Recent advances in the asymmetric phosphoric acid-catalyzed synthesis of axially chiral compounds

• Alemayehu Gashaw Woldegiorgis and
• Xufeng Lin

Beilstein J. Org. Chem. 2021, 17, 2729–2764, doi:10.3762/bjoc.17.185

• efforts have been made to find new efficient routes for the enantioselective construction of various atropisomeric aryl–aryl or aryl–heteroaryl, enantioselective spiranes and allenes. Despite the advances mentioned above, much of this area of research is still relatively unexplored. Compared to the use of

GlycoBioinformatics

• Kiyoko F. Aoki-Kinoshita,
• Frédérique Lisacek,
• Niclas Karlsson,
• Daniel Kolarich and
• Nicolle H. Packer

Beilstein J. Org. Chem. 2021, 17, 2726–2728, doi:10.3762/bjoc.17.184

• that important life science questions more often than not include an element of “glyco”. For this thematic issue, we have assembled publications from world-renowned glycoscience researchers who are involved in the current state-of-the-art glycobioinformatics approaches that are needed to find solutions

Synthesis of new bile acid-fused tetrazoles using the Schmidt reaction

• Dušan Đ. Škorić,
• Olivera R. Klisurić,
• Dimitar S. Jakimov,
• Marija N. Sakač and
• János J. Csanádi

Beilstein J. Org. Chem. 2021, 17, 2611–2620, doi:10.3762/bjoc.17.174

• solubilizers, bile acids are now recognized as metabolism regulators through specific receptors: farnesoid X receptor (FXR) and Takeda G protein receptor 5 (TGR5) [1][2][3]. Research efforts to find ligands for these receptors initiated several synthetic studies where bile acids are being used as a starting

Silica gel and microwave-promoted synthesis of dihydropyrrolizines and tetrahydroindolizines from enaminones

• Robin Klintworth,
• Garreth L. Morgans,
• Stefania M. Scalzullo,
• Charles B. de Koning,
• Willem A. L. van Otterlo and
• Joseph P. Michael

Beilstein J. Org. Chem. 2021, 17, 2543–2552, doi:10.3762/bjoc.17.170

• , entry 3). We were pleased to find that heating a solution of 25a in ethanol at 100 °C in a capped microwave tube, but at a much lower power setting (50 W), produced the desired product 26a in 82% yield with little obvious decomposition (Scheme 4). However, the reaction required four hours for the

Chemical syntheses and salient features of azulene-containing homo- and copolymers

• Vijayendra S. Shetti

Beilstein J. Org. Chem. 2021, 17, 2164–2185, doi:10.3762/bjoc.17.139

• synthesis of functional polymers is also an interesting proposition and such polymers can find promising applications in the organic electronics field such as organic field-effect transistors (OFET) and photovoltaic (PV) cells [15][16]. The synthesis of azulene-containing polymers can be envisaged through

Preparation of mono-substituted malonic acid half oxyesters (SMAHOs)

• Tania Xavier,
• Sylvie Condon,
• Christophe Pichon,
• Erwan Le Gall and
• Marc Presset

Beilstein J. Org. Chem. 2021, 17, 2085–2094, doi:10.3762/bjoc.17.135

• , they are not sufficiently documented to cover the preparation of more complex versions of these reagents, apart from 2-amido-MAHOs for which the parent aminomalonate is commercially available. Indeed, it is very rare to find two identical procedures or stoichiometries, and these methods are used for

A study on selective transformation of norbornadiene into fluorinated cyclopentane-fused isoxazolines

• Zsanett Benke,
• Attila M. Remete and
• Loránd Kiss

Beilstein J. Org. Chem. 2021, 17, 2051–2066, doi:10.3762/bjoc.17.132

• view of chemodifferentiation. The reactions were performed with various olefin metathesis catalysts to find the most optimal conditions (Figure 1). The starting divinyl-substituted bicyclic isoxazolines were synthesized according to literature methods, as shown in Figure 2, utilizing nitrile oxide

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• photocyclization of 1,3-distyrylbenzene derivatives 133 bearing different substituents at position 2 in order to find efficient blocking groups to afford dibenzoanthracene derivatives (Scheme 31) [65]. For the first time, their results established that butylthio and diphenylphosphino groups performed well as

Cationic oligonucleotide derivatives and conjugates: A favorable approach for enhanced DNA and RNA targeting oligonucleotides

• Mathias B. Danielsen and
• Jesper Wengel

Beilstein J. Org. Chem. 2021, 17, 1828–1848, doi:10.3762/bjoc.17.125

• hurdle that needs to be addressed before ASOs can find more widespread use [3][9][10][11][14]. A lack of efficient delivery of ASOs can be caused by various reasons such as degradation [15][16], insufficient endosomal escape [17], glomerular filtration [18], or binding to one or more proteins [19][20

Natural products in the predatory defence of the filamentous fungal pathogen Aspergillus fumigatus

• Jana M. Boysen,
• Nauman Saeed and
• Falk Hillmann

Beilstein J. Org. Chem. 2021, 17, 1814–1827, doi:10.3762/bjoc.17.124

• environmental niches remained elusive and has been limited by their biological complexity. It was thus surprising to find that the environmentally abundant, fungivorous amoeba P. aurantium does not only graze on yeast but can specifically target filamentous fungi such as A. fumigatus. The mechanism of action

Chemical approaches to discover the full potential of peptide nucleic acids in biomedical applications

• Nikita Brodyagin,
• Martins Katkevics,
• Venubabu Kotikam,
• Christopher A. Ryan and
• Eriks Rozners

Beilstein J. Org. Chem. 2021, 17, 1641–1688, doi:10.3762/bjoc.17.116

A recent overview on the synthesis of 1,4,5-trisubstituted 1,2,3-triazoles

• Pezhman Shiri,
• Ali Mohammad Amani and
• Thomas Mayer-Gall

Beilstein J. Org. Chem. 2021, 17, 1600–1628, doi:10.3762/bjoc.17.114

• -membered sulfur-containing cycle (Scheme 23) [52]. Some reactions were performed to screen the reaction mechanism in detail. To find out if the reaction proceeds through a radical pathway, tetramethylpiperidine-1-oxyl (TEMPO) was added to the reaction. The corresponding product was obtained in high yield

• Yasuike et al. (Scheme 25). To find the scope of this strategy, diverse ethynylstibanes 82 containing substituents including aryl, vinyl, and alkyl were reacted with organic azides 83 and diaryl diselenides 84 to form desired products. In addition, a variety of organic azides 83 containing substituents

• -triazole intermediate 107, followed by intramolecular 1,6-conjugate addition to afford the final product. To find the exact mechanism, the reaction was performed in CDCl3 as solvent in an NMR tube with a catalytic amount of AgSbF6 and then, the reaction mixture was analyzed using 1H NMR spectroscopy. The

Recent advances in the application of isoindigo derivatives in materials chemistry

• Andrei V. Bogdanov and
• Vladimir F. Mironov

Beilstein J. Org. Chem. 2021, 17, 1533–1564, doi:10.3762/bjoc.17.111

• = 0.07 cm2⋅V−1⋅s−1. Isoindigo-based sensor devices Isoindigo derivatives have begun to find an application in the design of sensor devices for the detection of simple and complex molecules in various aggregation states. Thus, it was shown that polymer structures based on isoindigo and thiophene 59a,b and

• existing polymer conductive binder mixed with carbon additives (Scheme 31). Isoindigo derivatives have begun to find use in biomedical applications. Thus, nanoparticles of isoindigoid polymers have shown good potential as agents for photoacoustic and photothermal cancer therapy [116][117][118][119][120

Co-crystallization of an organic solid and a tetraaryladamantane at room temperature

• Fabian Rami,
• Jan Nowak,
• Felix Krupp,
• Wolfgang Frey and
• Clemens Richert

Beilstein J. Org. Chem. 2021, 17, 1476–1480, doi:10.3762/bjoc.17.103

• initially suspected that a slow crystallization, induced by evaporation or diffusion, would make it unlikely to obtain co-crystals, as the long time intervals involved should favor a thermodynamic, rather than a kinetic product. In other words, starting from a solution (I), we expected to find a

Analogs of the carotane antibiotic fulvoferruginin from submerged cultures of a Thai Marasmius sp.

• Birthe Sandargo,
• Leon Kaysan,
• Rémy B. Teponno,
• Christian Richter,
• Benjarong Thongbai,
• Frank Surup and
• Marc Stadler

Beilstein J. Org. Chem. 2021, 17, 1385–1391, doi:10.3762/bjoc.17.97

• , Faculty of Science, University of Dschang, P.O. Box 67, Dschang, Cameroon, Institute of Microbiology, Technical University of Braunschweig, Germany 10.3762/bjoc.17.97 Abstract A recent find of a Marasmius species in Northern Thailand led to the isolation of five unprecedented derivatives of the carotane

• moderate antifungal activity. A recent find of a Marasmius species in Northern Thailand led, however, to the isolation and identification of five novel derivatives of this carotane-type sesquiterpenoid. The present study is dedicated to describing their isolation, and biological and physicochemical

Antiviral therapy in shrimp through plant virus VLP containing VP28 dsRNA against WSSV

• Santiago Ramos-Carreño,
• Ivone Giffard-Mena,
• Jose N. Zamudio-Ocadiz,
• Alfredo Nuñez-Rivera,
• Ricardo Valencia-Yañez,
• Jaime Ruiz-Garcia,
• Maria Teresa Viana and
• Ruben D. Cadena-Nava

Beilstein J. Org. Chem. 2021, 17, 1360–1373, doi:10.3762/bjoc.17.95

• virus. It is imperative to find prevention that works. Vaccines or antiviral therapies to effectively control or eliminate these outbreaks should be a priority in further investigations. The Government and private sector should work together to develop strategies to protect the profitability of the

A new glance at the chemosphere of macroalgal–bacterial interactions: In situ profiling of metabolites in symbiosis by mass spectrometry

• Marine Vallet,
• Filip Kaftan,
• Veit Grabe,
• Fatemeh Ghaderiardakani,
• Simona Fenizia,
• Aleš Svatoš,
• Georg Pohnert and
• Thomas Wichard

Beilstein J. Org. Chem. 2021, 17, 1313–1322, doi:10.3762/bjoc.17.91

• find significant differences in intensities and the presence or absence of metabolites in the samples. Pareto scaling and cube root transformation were conducted to normalise the datasets before the multivariate statistics. PCA highlighted the metabolic differences between axenic and alga in symbiosis

Enhanced target cell specificity and uptake of lipid nanoparticles using RNA aptamers and peptides

• Roslyn M. Ray,
• Anders Højgaard Hansen,
• Maria Taskova,
• Bernhard Jandl,
• Jonas Hansen,
• Citra Soemardy,
• Kevin V. Morris and
• Kira Astakhova

Beilstein J. Org. Chem. 2021, 17, 891–907, doi:10.3762/bjoc.17.75

• , effective transport systems for brain drug delivery are highly warranted. Herein, we find that the LNP platform can be applied as a vehicle to circumvent the BBB and effectively deliver oligonucleotide probes to antigen-expressing cell lines. For HIV-1 there is currently a need for more effective delivery

Kinetics of enzyme-catalysed desymmetrisation of prochiral substrates: product enantiomeric excess is not always constant

• Peter J. Halling

Beilstein J. Org. Chem. 2021, 17, 873–884, doi:10.3762/bjoc.17.73

• this comes with a conversion or yield at which it was obtained. However, I have heard anecdotally from people performing such reactions that the ee can appear to decline as the reaction proceeds. (I have been unable to find any published report of this effect). Perhaps because of the view that the

A chromatography-free and aqueous waste-free process for thioamide preparation with Lawesson’s reagent

• Ke Wu,
• Yichen Ling,
• An Ding,
• Liqun Jin,
• Nan Sun,
• Baoxiang Hu,
• Zhenlu Shen and
• Xinquan Hu

Beilstein J. Org. Chem. 2021, 17, 805–812, doi:10.3762/bjoc.17.69

• , in addition to ethylene glycol 1.0 mL of water was added to the mixture and we were pleased to find that compound A smoothly decomposed at 95 °C in 3.5 h. With the decline of compound A in the toluene layer, a new compound C2 emerged. It was also noticed that the pH value of the ethylene glycol layer

Effective microwave-assisted approach to 1,2,3-triazolobenzodiazepinones via tandem Ugi reaction/catalyst-free intramolecular azide–alkyne cycloaddition

• Maryna O. Mazur,
• Oleksii S. Zhelavskyi,
• Eugene M. Zviagin,
• Svitlana V. Shishkina,
• Vladimir I. Musatov,
• Maksim A. Kolosov,
• Elena H. Shvets,
• Anna Yu. Andryushchenko and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2021, 17, 678–687, doi:10.3762/bjoc.17.57

• . Increasing the temperature allowed higher yields of the product, exactly as it did when terminal alkynes were used as reactants (Table 1, entries 9 and 10). The investigation on the optimization of the reaction parameters to find safer and ecologically benign conditions included temperature, solvent, and

[2 + 1] Cycloaddition reactions of fullerene C₆₀ based on diazo compounds

• Yuliya N. Biglova

Beilstein J. Org. Chem. 2021, 17, 630–670, doi:10.3762/bjoc.17.55

• biologically active molecules that already find practical use. It has been found that complexation improves the transportation of a drug and prolongs its effect, and a synergistic effect is observed in some cases [36]. The situation with covalent binding in fullerene–drug conjugates is different. C60 is an

Valorisation of plastic waste via metal-catalysed depolymerisation

• Francesca Liguori,
• Carmen Moreno-Marrodán and
• Pierluigi Barbaro

Beilstein J. Org. Chem. 2021, 17, 589–621, doi:10.3762/bjoc.17.53

Synthesis of (Z)-3-[amino(phenyl)methylidene]-1,3-dihydro-2H-indol-2-ones using an Eschenmoser coupling reaction

• Lukáš Marek,
• Lukáš Kolman,
• Jiří Váňa,
• Jan Svoboda and
• Jiří Hanusek

Beilstein J. Org. Chem. 2021, 17, 527–539, doi:10.3762/bjoc.17.47

• us to find better or even universal reaction conditions compatible with all substituents present in both benzene rings (R1 and R2) as well as at the thioamide nitrogen (R3 and R4). In order to achieve the desired product of the Eschenmoser coupling reaction (route b), two main prerequisites must be

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

• -aminide ligand in a manganese complex [29], being the only structurally characterized complex with a neutral 1,3-dialkyltetrazolium-5-aminide. Therefore, it is of interest to compare the structural data for this compound with those obtained for compound 8a to find the influence of the complexation on the

• carried out for compound 8a being the simplest mesoionic compound among the investigated ones in the present work. The atom numbering used in this section corresponds to that shown in Figure 2. The molecule of 8a can be represented by several Lewis structures (Scheme 3). To find the best Lewis structure