Natural resorcylic lactones derived from alternariol

• Joachim Podlech

Beilstein J. Org. Chem. 2024, 20, 2171–2207, doi:10.3762/bjoc.20.187

Syntheses and medicinal chemistry of spiro heterocyclic steroids

• Laura L. Romero-Hernández,
• Ana Isabel Ahuja-Casarín,
• Penélope Merino-Montiel,
• Sara Montiel-Smith,
• José Luis Vega-Báez and
• Jesús Sandoval-Ramírez

Beilstein J. Org. Chem. 2024, 20, 1713–1745, doi:10.3762/bjoc.20.152

• steroidal 17-ketones were first alkylated in the presence of the lithium derivative of ethyl propiolate. After stereoselective formation of the corresponding adduct, the triple bond was chemoselectively reduced under catalytic hydrogenation using 5% palladium on charcoal. As a final step, a p

Regioselective quinazoline C2 modifications through the azide–tetrazole tautomeric equilibrium

• Dāgs Dāvis Līpiņš,
• Andris Jeminejs,
• Una Ušacka,
• Anatoly Mishnev,
• Māris Turks and
• Irina Novosjolova

Beilstein J. Org. Chem. 2024, 20, 675–683, doi:10.3762/bjoc.20.61

• form can be in either the azide (17e, 17f) or tetrazole form (17a–d). With derivatives 17e,f in hand, the reduction of the azido group in the C4 position was carried out by bubbling hydrogen through the solution in the presence of palladium on charcoal. In the last step, the product was acidified with

Synthesis and biological profile of 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines, a novel class of acyl-ACP thioesterase inhibitors

• Jens Frackenpohl,
• David M. Barber,
• Guido Bojack,
• Birgit Bollenbach-Wahl,
• Ralf Braun,
• Rahel Getachew,
• Sabine Hohmann,
• Kwang-Yoon Ko,
• Karoline Kurowski,
• Bernd Laber,
• Rebecca L. Mattison,
• Thomas Müller,
• Anna M. Reingruber,
• Dirk Schmutzler and
• Andrea Svejda

Beilstein J. Org. Chem. 2024, 20, 540–551, doi:10.3762/bjoc.20.46

• practicable and robust synthetic route enabling us to carry out a broad SAR study. Initial attempts to prepare 2,3-dihydro[1,3]thiazolo[4,5-b]pyridines 7a and 7b using hydrogen and palladium on charcoal under elevated pressure did not show any conversion of the starting material (Table 1, entries 1 and 2

Synthetic approach to 2-alkyl-4-quinolones and 2-alkyl-4-quinolone-3-carboxamides based on common β-keto amide precursors

• Yordanka Mollova-Sapundzhieva,
• Plamen Angelov,
• Danail Georgiev and
• Pavel Yanev

Beilstein J. Org. Chem. 2023, 19, 1804–1810, doi:10.3762/bjoc.19.132

• the nitro group with subsequent cyclization of the reduced intermediate (Scheme 2, conditions iv). We tried to carry out these reactions either with Zn in acetic acid/dichloromethane or by transfer hydrogenation with ammonium formate in the presence of Pd on charcoal. Both types of reductive

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

Inline purification in continuous flow synthesis – opportunities and challenges

• Jorge García-Lacuna and
• Marcus Baumann

Beilstein J. Org. Chem. 2022, 18, 1720–1740, doi:10.3762/bjoc.18.182

• heterogeneous fashion. This oftentimes leads to improved green credentials, safety, and sometimes efficiency, especially when it is applied to the downstream process. Commercially available resins, activated charcoal, polymer-supported species that trap spent reagents or side-products as well as related

• ineffective performance of pumps. A rotating sintered glass filter to remove solids before an inline separation was reported by Ley and co-workers [69]. In the same publication, a charcoal scavenger cartridge also acts as a particle filter. The incorporation of filtering membranes before chromatography is a

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

• )), 157.10 (H-C(6)); ESIMS (m/z): [M + H]+ calcd for 226.10; found, 226.10. 1-Deazahypoxanthine (30) Compound 31 (230 mg, 1.02 mmol) was dissolved in methanol (15 mL), then palladium on charcoal 10% (Pd/C, 400 mg, 337 µmol) was added and hydrogen (balloon with syringe and septum) was bubbled through the

Synthesis of odorants in flow and their applications in perfumery

• Merlin Kleoff,
• Paul Kiler and
• Philipp Heretsch

Beilstein J. Org. Chem. 2022, 18, 754–768, doi:10.3762/bjoc.18.76

• employed Stewart–Grubbs catalyst 71 is completely decomposed but its decomposition products could efficiently be removed by passing the reaction mixture through a cartridge containing a mixture of silica and charcoal providing 72 in 32% yield at a productivity of 0.2 g/h. The macrocycle 72 was already

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

• -operation and Development (OECD). The zebrafish were maintained under a 14/10 h light/dark cycle at the temperature (28 ± 0.5°C) in a closed flow-through system with charcoal-filtered tap water to ensure normal spawning. CuSO4-induced model of zebrafish In a manner similar to literature reference [11

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

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

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

• cultures released a strong garlic-like odor, presumptively due to a degradation of the DMSP derivatives to sulfur-containing volatiles, similar to the compounds known from garlic, through one of the pathways shown in Scheme 2. The emitted volatiles were captured on charcoal filter traps using a closed-loop

• extraction to a CLSA [33] for 24 h. The released volatiles were collected on charcoal filters (Chromtech, Idstein, Germany), followed by the extraction of the filters with dichloromethane (50 μL), and analysis of the extracts by GC–MS. For comparison, blank experiments with MB medium alone and with MB agar

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

• 27375T, C. halophilus DSM 26270T and C. indicus DSM 27257T, were collected through a closed-loop stripping apparatus (CLSA) on charcoal [37]. After extraction with dichloromethane the obtained extracts were analyzed by GC–MS (Figure 1). The compounds were identified by the comparison of the recorded EI

• Celeribacter spp. agar plate cultures were collected on charcoal filters (Chromtech, Idstein, Germany, precision charcoal filters charged with 5 mg of charcoal) by use of a closed-loop stripping apparatus as developed by Grob and Zürcher [37]. After a collection time of 24 h the charcoal was extracted with

Synthesis of legonmycins A and B, C(7a)-hydroxylated bacterial pyrrolizidines

• Wilfred J. M. Lewis,
• David M. Shaw and
• Jeremy Robertson

Beilstein J. Org. Chem. 2021, 17, 334–342, doi:10.3762/bjoc.17.31

• via cannula over 15 min. The reaction mixture was allowed to warm to rt over 14 h, the volatiles were removed, then pyridine (2 mL) and activated charcoal (5 g) were added. The resulting slurry was part-purified by column chromatography (dichloromethane → methanol) and the product-containing fractions

Total synthesis of decarboxyaltenusin

• Lucas Warmuth,
• Aaron Weiß,
• Marco Reinhardt,
• Anna Meschkov,
• Ute Schepers and
• Joachim Podlech

Beilstein J. Org. Chem. 2021, 17, 224–228, doi:10.3762/bjoc.17.22

• the product with 55% yield. The O-benzylation of phenol 8 furnishing the bromide 9b was accomplished with virtually quantitative yield. Suzuki coupling of the benzyl-protected compounds 6b and 9b led to biaryl 10b with 89% yield; it was deprotected with palladium on charcoal under eight bar hydrogen

Pauson–Khand reaction of fluorinated compounds

• Jorge Escorihuela,
• Daniel M. Sedgwick,
• Alberto Llobat,
• Mercedes Medio-Simón,
• Pablo Barrio and
• Santos Fustero

Beilstein J. Org. Chem. 2020, 16, 1662–1682, doi:10.3762/bjoc.16.138

• corresponding aldehyde in a 41% global yield. Bicyclic product 49a underwent diastereoselective (dr > 20:1) hydrogenation using palladium over activated charcoal under an atmosphere of hydrogen to afford saturated derivative 50 (Scheme 26). On the other hand, the tert-butanesulfonyl group could be removed

Synthesis of new asparagine-based glycopeptides for future scanning tunneling microscopy investigations

• Laura Sršan and
• Thomas Ziegler

Beilstein J. Org. Chem. 2020, 16, 888–894, doi:10.3762/bjoc.16.80

• glycosylamines 2a–f by hydrogenation with Pd on charcoal in ethyl acetate. Since an anomeric mixture of glycosylamines was obtained in most cases, with a strong predominance of the corresponding β-anomers, and TLC analysis showed no formation of other unwanted side products during hydrogenation, the latter

A systematic review on silica-, carbon-, and magnetic materials-supported copper species as efficient heterogeneous nanocatalysts in “click” reactions

• Pezhman Shiri and
• Jasem Aboonajmi

Beilstein J. Org. Chem. 2020, 16, 551–586, doi:10.3762/bjoc.16.52

• stirred using a catalytic amount of rGO/Cu2O (102) in water at 55 °C for 2 h to obtain 1,2,3-triazole derivatives substituted at the 1- and 4 position with high yields (Scheme 23). The catalyst 102 could be readily reused in six cycles [86]. In another study, charcoal-supported palladium and copper as a

• multitask nanocatalyst was used for one-pot Sonogashira-“click”/“click”-Heck sequences [87]. Palladium(II) acetate, copper(II) acetate, and charcoal were dispersed in methanol. In order to remove oxygen from the reaction mixture, hydrogen gas was passed through the medium. Then, the solution was stirred at

Synthesis of pyrrolo[1,2-a]quinolines by formal 1,3-dipolar cycloaddition reactions of quinolinium salts

• Anthony Choi,
• Rebecca M. Morley and
• Iain Coldham

Beilstein J. Org. Chem. 2019, 15, 1480–1484, doi:10.3762/bjoc.15.149

• explore the diversity of products that could be obtained from these adducts, we carried out a reduction of the alkene in compounds 9 and 10 by using hydrogen and palladium on charcoal (Scheme 4). This provides the tetrahydroquinoline adducts 11 and 12. Additionally, and in contrast, oxidation of the

Reaction of oxiranes with cyclodextrins under high-energy ball-milling conditions

• László Jicsinszky,
• Federica Calsolaro,
• Katia Martina,
• Fabio Bucciol,
• Maela Manzoli and
• Giancarlo Cravotto

Beilstein J. Org. Chem. 2019, 15, 1448–1459, doi:10.3762/bjoc.15.145

• methods. In order to reduce the colour intensity and remove the few insolubles, such as unsubstituted CDs, etc., from the solution, 5% charcoal was used. The addition of acetone to the concentrated MeOH solution, to around 50% product content, completely removed the formed PGs. It was found that sometimes

Stereo- and regioselective hydroboration of 1-exo-methylene pyranoses: discovery of aryltriazolylmethyl C-galactopyranosides as selective galectin-1 inhibitors

• Alexander Dahlqvist,
• Axel Furevi,
• Niklas Warlin,
• Hakon Leffler and
• Ulf J. Nilsson

Beilstein J. Org. Chem. 2019, 15, 1046–1060, doi:10.3762/bjoc.15.102

• infrared spectroscopy, samples were pelleted with potassium bromide and analyzed on a Shimadzu FTIR-84005. 1,2-Dideoxy-1-(4-phenyl-1H-1,2,3-triazol-1-yl)-β-D-galactoheptulose (1a): Compound 10a (42 mg, 0.062 mmol) was dissolved in cyclohexene/ethanol 2:1 (1.5 mL), palladium(II) hydroxide on charcoal (17 mg

• HPLC, UV–vis detection: 98.4%. 1,2-Dideoxy-1-[4-(4-fluorophenyl)-1H-1,2,3-triazol-1-yl]-β-D-galactoheptulose (1b): Compound 10b (50 mg, 0.147 mmol) was dissolved in cyclohexene/ethanol 2:1 (3 mL), palladium(II) hydroxide on charcoal (40 mg, 20 wt %) was added, and the mixture refluxed overnight at 80

• ; purity by HPLC, UV–vis detection: 95.6%. 1,2-Dideoxy-1-[4-(3-fluorophenyl)-1H-1,2,3-triazol-1-yl]-β-D-galactoheptulose (1c): Compound 10c (71 mg, 0.102 mmol) was dissolved in cyclohexene/ethanol 2:1 (4.5 mL), 27 mg of 20 wt % palladium(II) hydroxide on charcoal was added, and the mixture refluxed

Diaminoterephthalate–α-lipoic acid conjugates with fluorinated residues

• Leon Buschbeck,
• Aleksandra Markovic,
• Gunther Wittstock and
• Jens Christoffers

Beilstein J. Org. Chem. 2019, 15, 981–991, doi:10.3762/bjoc.15.96

• mg, 0.05 equiv) was added and the mixture was stirred for 1 h at ambient temperature under an inert atmosphere. After adding charcoal (2 mg), it was stirred for 5 min at ambient temperature and then filtered. The filtrate was evaporated and the residue chromatographed (SiO2, EtOAc/MeOH 6:1 with 1 vol

Synthesis of the aglycon of scorzodihydrostilbenes B and D

• Katja Weimann and
• Manfred Braun

Beilstein J. Org. Chem. 2019, 15, 610–616, doi:10.3762/bjoc.15.56

• , the yield was lower (Scheme 2). In order to bring about the cleavage of the benzyl protecting groups in the ketones 8a and 8b by hydrogenolysis [17][18], various metal catalysts were tested. It turned out that palladium on charcoal was the only catalytic system that provided satisfying results. Ethyl

• , 69.56; H, 6.73. General procedure for the synthesis of phenols 9–11 by hydrogenolytic cleavage of benzyl ether protecting groups: An autoclave was equipped with a stirring bar and charged with O-protected dihydrostilbenes 8a,b (0.8 mmol), palladium on charcoal (50 mg) and ethyl acetate (12 mL). The

• mg, 1.5 mmol), palladium on charcoal (200 mg) in ethyl acetate (15 mL) at 3 bar hydrogen pressure for 72 h. The crude product was purified by column chromatography (silica gel; ethyl acetate/n-hexane, 1:7) to give 9 as a greenish syrup in 75% yield (356 mg); Rf 0.1; 1H NMR (CDCl3, 600 MHz) δ 2.63 (s

Syntheses and chemical properties of β-nicotinamide riboside and its analogues and derivatives

• Mikhail V. Makarov and
• Marie E. Migaud

Beilstein J. Org. Chem. 2019, 15, 401–430, doi:10.3762/bjoc.15.36

• % of the α-anomer. This anomer was removed from the crude mixture by chromatography on activated charcoal and crystallization to afford the desired β-NR+OTf− in 58% yield. The predominant formation of the β-isomer of NR+ is due to the generation of a type F cationic intermediate in the course of

• -Dihydronicotinamide riboside, NRH, may be subsequently oxidized into NR+ salts using activated charcoal [31], salts for which a pharmaceutically acceptable counter anion X− can be introduced when using an aqueous medium containing the corresponding ammonium salt NH4X. The oxidation may also be achieved with