Inductive heating and flow chemistry – a perfect synergy of emerging enabling technologies

• Conrad Kuhwald,
• Sibel Türkhan and
• Andreas Kirschning

Beilstein J. Org. Chem. 2022, 18, 688–706, doi:10.3762/bjoc.18.70

• increased by 5 °C. The authors suggested that the use of RF heating may allow water splitting near the equilibrium voltage at room temperature. Although it was expected that the magnetic field applied by inductive heating would disturb the flowing current, mainly positive effects were observed. 3 Micro- and

• 56% (87 + 88) was obtained for the Diels–Alder cycloaddition, and suppressed polymerization at room temperature. This mixture was then converted in a second step and an Amberlyst 15TM-catalyzed cyclization at 60 °C gave 88 with a selectivity of 95%. Reactions such as polymerizations that inhibit the

Tri(n-butyl)phosphine-promoted domino reaction for the efficient construction of spiro[cyclohexane-1,3'-indolines] and spiro[indoline-3,2'-furan-3',3''-indolines]

• Hui Zheng,
• Ying Han,
• Jing Sun and
• Chao-Guo Yan

Beilstein J. Org. Chem. 2022, 18, 669–679, doi:10.3762/bjoc.18.68

• and 2 in Table 1). Additionally, no reaction was observed when triphenylphosphine was used as catalyst (Table 1, entry 3). However, in the presence of tri(n-butyl)phosphine, the reaction in methylene dichloride, chloroform, and toluene at room temperature gave the expected functionalized spiro

• , isatylidene cyanoacetate (0.3 mmol) and isatin (0.3 mmol) were dissolved in acetonitrile (10.0 mL). Then, tri(n-butyl)phosphine (0.6 mmol) was added by syringe and the solution was stirred at room temperature for two hours. After removing the solvent at reduced pressure, the residue was subjected to column

New synthesis of a late-stage tetracyclic key intermediate of lumateperone

• Mátyás Milen,
• Bálint Nyulasi,
• Tamás Nagy,
• Gyula Simig and
• Balázs Volk

Beilstein J. Org. Chem. 2022, 18, 653–659, doi:10.3762/bjoc.18.66

• 24 was accomplished in neat conditions within 3 days of reaction time using a literature procedure [5]. Attempts in acetonitrile as solvent were unsuccessful: after 1 day at room temperature, product 28 was isolated in only 20% yield, while at reflux temperature, a decomposition has been observed

Direct C–H amination reactions of arenes with N-hydroxyphthalimides catalyzed by cuprous bromide

• Dongming Zhang,
• Bin Lv,
• Pan Gao,
• Xiaodong Jia and
• Yu Yuan

Beilstein J. Org. Chem. 2022, 18, 647–652, doi:10.3762/bjoc.18.65

• mL) were added into a 15 mL sealed tube. The resulting mixture was stirred at 100 °C under air for 12 h, and the progress was monitored by TLC. The solution was then cooled to room temperature and the solvent was removed under vacuum. The crude residue was purified by column chromatography on silica

Cholyl 1,3,4-oxadiazole hybrid compounds: design, synthesis and antimicrobial assessment

• Anas J. Rasras,
• Mohamed El-Naggar,
• Nesreen A. Safwat and
• Raed A. Al-Qawasmeh

Beilstein J. Org. Chem. 2022, 18, 631–638, doi:10.3762/bjoc.18.63

• of 22 diverse compounds. Briefly, the alkyne 3 was treated with formaldehyde, a secondary amine, and CuI as catalyst in DMSO (Scheme 3). The three components were stirred at room temperature for 3 h to furnish the desired compounds 4a–v in moderate to excellent yields [14][34]. By this route, diverse

A study of the photochemical behavior of terarylenes containing allomaltol and pyrazole fragments

• Constantine V. Milyutin,
• Andrey N. Komogortsev,
• Boris V. Lichitsky and
• Valeriya G. Melekhina

Beilstein J. Org. Chem. 2022, 18, 588–596, doi:10.3762/bjoc.18.61

• darkness at room temperature for 5 days resulted in complete decomposition. Despite the labile nature of α-hydroxy-1,2-diketone 14a we attempted to isolate this product in pure form. It should be noted that in contrast to the methylated derivative 16, pyrazole 12a has a low solubility in most organic

Shift of the reaction equilibrium at high pressure in the continuous synthesis of neuraminic acid

• Jannis A. Reich,
• Miriam Aßmann,
• Kristin Hölting,
• Paul Bubenheim,
• Jürgen Kuballa and
• Andreas Liese

Beilstein J. Org. Chem. 2022, 18, 567–579, doi:10.3762/bjoc.18.59

• % glutaraldehyde solution 1:4 (w/v). After addition of the 2% glutaraldehyde solution, the mixture was incubated for 1 h at room temperature under slow rotation at 8 rpm using a sample mixer (MXIC1 sample mixer, Dynal Biotech Ltd., Bromborough, UK). Afterwards, the activated carrier was filtered and carefully

• mM ManNAc, 2 mM NAD, and 0.05 mL ManDH solution with 3 kU/mL. After starting the reaction, the mixture was incubated at room temperature for 30 minutes. The resulting NADH concentration was measured with an Eppendorf spectrophotometer at 340 nm. High-pressure set-up An HPLC pump (Nexera X2 LC-30AD

Terpenoids from Glechoma hederacea var. longituba and their biological activities

• Dong Hyun Kim,
• Song Lim Ham,
• Zahra Khan,
• Sun Yeou Kim,
• Sang Un Choi,
• Chung Sub Kim and
• Kang Ro Lee

Beilstein J. Org. Chem. 2022, 18, 555–566, doi:10.3762/bjoc.18.58

• School of Pharmacy, Sungkyunkwan University, Suwon, Korea. Extraction and isolation. The dried aerial parts of G. hederacea var. longituba (3.0 kg) were extracted with 80% MeOH (each 12.0 L × 1 day, 3 times) at room temperature and filtered. The filtrate was evaporated in vacuo to yield an 80% MeOH

Synthesis of a new water-soluble hexacarboxylated tribenzotriquinacene derivative and its competitive host–guest interaction for drug delivery

• Man-Ping Li,
• Nan Yang and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2022, 18, 539–548, doi:10.3762/bjoc.18.56

• 40% ammonium hydroxide solution (30 mL) and stirred at room temperature for 5 h. The solvent was removed by distillation, and the residue was dissolved in water and washed several times with dichloromethane. The aqueous layer was collected and freeze-dried to afford compound TBTQ-CB6 as a colorless

Chemistry of polyhalogenated nitrobutadienes, 17: Efficient synthesis of persubstituted chloroquinolinyl-1H-pyrazoles and evaluation of their antimalarial, anti-SARS-CoV-2, antibacterial, and cytotoxic activities

• Viktor A. Zapol’skii,
• Isabell Berneburg,
• Ursula Bilitewski,
• Melissa Dillenberger,
• Katja Becker,
• Stefan Jungwirth,
• Aditya Shekhar,
• Bastian Krueger and
• Dieter E. Kaufmann

Beilstein J. Org. Chem. 2022, 18, 524–532, doi:10.3762/bjoc.18.54

• structure) to 85% (by using MNDO) at the C1 carbon atom [8]. The treatment of the azolylbutadienes 2 with 7-chloro-4-hydrazinylquinoline in methanol at room temperature using triethylamine as a base leads to the formation of the 7-chloro-4-(5-(dichloromethyl)-3-azolyl-4-nitro-1H-pyrazol-1-yl)quinolines 3a–c

• in 67–88% yields (Scheme 7). The sulfanes 8a–e were formed as single isomers, among them 1,3,4,4-tetrachloro-1-(4-chlorophenylsulfanyl)-2-nitrobuta-1,3-diene (8e) as E-isomer (X-ray) [29]. Thiodienes 8a–e reacted with equimolar amounts of 7-chloro-4-hydrazinylquinoline in DCM at room temperature

• using triethylamine as base to give the corresponding 3-thiopyrazoles 9a–e in moderate yields (28–69%). By oxidation of sulfane 9d with m-chloroperbenzoic acid in chloroform at room temperature the sulfoxide 10d was obtained in 43% yield (Scheme 7). For comparing the biological activity of the newly

BINOL as a chiral element in mechanically interlocked molecules

• Matthias Krajnc and
• Jochen Niemeyer

Beilstein J. Org. Chem. 2022, 18, 508–523, doi:10.3762/bjoc.18.53

• timescale at room temperature (for 22), the other two dynamic processes, namely circumrotation of the tetracationic cyclophane through the cavity of the polyether and a “rocking motion” of the oxygen–oxygen axis of the hydroquinone units, were fast on the NMR timescale at room temperature. In a follow-up

Substituent effect on TADF properties of 2-modified 4,6-bis(3,6-di-tert-butyl-9-carbazolyl)-5-methylpyrimidines

• Irina Fiodorova,
• Tomas Serevičius,
• Rokas Skaisgiris,
• Saulius Juršėnas and
• Sigitas Tumkevicius

Beilstein J. Org. Chem. 2022, 18, 497–507, doi:10.3762/bjoc.18.52

• rest of compounds with low-energy shoulder. More detailed analysis (see Figure S30 in Supporting Information File 1) revealed the presence of room-temperature phosphorescence (RTP), perturbing the lineshape of PL spectra. The estimated singlet–triplet energy gaps (ΔEST) of carbazole–pyrimidine TADF

Bioinspired tetraamino-bisthiourea chiral macrocycles in catalyzing decarboxylative Mannich reactions

• Hao Guo,
• Yu-Fei Ao,
• De-Xian Wang and
• Qi-Qiang Wang

Beilstein J. Org. Chem. 2022, 18, 486–496, doi:10.3762/bjoc.18.51

• room temperature with just 2 mol % loading of the chiral macrocycle catalysts (Table 1). All macrocycles were evaluated, and in all cases product 8a was obtained in moderate yields. Different diamine linking components and different substituents on the tertiary amine sites showed an important influence

Tosylhydrazine-promoted self-conjugate reduction–Michael/aldol reaction of 3-phenacylideneoxindoles towards dispirocyclopentanebisoxindole derivatives

• Sayan Pramanik and
• Chhanda Mukhopadhyay

Beilstein J. Org. Chem. 2022, 18, 469–478, doi:10.3762/bjoc.18.49

• mL round bottomed flask provided with a reflux condenser. Then the reaction mixture was stirred at 60–70 °C for 6 hours. After reaching the completion, the reaction mixture was examined by TLC. Then the reaction mixture was cooled to room temperature, diluted with 10 mL of water and extracted with

Synthesis of 3,4,5-trisubstituted isoxazoles in water via a [3 + 2]-cycloaddition of nitrile oxides and 1,3-diketones, β-ketoesters, or β-ketoamides

• Md Imran Hossain,
• Md Imdadul H. Khan,
• Seong Jong Kim and
• Hoang V. Le

Beilstein J. Org. Chem. 2022, 18, 446–458, doi:10.3762/bjoc.18.47

• Agriculture, Agricultural Research Service, University of Mississippi, Mississippi 38677, USA 10.3762/bjoc.18.47 Abstract Herein we report a method for the synthesis of 3,4,5-trisubstituted isoxazoles in water under mild basic conditions at room temperature via a [3 + 2]-cycloaddition of nitrile oxides and

• reaction proceed at room temperature and improve both the regioselectivity and yields of the isoxazoles. However, these catalysts only work for the reaction with terminal alkynes and only produce 3,5-disubstituted isoxazole products (Figure 1) [19][20]. The synthesis of 3,4,5-trisubstituted isoxazoles from

• highly substituted non-terminal alkynes does not proceed with copper catalysts at room temperature. As an alternative, the usage of ruthenium(II) catalysts enables the reaction to proceed smoothly at room temperature and produces high yields and regioselectivity for both, 3,5-disubstituted and 3,4,5

The asymmetric Henry reaction as synthetic tool for the preparation of the drugs linezolid and rivaroxaban

• Martin Vrbický,
• Karel Macek,
• Jaroslav Pochobradský,
• Jan Svoboda,
• Miloš Sedlák and
• Pavel Drabina

Beilstein J. Org. Chem. 2022, 18, 438–445, doi:10.3762/bjoc.18.46

• ., with ligands IIa, IIIa, and IV) and, expectedly, it enabled the achievement of a higher chemical yield. Performing of the reaction at room temperature also increased the chemical yield, however, a certain drop of the ee was observed, especially in the case of catalysts derived from ligands IIa and VII

Cs₂CO₃-Promoted reaction of tertiary bromopropargylic alcohols and phenols in DMF: a novel approach to α-phenoxyketones

• Ol'ga G. Volostnykh,
• Olesya A. Shemyakina,
• Anton V. Stepanov and
• Igor' A. Ushakov

Beilstein J. Org. Chem. 2022, 18, 420–428, doi:10.3762/bjoc.18.44

• 5% preparative yield (Table 1, entry 4), whereas the use of 2 equiv of Cs2CO3 led to slightly more selective reaction (Table 1, entry 5). Further lowering the temperature reduces the selectivity toward phenoxyketone 4a. At room temperature, the full conversion of bromopropargylic alcohol 1a took 15

Menadione: a platform and a target to valuable compounds synthesis

• Acácio S. de Souza,
• Ruan Carlos B. Ribeiro,
• Dora C. S. Costa,
• Fernanda P. Pauli,
• David R. Pinho,
• Matheus G. de Moraes,
• Fernando de C. da Silva,
• Luana da S. M. Forezi and
• Vitor F. Ferreira

Beilstein J. Org. Chem. 2022, 18, 381–419, doi:10.3762/bjoc.18.43

Four bioactive new steroids from the soft coral Lobophytum pauciflorum collected in South China Sea

• Di Zhang,
• Zhe Wang,
• Xiao Han,
• Xiao-Lei Li,
• Zhong-Yu Lu,
• Bei-Bei Dou,
• Wen-Ze Zhang,
• Xu-Li Tang,
• Ping-Lin Li and
• Guo-Qiang Li

Beilstein J. Org. Chem. 2022, 18, 374–380, doi:10.3762/bjoc.18.42

• pauciflorum (3.6 kg, wet weight; 1.1 kg, dry weight) were cut into pieces and exhaustively extracted with MeOH five times at room temperature. The solvent was removed under reduced pressure and the combined organic extract was desalted three times by anhydrous methanol. The desalted residue (110 g) was

Borylated norbornadiene derivatives: Synthesis and application in Pd-catalyzed Suzuki–Miyaura coupling reactions

• Robin Schulte and
• Heiko Ihmels

Beilstein J. Org. Chem. 2022, 18, 368–373, doi:10.3762/bjoc.18.41

• with Pd2(dba)3/(t-Bu)3PHBF4 as catalytic system and CsF as additive in THF at room temperature, because these conditions have been shown to be well-suitable for Suzuki–Miyaura reactions of halogen-substituted norbornadiene derivatives with arylboronic acids [28]. However, under these conditions the

Amamistatins isolated from Nocardia altamirensis

• Till Steinmetz,
• Wolf Hiller and
• Markus Nett

Beilstein J. Org. Chem. 2022, 18, 360–367, doi:10.3762/bjoc.18.40

• dilution of compounds 1–6 dissolved in DMSO) were added to every well. EDTA was used as a reference and dissolved in water. The microtiter plate was gently shaken for 4 h at room temperature. After this incubation period the remaining CAS–Fe3+ complex in each well was quantified by measuring the absorbance

A resorcin[4]arene hexameric capsule as a supramolecular catalyst in elimination and isomerization reactions

• Tommaso Lorenzetto,
• Fabrizio Fabris and
• Alessandro Scarso

Beilstein J. Org. Chem. 2022, 18, 337–349, doi:10.3762/bjoc.18.38

• -pinene at room temperature (Figure 5 and Table 5) confirming that substrate conversion was higher when using the symmetrical capsule A (16·8H2O) under low water content conditions [22], with respect to capsule 16 as mixture of A and B (Figure 5A and E). A possible explanation could be related to the fact

• prepared by adding, at room temperature, a few drops of bi-distilled water to a 100 mL bottle chloroform-d previously passed on basic alumina in agreement with recent literature results to avoid interference by HCl [45]. Resorcin[4]arene 1 was synthesized and purified according to the procedure reported in

• recorded after 64 h at room temperature, while A and B were recorder right after sample preparation. Resorcin[4]arene 1 forming the corresponding hexameric capsule 16 and the species used for control experiments like 4-n-hexylresorcinol (2) to mimic the H-bonding properties of the capsule

A Se···O bonding catalysis approach to the synthesis of calix[4]pyrroles

• Qingzhe Tong,
• Zhiguo Zhao and
• Yao Wang

Beilstein J. Org. Chem. 2022, 18, 325–330, doi:10.3762/bjoc.18.36

• approach was efficient since only 5 mol % catalyst loading was used to promote the consecutive condensation processes while the reactions could be carried out at room temperature, thus highlighting the potential of this type of nonclassical interactions in catalyzing relative complex transformations

• efficiently at room temperature. We note that this reaction did not stop at a bis(pyrrole)methane stage, but consecutive condensations between four molecules of acetone and four molecules of pyrrole took place to give calix[4]pyrrole 2a in 91% yield after 4 h (Scheme 2). Further investigations revealed that

• investigated (Scheme 3). Both linear and cyclic aliphatic ketones could be used to synthesize calix[4]pyrrole derivatives under catalysis of 5 mol % Ch1 at room temperature. It was found that this chalcogen bonding catalysis approach was susceptible to the variation of the steric environment of ketones. Upon

Site-selective reactions mediated by molecular containers

• Rui Wang and
• Yang Yu

Beilstein J. Org. Chem. 2022, 18, 309–324, doi:10.3762/bjoc.18.35

• employed, the site-selectivity turned back to the 1,9-position, and with catalytic turnover (Figure 1d). Only 10 mol % of B promoted the Diels–Alder reaction of 1 and N-phenylphthalimide (5) almost quantitatively affording the 9,10-adduct 6 at room temperature for 5 hours. Control experiments proved the

• molecular containers, the authors designed to investigate the Diels–Alder reaction between 2 and naphthalene 7. As expected, the reactants were encapsulated within the cage host A successfully at room temperature and formed a ternary complex A•(7•2), and after being heated at 100 °C for 8 hours, the site

• polyenol substrate 24, derived from linolenic acid, was monohydrogenated at the terminal, sterically accessible site inside the supramolecular supported catalyst to 25 with 74% yield at room temperature for 20 hours (Figure 7b). A control experiment showed that this kind of site-selectivity could not be

Unexpected chiral vicinal tetrasubstituted diamines via borylcopper-mediated homocoupling of isatin imines

• Marco Manenti,
• Leonardo Lo Presti,
• Giorgio Molteni and
• Alessandra Silvani

Beilstein J. Org. Chem. 2022, 18, 303–308, doi:10.3762/bjoc.18.34

• . Results and Discussion We began our investigation using the known (R)-1-methylisatin-derived N-tert-butanesulfinyl ketimine 1a, bis(pinacolato)diboron, CuSO4/(Cy)3P catalyst and benzylamine, as reported in Scheme 1. The first reaction was carried out at room temperature in toluene/water (5:1), as

• parentheses). Reaction conducted according to the Ellman protocol. Proposed mechanism for the borylcopper-mediated homocoupling of ketimines 1. Screening of the reaction conditions for compound 2a.a Intramolecular hydrogen bonds in 2a at room temperature, which involve the NH groups with one keto oxygen (O2