The B & B approach: Ball-milling conjugation of dextran with phenylboronic acid (PBA)-functionalized BODIPY

• Patrizia Andreozzi,
• Lorenza Tamberi,
• Elisamaria Tasca,
• Gina Elena Giacomazzo,
• Marta Martinez,
• Mirko Severi,
• Marco Marradi,
• Stefano Cicchi,
• Sergio Moya,
• Giacomo Biagiotti and
• Barbara Richichi

Beilstein J. Org. Chem. 2020, 16, 2272–2281, doi:10.3762/bjoc.16.188

• 0.1 equiv of 1). Supporting Information Supporting Information File 426: Methods for UV–vis and fluorescence measurements, UV–vis and fluorescence spectra of Dex-1b, Dex-1c, and 1 in DMSO, FTIR spectra of PBA-BODIPY 1, dextran and Dex-1a–d; MTT assay and correlation coefficient of Dex-1b

Tools for generating and analyzing glycan microarray data

• Akul Y. Mehta,
• Jamie Heimburg-Molinaro and
• Richard D. Cummings

Beilstein J. Org. Chem. 2020, 16, 2260–2271, doi:10.3762/bjoc.16.187

• Dashboard (GLAD) is a tool to visualize, analyze, compare and mine glycan array data. The tool allows users to visualize glycan array data alongside the structures using bar charts, heatmaps, calendar heatmaps, force directed graphs and correlation plots. In addition, the tool also couples some data mining

Naphthalene diimide bis-guanidinio-carbonyl-pyrrole as a pH-switchable threading DNA intercalator

• Poulami Jana,
• Filip Šupljika,
• Carsten Schmuck and
• Ivo Piantanida

Beilstein J. Org. Chem. 2020, 16, 2201–2211, doi:10.3762/bjoc.16.185

• for Ka and n given in Table 1 all have satisfactory correlation coefficients (>0.999). Thermal melting curves for DNA, RNA, and their complexes with the studied compound were determined as previously described [37] by following the absorption change at 260 nm as a function of temperature. The

Regioselective cobalt(II)-catalyzed [2 + 3] cycloaddition reaction of fluoroalkylated alkynes with 2-formylphenylboronic acids: easy access to 2-fluoroalkylated indenols

• Tatsuya Kumon,
• Miroku Shimada,
• Jianyan Wu,
• Shigeyuki Yamada and
• Tsutomu Konno

Beilstein J. Org. Chem. 2020, 16, 2193–2200, doi:10.3762/bjoc.16.184

• out based on NMR techniques, as shown in Scheme 4 [36]. A strong correlation between the carbonyl carbon atom and Ha was obtained, whereas the cross-peak between the carbonyl carbon atom and Hb was not observed, strongly indicating that the indanone 5aA possessed a CF3 group at the 3-position. On the

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

• ]. We have previously used the SMD implicit solvation model with the MN15 functional in theoretical lipophilicity predictions of linear fluorohydrins [27][28], which gave an excellent correlation with the experimental values (r2 = 0.957), although the absolute values were much higher (a slope of >2 was

• to have essentially the same lipophilicities. The correlation with the experimental values shows a coefficient of determination value of 0.776 (Figure 10A), which is worse than many of the investigated fragment-based clogP methods (see above), for which such clustering is not observed. When these

• values are combined with the full available set of fluorohydrins calculated with the MN15 functional (Figure 10B), the correlation is now reduced from r2 = 0.957 to 0.860. Interestingly, the theoretical and experimental values, while much different in absolute value and in relative difference, correspond

Clustering and curation of electropherograms: an efficient method for analyzing large cohorts of capillary electrophoresis glycomic profiles for bioprocessing operations

• Ian Walsh,
• Matthew S. F. Choo,
• Sim Lyn Chiin,
• Amelia Mak,
• Shi Jie Tay,
• Pauline M. Rudd,
• Yang Yuansheng,
• Andre Choo,
• Ho Ying Swan and
• Terry Nguyen-Khuong

Beilstein J. Org. Chem. 2020, 16, 2087–2099, doi:10.3762/bjoc.16.176

• , migration time is generally calculated by correlation with internal standards that bracket the time of elution of the glycans of interest [10]. This process is used to calculate a glucose unit (GU) which helps to align the datasets so that the GU of each glycan can be used to identify the glycan through

• average total abundance. If peaks <1% are not considered it might seem insignificant but it affects the relative abundance of other peaks to an extent of 3.8% in total. Supporting Information File 1, Figure S1 shows the correlation between clustering + HappyTools and the automated software quantitative

• FA1/FA2G2S1/A2 only (red box peak not picked by 32 Karat), (H) M5 peaks only (red box peak not picked by 32 Karat, and (I) when FA1/FA2G2S1/A2 and M5 peak areas were combined there was excellent correlation between both approaches suggesting 32 Karat integrates the two peaks as a whole. The clustering

Isolation and structure determination of a tetrameric sulfonyl dilithio methandiide in solution based on crystal structure analysis and ⁶Li/¹³C NMR spectroscopic data

• Jürgen Vollhardt,
• Hans Jörg Lindner and
• Hans-Joachim Gais

Beilstein J. Org. Chem. 2020, 16, 2057–2063, doi:10.3762/bjoc.16.172

• ) for C1B (δ = 51.4 ppm) due to 6Li,13C spin coupling. The 6Li NMR spectrum of 2a-I at −103 °C displayed three signals split by 6Li,13C spin coupling. Selective 6Li{13C} double resonance and two-dimensional double quantum based shift correlation experiments had served to establish the 6Li–13C

• the tetramer (2a)4·(THF)6 in the crystal. Although the lithium oxygen bonds of 2a-I evaded a direct detection by NMR spectroscopy, the 13C,6Li shift correlation experiments of 2a-I had shown two 6Li signals, lacking correlation with 13C signals [15]. Thus, there is good reason to believe that the

Naphthalene diimide–amino acid conjugates as novel fluorimetric and CD probes for differentiation between ds-DNA and ds-RNA

• Annike Weißenstein,
• Myroslav O. Vysotsky,
• Ivo Piantanida and
• Frank Würthner

Beilstein J. Org. Chem. 2020, 16, 2032–2045, doi:10.3762/bjoc.16.170

• ][41][42]. Values for Ks and n given in Table 3 all have satisfactory correlation coefficients (>0.999). Thermal melting curves for DNA, RNA, and their complexes with the studied compounds (Table 2) were determined as previously described [39][61] by following the absorption change at 260 nm as a

Automated high-content imaging for cellular uptake, from the Schmuck cation to the latest cyclic oligochalcogenides

• Rémi Martinent,
• Javier López-Andarias,
• Dimitri Moreau,
• Yangyang Cheng,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2020, 16, 2007–2016, doi:10.3762/bjoc.16.167

• (Figure 11a). This very poor correlation for the transient transfection of the HaloTags on the Golgi contrasted sharply with an r2 value of 0.983 obtained with the stable HGM cells with the HaloTags expressed on the mitochondria. The difference between the two plots in Figure 11a and Figure 8a was

• signal from the Golgi apparatus without an initial cell selection was tested next (Figure 10a, yellow only). With this Golgi mask without cell selection, the correlation of the fluorescence of the GFP and 26, with an r2 value of 0.549, was even worse than the r2 value of 0.626 for the whole-cell mask

• , yellow only). The application of both the cell selection and the Golgi mask to the analysis finally improved the correlation of the GFP and the 26 emission to r2 = 0.816 (Figure 11d). This value was slowly approaching the precision realized without further effort using the stable cell line HGM (Figure 8b

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• carbons, which also showed a correlation with the regioselectivity. In 2016, León and Fernández reported the first intermolecular PKR of internal alkynylboronic esters with norbornadiene [81]. For this purpose, terminal alkynes were converted into their corresponding alkynylboronic pinacol esters, and

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

• 3–5). In addition, a nearly linear correlation between the equivalents of added H2O and the product yield was observed (Table 2 insert). Cognisant that H2O is likely being introduced to the reaction via the HF source, and to prevent reproducibility issues due to variation of the H2O content, 1.0

Synthesis of new dihydroberberine and tetrahydroberberine analogues and evaluation of their antiproliferative activity on NCI-H1975 cells

• Giacomo Mari,
• Lucia De Crescentini,
• Serena Benedetti,
• Francesco Palma,
• Stefania Santeusanio and
• Fabio Mantellini

Beilstein J. Org. Chem. 2020, 16, 1606–1616, doi:10.3762/bjoc.16.133

• of 13a-C, 13-C and 15-C (signals highlighted in green, Figure 3). It is noteworthy that in the reduction process of the DHBER 2 precursors, a single diastereoisomer of the corresponding THBERs 3 is produced according to 1H and 13C NMR data. In particular, the NOE correlation between C13−H and C13a−H

• . 1H,1H-COSY spectrum of DHBER 2a [65]. Detail of the hydrazone signal in the HMBC spectrum of THBER 3a. Comparison between 1H NMR spectra of DHBER 2a and of THBER 3a. NOE correlation between C13−H and C13a−H of THBER 3a. Effects of 25 µM hydrazono-DHBERs 2a–n (A) and hydrazono-THBERs 3a–g,i–n [70] (B

Antibacterial scalarane from Doriprismatica stellata nudibranchs (Gastropoda, Nudibranchia), egg ribbons, and their dietary sponge Spongia cf. agaricina (Demospongiae, Dictyoceratida)

• Cora Hertzer,
• Stefan Kehraus,
• Nils Böhringer,
• Fontje Kaligis,
• Robert Bara,
• Dirk Erpenbeck,
• Gert Wörheide,
• Till F. Schäberle,
• Heike Wägele and
• Gabriele M. König

Beilstein J. Org. Chem. 2020, 16, 1596–1605, doi:10.3762/bjoc.16.132

• correlation between the methylene protons H2-22 (δ −0.06 brt, J = 4.8 Hz, δ 0.43 dd, J = 3.9, 9.2 Hz), and the methine proton H-3 (δ 0.55 m), based on HMBC cross peaks between the protons H2-22 and the carbon atoms C-2 (δ 19.0), C-5 (δ 53.2) and C-21 (δ 23.3). The entire assignment of all NMR data is given in

Five-component, one-pot synthesis of an electroactive rotaxane comprising a bisferrocene macrocycle

• Natalie Lagesse,
• Luca Pisciottani,
• Maxime Douarre,
• Pascale Godard,
• Brice Kauffmann,
• Vicente Martí-Centelles and
• Nathan D. McClenaghan

Beilstein J. Org. Chem. 2020, 16, 1564–1571, doi:10.3762/bjoc.16.128

• , k, l, and m). Further evidence of the interlocked nature of rotaxane 1a could be obtained from the 1H,1H-ROESY NMR spectrum. Multiple through-space cross-coupling correlation between the thread and the macrocycle protons were observed between the mechanically-bonded macrocycle and the thread (Figure

• Rigaku FRX® high flux rotating anode with a Pilatus 200K hybrid pixel detector. Using Olex2 [27], the structure was solved with the ShelXT [28] structure solution program using Intrinsic Phasing and refined with the ShelXL [29] refinement package using the full least-squares correlation matrix. The non

4-Hydroxy-3-methyl-2(1H)-quinolone, originally discovered from a Brassicaceae plant, produced by a soil bacterium of the genus Burkholderia sp.: determination of a preferred tautomer and antioxidant activity

• Dandan Li,
• Naoya Oku,
• Yukiko Shinozaki,
• Yoichi Kurokawa and
• Yasuhiro Igarashi

Beilstein J. Org. Chem. 2020, 16, 1489–1494, doi:10.3762/bjoc.16.124

• assembled into a C4 enol-amidyl or enol-imidic acyl unit based on HMBC correlations from the methyl proton H39 to the three nonprotonated carbons C4 (δ 157.4), C3 (δ 106.9), and C2 (δ 164.0). Connection of this unit to C4a of the benzene ring was implied by an HMBC correlation from H39 to C4a, and

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

• for each reaction and in most cases showed a good correlation with the ZPE-corrected energy (Table 6). All the endo approaches were lower in energy than the exo approaches, reaching the TSs from the supramolecular complexes (SCs) [53]. For most of the cycloadditions, the difference in energy of the

[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

• regression analysis of the chemical shifts depending on the β-CD concentration, to a complexation model with 1:1 stoichiometry, showed good correlation (Figure 2 and Figure S2 in Supporting Information File 1), with the stability constant for 2@β-CD K = 190 ± 50 M−1. Formation of the inclusion complex was

Synthesis, antiinflammatory activity, and molecular docking studies of bisphosphonic esters as potential MMP-8 and MMP-9 inhibitors

• Abimelek Cortes-Pacheco,
• María Adelina Jiménez-Arellanes,
• Francisco José Palacios-Can,
• José Antonio Valcarcel-Gamiño,
• Rodrigo Said Razo-Hernández,
• María del Carmen Juárez-Vázquez,
• Adolfo López-Torres and
• Oscar Abelardo Ramírez-Marroquín

Beilstein J. Org. Chem. 2020, 16, 1277–1287, doi:10.3762/bjoc.16.108

• 5 (13.8% edema inhibition) and 6 (9.1% edema inhibition) where a low antiinflammatory activity was observed. In this regard, a clear correlation between the experimental and predicted activity was observed. Thus, the compounds 3 and 4 were predicted to be more bioactive than 5 and 6 (Table 2

• Equation 2, which are based in the Koopman’s theorem for the determination of the global chemical reactivity descriptors. From Table 3, we observed that a correlation between the antiinflammatory activity of the compounds and the molecular properties can be established. The structural modifications are

• ligand efficiency (LE) of each bisphosphonate is shown; the ligand efficiency stands for the coefficient of the interaction energy by the number of atoms in the molecule (excluding hydrogen atoms). By the inspection of the results above, there is a correlation between the LE parameter in MMP-8 and 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

• carbon characterization Many production methods and possible precursors for activated carbon preparation are known. Also many characterization methods have been reported. In most cases, several characterization methods are used to allow a correlation of the resulting activities and activated carbon

Synthesis and properties of quinazoline-based versatile exciplex-forming compounds

• Rasa Keruckiene,
• Simona Vekteryte,
• Ervinas Urbonas,
• Matas Guzauskas,
• Eigirdas Skuodis,
• Dmytro Volyniuk and
• Juozas V. Grazulevicius

Beilstein J. Org. Chem. 2020, 16, 1142–1153, doi:10.3762/bjoc.16.101

• . The potentials were calibrated against the standard ferrocene/ferrocenium (Fc/Fc+) redox system [24]. The ground-state geometries were optimized by using the B3LYP (Becke three parameters hybrid functional with Lee–Yang–Perdew correlation) [25] functional at the 6-31G (d, p) level of theory in vacuum

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

• . Protons H-8 and H-9 showed three-bond couplings (J = 8.2 Hz), while H-9 showed a weak four-bond correlation with H-5 (J = 1.9 Hz). Relatively intense cross peaks from H-5 and H-9 to the deshielded carbon C-7 (δC 152.8) suggested the oxygen functionality at the meta-position to C-5 and C-9. Intense HMBC

• to C-26 was then connected at C-20 by HMBC correlations from H3-39 to C-19, C-20, and C-21. The carbon chain was further extended from C-26, via the spiro carbon C-27 (δC 98.6) and a methylene C-29, to the terminal methyl C-34 on the basis of COSY and HMBC correlations. Finally, an HMBC correlation

• C-16/C-17 and C-18/C-19 double bonds in s-trans conformation was determined by the NOESY correlation between H-16 and H-18 and the large vicinal coupling constants (JH-16,H-17 = 15.7 Hz, JH-18,H-19 = 14.9 Hz). The relative configuration of the spiroacetal moiety in 2 was determined by NOESY analysis

Suzuki–Miyaura cross coupling is not an informative reaction to demonstrate the performance of new solvents

• James Sherwood

Beilstein J. Org. Chem. 2020, 16, 1001–1005, doi:10.3762/bjoc.16.89

• ™, GVL, and 2-MeTHF were poor solvents. Replacing potassium carbonate with triethylamine, the conversion in Cyrene™ rose slightly to 10%. Despite the variation between experiments no discernible correlation between any solvent properties and the observed conversions was found. The results achieved in DMI

Diversity-oriented synthesis of 17-spirosteroids

• Benjamin Laroche,
• Thomas Bouvarel,
• Martin Louis-Sylvestre and
• Bastien Nay

Beilstein J. Org. Chem. 2020, 16, 880–887, doi:10.3762/bjoc.16.79

• H-12 (the dotted line indicates a weak correlation); (b) Model to explain the diene–dienophile interaction during the Diels–Alder reaction. Two diversity-oriented strategies: (a) Diversity installed during the construction of the skeleton; (b) Diversity installed lately by functionalization

Preparation of 2-phospholene oxides by the isomerization of 3-phospholene oxides

• Péter Bagi,
• Réka Herbay,
• Nikolett Péczka,
• Zoltán Mucsi,
• István Timári and
• György Keglevich

Beilstein J. Org. Chem. 2020, 16, 818–832, doi:10.3762/bjoc.16.75

• the preferred isomers for the unsubstituted and methyl-substituted phospholene core. In contrast, the calculations predicted a 73:27 ratio for the dimethyl-substituted 2- and 3-phoshopholene oxides (10 and 8) (Table 5, entry 10). These predictions showed strong correlation with the experimental

Efficient synthesis of dipeptide analogues of α-fluorinated β-aminophosphonates

• Marcin Kaźmierczak and
• Henryk Koroniak

Beilstein J. Org. Chem. 2020, 16, 756–762, doi:10.3762/bjoc.16.69

•  2, for all tested conditions see Table S1 in Supporting Information File 1). In our experience, there was no significant correlation between steric bulkiness of the base (from DBU to BTPP) used, and the yield of α-isomer 11 formation. It is worth mentioning that application of PBSF gives slightly