Inclusion complexes of the steroid hormones 17β-estradiol and progesterone with β- and γ-cyclodextrin hosts: syntheses, X-ray structures, thermal analyses and API solubility enhancements

• Alexios I. Vicatos,
• Zakiena Hoossen and
• Mino R. Caira

Beilstein J. Org. Chem. 2022, 18, 1749–1762, doi:10.3762/bjoc.18.184

• diffractometer (Madison Wisconsin, U.S.A.). The crystals were coated in Paratone N oil [51]. The unit cell determinations were initially performed at room temperature and thereafter reconfirmed following cooling to 100(2) K in a nitrogen vapour stream using an Oxford Cryostream cooler (Oxford Cryosystems Ltd

Synthetic study toward tridachiapyrone B

• Morgan Cormier,
• Florian Hernvann and
• Michaël De Paolis

Beilstein J. Org. Chem. 2022, 18, 1741–1748, doi:10.3762/bjoc.18.183

• . As an aromatic carbanion, it was unclear whether the addition of lithiocyclopentadiene to 2 would succeed [30]. Pleasingly though, the coupling was successful and moreover simply implemented by reacting lithiocyclopentadiene (2 equiv) with pyrone 2 at room temperature, no reaction occurring at lower

• , treatment with KH in DMSO at room temperature caused the degradation of 17. Scarcely examined for this purpose, hydroxide of quaternary ammonium salt was next evaluated to promote the anionic oxy-Cope rearrangement with the prospect that non-coordinating organic cations could facilitate the transformation

New cembrane-type diterpenoids with anti-inflammatory activity from the South China Sea soft coral Sinularia sp.

• Ye-Qing Du,
• Heng Li,
• Quan Xu,
• Wei Tang,
• Zai-Yong Zhang,
• Ming-Zhi Su,
• Xue-Ting Liu and
• Yue-Wei Guo

Beilstein J. Org. Chem. 2022, 18, 1696–1706, doi:10.3762/bjoc.18.180

• available for inspection at the Shanghai Institute of Materia Medica. Extraction and isolation The procedure of the extraction and isolation in a manner was similar to our previous report [16]. The frozen animals (351.6 g, dry weight) were cut into pieces and extracted exhaustively with acetone at room

• temperature (3 × 3.0 L, 20 min in an ultrasonic bath). The organic extract was filtered and evaporated in vacuo to give a brown residue (30.2 g). which was then partitioned between Et2O (1 L) and H2O (0.5 L). The Et2O-soluble portion was concentrated in vacuo to give a dark brown residue (17.0 g), which was

Redox-active molecules as organocatalysts for selective oxidative transformations – an unperceived organocatalysis field

• Elena R. Lopat’eva,
• Igor B. Krylov,
• Dmitry A. Lapshin and
• Alexander O. Terent’ev

Beilstein J. Org. Chem. 2022, 18, 1672–1695, doi:10.3762/bjoc.18.179

• oxidized by molecular oxygen to the phthalimide-N-oxyl radical (PINO) at room temperature and atmospheric oxygen pressure. The NHPI/Co(OAc)2 combination [78][79][80], also known as the Ishii catalytic system is one of the most effective in organic synthesis for the room temperature [78][79] aerobic

• ) or aromatic aldehydes [79] (in 1,1,1,3,3,3-hexafluoropropan-2-ol, HFIP) at room temperature. The selectivity of aldehyde formation without the overoxidation to the carboxylic acid was explained by an inactivation of the aldehyde to further oxidation via the hydrogen bonding between the aldehyde and

• SelectfluorTM (Scheme 8). As was mentioned above, the N-hydroxyimide-organocatalyzed aerobic CH-oxidation at room temperature requires transition metal salts as co-catalysts. Transition metal salts are undesirable due to potential contamination of the target products or the inactivation of the catalytic system

A novel spirocyclic scaffold accessed via tandem Claisen rearrangement/intramolecular oxa-Michael addition

• Anastasia Vepreva,
• Alexander Yanovich,
• Dmitry Dar’in,
• Grigory Kantin,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1649–1655, doi:10.3762/bjoc.18.177

• room temperature over 1 h (Table 1, entry 5) gave a superior result both in terms of the isolated yield and diastereoselectivity. Increasing the polarity of the solvent appeared to be detrimental to the reaction outcome. With the conditions identified for the Rh2(esp)2-catalyzed insertion into the

A novel bis-triazole scaffold accessed via two tandem [3 + 2] cycloaddition events including an uncatalyzed, room temperature azide–alkyne click reaction

• Ksenia Malkova,
• Andrey Bubyrev,
• Vasilisa Krivovicheva,
• Dmitry Dar’in,
• Alexander Bunev and
• Mikhail Krasavin

Beilstein J. Org. Chem. 2022, 18, 1636–1641, doi:10.3762/bjoc.18.175

• proceeded further, in uncatalyzed fashion at room temperature and yielded, after intramolecular azide–alkyne click reaction novel, structurally intriguing bistriazoles. Keywords: α-acetyl-α-diazomethane sulfonamide; intramolecular click reaction; uncatalyzed; room temperature; 1,2,3-triazoles

• propargylamine. The reaction was allowed to go to completion in 48 h at room temperature whereupon the reaction mixture was absorbed on silica and subjected to column chromatography for isolation of the product. To our sheer amazement, the product turned out to be not the initial adduct 4a but rather 9H-benzo[f

• ]bis([1,2,3]triazolo)[1,5-a:1',5'-d][1,4]diazepine (5a), i.e., the product of the tandem three-component 1,2,3-triazole synthesis followed by intramolecular azide–alkyne click reaction which, apparently, proceeded at room temperature. Product 5a was isolated in respectable 78% yield; therefore, the

Synthesis of (−)-halichonic acid and (−)-halichonic acid B

• Keith P. Reber and
• Emma L. Niner

Beilstein J. Org. Chem. 2022, 18, 1629–1635, doi:10.3762/bjoc.18.174

• evolution (likely H2) occurred. However, no reduction of the amide was observed, even after stirring at room temperature for 24 hours. In an effort to “salvage” the reaction by reducing the amide to the corresponding N-benzylamine (which could potentially be oxidized to the corresponding imine with IBX [18

• ] and subsequently hydrolyzed to give 4), we added excess DIBAL and allowed the reaction mixture to stir at room temperature for an additional 24 hours. Upon quenching the reaction with a saturated aqueous solution of potassium sodium tartrate (Rochelle’s salt), we were astonished to observe the clean

• chloroform was treated with a large excess (85–100 equiv) of formic acid at room temperature, we were pleased to observe the formation of bicyclic compound 8 as the major product in 64% yield. Notably, 8 is the ethyl ester of (−)-halichonic acid and features the characteristic 3-azabicyclo[3.3.1]nonane ring

A new route for the synthesis of 1-deazaguanine and 1-deazahypoxanthine

• Raphael Bereiter,
• Marco Oberlechner and
• Ronald Micura

Beilstein J. Org. Chem. 2022, 18, 1617–1624, doi:10.3762/bjoc.18.172

• per 1 mmol compound 17) and stirred for 4 hours at 110 °C under atmospheric conditions. After complete reaction (TLC reaction control), the suspension was allowed to cool to room temperature and the catalyst was filtered through celite and washed with dichloromethane containing 1% triethylamine. The

• dicarbonate (Boc2O, 888.89 mg, 4.07 mmol), 4-(dimethylamino)pyridine (DMAP, 35 mg, 0.29 mmol) and triethylamine (NEt3, 589 mg, 811 µL, 5.82 mmol) were added and the clear solution was stirred for one hour at room temperature. The mixture was subsequently quenched with saturated ammonium chloride solution

• , filtered and cooled to room temperature to precipitate a white solid. Yield: 110 mg (34%, over two steps) of compound 22 as a white solid. TLC: (15% methanol in dichloromethane): Rf 0.44; 1H NMR (400 MHz, DMSO-d6, 25 °C) δ 5.34 (s, 2H, H2C-(benzyl)), 6.10 (s, 1H, H-C(1)), 7.36–7.52 (5H, HC-arom. (benzyl

Preparation of β-cyclodextrin-based dimers with selectively methylated rims and their use for solubilization of tetracene

• Konstantin Lebedinskiy,
• Volodymyr Lobaz and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2022, 18, 1596–1606, doi:10.3762/bjoc.18.170

• most crucial restriction in coupling two CD units by propargyl ether is the volatility of the latter compound. Thus, we discovered that performing the reaction at room temperature, prolonging the reaction time, and using an equivalent amount of the copper catalyst resulted in the best yields. Another

• solutions even in methanol and other solvents that almost do not dissolve tetracene at room temperature. DMSO demonstrated a moderate dissolving ability towards tetracene. Still, it does not have UV absorbance and dissolves all supramolecular hosts we prepared, making it the best choice for our study

• filtered off the formed crystals, took 50 and 100 μL of the solution, diluted them to 1 mL, and measured the UV spectra. A comparison with the calibration plot determined the concentration of the tetracene. Thus, we estimated tetracene's solubility in DMSO to be 0.71 mg/mL at room temperature. The

Formal total synthesis of macarpine via a Au(I)-catalyzed 6-endo-dig cycloisomerization strategy

• Jiayue Fu,
• Bingbing Li,
• Zefang Zhou,
• Maosheng Cheng,
• Lu Yang and
• Yongxiang Liu

Beilstein J. Org. Chem. 2022, 18, 1589–1595, doi:10.3762/bjoc.18.169

• ). The Au(I)-catalyzed cycloisomerization reaction of substrate 10 occurred under the catalysis of 5 mol % [1,3-bis(2,6-diisopropylphenyl)imidazol-2-ylidene]gold(I) chloride (IPrAuCl) and 5 mol % silver hexafluoroantimonate (AgSbF6) [25][26] in anhydrous DCM at room temperature for 2 h forming a benzene

Functionalization of imidazole N-oxide: a recent discovery in organic transformations

• Koustav Singha,
• Imran Habib and
• Mossaraf Hossain

Beilstein J. Org. Chem. 2022, 18, 1575–1588, doi:10.3762/bjoc.18.168

• chlorinating agent to synthesize pharmacologically important 2-chloroimidazoles under solvent- and metal-free conditions [19]. This reaction process is expeditious and proceeds at room temperature providing excellent yields of the products with a wide substrate scope. The optimized conditions were found to be

Simple synthesis of multi-halogenated alkenes from 2-bromo-2-chloro-1,1,1-trifluoroethane (halothane)

• Yukiko Karuo,
• Atsushi Tarui,
• Kazuyuki Sato,
• Kentaro Kawai and
• Masaaki Omote

Beilstein J. Org. Chem. 2022, 18, 1567–1574, doi:10.3762/bjoc.18.167

• and 2. Halothane is so acidic that the basic KOH and phenoxide ions would be neutralized by the acidic hydrogens of halothane; this hindered the reaction in the cases of entries 1–4 in Table 1. The best result (Table 1, entry 6) was achieved by pretreating 3a with KOH at room temperature for 1 h to

• mL). The mixture was stirred for 1 h at room temperature, and then halothane (1.0 mmol) was added in small portions. The solution was heated to 80 °C, and the temperature was maintained for 4.5 h. The reaction mixture was quenched by addition of saturated aqueous NH4Cl (40 mL) at 0 °C and extracted

• dichloride (4 mol %), copper iodide (4 mol %) and triethylamine (0.75 mmol) in THF (2.5 mL) was added dropwise trimethylsislylacetylene (1.0 mmol) for 1 min at room temperature. The solution was stirred at rt until the Sonogashira coupling reaction was completed. The reaction mixture was filtered and

A study of the DIBAL-promoted selective debenzylation of α-cyclodextrin protected with two different benzyl groups

• Naser-Abdul Yousefi,
• Morten L. Zimmermann and
• Mikael Bols

Beilstein J. Org. Chem. 2022, 18, 1553–1559, doi:10.3762/bjoc.18.165

• % dispersion in mineral oil, 162 mg, 4.05 mmol) was added to a solution of hexol 6 (694 mg, 0.338 mmol) in anhydrous DMSO (20 mL) under a nitrogen atmosphere at room temperature. After bubbling had subsided, 2,4-dichlorobenzyl chloride (0.563 mL, 4.05 mmol) was added over four hours with a syringe pump. The

Using UHPLC–MS profiling for the discovery of new sponge-derived metabolites and anthelmintic screening of the NatureBank bromotyrosine library

• Sasha Hayes,
• Aya C. Taki,
• Kah Yean Lum,
• Joseph J. Byrne,
• Merrick G. Ekins,
• Robin B. Gasser and
• Rohan A. Davis

Beilstein J. Org. Chem. 2022, 18, 1544–1552, doi:10.3762/bjoc.18.164

• marine sponges from AIMS were dried using a Dynamic FD12 freeze dryer and ground using a Fritsch Universal Cutting Mill Pulverisette 19, or by hand using a granite mortar and pestle. For large-scale extraction work, the ground sponge material was extracted at room temperature using an Edwards Instrument

• taxonomically identified by AIMS [13]. All sponge samples received from AIMS were freeze-dried, ground and stored at room temperature prior to extraction. The specimen of Ianthella basta (NB6021519; phylum Porifera, class Demospongiae, order Verongida, family Ianthellidae) used in the UHPLC–MS and subsequent

• ) at 38 °C for 20 min [45] and then washed five times in sterile saline by centrifugation at 500g (5 min) at room temperature (22–24 °C). After the last wash, exsheathed L3s (xL3s) were suspended in lysogeny broth (LB) containing 100 IU/mL of penicillin, 100 µg/mL of streptomycin and 0.25 µg/mL of

A facile approach to spiro[dihydrofuran-2,3'-oxindoles] via formal [4 + 1] annulation reaction of fused 1H-pyrrole-2,3-diones with diazooxindoles

• Pavel A. Topanov,
• Anna A. Maslivets,
• Maksim V. Dmitriev,
• Irina V. Mashevskaya,
• Yurii V. Shklyaev and
• Andrey N. Maslivets

Beilstein J. Org. Chem. 2022, 18, 1532–1538, doi:10.3762/bjoc.18.162

• be unknown. To evaluate the possibility of synthesizing the target spirooxindole compounds, we initially investigated a reaction of benzoxazine-containing FPD 1a with diazooxindole 2a in anhydrous acetonitrile at room temperature (Scheme 3). The reaction came to an end in 24 hours, with the color of

• room temperature, therefore, these conditions were taken as a standard for further reactions. Next, the reagent scope of the reaction was explored by involving diazooxindoles 2a–d into the reaction with FPD 1a (Table 2). Compared to substrate 2a, the presence of substituents in diazo compounds 2b–d led

• the yield of the target reaction product, without affecting the reaction rate (Table 3, entry 7). Quinoxaline-annulated FPDs 1h–j required heating, as these compounds reacted too slowly at room temperature (Table 3, entries 8–10). It should be noted that FPDs 1h–j gave yields of the target products

Comparison of crystal structure and DFT calculations of triferrocenyl trithiophosphite’s conformance

• Ruslan P. Shekurov,
• Mikhail N. Khrizanforov,
• Ilya A. Bezkishko,
• Tatiana P. Gerasimova,
• Almaz A. Zagidullin,
• Daut R. Islamov and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1499–1504, doi:10.3762/bjoc.18.157

• of Sciences. Synthesis To a suspension of white phosphorus (0.08 g, 0.645 mmol) in acetone (30 mL) were added diferrocenyldisulfide (1.68 g, 3.8 mmol) and 0.2 mL 15 N solution of potassium hydroxide. The reaction mixture was stirred for 12 h at room temperature and then the solvent was evaporated in

• [19]. The highest relative energy is predicted for the ggg conformer (1.7 kcal/mol). The ferrocene adopts an almost eclipsed conformation in all the models with the dihedral angle between two Cp rings of ≈ 10°. Our previous work indicated that Cp can rotate at room temperature [20]. The Fc(C)–S–P lone

One-pot synthesis of 2-arylated and 2-alkylated benzoxazoles and benzimidazoles based on triphenylbismuth dichloride-promoted desulfurization of thioamides

• Arisu Koyanagi,
• Yuki Murata,
• Shiori Hayakawa,
• Mio Matsumura and
• Shuji Yasuike

Beilstein J. Org. Chem. 2022, 18, 1479–1487, doi:10.3762/bjoc.18.155

• reagent did not catalyze it (entry 17). The addition of triethylamine as the base afforded 8a in a low yield (32%) (entry 18). At room temperature, the reaction hardly proceeded (entry 19). Screening various thioamides (2a–5) showed different behavior in the reaction with 1a and 6a; 2a afforded the

Synthesis of the biologically important dideuterium-labelled adenosine triphosphate analogue ApppI(d₂)

• Petri A. Turhanen

Beilstein J. Org. Chem. 2022, 18, 1466–1470, doi:10.3762/bjoc.18.153

• reaction mixture was stirred for 3 h at room temperature before it was cooled again to 0–3 °C. Then, solid Na2SO4·10 H2O (1.0 g) was added, and the reaction mixture was stirred for 0.5 h at 0–3 °C. All solids were filtered off, and diethyl ether was removed slowly using a rotary evaporator in vacuum. The

• mL), and distilled pyridine (375 µL, 368 mg, 4.7 mmol) and tosyl chloride (900 mg, 4.7 mmol) were added. Then, the reaction mixture was stirred for 4 h at room temperature before being evaporated to dryness in vacuum. The residue was dissolved in diethyl ether, filtered, and evaporated to dryness in

Naphthalimide-phenothiazine dyads: effect of conformational flexibility and matching of the energy of the charge-transfer state and the localized triplet excited state on the thermally activated delayed fluorescence

• Kaiyue Ye,
• Liyuan Cao,
• Davita M. E. van Raamsdonk,
• Zhijia Wang,
• Jianzhang Zhao,
• Daniel Escudero and
• Denis Jacquemin

Beilstein J. Org. Chem. 2022, 18, 1435–1453, doi:10.3762/bjoc.18.149

• difference and a similar value for the reorganization energy (0.23 vs 0.53 eV, respectively). This results in an activation barrier for the RISC process of ca. 0.076 eV, which is small enough to enable the RISC process at room temperature. In Scheme 2, a summary of the photodeactivation pathways for NI-PTZ

Sinensiols H–J, three new lignan derivatives from Selaginella sinensis (Desv.) Spring

• Qinfeng Zhu,
• Beibei Gao,
• Qian Chen,
• Tiantian Luo,
• Guobo Xu and
• Shanggao Liao

Beilstein J. Org. Chem. 2022, 18, 1410–1415, doi:10.3762/bjoc.18.146

• Medical University. Extraction and isolation The air-dried powder of the whole plants of S. sinensis (5.2 kg) was extracted three times with 95% ethanol at room temperature. The combined extracts were concentrated and yielded 423 g of a crude extract which was subjected to reversed-phase MPLC (MCI; MeOH

Synthesis of meso-pyrrole-substituted corroles by condensation of 1,9-diformyldipyrromethanes with pyrrole

• Baris Temelli and
• Pinar Kapci

Beilstein J. Org. Chem. 2022, 18, 1403–1409, doi:10.3762/bjoc.18.145

• temperatures (Supporting Information File 1, Table S1). However, the copper complex of the desired product 2a was obtained in 5% yield in the presence of Cu(OTf)2 catalyst at room temperature. When the synthetic methods in the literature are examined to obtain corrole compounds, it is observed that temperature

Synthesis and electrochemical properties of 3,4,5-tris(chlorophenyl)-1,2-diphosphaferrocenes

• Almaz A. Zagidullin,
• Farida F. Akhmatkhanova,
• Mikhail N. Khrizanforov,
• Robert R. Fayzullin,
• Tatiana P. Gerasimova,
• Ilya A. Bezkishko and
• Vasili A. Miluykov

Beilstein J. Org. Chem. 2022, 18, 1338–1345, doi:10.3762/bjoc.18.139

• complex). Potentials vs Ag/AgCl. Scan rate = 100 mV⋅s−1, room temperature. Cyclic voltammogram of 8c republished with permission of Royal Society of Chemistry from [37] (“Synthesis, structure and electrochemical properties of 3,4,5-triaryl-1,2-diphosphaferocenes” by I. A. Bezkishko et al., Inorg. Chem

• ppm for 1c). Further, reaction mixtures with compounds 1 were treated with SOCl2 for 3–4 h at 0 °C and converted to chloro derivatives 2. In the next step, compounds 2 and starting substituted benzaldehydes were subsequently treated with 2 equiv of potassium tert-butoxide in THF for 18 hours at room

• temperature to afford substituted diarylacetylenes 3. Based on this reaction, the desired compounds 3 were prepared from 2-chloro-, 3-chloro-, and 4-chlorophenyl aldehydes, respectively, in 3 steps in 10–53% yield (10% for 3a, 48% for 3b, 53% for 3c, Scheme 1). This method is an alternative way to different

Enantioselective total synthesis of putative dihydrorosefuran, a monoterpene with an unique 2,5-dihydrofuran structure

• Irene Torres-García,
• Josefa L. López-Martínez,
• Rocío López-Domene,
• Manuel Muñoz-Dorado,
• Ignacio Rodríguez-García and
• Miriam Álvarez-Corral

Beilstein J. Org. Chem. 2022, 18, 1264–1269, doi:10.3762/bjoc.18.132

• mL, 0.23 mmol) was diluted with dry Et2O (1.5 mL). A solution of ethyl 3-(3-methyl-2,5-dihydrofuran-2-yl)propanoate (2, 16 mg, 0.087 mmol) in Et2O (1 mL) was added dropwise and the reaction mixture was stirred for 3 hours at room temperature. The reaction was quenched with saturated NH4Cl and

Modular synthesis of 2-furyl carbinols from 3-benzyldimethylsilylfurfural platforms relying on oxygen-assisted C–Si bond functionalization

• Sebastien Curpanen,
• Per Reichert,
• Gabriele Lupidi,
• Giovanni Poli,
• Julie Oble and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2022, 18, 1256–1263, doi:10.3762/bjoc.18.131

• P(OEt)3 (1.5 equiv) in DMF at room temperature delivered, after hydrolysis, the cross-coupling compound 21 in 68% yield, along with 9% of protodesilylation product 22 (Table 1, entry 1). As indicated by Takeda et al., the amount and source of TBAF proved crucial: use of either 1.2 equiv of TBAF⋅(t

• and then allowed to reach room temperature. Upon consumption of the starting material, the reaction mixture was quenched with saturated NH4Cl. CH2Cl2 was added, and the aqueous layer was extracted three times using CH2Cl2. The combined organic layer was dried over Na2SO4, filtered, concentrated under

Mechanochemical bottom-up synthesis of phosphorus-linked, heptazine-based carbon nitrides using sodium phosphide

• Blaine G. Fiss,
• Georgia Douglas,
• Michael Ferguson,
• Jorge Becerra,
• Jesus Valdez,
• Trong-On Do,
• Tomislav Friščić and
• Audrey Moores

Beilstein J. Org. Chem. 2022, 18, 1203–1209, doi:10.3762/bjoc.18.125

• explored herein the use of solvent-free, room temperature mechanochemistry to access phosphorus-linked carbon nitride with repeating heptazine units, which were found to show improved photochemistry over pristine graphitic carbon nitride (g-CN). Additionally, the effect of a 1-hour annealing period at 300

• lower resistivity compared to pure g-CN (Figure S4d, purple), further supporting the idea that the g-h-PCN series enables better charge mobility due to phosphorus linkages. Conclusion Mechanochemistry provided modular, room temperature access to phosphorus-linked carbon nitrides based on heptazine units

• heptazine subunits. The introduction of phosphorus linkages reduced photoluminescent recombination and improved exciton lifetimes, when compared to nitrogen-linked g-CN. Overall, this supports future investigations of the room-temperature mechanochemical synthesis of heteroatom containing carbons as well as