A new and efficient methodology for olefin epoxidation catalyzed by supported cobalt nanoparticles

• Lucía Rossi-Fernández,
• Viviana Dorn and
• Gabriel Radivoy

Beilstein J. Org. Chem. 2021, 17, 519–526, doi:10.3762/bjoc.17.46

• , operated at an acceleration voltage of 100 kV. Approximately one hundred metal particles were measured to perform the particle size distribution. The cobalt content in the supported catalyst was determined by inductively coupled plasma atomic emission spectroscopy (ICP-AES), on a Spectro Arcos instrument

• ). The recovered solid catalyst was washed with acetonitrile (3 × 2 mL) and dried in an oven (150 °C, 1 h) for its reuse. TEM micrograph and size distribution graphic for CoNPs@MgO catalyst (scale bar = 20 nm). Plausible mechanistic pathway for olefin epoxidation catalyzed by CoNPs/MgO in the presence of

Synthesis and physicochemical evaluation of fluorinated lipopeptide precursors of ligands for microbubble targeting

• Masayori Hagimori,
• Estefanía E. Mendoza-Ortega and
• Marie Pierre Krafft

Beilstein J. Org. Chem. 2021, 17, 511–518, doi:10.3762/bjoc.17.45

• blood circulation times by allowing them to evade immune detection. PEGs often play a key role in the design of the ligands as a spacer between the nanocarrier surface and the lipid. PEGs have, however, some shortcomings, such as a broad molecular weight distribution, large steric hindrance, and the

• with a Nikon Eclipse 90i microscope (transmission mode, Nikon Instruments Europe, Amsterdam, The Netherlands). A rapid image acquisition was achieved using a Lumenera Infinity 2 charge-coupled device (CCD) camera (Lumenera, Ottawa, Canada). The bubble mean diameter and distribution width after

• ). Optical micrographs and corresponding size distribution of the perfluorohexane-stabilized microbubbles with a shell of a) DPPC, b) DPPC/F-lipopeptide 3, and c) DPPC/hydrocarbon analog 4. Half-lives of microbubbles (25 °C) containing F-lipopeptides 1–3 and hydrocarbon analog 4. a) Schematic representation

Mesoionic tetrazolium-5-aminides: Synthesis, molecular and crystal structures, UV–vis spectra, and DFT calculations

• Vladislav A. Budevich,
• Sergei V. Voitekhovich,
• Alexander V. Zuraev,
• Vadim E. Matulis,
• Vitaly E. Matulis,
• Alexander S. Lyakhov,
• Ludmila S. Ivashkevich and
• Oleg A. Ivashkevich

Beilstein J. Org. Chem. 2021, 17, 385–395, doi:10.3762/bjoc.17.34

• water vs 0.017 Å in n-hexane). Note, that a greater positive τ index indicates a stronger charge separation as a result of the electron transition [36]. Hence, in the case of n-hexane, the distribution of the positive and negative charge is almost not separated, and the CT is small. However, for the

• water solution, the distribution of the positive and negative charge is significantly separated due to a strong CT. Considering that in polar media the S0→S1 electron excitation corresponds to the n→π* transition, leading to a significant CT from the =N5–H group to the tetrazole ring, we can explain the

Annulation of a 1,3-dithiole ring to a sterically hindered o-quinone core. Novel ditopic redox-active ligands

• Sergey V. Norkov,
• Anton V. Cherkasov,
• Andrey S. Shavyrin,
• Maxim V. Arsenyev,
• Viacheslav A. Kuropatov and
• Vladimir K. Cherkasov

Beilstein J. Org. Chem. 2021, 17, 273–282, doi:10.3762/bjoc.17.26

• mixture. X-ray diffraction data revealed that the bond lengths distribution in the six-membered ring of 6b is typical of sterically hindered o-quinones. The annulated fragment including the 1,3-dithiole cycle and the malononitrile unit is almost flat. The six-membered o-quinone ring is distorted due to

• -quinone 4. Each o-quinone molecule bridges two adjacent sodium ions. The bond lengths distribution in the o-quinone moiety in 8 is typical of sterically hindered o-quinones (Table S1 in Supporting Information File 1). According to 1H and 13C NMR spectroscopy data, adduct 8 in CD3OD solution exists as

• -Semiquinones are often used as convenient spin labels to determine the spatial arrangement of ligands and to monitor the processes in the coordination sphere of metal ions in real time [42][43][44][45][46]. The spin density distribution and thus the hyperfine coupling constants for the magnetic nuclei at the

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• it can profoundly modify the physicochemical properties of the parent molecules. In biologically active materials fluorine substituents can affect the charge distribution, electrostatic surface, and solubility of chemical entities, thus often leading to useful outcomes. Incorporating a fluorine group

Exploring the possibility of using fluorine-involved non-conjugated electron-withdrawing groups for thermally activated delayed fluorescence emitters by TD-DFT calculation

• Dongyang Chen and
• Eli Zysman-Colman

Beilstein J. Org. Chem. 2021, 17, 210–223, doi:10.3762/bjoc.17.21

• -containing emitters 2CzCF3, 2CzOCF3, 2CzSCF3, and 2CzSF5. The HOMOs in these compounds are mainly located on the two carbazole moieties and a small part on the bridging central benzene ring. The LUMOs of 2CzCF3, 2CzSCF3, and 2CzSF5 are mainly located on the benzene ring and a small distribution onto the

• (4.06 eV), and 2CzBP (3.93 eV) are all significantly smaller compared to those of 2CzCF3, 2CzOCF3, 2CzSCF3, and 2CzSF5. The emissive S1 state for the seven Type I molecules is characterized mainly by a HOMO to LUMO transition, while the distribution of highest occupied natural transition orbitals

• for the Type II emitters are shown in Figure 7 and Figure 8. The HOMOs of 5CzCF3, 5CzOCF3, and 5CzSCF3 are mainly located on the carbazole moieties located ortho and meta to the acceptor group, with only a small distribution on the para-carbazole. For 5CzSF5, the HOMO is evenly distributed over the

Multiswitchable photoacid–hydroxyflavylium–polyelectrolyte nano-assemblies

• Alexander Zika and
• Franziska Gröhn

Beilstein J. Org. Chem. 2021, 17, 166–185, doi:10.3762/bjoc.17.17

• strength may be understood based on the molecular parameters of the building blocks and in particular the polar surface area (PSA), which relates to the three-dimensional charge distribution of the molecule. The PSA results from the area of the polar groups in the molecule taking into account the

• electric field autocorrelation function g1(τ). By a regularized inverse Laplace transformation, the electric field autocorrelation function g1(τ) was transformed into the distribution of relaxation times A(τ). The apparent diffusion coefficients Dapp were calculated by Equation 3 The diffusion coefficients

• nano-assemblies for cycle I (a) and cycle II (b). Dynamic light scattering: Electric field autocorrelation function g1(τ) and distribution of relaxation times A(τ) at a scattering angle of θ = 90° for cycle I (a) and cycle II (b,c). Cycle II is separated for better distinguishability: b) the states A

Novel library synthesis of 3,4-disubstituted pyridin-2(1H)-ones via cleavage of pyridine-2-oxy-7-azabenzotriazole ethers under ionic hydrogenation conditions at room temperature

• Romain Pierre,
• Anne Brethon,
• Sylvain A. Jacques,
• Aurélie Blond,
• Sandrine Chambon,
• Sandrine Talano,
• Catherine Raffin,
• Branislav Musicki,
• Claire Bouix-Peter,
• Loic Tomas,
• Gilles Ouvry,
• Rémy Morgentin,
• Laurent F. Hennequin and
• Craig S. Harris

Beilstein J. Org. Chem. 2021, 17, 156–165, doi:10.3762/bjoc.17.16

• (Table 3, entry 5). To decrease reaction times further, we carried out the reaction in neat TFA/TES mixture (4:1 v/v, 5 volumes) and obtained a 62% conversion at just rt after 24 h (Table 3, entry 6). The product distribution was even further improved by addition of water to the reaction mixture to avoid

Insight into functionalized-macrocycles-guided supramolecular photocatalysis

• Minzan Zuo,
• Krishnasamy Velmurugan,
• Kaiya Wang,
• Xueqi Tian and
• Xiao-Yu Hu

Beilstein J. Org. Chem. 2021, 17, 139–155, doi:10.3762/bjoc.17.15

• a stabilizer to control the size and distribution of the NPs and are able to intensely regulate the photocatalytic performance. 5) To improve the sustainability, noble metals need to be replaced by earth-abundant metals. However, in most cases, earth-abundant metals have a lower photocatalytic

Control over size, shape, and photonics of self-assembled organic nanocrystals

• Chen Shahar,
• Yaron Tidhar,
• Yunmin Jung,
• Haim Weissman,
• Sidney R. Cohen,
• Ronit Bitton,
• Iddo Pinkas,
• Gilad Haran and
• Boris Rybtchinski

Beilstein J. Org. Chem. 2021, 17, 42–51, doi:10.3762/bjoc.17.5

• , Supporting Information File 1) are less homogeneous and demonstrate a larger size distribution than the crystals obtained by exerting control through the THF content. In order to gain insight into the crystallization mechanism and the effect of the THF concentration on the crystallization process, we

Molecular basis for protein–protein interactions

• Brandon Charles Seychell and
• Tobias Beck

Beilstein J. Org. Chem. 2021, 17, 1–10, doi:10.3762/bjoc.17.1

• effect is termed the desalting effect [52] and is comparable to desolvation. This effect is also dependent on the charge–charge interactions of the complex as different charges might alter the ion distribution in the solvent, changing the ion interactions. On the other hand, an example of the ionic

Secondary metabolites of Bacillus subtilis impact the assembly of soil-derived semisynthetic bacterial communities

• Heiko T. Kiesewalter,
• Carlos N. Lozano-Andrade,
• Mikael L. Strube and
• Ákos T. Kovács

Beilstein J. Org. Chem. 2020, 16, 2983–2998, doi:10.3762/bjoc.16.248

• prolonged incubation. The B. subtilis strains were added at a community assembly phase when Bacillus was the dominating genus, so that the general genera distribution was not expected to be influenced extensively. Nevertheless, after 48 h cocultivation, the final relative abundance of the Bacillus genus was

A novel and robust heterogeneous Cu catalyst using modified lignosulfonate as support for the synthesis of nitrogen-containing heterocycles

• Bingbing Lai,
• Meng Ye,
• Ping Liu,
• Minghao Li,
• Rongxian Bai and
• Yanlong Gu

Beilstein J. Org. Chem. 2020, 16, 2888–2902, doi:10.3762/bjoc.16.238

• the results are presented in Figure 4. The LS-FAS-Cu catalyst featured irregular and blocky morphology with uneven size from 100 nm to 400 nm (Figure 4a–d). In addition, the elemental mapping images clearly revealed the presence and uniform distribution of C, Cu, O, and S in LAS-FAS-Cu. XPS was

Dirhamnolipid ester – formation of reverse wormlike micelles in a binary (primerless) system

• David Liese,
• Hans Henning Wenk,
• Xin Lu,
• Jochen Kleinen and
• Gebhard Haberhauer

Beilstein J. Org. Chem. 2020, 16, 2820–2830, doi:10.3762/bjoc.16.232

• rare case where no primer is needed for the formation of RWLM. To our knowledge, there is only one other example of a binary system with such a behavior [59]. Moreover, the surfactant, that was used as a precursor exhibits a certain distribution of the molecular weight but still was able to form

3-Acetoxy-fatty acid isoprenyl esters from androconia of the ithomiine butterfly Ithomia salapia

• Florian Mann,
• Daiane Szczerbowski,
• Lisa de Silva,
• Melanie McClure,
• Marianne Elias and
• Stefan Schulz

Beilstein J. Org. Chem. 2020, 16, 2776–2787, doi:10.3762/bjoc.16.228

• color patterns (see Supporting Information File 1, Figure S1) [4], are widely distributed, and parapatric in north-eastern Peru [5]. Despite the geographic overlap in distribution, a recent genetic study showed limited gene flow [4]. Reproductive isolation in mimetic butterflies can be driven by

• . The position of the double bonds in the acyl chain of the esters can be explained by a biosynthetic pathway described in detail in Scheme 5. The double bond distribution is consistent with both desaturases acting on palmitic acid, leading to the respective hexadecenoic acids. These acids are the

Nocarimidazoles C and D, antimicrobial alkanoylimidazoles from a coral-derived actinomycete Kocuria sp.: application of ¹J_C,H coupling constants for the unequivocal determination of substituted imidazoles and stereochemical diversity of anteisoalkyl chains in microbial metabolites

• Md. Rokon Ul Karim,
• Enjuro Harunari,
• Amit Raj Sharma,
• Naoya Oku,
• Kazuaki Akasaka,
• Daisuke Urabe,
• Mada Triandala Sibero and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 2719–2727, doi:10.3762/bjoc.16.222

• members, nocarimidazoles C (1) and D (2), were obtained from a marine-derived actinomycete of the genus Kocuria. The exclusive origin of these metabolites from marine bacteria, as well as the distribution among phylogenetically distinct taxa imply their potential function in the adaptation of the

Optical detection of di- and triphosphate anions with mixed monolayer-protected gold nanoparticles containing zinc(II)–dipicolylamine complexes

• Lena Reinke,
• Julia Bartl,
• Marcus Koch and
• Stefan Kubik

Beilstein J. Org. Chem. 2020, 16, 2687–2700, doi:10.3762/bjoc.16.219

• nanoparticles with the desired diameter of 8–10 nm and a relatively narrow size distribution [40]. This method entailed the rapid addition of a hot aqueous solution of tetrachloroauric(III) acid to aqueous sodium citrate at 100 °C. After dialysis to remove excess citrate, the resulting solution was treated with

Vicinal difluorination as a C=C surrogate: an analog of piperine with enhanced solubility, photostability, and acetylcholinesterase inhibitory activity

• Yuvixza Lizarme-Salas,
• Alexandra Daryl Ariawan,
• Ranjala Ratnayake,
• Hendrik Luesch,
• Angela Finch and
• Luke Hunter

Beilstein J. Org. Chem. 2020, 16, 2663–2670, doi:10.3762/bjoc.16.216

• seem to dominate the conformer population distribution of 2 in chloroform solution, because the weight-averaged calculated J-values of 2a–c match the experimentally-measured J-values quite well (Figure 2). But none of the structures 2a–c are a close conformational match with piperine (1). A noteworthy

A consensus-based and readable extension of Linear Code for Reaction Rules (LiCoRR)

• Benjamin P. Kellman,
• Yujie Zhang,
• Emma Logomasini,
• Eric Meinhardt,
• Karla P. Godinez-Macias,
• Austin W. T. Chiang,
• James T. Sorrentino,
• Chenguang Liang,
• Bokan Bao,
• Yusen Zhou,
• Sachiko Akase,
• Isami Sogabe,
• Thukaa Kouka,
• Elizabeth A. Winzeler,
• Iain B. H. Wilson,
• Matthew P. Campbell,
• Sriram Neelamegham,
• Frederick J. Krambeck,
• Kiyoko F. Aoki-Kinoshita and
• Nathan E. Lewis

Beilstein J. Org. Chem. 2020, 16, 2645–2662, doi:10.3762/bjoc.16.215

• discussed or described. We hope to encourage that adoption through our LiCoRRICE examples. Increased FAIRness will facilitate the validation and distribution of developing glycoinformatics toolkits. Easy-to-use glycoinformatics toolkits, made possible by the fluency of interoperability across tools, are one

Particle size effect in the mechanically assisted synthesis of β-cyclodextrin mesitylene sulfonate

• Stéphane Menuel,
• Sébastien Saitzek,
• Eric Monflier and
• Frédéric Hapiot

Beilstein J. Org. Chem. 2020, 16, 2598–2606, doi:10.3762/bjoc.16.211

• size distribution was measured from the desorption branch using the nonlocal density functional theory (NLDFT) model assuming a cylindrical pore structure. The average pore size was determined by the Dubinin–Radushkevich (DR) plot of the N2 desorption isotherm. The relative microporosity percentage is

Comparative ligand structural analytics illustrated on variably glycosylated MUC1 antigen–antibody binding

• Christopher B. Barnett,
• Tharindu Senapathi and
• Kevin J. Naidoo

Beilstein J. Org. Chem. 2020, 16, 2540–2550, doi:10.3762/bjoc.16.206

• -antigen’. Root-mean-square-analysis In solution (unbound), the RMSD (Figure 2) has a broad spread and a similar center for both the antigen and Tn-antigen. It is readily apparent that the glycosylated antigen has a bimodal distribution (secondary peak at 5.7 Å), indicating at least one other interesting

• conformation. On consideration of the RMSD for the bound antigens, a narrowing in the distributions is noted. Bound Tn-antigen (Figure 2F) has the narrowest distribution, with a spread from 0.8 Å to 1.6 Å; this unimodal distribution is centered at 1.25 Å. There is no longer a secondary peak, indicating that

• there is restricted movement on binding. The bound antigen (Figure 2E), instead has a bimodal distribution with a significant population centered at 1.25 Å, a minor population centered at 2.25 Å, and a broad tail that extends to 3.5 Å. While there is restricted movement on binding, the antigen shows

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

• sequestration [7]. Still, photochemistry has not been exploited much in industry since the distribution of light inside a photoreactor brings a lot of complexity to the reactor design. Unlike thermochemical reactions, it is not feasible to scale up photoreactions by increasing the dimensions of the reactor due

• to the exponential attenuation of light. Nonuniform light distribution often leads to a lower selectivity and longer reaction times, which in turn lowers the productivity [8][9]. Since photoreactions are intrinsically quite fast, mass transfer limitations should also be taken into account while

• emerged as alternatives to batch operation. Due to the small characteristic length of microreactors, more uniform light distribution could be obtained. The elimination of overirradiation or dark zones results in less side product formation. Mass transfer limitations can be alleviated in these

Palladium nanoparticles supported on chitin-based nanomaterials as heterogeneous catalysts for the Heck coupling reaction

• Tony Jin,
• Malickah Hicks,
• Davis Kurdyla,
• Sabahudin Hrapovic,
• Edmond Lam and
• Audrey Moores

Beilstein J. Org. Chem. 2020, 16, 2477–2483, doi:10.3762/bjoc.16.201

• Figure 1, a relatively uniform distribution for both ChNCs and ChsNCs with individual rod-like nanocrystals was observed, with an average length of 231 ± 38 nm for the ChNC and 159 ± 34 nm for the ChsNC (Supporting Information File 1, Figure S1). These measures were made from parts in the grid where the

• survey XPS scan showed no Cl contribution to the overall atom distribution suggesting that no PdCl2 species were present in the nanocomposites. For the second point, high-resolution XPS spectra on the O 1s scan of both the PdNP@ChNC and PdNP@ChsNC samples show the exact same symmetric peak, similar to

Conformational preferences of fluorine-containing agrochemicals and their implications for lipophilicity prediction

• Daniela Rodrigues Silva,
• Joyce K. Daré and
• Matheus P. Freitas

Beilstein J. Org. Chem. 2020, 16, 2469–2476, doi:10.3762/bjoc.16.200

• . Penoxsulam (I) has a rotatable C–C(F) bond (as analyzed in the previous section) and, consequently, has the dependence of the molecular dipole moment μ with the rotation around this bond. It is well-known that μ is influenced by two main factors: the molecular dimensions and the electron distribution [26

Hierarchically assembled helicates as reaction platform – from stoichiometric Diels–Alder reactions to enamine catalysis

• David Van Craen,
• Jenny Begall,
• Johannes Großkurth,
• Leonard Himmel,
• Oliver Linnenberg,
• Elisabeth Isaak and
• Markus Albrecht

Beilstein J. Org. Chem. 2020, 16, 2338–2345, doi:10.3762/bjoc.16.195

• statistical ligand distribution Li[Li3(1)3(L*)3Ti2] (L* = 3–7-H2). The given formula only describes the ratio of the ligands but in fact a statistical mixture of complexes Li[Li3(L*)6Ti2], Li[Li3(1)(L*)5Ti2], Li[Li3(1)2(L*)4Ti2], Li[Li3(1)3(L*)3Ti2], Li[Li3(1)4(L*)2Ti2], Li[Li3(1)5(L*)1Ti2], and Li[Li3(1)6Ti2

• residues were introduced instead of the diene ligands. Again helicates with a statistical distribution of chiral ligands and of the new amine ligands in the complex were investigated as catalysts. The ligands with potential catalytic activity were synthesized in a three-step approach (Scheme 4). Initially

• ][31] stereoselectivity of a Diels–Alder reaction by use of different solvents. The heteroleptic complexes are mixtures with an average ligand distribution as shown [13]. Elucidating the pathway of the stereoinduction of the Diels–Alder reaction. Ten equivalents of chiral ammonium salt are added to the