Tandem Hock and Friedel–Crafts reactions allowing an expedient synthesis of a cyclolignan-type scaffold

• Viktoria A. Ikonnikova,
• Cristina Cheibas,
• Oscar Gayraud,
• Alexandra E. Bosnidou,
• Nicolas Casaretto,
• Gilles Frison and
• Bastien Nay

Beilstein J. Org. Chem. 2024, 20, 162–169, doi:10.3762/bjoc.20.15

• surrogate readilly unmasked under Hock cleavage conditions. The oxidative cleavage of this alkene would not only release the aldehyde group, but also volatile acetone originated from the traceless isopropylidene motif. Overall, a three-reaction process will thus be performed in one pot (Scheme 1c

Multi-redox indenofluorene chromophores incorporating dithiafulvene donor and ene/enediyne acceptor units

• Christina Schøttler,
• Kasper Lund-Rasmussen,
• Line Broløs,
• Philip Vinterberg,
• Ema Bazikova,
• Viktor B. R. Pedersen and
• Mogens Brøndsted Nielsen

Beilstein J. Org. Chem. 2024, 20, 59–73, doi:10.3762/bjoc.20.8

• CH2Cl2 (CD2Cl2, 1H = 5.32 ppm, 13C = 54.00 ppm), deuterated DMSO ((CD3)2SO, 1H = 2.50 ppm, 13C = 39.53 ppm), deuterated acetone ((CD3)2CO, 1H = 2.05 ppm, 13C = 29.84 ppm), or deuterated benzene (C6D6, 1H = 7.16 ppm, 13C = 128.39 ppm) were used as solvents and internal references. Chemical shift values

Preparing a liquid crystalline dispersion of carbon nanotubes with high aspect ratio

• Keiko Kojima,
• Nodoka Kosugi,
• Hirokuni Jintoku,
• Kazufumi Kobashi and
• Toshiya Okazaki

Beilstein J. Org. Chem. 2024, 20, 52–58, doi:10.3762/bjoc.20.7

• acetone using a bath-type sonicator and were put onto a copper grid with carbon mesh. To perform thermogravimetric analysis (TGA), a TG/DTA7300 instrument from SII Nano Technology Inc. was utilized. The DWCNT powder was preheated at 180 °C for ten minutes under vacuum and subsequently measured under

• ) analysis (CPS Instruments, CPS 24000UHR (CR-39)). The shape and size of the DWCNTs in dispersion were observed by settling them on a silicon substrate, washed with acetone, and exposed to UV light for 20 minutes using an ozone cleaner (Meiwafosis, PC-450 plus) via dip-coating. The structures of DWCNTs were

• , the glass slide was washed with acetone and then irradiated with UV light for a duration of 1 hour via an ozone cleaner (Meiwafosis, PC-450 plus). Later, the substrate was coated using a bar coater (OSG SYSTEM PRODUCTS Co., LTD, Select-Roller L60, OSP-10 (bar groove pitch: 0.2 mm, depth: 24 μm)) with

Aromatic systems with two and three pyridine-2,6-dicarbazolyl-3,5-dicarbonitrile fragments as electron-transporting organic semiconductors exhibiting long-lived emissions

• Karolis Leitonas,
• Brigita Vigante,
• Dmytro Volyniuk,
• Audrius Bucinskas,
• Pavels Dimitrijevs,
• Sindija Lapcinska,
• Pavel Arsenyan and
• Juozas Vidas Grazulevicius

Beilstein J. Org. Chem. 2023, 19, 1867–1880, doi:10.3762/bjoc.19.139

• dried over Na2SO4. After evaporation of the solvent, the crude residue was purified by flash chromatography on silica gel using a mixture of chloroform/petroleum ether/acetone 9:12:0.4 as eluent. 2,6-Bis(3,6-di-tert-butyl-9H-carbazol-9-yl)-4-(4-(trimethylsilylethynyl)phenyl)pyridine-3,5-dicarbonitrile

• was purified by flash chromatography on silica gel with chloroform/petroleum ether/acetone 9:15:0.4 by volume. The product 8 was obtained as orange powder (172 mg, 20%). Mp > 200 °C; IR νmax (film): 2252, 2240, 1538, 1532, 1425; 1H NMR (400 MHz, CDCl3) 8.11 (d, J = 2.0 Hz, 8H), 7.93–7.80 (m, 8H), 7.73

A novel recyclable organocatalyst for the gram-scale enantioselective synthesis of (S)-baclofen

• Gyula Dargó,
• Dóra Erdélyi,
• Balázs Molnár,
• Péter Kisszékelyi,
• Zsófia Garádi and
• József Kupai

Beilstein J. Org. Chem. 2023, 19, 1811–1824, doi:10.3762/bjoc.19.133

• (SiO2, hexane/acetone 1:3, Rf 0.85); mp 61–69 °C; −5.7 (c 1.00, CHCl3); IR (cm−1) νmax 2941, 2860, 1780, 1744, 1709, 1637, 1553, 1493, 1448, 1433, 1416, 1367, 1339, 1299, 1272, 1223, 1184, 1133, 1091, 1068, 1036, 1014, 998, 976, 956, 912, 49, 825, 783, 743, 718, 679, 654, 530, 425; 1H NMR (500 MHz

Recent advancements in iodide/phosphine-mediated photoredox radical reactions

• Tinglan Liu,
• Yu Zhou,
• Junhong Tang and
• Chengming Wang

Beilstein J. Org. Chem. 2023, 19, 1785–1803, doi:10.3762/bjoc.19.131

• light irradiation at either 440 nm or 456 nm, and they occurred in acetone at room temperature, without the need for transition metals or organic dyes as photosensitizers. Interestingly, it was discovered that solvation played a vital role in the overall process. These findings shed light on the

Active-metal template clipping synthesis of novel [2]rotaxanes

• Cătălin C. Anghel,
• Teodor A. Cucuiet,
• Niculina D. Hădade and
• Ion Grosu

Beilstein J. Org. Chem. 2023, 19, 1776–1784, doi:10.3762/bjoc.19.130

• (1.52 g, 3.02 mmol, 1 equiv) was dissolved in acetone (100 mL), followed by the addition of K2CO3 (4.17 g, 30.2 mmol, 10 equiv). After 30 min of stirring 1,5-dibromopentane (3.47 g, 15.1 mmol, 5 equiv) was added and the mixture was kept under reflux for 48 hours. Upon cooling, the compound was isolated

• added and the compound was extracted with DCM (3 × 50 mL). The combined organic phases were washed with water and brine, followed by drying over MgSO4. After solvent evaporation the compound was purified by column chromatography (silica, acetone/toluene = 1:6, Rf = 0.47) to afford a yellowish solid

• (0.69 g, 77%); mp 128–130 °C, Rf = 0.47 (silica, acetone/toluene = 1:6). 1H NMR (CD2Cl2, 600 MHz) δ 7.72 (t, 3J = 7.7 Hz, 1H, Hpyridine), 7.36 (d, 3J = 7.7 Hz, 2H, Hpyridine), 7.33 (d, 3J = 8.6 Hz, 4H, HAr), 6.96 (d, 3J = 8.6 Hz, 4H, HAr), 4.70 (d, 3J = 2.4 Hz, 4H, CH2 (propargyl)), 4.60 (s, 4H, CH2

Synthesis and biological evaluation of Argemone mexicana-inspired antimicrobials

• Jessica Villegas,
• Bryce C. Ball,
• Katelyn M. Shouse,
• Caleb W. VanArragon,
• Ashley N. Wasserman,
• Hannah E. Bhakta,
• Allen G. Oliver,
• Danielle A. Orozco-Nunnelly and
• Jeffrey M. Pruet

Beilstein J. Org. Chem. 2023, 19, 1511–1524, doi:10.3762/bjoc.19.108

• considered ways to further enhance this activity. We first explored the effects of structural modifications to berberine itself. The cationic iminium within berberine and its derivatives is susceptible to nucleophilic attack [10][14]. Through use of an acetone enolate, as well as partial or full reduction by

• effects of each modification. It was found that the acetone adduct B9 and the partially reduced variant B10 were more potent, while the fully reduced variant B11 was significantly less active (Table 2). These results suggested the activity of B1 could be similarly altered by the same modifications to the

N-Sulfenylsuccinimide/phthalimide: an alternative sulfenylating reagent in organic transformations

• Fatemeh Doraghi,
• Seyedeh Pegah Aledavoud,
• Mehdi Ghanbarlou,
• Bagher Larijani and
• Mohammad Mahdavi

Beilstein J. Org. Chem. 2023, 19, 1471–1502, doi:10.3762/bjoc.19.106

• pyrazolone derivatives with N-thiophthalimides catalyzed by 1 mol % of chiral iminophosphorane organocatalyst was carried out under mild conditions [103]. Solvent control in the procedure can affect the yield of products due to the solubility of the catalysts. Various solvents, such as acetone, ethyl acetate

α-(Aminomethyl)acrylates as acceptors in radical–polar crossover 1,4-additions of dialkylzincs: insights into enolate formation and trapping

• Angel Palillero-Cisneros,
• Paola G. Gordillo-Guerra,
• Fernando García-Alvarez,
• Olivier Jackowski,
• Franck Ferreira,
• Fabrice Chemla,
• Joel L. Terán and
• Alejandro Perez-Luna

Beilstein J. Org. Chem. 2023, 19, 1443–1451, doi:10.3762/bjoc.19.103

• stereocenter. α-(Aminomethyl)acrylates 5–7 reacted smoothly at −33 °C within 2 h with Et2Zn in the presence of cyclohexanone to afford amino alcohols 18–20 in quite good yields (63–68%). Even better yields were obtained with enoates 8a and 8b both with cyclohexanone and acetone as carbonyl partners. Starting

Application of N-heterocyclic carbene–Cu(I) complexes as catalysts in organic synthesis: a review

• Nosheen Beig,
• Varsha Goyal and
• Raj K. Bansal

Beilstein J. Org. Chem. 2023, 19, 1408–1442, doi:10.3762/bjoc.19.102

• (Scheme 55). A wide range of combinations of aldehydes, alkynes, and secondary amines including aromatic as well as aliphatic substrates were used and the products were obtained in up to 95% yield. The effects of solvents and temperature were also investigated. Polar solvents such as acetone or

Synthesis of ether lipids: natural compounds and analogues

• Marco Antônio G. B. Gomes,
• Alicia Bauduin,
• Chloé Le Roux,
• Romain Fouinneteau,
• Wilfried Berthe,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2023, 19, 1299–1369, doi:10.3762/bjoc.19.96

• reported by H. Eilb [72]. Accordingly, ᴅ-mannitol was transformed in 1,2,5,6-diisopropylidene-ᴅ-mannitol (4.2) by reaction with acetone and ZnCl2. Of note, compound 4.2 was isolated with 5–10% of 1,2,3,4,5,6-triisopropylidene-ᴅ-mannitol. The oxidative cleavage of 4.2 with sodium periodate yields 4.3 that

• alcohol. This step was achieved by the deprotonation of 21.3 followed by the reaction with 1-bromooctadecane. Compound 21.4 was purified by chromatography on silica gel followed by a recrystallization in acetone. Deprotonation of the secondary alcohol present in 21.4 followed by the addition of

• mesylated to 29.2. Then, a bromine atom was introduced via a nucleophilic substitution with LiBr in acetone to form 29.3. Finally, the primary bromide was used to introduce different ammonium salts as illustrated with compound 29.4. A variation of this sequence consisted in placing an ether function in

Non-noble metal-catalyzed cross-dehydrogenation coupling (CDC) involving ether α-C(sp³)–H to construct C–C bonds

• Hui Yu and
• Feng Xu

Beilstein J. Org. Chem. 2023, 19, 1259–1288, doi:10.3762/bjoc.19.94

• in functionalizing unactivated C(sp3)–H substrates, including ethers [109][110][111][112][113][114]. In 2018, Wang et al. reported the photocatalytic CDC α-alkylation of N-heteroarenes in acetone solution, using noble-metal Ir as a photocatalyst to induce the reaction (Scheme 41) [115]. Subsequently

Metal catalyst-free N-allylation/alkylation of imidazole and benzimidazole with Morita–Baylis–Hillman (MBH) alcohols and acetates

• Olfa Mhasni,
• Jalloul Bouajila and
• Farhat Rezgui

Beilstein J. Org. Chem. 2023, 19, 1251–1258, doi:10.3762/bjoc.19.93

• under reflux (for 5a) or in a Dean–Stark apparatus (for 4a). After completion (TLC), the reaction mixture was cooled, washed with brine, and dried. The toluene was removed and the residue was purified by column chromatography on silica gel (acetone/ether 8:2) to give the pure N-substituted imidazole 6a

• mL) was added. The mixture was washed with brine and dried. Finally, the solvent was removed and the residue was purified by column chromatography on silica gel, using acetone/ether as eluent, to give the pure imidazole derivative 8. Medicines containing an imidazole nucleus. Synthesis of N

Photoredox catalysis harvesting multiple photon or electrochemical energies

• Mattia Lepori,
• Simon Schmid and
• Joshua P. Barham

Beilstein J. Org. Chem. 2023, 19, 1055–1145, doi:10.3762/bjoc.19.81

Five new sesquiterpenoids from agarwood of Aquilaria sinensis

• Hong Zhou,
• Xu-Yang Li,
• Hong-Bin Fang,
• He-Zhong Jiang and
• Yong-Xian Cheng

Beilstein J. Org. Chem. 2023, 19, 998–1007, doi:10.3762/bjoc.19.75

• .6.3.1–Fr.6.3.4) by a vacuum liquid chromatography (VLC) on a silica gel column with petroleum ether/acetone (50:1–3:7) as solvents. Fr.6.3.1 (808.5 mg) was subjected to preparative thin-layer chromatography (PTLC) (dichloromethane) to give Fr.6.3.1.1–Fr.6.3.1.7, of which Fr.6.3.1.4 (255.9 mg) was

• column washed with petroleum ether/EtOAC (50:1–1:1). Among them, Fr.6.5.7 (355.7 mg) was subjected to PTLC (petroleum ether/acetone 5:1) to give Fr.6.5.7.1–Fr.6.5.7.7. Fr.6.5.7.1 (34.3 mg) was purified by semi-preparative HPLC on SEP Basic 120 C18 (aqueous MeOH, 65%) to give compound 9 (4.9 mg, tR = 9.4

• min, flow rate: 3 mL/min). Fr.6.5.8 (787.3 mg) was separated by VLC on silica gel eluted with petroleum ether/acetone (25:1–1:1) to provide six portions (Fr.6.5.8.1–Fr.6.5.8.6). Fr.6.5.8.4 (91.0 mg) was further purified by semi-preparative HPLC on SEP Basic 120 C18 with aqueous MeCN (46%) to afford 10

Synthesis of imidazo[1,2-a]pyridine-containing peptidomimetics by tandem of Groebke–Blackburn–Bienaymé and Ugi reactions

• Oleksandr V. Kolomiiets,
• Alexander V. Tsygankov,
• Maryna N. Kornet,
• Aleksander A. Brazhko,
• Vladimir I. Musatov and
• Valentyn A. Chebanov

Beilstein J. Org. Chem. 2023, 19, 727–735, doi:10.3762/bjoc.19.53

• -chlorobenzaldehyde (5b), 4-methoxyaniline (6a) and tert-butyl isocyanide (3a). It should be especially noted that the solubility of compound 8a is very low (soluble in DMSO and N-methyl-2-pyrrolidone (NMP), slightly soluble in methanol, 1- and 2-propanol, acetone, DMF and insoluble in water, ethanol, acetonitrile

Cassane diterpenoids with α-glucosidase inhibitory activity from the fruits of Pterolobium macropterum

• Sarot Cheenpracha,
• Ratchanaporn Chokchaisiri,
• Lucksagoon Ganranoo,
• Sareeya Bureekaew,
• Thunwadee Limtharakul and
• Surat Laphookhieo

Beilstein J. Org. Chem. 2023, 19, 658–665, doi:10.3762/bjoc.19.47

• with hexanes–acetone (100:0 → 0:100, v/v) to afford 10 fractions (Fr.1–Fr.10). Fr.5 (142.0 mg) was further fractionated over a Sephadex LH-20 column with a mixture of CH2Cl2–MeOH (1:1, v/v) affording five subfractions (Fr.5.1–Fr5.5). Subfraction Fr.5.2 (17.2 mg) was chromatographed over silica gel CC

• eluting with acetone–hexanes (1:19, v/v) to give compound 3 (1.1 mg). Fr.6 (842.0 mg) was chromatographed over silica gel CC eluting with acetone–hexanes (1:19, v/v), and then purified by silica gel CC using 100% CH2Cl2 to afford compound 1 (12.5 mg). Chromatographic purification of Fr.8 (1.2 g) over a

• Sephadex LH-20 column with a mixture of CH2Cl2–MeOH (1:1, v/v) afforded three subfractions (Fr.8.1–Fr8.3). Fr.8.2 (257.2 mg) was purified by silica gel CC eluting with acetone–hexanes (1:9, v/v), to provide five subfractions (Fr.8.2.1–Fr.8.2.5). Subfraction Fr.8.2.5 (28.8 mg), was chromatographed over

pH-Responsive fluorescent supramolecular nanoparticles based on tetraphenylethylene-labelled chitosan and a six-fold carboxylated tribenzotriquinacene

• Nan Yang,
• Yi-Yan Zhu,
• Wei-Xiu Lin,
• Yi-Long Lu and
• Wen-Rong Xu

Beilstein J. Org. Chem. 2023, 19, 635–645, doi:10.3762/bjoc.19.45

• ) with vigorous stirring for 30 min, followed by slow addition of sodium borohydride (40 mg, 1.1 mmol). The mixture was stirred at room temperature for 24 h and then quenched with ice water. The precipitate was collected by suction filtration, washed with acetone (3 × 100 mL), and dried under vacuum to

Combretastatins D series and analogues: from isolation, synthetic challenges and biological activities

• Jorge de Lima Neto and
• Paulo Henrique Menezes

Beilstein J. Org. Chem. 2023, 19, 399–427, doi:10.3762/bjoc.19.31

• chromatography on silica gel to yield several fractions. Some of them were tested and the ones that exhibited antimicrobial activity were further fractionated on silica gel chromatographic column eluted with hexane and acetone (8:2) to yield four different fractions. The fractions comprised 11-O

• -methylcorniculatolide A (5, 10 mg), 12-hydroxy-11-O-methylcorniculatolide A (6, 1 mg) and 11-O-methylisocorniculatolide A (8, 2 mg). The authors had some difficulties to isolate isocorniculatolide A (5) using chromatography, however, it was obtained by crystallization from hexane and acetone (4 mg). The same strategy

• Indian Ocean coastline. The air-dried stems of X. granatum (5 kg) were powdered and extracted successively within hexane, CHCl3, and acetone in a Soxhlet apparatus. The crude CHCl3 extract (21 g) was chromatographed on silica gel (230–400 mesh) vacuum liquid chromatography (VLC) in different gradients of

CuAAC-inspired synthesis of 1,2,3-triazole-bridged porphyrin conjugates: an overview

• Dileep Kumar Singh

Beilstein J. Org. Chem. 2023, 19, 349–379, doi:10.3762/bjoc.19.29

• metal exchange reaction of porphyrin 90 with excess CoCl2·6H2O in an acetone/THF (1:1) mixture. The results of the photophysical investigations demonstrated that these dyads exhibit adequate electronic interactions between the sensitizer and catalyst in the excited state. In this study, NiO films were

• , rt, 24 h, aq PF6−, (iii) CoCl2∙6H2O, THF/acetone, rt, air bubbling, overnight, (iv) KBr, THF/acetone, rt, 5 d. Synthesis of triazole-linked porphyrin-bearing N-doped graphene hybrid 96. Synthesis of meso-triazole-linked porphyrin-fullerene dyads 100a–d and 104a,b. Synthesis of meso-triazole-bridged

Continuous flow synthesis of 6-monoamino-6-monodeoxy-β-cyclodextrin

• János Máté Orosz,
• Dóra Ujj,
• Petr Kasal,
• Gábor Benkovics and
• Erika Bálint

Beilstein J. Org. Chem. 2023, 19, 294–302, doi:10.3762/bjoc.19.25

• acetone in order to obtain solid β-CD compounds. Two important things need to be mentioned before closing this part. First, the amounts of TsCl range from 0.5 to 9 equiv in the literature and there is no direct correlation between the yield and the amount of TsCl. Usually 1 to 1.3 equiv are sufficient to

• and non-toxicity. However, partial hydrolysis of the p-toluenesulfonyl group takes place, so the final product is always contaminated with native β-CD (1). Despite this, the product mixture after precipitation from acetone was used in the next reaction step and a proper purification of the targeted

• 60–80% can be achieved. Partial hydrolysis can be avoided by using anhydrous DMF and purifying the starting Ts-β-CD (2) by crystallization. In this case, a lower amount of NaN3 (1–2 equiv) is required and only purification by precipitation from acetone is necessary. In order to prepare N3-β-CD (3) in

Germacrene B – a central intermediate in sesquiterpene biosynthesis

• Houchao Xu and
• Jeroen S. Dickschat

Beilstein J. Org. Chem. 2023, 19, 186–203, doi:10.3762/bjoc.19.18

• -selinene (10) (Scheme 4A) [43]. Interestingly, while racemic juniper camphor (11) is formed from 1 upon acid treatment [50], this reaction with diluted sulfuric acid in acetone results in (rac)-11 quantitatively. This observation is explained by a protonation-induced cyclisation, successive addition of

• acetone and water to a hemiacetal that can decompose to 11 (Scheme 4B) [43]. Furthermore, 1 shows an interesting photochemistry (Scheme 4C). A [2 + 2] cycloaddition of the endocyclic double bonds yields 12 whose formation is understandable from conformers 1c and 1d. The all-cis stereoisomer 14 requires a

• ) Cyclisation of 1 to 9 and 10 upon treatment with alumina, B) conversion into (rac)-11 by treatment with diluted sulfuric acid in acetone, C) photochemical products from 1, and D) planar chirality of 1 and its derivative 17. Possible cyclisation reactions upon reprotonation of 1. A) Cyclisations to eudesmane

Insight into oral amphiphilic cyclodextrin nanoparticles for colorectal cancer: comprehensive mathematical model of drug release kinetic studies and antitumoral efficacy in 3D spheroid colon tumors

• Sedat Ünal,
• Gamze Varan,
• Juan M. Benito,
• Yeşim Aktaş and
• Erem Bilensoy

Beilstein J. Org. Chem. 2023, 19, 139–157, doi:10.3762/bjoc.19.14

• investigations, the ideal formulation parameters and component ratios were identified [9][11][74]. Thus, organic solvent (acetone), polycationic CD derivate (0.1% w/v), organic phase:aqueous phase ratio 1:2 (v/v), and 600 rpm stirring rate were applied [9]. In brief, a determined quantity of amphiphilic CD was

• dissolved in 1 mL of acetone to achieve an organic phase concentration of 0.1% (w/v). This organic phase was added drop-by-drop into 2 mL of the aqueous phase with magnetic stirring at room temperature for 30 min. The organic solvent was evaporated under vacuum at 45 °C to a final dispersion volume of 2 mL

Revisiting the bromination of 3β-hydroxycholest-5-ene with CBr₄/PPh₃ and the subsequent azidolysis of the resulting bromide, disparity in stereochemical behavior

• Christian Schumacher,
• Jas S. Ward,
• Kari Rissanen,
• Carsten Bolm and
• Mohamed Ramadan El Sayed Aly

Beilstein J. Org. Chem. 2023, 19, 91–99, doi:10.3762/bjoc.19.9

• purchased from Sigma-Aldrich, while petroleum ether (60–80 °C) and acetone were purchased from Oxford chemicals/India and DMF was purchased from Loba/India. All solvents were pure and used without further purification. Dichloromethane was purchased from Al Nasr/Egypt and dried over CaO before distillation