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

• [13]. For example, leaving them exposed to air leads to loss of the solvent and a brittle material that slowly loses its crystalline order. Solvates (II) may thus have played a role as intermediates. They may have formed while the dichloromethane content was still high, but may have given way to co

Fritsch–Buttenberg–Wiechell rearrangement of magnesium alkylidene carbenoids leading to the formation of alkynes

• Tsutomu Kimura,
• Koto Sekiguchi,
• Akane Ando and
• Aki Imafuji

Beilstein J. Org. Chem. 2021, 17, 1352–1359, doi:10.3762/bjoc.17.94

• air- or water-sensitive compounds were conducted under an argon atmosphere. Argon gas was dried by passage through P2O5. Anhydrous THF and toluene were purchased and used as supplied. Silica gel 60N containing 0.5% fluorescence reagent 254 and a quartz column were used for column chromatography, and

Icilio Guareschi and his amazing “1897 reaction”

• Gian Cesare Tron,
• Alberto Minassi,
• Giovanni Sorba,
• Mara Fausone and
• Giovanni Appendino

Beilstein J. Org. Chem. 2021, 17, 1335–1351, doi:10.3762/bjoc.17.93

• before the introduction of GC–MS, and the elemental analysis of gases required special attention [55]. Guareschi also made the observation that air was necessary for the development of the gas, proposing a general scheme for the transformation that provides, however, no clue for a possible mechanism. In

Photoinduced post-modification of graphitic carbon nitride-embedded hydrogels: synthesis of 'hydrophobic hydrogels' and pore substructuring

• Cansu Esen and
• Baris Kumru

Beilstein J. Org. Chem. 2021, 17, 1323–1334, doi:10.3762/bjoc.17.92

• delivered over a certain amount of time, yet a hydrophobicity for a long-term open-air application must be possessed in order to prevent the drying and a loss of a part [44]. Hydrophobic hydrogel is a novel concept that administers the surface properties of the initial network. In this section, we will

A comprehensive review of flow chemistry techniques tailored to the flavours and fragrances industries

• Guido Gambacorta,
• James S. Sharley and
• Ian R. Baxendale

Beilstein J. Org. Chem. 2021, 17, 1181–1312, doi:10.3762/bjoc.17.90

Heterogeneous photocatalytic cyanomethylarylation of alkenes with acetonitrile: synthesis of diverse nitrogenous heterocyclic compounds

• Guanglong Pan,
• Qian Yang,
• Wentao Wang,
• Yurong Tang and
• Yunfei Cai

Beilstein J. Org. Chem. 2021, 17, 1171–1180, doi:10.3762/bjoc.17.89

• detected under air, further indicating a radical-initiated process was involved in the reaction (Table 1, entry 14). Under the optimal reaction conditions, we first evaluated the scope of N-arylallylamines for the synthesis of indolines. As shown in Scheme 2, substrates with various electron-donating

N-tert-Butanesulfinyl imines in the asymmetric synthesis of nitrogen-containing heterocycles

• Joseane A. Mendes,
• Paulo R. R. Costa,
• Miguel Yus,
• Francisco Foubelo and
• Camilla D. Buarque

Beilstein J. Org. Chem. 2021, 17, 1096–1140, doi:10.3762/bjoc.17.86

• with sodium tetraarylboronates 64 was found to proceed with high diastereoselectivity under rhodium catalysis. Reddy and co-workers applied this methodology to the synthesis of 2-substituted pyrrolidines 66 [95]. The arylation of chlorinated imine (RS)-63 was performed with 2 mol % of an air-stable

Recent advances in palladium-catalysed asymmetric 1,4–additions of arylboronic acids to conjugated enones and chromones

• Jan Bartáček,
• Jan Svoboda,
• Martin Kocúrik,
• Jaroslav Pochobradský,
• Alexander Čegan,
• Miloš Sedlák and
• Jiří Váňa

Beilstein J. Org. Chem. 2021, 17, 1048–1085, doi:10.3762/bjoc.17.84

• 2011 [47]. The most efficient catalytic system was identified as a combination of (S)-t-Bu-PyOx (L9) with Pd(TFA)2 (Table 17). This system exhibited a remarkable tolerance for water and air. It was demonstrated by the addition of 10 equiv of water into the reaction mixture that caused only a very small

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

• , placed on a slide and air-dried. Once dried, a small drop of Diamond Anti-Fade Mountant with DAPI (Invitrogen™, Thermo Fisher Scientific, MA) was added and a coverslip placed over the membrane. Slides were cured overnight at 4 °C before being visualized using a Zeiss Axio Vert A.1 light microscope with a

Microwave-assisted multicomponent reactions in heterocyclic chemistry and mechanistic aspects

• Shivani Gulati,
• Stephy Elza John and
• Nagula Shankaraiah

Beilstein J. Org. Chem. 2021, 17, 819–865, doi:10.3762/bjoc.17.71

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

• to the action of chemical (acids, air, halogens, solvents) or physical agents (heat, light). For polymers, the properties involved are, for instance, tensile strength, colour or shape, the change of which is usually associated with a modification of the chemical composition (e.g., as a consequence of

• products, such as coffee cups or take-away containers, can be recycled into videocassette cases or office equipment. Incineration at a temperature below 1000 °C and insufficient air is believed to produce a mixture of volatile compounds, including hazardous polycyclic aromatic hydrocarbons, alkylbenzenes

Breakdown of 3-(allylsulfonio)propanoates in bacteria from the Roseobacter group yields garlic oil constituents

• Anuj Kumar Chhalodia and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 569–580, doi:10.3762/bjoc.17.51

• the demethylation pathway that is fully established in P. inhibens by genes coding for DmdA–D (Scheme 4A). In the presence of air thiol 13 can then undergo an oxidative dimerization, or react analogously with MeSH to form allyl methyl disulfide (30, Scheme 4B). Similar oxidations requiring one

• index to the volatile 27 (Scheme 5B). This compound may arise from 23 by the action of an oxygenase that is restricted to O. indolifex and not encoded in the genomes of the other two species. Its spontaneous formation from 23 in the presence of air can be excluded, because other cultures forming 23 did

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

• the olefin to give π-bonded species of type B which could then lead to the formation of the corresponding epoxide product via the metalloepoxi species C [55][56]. On the other hand, considering that the reaction is carried out under air atmosphere, and that in the absence of TBHP the epoxidation also

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

• synthesized for comparison. The capacity for the F-lipopeptides to spontaneously adsorb at the air/water interface and form monolayers when combined with dipalmitoylphosphatidylcholine (DPPC) was investigated. The F-lipopeptides 1–3 demonstrated a markedly enhanced tendency to form monolayers at the air/water

• ability to self-assemble into spontaneously adsorbed monolayers at the air/water interface and also to adsorb on a DPPC monolayer spread at the air/water interface. Finally, the size and stability characteristics of perfluorohexane (F-hexane)-stabilized microbubbles with DPPC/DPPE-PEG2000 shells and

• analysis, the products 1–4 had high purity (>99%) (Supporting Information File 1, Figures S1–S12). Behavior of lipid-peptide conjugates at the air/water interface Spontaneous adsorption of lipid–peptide conjugates at the air/water interface. In order to investigate the capacity for F-lipopeptides 1–3 to

Identification of volatiles from six marine Celeribacter strains

• Anuj Kumar Chhalodia,
• Jan Rinkel,
• Dorota Konvalinkova,
• Jörn Petersen and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2021, 17, 420–430, doi:10.3762/bjoc.17.38

• -(methylsulfanyl)acrylate (42), thus questioning their natural source from Celeribacter. These results demonstrate that the six Celeribacter strains are able to degrade methionine and DMSP with formation of MeSH as a source for the likely non-enzymatic oxidation in the presence of air to 37 and 38, opening

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

• -quinone 3a, which was previously reported by us [14]. The product 6a is air-stable at ambient conditions both in solid state and in solution. According to X-ray data, the 1,3-dithiole ring in the molecule is almost planar, its geometry is typical of 1,3-dithiole-2-thione species [26][27][28] (Figure S1 in

• similar observations were reported previously for monocyclic thiete compounds [35][36]. Benzothietes usually behave as highly reactive and labile species, however, solid samples of o-quinone 7 could be stored for months on air at ambient conditions without significant changes. Most probably, such

• tested only typical properties of the dioxolene function of the novel synthesized species. As mentioned above, all new o-quinones 6a–d and 7 are stable at rt on air both in crystalline form and in solution. Like other sterically hindered o-quinones, they can undergo two consecutive one-electron

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

• : PDFA is available from the reaction of triphenylphosphine with halodifluoroacetate salts such as BrCF2CO2K. It exists as a free-flowing white solid that is not sensitive to air or moisture [33]. Upon heating to 80 °C in N-methylpyrrolidone, the compound decarboxylates and acts as a source of the ylide

• (trifluoromethyl)mercury (IHgCF3) and bis(trifluoromethyl)mercury (Hg(CF3)2) [57]. However, despite good synthetic conversions having been obtained with Seyferth's reagent [58] and the general insensitivity of organomercurials to air and moisture, the presence of mercury in all of these structures is a major

• -difluorocyclopropane derivative 53 plus cadmium fluoride [61][62]. However, cadmium compounds are highly toxic and furthermore (CF3)2Cd is pyrophoric in air and liable to explode upon warming to room temperature. Tris(trifluoromethyl)bismuth (54) is also a source of difluorocarbene, that is generated during the

Selective synthesis of α-organylthio esters and α-organylthio ketones from β-keto esters and sodium S-organyl sulfurothioates under basic conditions

• Jean C. Kazmierczak,
• Roberta Cargnelutti,
• Thiago Barcellos,
• Claudio C. Silveira and
• Ricardo F. Schumacher

Beilstein J. Org. Chem. 2021, 17, 234–244, doi:10.3762/bjoc.17.24

• 4 equivalents of a base were used, a series of differently substituted α-thio esters were obtained with up to 90% yield. On the other hand, employing 2 equivalents of a base, α-thio ketones were achieved after 18 h under air. Furthermore, after a shorter reaction time, the isolation of keto–enol

• methods. Thus, the main features of the current strategy include the use of Bunte salts, avoiding air-sensitive and foul-smelling starting materials [53][54] to react with β-keto esters under NaOH-mediation to selectively produce α-thio esters or α-thio ketones as target products. Additionally, no

• starting materials to establish the best reaction conditions under an air atmosphere (Table 1). In our preliminary experiment, a mixture of 1a (1.0 mmol) and 2a (0.5 mmol), using NaOH (2 equiv) as a base in toluene (3.0 mL), was stirred at 100 °C for 18 h. Under these reaction conditions, the products

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

• intensities were recorded in dependence on the scattering angle. The absorption spectra were recorded on a SHIMADZU UV Spectrophotometer (UV-1800) with a slit width of 1.0 nm and a range of 200 nm ≤ λ ≤ 800 nm. The spectra were recorded against air as a reference. For all measurements 10 mm quartz cuvettes

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

• ) and 25 (syn-HT) in an aqueous solution increased from 23 to 76% (60 min, under N2, O2, and air), with a high selectivity (>99%). However, for reactions without adding CB[8] as a catalyst, the conversion yield was below 10%. In addition, the fluorescence enhancement was also observed at a host/guest CB

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

• measurements of the assembled compound 1 were employed. An air-dried sample of compound 1 deposited on a Si substrate (see Supporting Information File 1) gave rise to rectangular structures with well-defined edges (Figure S3, Supporting Information File 1), 3.2 ± 0.4 nm in height. This is in good agreement

Amine–borane complex-initiated SF₅Cl radical addition on alkenes and alkynes

• Audrey Gilbert,
• Pauline Langowski,
• Marine Delgado,
• Laurent Chabaud,
• Mathieu Pucheault and
• Jean-François Paquin

Beilstein J. Org. Chem. 2020, 16, 3069–3077, doi:10.3762/bjoc.16.256

• , France 10.3762/bjoc.16.256 Abstract The SF5Cl radical addition on unsaturated compounds was performed using an air-stable amine–borane complex as the radical initiator. This method showed to be complementary to the classic Et3B-mediated SF5Cl addition on alkenes and alkynes. A total of seven alkene and

• temperatures, which requires the use of air-free techniques in the laboratory. Et3B in the pure form has limited commercial availability and is known to spontaneously react with oxygen to produce a green flame [36]. To avoid the pyrophoric properties of triethylborane, this reagent is mostly sold in low

• freshly prepared [37]. It is therefore of interest to address this challenge in order to widen the scope of this transformation. Compared to trialkylboranes, amine–borane complexes have shown to be more stable [38]. Indeed, they are usually air-stable, and their preparation from NaBH4, H2SO4 and amines

Deoxyfluorination of acyl fluorides to trifluoromethyl compounds by FLUOLEAD^®/Olah’s reagent under solvent-free conditions

• Yumeng Liang,
• Akihito Taya,
• Zhengyu Zhao,
• Norimichi Saito and
• Norio Shibata

Beilstein J. Org. Chem. 2020, 16, 3052–3058, doi:10.3762/bjoc.16.254

• the deoxyfluorination. FLUOLEAD® is a stable crystalline solid and has sufficient stability against moisture to be handled open to air without the emission of fumes, and it is available in quantities that can exceed 100 kg from Ube Industries, Ltd [31]. FLUOLEAD® is an attractive alternative to the

Controlled decomposition of SF₆ by electrochemical reduction

• Sébastien Bouvet,
• Bruce Pégot,
• Stéphane Sengmany,
• Erwan Le Gall,
• Eric Léonel,
• Anne-Marie Goncalves and
• Emmanuel Magnier

Beilstein J. Org. Chem. 2020, 16, 2948–2953, doi:10.3762/bjoc.16.244

• chemically and physiologically, it is non-flammable, has a high density and a high dielectric constant (2.5 times greater than that of air) [2][3][4][5]. These properties explain that this compound is widely used industrially as an electrical insulating gas in circuit breakers or in electrical substations [6

UV resonance Raman spectroscopy of the supramolecular ligand guanidiniocarbonyl indole (GCI) with 244 nm laser excitation

• Tim Holtum,
• Vikas Kumar,
• Daniel Sebena,
• Jens Voskuhl and
• Sebastian Schlücker

Beilstein J. Org. Chem. 2020, 16, 2911–2919, doi:10.3762/bjoc.16.240

• for deep UVRR studies [24]. This closed-loop system is driven by a peristaltic pump. A half air-filled syringe acts as an upper reservoir to flatten pressure oscillations from the peristaltic pump. An injection needle with an 0.8 mm outer diameter is attached to the syringe as the output nozzle to

• form a laminar liquid column in air at the laser focus. The laser radiation was focused by two cylindrical lenses to create a line focus along the sample liquid column and a 90° scattering geometry was used for collecting the Raman scattered light. The UV–vis absorption spectra were acquired with a UV