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

Bacterial terpene biosynthesis: challenges and opportunities for pathway engineering

• Eric J. N. Helfrich,
• Geng-Min Lin,
• Christopher A. Voigt and
• Jon Clardy

Beilstein J. Org. Chem. 2019, 15, 2889–2906, doi:10.3762/bjoc.15.283

• functional roles, which range from widely distributed metabolites like cholesterol, to those with more restricted distribution like vitamins A and D, carotenoids, and steroid hormones, to some with highly restricted distribution like pheromones, fragrances, and defense metabolites [2][3]. Many of the more

• be obtained via feeding the engineered strain with substrate analogs. This integration of multiple strategies highlights the great potential of synthetic biology for the production of valuable complex terpenoids [157]. Conclusion Despite the ubiquitous distribution of terpene biosynthetic pathways in

• ) Terpene biosynthesis. LG: leaving group, black ball: acyl carrier protein. Abundance and distribution of bacterial terpene biosynthetic gene clusters as determined by genome mining (black) compared to experimentally characterized bacterial terpene BGCs (red). Terpenoid biosynthesis. Terpenoid biosynthesis

Emission and biosynthesis of volatile terpenoids from the plasmodial slime mold Physarum polycephalum

• Xinlu Chen,
• Tobias G. Köllner,
• Wangdan Xiong,
• Guo Wei and
• Feng Chen

Beilstein J. Org. Chem. 2019, 15, 2872–2880, doi:10.3762/bjoc.15.281

• amoeba now indicates a broader distribution of TPS genes. To understand whether TPS genes occur in other groups of amoebae, in this study, we investigated Physarum polycephalum. P. polycephalum belongs to the class of Myxogastria whereas social amoeba belongs to the class of Dictyostelia, but they both

Carbazole-functionalized hyper-cross-linked polymers for CO₂ uptake based on Friedel–Crafts polymerization on 9-phenylcarbazole

• Dandan Fang,
• Xiaodong Li,
• Meishuai Zou,
• Xiaoyan Guo and
• Aijuan Zhang

Beilstein J. Org. Chem. 2019, 15, 2856–2863, doi:10.3762/bjoc.15.279

• a high surface area and a high total pore volume. The BET specific surface areas of P3 was up to 769 m2 g−1 with narrow pore size distribution and the CO2 adsorption capacity of P11 was up to 52.4 cm3 g−1 (273 K/1.00 bar). Keywords: 9-phenylcarbazole; CO2 uptake; Friedel–Crafts polymerization

• ]. The hysteresis between adsorption and desorption of P2–P4 indicates that the polymers contain mesopores [37]. There is no sharp rise at high relative pressures (P/P0 > 0.9) of P1–P5, which means that scarcely macropores exist in the networks [38]. The pore size distribution (Figure 6b) was calculated

• from the adsorption branches using nonlocal density functional theory (NLDFT) methods. P2–P5 exhibited narrow pore size distribution in the micropore scopes (<2 nm), while P1 showed a wide pore size distribution. The surface areas of P1–P5 ranged from 350 to 769 m2 g−1 (Table 2). The lowest specific

A combinatorial approach to improving the performance of azoarene photoswitches

• Joaquin Calbo,
• Aditya R. Thawani,
• Rosina S. L. Gibson,
• Andrew J. P. White and
• Matthew J. Fuchter

Beilstein J. Org. Chem. 2019, 15, 2753–2764, doi:10.3762/bjoc.15.266

• accurate enough for TS analysis. We refer to our prior publication [18] for details of the theoretical protocol used to compute half-lives. The Boltzmann distribution was applied to the energy barriers [18] and to the relative energy differences between all possible Z-conformers. Note that half-lives are

Plasma membrane imaging with a fluorescent benzothiadiazole derivative

• Pedro H. P. R. Carvalho,
• Jose R. Correa,
• Karen L. R. Paiva,
• Daniel F. S. Machado,
• Jackson D. Scholten and
• Brenno A. D. Neto

Beilstein J. Org. Chem. 2019, 15, 2644–2654, doi:10.3762/bjoc.15.257

• incubated with BTD-4APTEG (1 μM) in live (A) and (B) and fixed cells (C) and (D). (A) and (C) show the staining distribution of the new dye BTD-4APTEG in the plasma membrane of the cells. (B) and (D) show the normal morphological aspects of the samples by phase contrast microscopy. The dye was found

Probing of local polarity in poly(methyl methacrylate) with the charge transfer transition in Nile red

• Aydan Yadigarli,
• Qimeng Song,
• Sergey I. Druzhinin and
• Holger Schönherr

Beilstein J. Org. Chem. 2019, 15, 2552–2562, doi:10.3762/bjoc.15.248

• permittivity of polymers and its spatial distribution play a crucial role in the behavior of thin films, such as those used, e.g., as sensor coatings. In an attempt to develop a conclusive approach to determine these quantities, the polarity of the model polymer poly(methyl methacrylate) (PMMA) in 600 nm thin

• particular, the spatial distribution of the dielectric constant measured for thin PMMA films was described using NR as a reported dye [15]. Because NR is (i) a photostable dye, (ii) possesses convenient optical properties, such as excitation with visible light, and fluorescence, which does not overlay with

• absorption of many biomolecules, and (iii) exhibits fluorescence, which is strongly influenced by the polarity of the environment, it has been employed as a polarity probe in biological applications [16][17][18][19] and materials/nanoscience [15][20][21][22][23]. For instance, the spatial distribution of the

Ultrafast processes triggered by one- and two-photon excitation of a photochromic and luminescent hydrazone

• Alessandro Iagatti,
• Baihao Shao,
• Alberto Credi,
• Barbara Ventura,
• Ivan Aprahamian and
• Mariangela Di Donato

Beilstein J. Org. Chem. 2019, 15, 2438–2446, doi:10.3762/bjoc.15.236

• distribution of the excited-state decays reveals the presence of a short component in the blue region of the spectrum (440–460 nm) which is not present in the remaining emission region (500–600 nm). A weak emission in this region is also observed in the steady-state fluorescence spectra obtained upon

• positive signal at <380 nm, where absorption of the E-isomer is expected, signals the occurrence of isomerization. This event is also associated to the aforementioned evolution in the visible region, clearly indicating a variation of the excited state electronic distribution. No further band-shape changes

Current understanding and biotechnological application of the bacterial diterpene synthase CotB2

• Ronja Driller,
• Daniel Garbe,
• Norbert Mehlmer,
• Monika Fuchs,
• Keren Raz,
• Dan Thomas Major,
• Thomas Brück and
• Bernhard Loll

Beilstein J. Org. Chem. 2019, 15, 2355–2368, doi:10.3762/bjoc.15.228

• three Mg2+ ions [1][22]. Notably, the PtmT1 diterpene synthase from S. platensis lacks both catalytic motifs [20][23]. The NSE/DTE motif illustrates the distribution of DTE motifs, which are predominantly found in plant TPSs, and NSE motifs, which are more common in bacterial and fungal TPSs. For the

Isolation of fungi using the diffusion chamber device FIND technology

• Benjamin Libor,
• Henrik Harms,
• Stefan Kehraus,
• Ekaterina Egereva,
• Max Crüsemann and
• Gabriele M. König

Beilstein J. Org. Chem. 2019, 15, 2191–2203, doi:10.3762/bjoc.15.216

• inserted into a tank containing 40 L of soil for experiment 1, 2 L of sea water and sediment for experiment 2, 20 L of sea water and sediment for experiment 3 and sea water for experiment 4. An aquarium powerhead pump provided water current for simulation, oxygenation and distribution purposes for

Click chemistry towards thermally reversible photochromic 4,5-bisthiazolyl-1,2,3-triazoles

• Chenxia Zhang,
• Kaori Morinaka,
• Mahmut Kose,
• Takashi Ubukata and
• Yasushi Yokoyama

Beilstein J. Org. Chem. 2019, 15, 2161–2169, doi:10.3762/bjoc.15.213

• are compared, the thermal back reaction rate of 3 is extremely faster than the others, although the central aromatic ring is common to these compounds. As shown in Table 4, neither electronic charge distribution on the carbon atoms (natural charge [42]) comprising the thermally breaking C–C bond, its

Genome mining in Trichoderma viride J1-030: discovery and identification of novel sesquiterpene synthase and its products

• Xiang Sun,
• You-Sheng Cai,
• Yujie Yuan,
• Guangkai Bian,
• Ziling Ye,
• Zixin Deng and
• Tiangang Liu

Beilstein J. Org. Chem. 2019, 15, 2052–2058, doi:10.3762/bjoc.15.202

• . viride to date. Keywords: genome mining; metabolic engineering; natural products; sesquiterpene synthase; terpenes; Trichoderma viride J1-030; Introduction Terpenoids represent the most diverse group of natural products, with a wide distribution in microorganisms, plants, insects and various marine

Attempted synthesis of a meta-metalated calix[4]arene

• Christopher D. Jurisch and
• Gareth E. Arnott

Beilstein J. Org. Chem. 2019, 15, 1996–2002, doi:10.3762/bjoc.15.195

• dichloro(p-cymene)ruthenium(II) dimer or the triazolium chloride salt already observed. As a last attempt to find evidence for the ruthenacycle, a high-resolution mass spectrum was acquired directly after the reaction was completed. The most important isotopic distribution detected was at 984.4283 Da

• , which corresponded to the expected [M − Cl]+ ion with Δmi = 2.30 ppm (Figure 4). However, this peak was very small and overlapped slightly with another isotopic distribution pattern that corresponded to [M + H − C3H6], i.e., loss of propene (see Supporting Information File 1 for a closer view of this

• ). The major peak observed had a monoisotopic mass of 1020.4040 Da which fitted the predicted value for [M + H]+ of 1020.4020 Da (Δmi = 1.95 ppm) including the isotopic distribution pattern (Figure 4). Unfortunately, whilst this could represent the ruthenacycle, the more likely assignment would be for

Reactions of 2-carbonyl- and 2-hydroxy(or methoxy)alkyl-substituted benzimidazoles with arenes in the superacid CF₃SO₃H. NMR and DFT studies of dicationic electrophilic species

• Dmitry S. Ryabukhin,
• Alexey N. Turdakov,
• Natalia S. Soldatova,
• Mikhail O. Kompanets,
• Alexander Yu. Ivanov,
• Irina A. Boyarskaya and
• Aleksander V. Vasilyev

Beilstein J. Org. Chem. 2019, 15, 1962–1973, doi:10.3762/bjoc.15.191

• the formation of heteroaromatic benzyl-type dications IV, VI, and IX, respectively. Electronic characteristics, energies of HOMO/LUMO, electrophilicity indices ω [25][26], charge distribution, and contribution of atomic orbital into the LUMO of species I–IX were calculated by DFT method to estimate

Identification of optimal fluorescent probes for G-quadruplex nucleic acids through systematic exploration of mono- and distyryl dye libraries

• Xiao Xie,
• Michela Zuffo,
• Marie-Paule Teulade-Fichou and
• Anton Granzhan

Beilstein J. Org. Chem. 2019, 15, 1872–1889, doi:10.3762/bjoc.15.183

• dot distribution in the plot, the mono-styryl motif and the pyrrole substituent within the distyryl motif (1x, 7x) clearly promote the selectivity for the parallel G4 structures. On the other side, the effect of the indole motif is less clear, with most of the dyes not displaying any well-defined

• light-up data matrix for all dyes (ct DNA and cl RNA were excluded, as well as TBA and c-myb due to their low light-up factors). Color coding highlights the distribution of the dyes sharing similar structural motifs. Dual-dye conformational analysis of an extended panel of 33 DNA oligonucleotides. This

Halide metathesis in overdrive: mechanochemical synthesis of a heterometallic group 1 allyl complex

• Ross F. Koby,
• Nicholas R. Rightmire,
• Nathan D. Schley,
• Timothy P. Hanusa and
• William W. Brennessel

Beilstein J. Org. Chem. 2019, 15, 1856–1863, doi:10.3762/bjoc.15.181

• sites, the value of ∆S = +17 J mol−1 K−1 is obtained. At 298 K, the −T∆S value is −5.1 kJ mol−1. As imperfect as this approximation is (e.g., the distribution of metal ions is not completely random, and the coordination environments are not exactly the same), it does suggest one source of driving force

Transient and intermediate carbocations in ruthenium tetroxide oxidation of saturated rings

• Manuel Pedrón,
• Laura Legnani,
• Maria-Assunta Chiacchio,
• Pierluigi Caramella,
• Tomás Tejero and
• Pedro Merino

Beilstein J. Org. Chem. 2019, 15, 1552–1562, doi:10.3762/bjoc.15.158

• corresponding to TS1, TS2 and TS3 have allowed identifying changes in the electron distribution of atoms and bonds during the reaction coordinate and the precise moment in which bonds are broken and formed. The ELF analysis of the oxidation of cyclopentane (Figure 2) showed an asynchronous concerted process

A heteroditopic macrocycle as organocatalytic nanoreactor for pyrroloacridinone synthesis in water

• Piyali Sarkar,
• Sayan Sarkar and
• Pradyut Ghosh

Beilstein J. Org. Chem. 2019, 15, 1505–1514, doi:10.3762/bjoc.15.152

• issue for the stabilization of the activated complex by a hydrophobic catalyst [31]. Again, the efficiency of an organocatalyst could be enhanced by downsizing the catalyst at nanorange distribution (i.e., nanoreactor) [13][14]. This is because a nanoreactor allows for precise interactions with the

• subjected to various studies like SEM, TEM and DLS experiments. The DLS data revealed that the dispersed particles size in the aqueous phase varied from ≈60 nm to ≈105 nm (Figure 2a). Interestingly, when the same dispersion was used for the analysis of the particle size distribution on a solid surface, i.e

• using 60–120 mesh silica gel and petroleum ether/ethyl acetate mixture as eluent. We got pure products at 3–4% ethyl acetate in petroleum ether and the pure catalyst using 5% methanol in dichloromethane. Bis-amido-tris-amine macrocycle BATA-MC. (a) Number distribution plot with particle size in DLS, (b

Reaction of oxiranes with cyclodextrins under high-energy ball-milling conditions

• László Jicsinszky,
• Federica Calsolaro,
• Katia Martina,
• Fabio Bucciol,
• Maela Manzoli and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2019, 15, 1448–1459, doi:10.3762/bjoc.15.145

• and slightly waxy, which demonstrates their PG content. A comparison of DS, by 1H NMR, and the product distribution of the ESIMS data showed a Gaussian-like distribution of masses in the range of 1–11, which was independent of the target DS. The ESIMS of the neutral HPCDs resulted in a complex

• the formed polymers are in progress. Under an electron microscope, the bead polymer showed a smooth surface and a non-Gaussian particle-size distribution that was centred around 65–70 µm, while the ball-milled CDPs were completely bumpy and considerably smaller than the bead polymer, as seen in Figure

•  2 and Figure 3. Higher aggregation of particles of β-CDP was found when it had been prepared on a 2 mmol scale as compared to either the γ-CDP or β-CDP on a 20 mmol scale. The particle-size distribution, which was determined using the quasi elastic light scattering (QELS) method, was relatively