Gerasimov,
• Ashot S. Saghyan and
• Yuri N. Belokon

Beilstein J. Org. Chem. 2020, 16, 1124–1134, doi:10.3762/bjoc.16.99

• architectures have been discovered, which allow a rigid and uniform distribution of a single well-defined catalytic or precatalytic center within a solid matrix. Of these, metal–organic frameworks (MOFs) [13][14][15][16][17][18] and covalent organic frameworks (COFs) [19][20][21][22] have been the forerunners

• ][31], gas separation and absorption [28][29], enzyme encapsulation [36], and even asymmetric synthesis (albeit with a framework that contained a transition metal ion) [37]. However, for the HOF and CAHOF catalysts to have a similar appeal to other regular active site distribution materials, such as

• . It had a “tangerine wedge” morphology (Figure 3 and Figures S9 and S10, Supporting Information File 1), with evident macropores present on the surface of the particles. The size distribution of the F-1 particles was in the range of 3–5 to 45–50 μm, and most of the particles had a size within a range

A cyclopeptide and three oligomycin-class polyketides produced by an underexplored actinomycete of the genus Pseudosporangium

• Shun Saito,
• Kota Atsumi,
• Tao Zhou,
• Keisuke Fukaya,
• Daisuke Urabe,
• Naoya Oku,
• Md. Rokon Ul Karim,
• Hisayuki Komaki and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1100–1110, doi:10.3762/bjoc.16.97

• species demonstrated that the distribution of secondary metabolite biosynthetic genes was not the same even in phylogenetically close species [11]. This finding became our starting point to explore the secondary metabolism in actinomycete genera from which no secondary metabolites were described. “Rare

• minimum energy. The ECD spectra of the 6 structures were simulated by the calculation of 25 states using TD-DFT at the ωB97X-D/Def2-TZVP-PCM(MeCN) level of theory, and then averaged based on their Boltzmann distribution. The calculated ECD spectra were red-shifted by 15 nm. The NMR and ECD spectra of

Aldehydes as powerful initiators for photochemical transformations

• Maria A. Theodoropoulou,
• Nikolaos F. Nikitas and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2020, 16, 833–857, doi:10.3762/bjoc.16.76

• electronic distribution and the spectroscopy of the excited states of benzaldehyde (8) have been examined. These studies illuminate the ways that the various excited states of benzaldehyde (8) decay, either through phosphorescence or through the dissociation to benzene (21) and carbon monoxide (22) or to a

One-pot synthesis of dicyclopenta-fused peropyrene via a fourfold alkyne annulation

• Ji Ma,
• Yubin Fu,
• Junzhi Liu and
• Xinliang Feng

Beilstein J. Org. Chem. 2020, 16, 791–797, doi:10.3762/bjoc.16.72

• peropyrene 1. Furthermore, the observed isotopic distribution was fully consistent with its simulated spectrum (Figure 1). Characterization of the resultant product by single crystal X-ray analysis unambiguously revealed the selective formation of 1 through twofold [3 + 2] pentannulation and sequent twofold

• -fused PAHs in large π-systems. High-resolution MALDI-TOF mass spectrum of 1. Inset: isotopic distribution compared to mass spectrum simulated for C84H50. Single-crystal X-ray structure of 1. (a) Top view and (b) side view of the (P,P) isomer. c) Crystal packing of the enantiomer pairs (P,P and M,M) of 1

Direct borylation of terrylene and quaterrylene

• Haruka Kano,
• Keiji Uehara,
• Kyohei Matsuo,
• Hironobu Hayashi,
• Hiroko Yamada and
• Naoki Aratani

Beilstein J. Org. Chem. 2020, 16, 621–627, doi:10.3762/bjoc.16.58

• )-catalyzed direct C–H borylation [22][23][24][25] gives 2,5,8,11-tetraborylated perylene [26]. The regioselectivity of the perylene borylation is determined by the steric factors rather than by the electron distribution in the arene and this regioselectivity complements that of electrophilic substitutions

• at the B3LYP/6-31G(d) level and with Gaussian 09, to make these electronic features understandable (Figure 4) [27]. The HOMO, HOMO–1, LUMO, and LUMO+1 for terrylene are nondegenerative and the coefficient distribution in these four frontier MOs seem to be delocalized over the whole aromatic core. The

• ], a slightly red-shifted absorption peak at 668 nm is observed. Interestingly, QB4 emits only weak fluorescence as was described for tetra-tert-butylquaterrylene [20]. The coefficient distribution of four frontier MOs of quaterrylenes basically exhibits the same symmetric pattern with terrylenes

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• , with a high surface area, could be employed as electronic devices, thermal or electronic insulators, catalysts, and humidity sensors [24]. Moreover, mesoporous silica nanomaterials benefit from unique properties, including a large surface area, uniform pore size and distribution, high chemical/thermal

Photophysics and photochemistry of NIR absorbers derived from cyanines: key to new technologies based on chemistry 4.0

• Bernd Strehmel,
• Christian Schmitz,
• Ceren Kütahya,
• Yulian Pang,
• Anke Drewitz and
• Heinz Mustroph

Beilstein J. Org. Chem. 2020, 16, 415–444, doi:10.3762/bjoc.16.40

Formal preparation of regioregular and alternating thiophene–thiophene copolymers bearing different substituents

• Atsunori Mori,
• Keisuke Fujita,
• Chihiro Kubota,
• Toyoko Suzuki,
• Kentaro Okano,
• Takuya Matsumoto,
• Takashi Nishino and
• Masaki Horie

Beilstein J. Org. Chem. 2020, 16, 317–324, doi:10.3762/bjoc.16.31

• weight (Mn) and the molecular weight distribution (Mw/Mn) were estimated by SEC analysis. HT = 98%, Mn = 10400, Mw = 16900, Mw/Mn = 1.62; 1H NMR (400 MHz, CDCl3) δ 0.02–0.08 (br, 15H), 0.50–0.63 (m, 2H), 1.41–1.52 (m, 2H), 1.64–1.78 (m, 2H), 2.44 (s, 3H), 2.75–2.85 (m, 2H), 6.95 (s, 1H), 6.99 (s, 1H); IR

Two antibacterial and PPARα/γ-agonistic unsaturated keto fatty acids from a coral-associated actinomycete of the genus Micrococcus

• Amit Raj Sharma,
• Enjuro Harunari,
• Naoya Oku,
• Nobuyasu Matsuura,
• Agus Trianto and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 297–304, doi:10.3762/bjoc.16.29

• . Unlike the majority of actinomycetes, they typically form tetrad clusters but not hyphae [10]. Micrococcus is ubiquitous in distribution and, similar to other actinomycetes, marine Micrococcus are commonly associated with marine invertebrates, such as sponges and corals [4][11][12]. Distinct classes of

• fatty acids bearing a keto group in the middle of the carbon chain are relatively limited in their distribution in nature. Many of such natural keto fatty acids were found in plants, mainly as a constituent of seed oil [21][22][23][24][25][26][27][28][29]. Among them, rabdosia acids [30] and (10E,12E)-9

Combination of multicomponent KA² and Pauson–Khand reactions: short synthesis of spirocyclic pyrrolocyclopentenones

• Riccardo Innocenti,
• Elena Lenci,
• Gloria Menchi and
• Andrea Trabocchi

Beilstein J. Org. Chem. 2020, 16, 200–211, doi:10.3762/bjoc.16.23

• of compounds 3–39, in comparison with a reference set of 40 brand-name blockbuster drugs [66][67] (Figure 3), showed the different distribution of compounds 3–39 in two different clusters. Most of the compounds reside in the first cluster, positioned in the negative direction of x axis, in a region

Synthesis of 3-alkenylindoles through regioselective C–H alkenylation of indoles by a ruthenium nanocatalyst

• Abhijit Paul,
• Debnath Chatterjee,
• Srirupa Banerjee and
• Somnath Yadav

Beilstein J. Org. Chem. 2020, 16, 140–148, doi:10.3762/bjoc.16.16

• photolysis, was characterised by TEM (Figure S1, Supporting Information File 1), which showed polydispersed spherical particles of a size distribution mainly in the range of 10–25 nm, with a mean diameter of 15 nm. The size distribution of the particles from Figure S1, Supporting Information File 1, is

Pigmentosins from Gibellula sp. as antibiofilm agents and a new glycosylated asperfuran from Cordyceps javanica

• Soleiman E. Helaly,
• Wilawan Kuephadungphan,
• Patima Phainuphong,
• Mahmoud A. A. Ibrahim,
• Kanoksri Tasanathai,
• Suchada Mongkolsamrit,
• Janet Jennifer Luangsa-ard,
• Souwalak Phongpaichit,
• Vatcharin Rukachaisirikul and
• Marc Stadler

Beilstein J. Org. Chem. 2019, 15, 2968–2981, doi:10.3762/bjoc.15.293

• of the 2D NMR data revealed that beauverolide Jb (6) comprised a leucine moiety instead of isoleucine in beauverolide Ja (see NMR data in the Experimental section and Figures S30–S34 in Supporting Information File 1). Chemotaxonomic investigation In order to investigate the distribution patterns of

Synthesis and optoelectronic properties of benzoquinone-based donor–acceptor compounds

• Daniel R. Sutherland,
• Nidhi Sharma,
• Georgina M. Rosair,
• Ifor D. W. Samuel,
• Ai-Lan Lee and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2019, 15, 2914–2921, doi:10.3762/bjoc.15.285

• of 3 and 4. HOMO/LUMO and S1/T1 energies as well as HOMO/LUMO electron density distribution profiles of 2–5. Cyclic voltammograms and differential pulse voltammograms of 2–5 in degassed DCM (scan rate = 100 mV·s−1). UV–vis absorption spectra of 2–5 in DCM and photoluminescence spectrum of 3 in