Synthesis, structure, ionochromic and cytotoxic properties of new 2-(indolin-2-yl)-1,3-tropolones

• Yurii A. Sayapin,
• Eugeny A. Gusakov,
• Inna O. Tupaeva,
• Alexander D. Dubonosov,
• Igor V. Dorogan,
• Valery V. Tkachev,
• Anna S. Goncharova,
• Gennady V. Shilov,
• Natalia S. Kuznetsova,
• Svetlana Y. Filippova,
• Tatyana A. Krasnikova,
• Yanis A. Boumber,
• Alexey Y. Maksimov,
• Sergey M. Aldoshin and
• Vladimir I. Minkin

Beilstein J. Org. Chem. 2025, 21, 358–368, doi:10.3762/bjoc.21.26

• temperature (23 °C). Chromatography was carried out on columns filled with Al2O3 of II–III degree of activity according to Brockmann. Melting points were determined on a Fisher-Johns melting point apparatus. 1,1,2-Trimethyl-1H-benzo[e]indolenine (2a, 98%, Alfa Aesar), 2,3,3-trimethyl-3H-benzo[g]indolenine (2b

Facile preparation of fluorine-containing 2,3-epoxypropanoates and their epoxy ring-opening reactions with various nucleophiles

• Yutaro Miyashita,
• Sae Someya,
• Tomoko Kawasaki-Takasuka,
• Tomohiro Agou and
• Takashi Yamazaki

Beilstein J. Org. Chem. 2024, 20, 2421–2433, doi:10.3762/bjoc.20.206

• its convenient handling and availability at a low cost. Following to the reported protocol [41], although a catalytic amount of Al2O3 and MgO worked nicely (entries 1 and 2 in Table 1), it was clarified that these additives were not necessary for the attainment of the same level of chemical yields

Oxidation of benzylic alcohols to carbonyls using N-heterocyclic stabilized λ³-iodanes

• Thomas J. Kuczmera,
• Pim Puylaert and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2024, 20, 1677–1683, doi:10.3762/bjoc.20.149

• the corresponding carboxylic acids [16]. Additives such as bromide salts or Al2O3 can eliminate this problem and allow selective oxidation to some extent [17][18][19][20]. During the past years, N-heterocycle-stabilized iodanes (NHIs) were demonstrated as suitable tools for various applications among

Synthetic applications of the Cannizzaro reaction

• Bhaskar Chatterjee,
• Dhananjoy Mondal and
• Smritilekha Bera

Beilstein J. Org. Chem. 2024, 20, 1376–1395, doi:10.3762/bjoc.20.120

• in subsequent reactions. Reddy and coworkers carried out the Cannizzaro reaction of aromatic aldehydes to the corresponding alcohols in high yields by crossed-Cannizzaro reactions employing solid-supported KF-Al2O3 as catalyst [26] under microwave irradiation using solvent-free conditions. The use of

Competing electrophilic substitution and oxidative polymerization of arylamines with selenium dioxide

• Vishnu Selladurai and
• Selvakumar Karuthapandi

Beilstein J. Org. Chem. 2024, 20, 1221–1235, doi:10.3762/bjoc.20.105

• mechanism for the formation of oxamide is shown in Scheme 6. Formation of acetanilide in the reaction of aniline and acetonitrile is known to occur in the presence of Lewis acid catalyst Al2O3 [55]. In our case, either SeO2 (Lewis acid) or H2SeO3 (Brønsted acid) may act as acid catalyst to convert aniline

Green and sustainable approaches for the Friedel–Crafts reaction between aldehydes and indoles

• Periklis X. Kolagkis,
• Eirini M. Galathri and
• Christoforos G. Kokotos

Beilstein J. Org. Chem. 2024, 20, 379–426, doi:10.3762/bjoc.20.36

Synthesis of π-conjugated polycyclic compounds by late-stage extrusion of chalcogen fragments

• Aissam Okba,
• Pablo Simón Marqués,
• Kyohei Matsuo,
• Naoki Aratani,
• Hiroko Yamada,
• Gwénaël Rapenne and
• Claire Kammerer

Beilstein J. Org. Chem. 2024, 20, 287–305, doi:10.3762/bjoc.20.30

• ” was next tested at the device fabrication stage in the case of OFETs. An Al2O3/SiO2 dielectric layer with a self-assembled monolayer of 12-cyclohexyldodecylphosphonic acid was chosen as substrate and thin-films of sulfoxide 4a were formed by spin-coating from a chloroform solution. After thermal

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

Synthesis, structure, and properties of switchable cross-conjugated 1,4-diaryl-1,3-butadiynes based on 1,8-bis(dimethylamino)naphthalene

• Semyon V. Tsybulin,
• Ekaterina A. Filatova,
• Alexander F. Pozharskii,
• Valery A. Ozeryanskii and
• Anna V. Gulevskaya

Beilstein J. Org. Chem. 2023, 19, 674–686, doi:10.3762/bjoc.19.49

• 10a–e on Al2O3 resulted in their quantitative desilylation with the formation of the target monomers 6a–e, thus eliminating the need to remove the trimethylsilyl protection. Pure samples of compounds 10a–e could be obtained by extraction of the reaction mixture with hexane followed by

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

• and warm odor; interestingly, it is also strongly antiseptic [9]. In 2005, Poliakoff and co-workers developed a synthesis of thymol by alkylation of m-cresol (39) in supercritical carbon dioxide (scCO2) using γ-Al2O3 in a packed-bed reactor (Scheme 9) [40]. In the presence of Brønsted-acidic Nafion

• SAC-13, alkylation of m-cresol with isopropanol proceeds via a Friedel–Crafts-type mechanism in much lower selectivity. In contrast, the authors proposed that employing γ-Al2O3 as Lewis acid catalyst, reaction of 39 and isopropanol leads to isopropyl ether 40. This intermediate undergoes a Fries-type

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

• reductive coupling of acid halides with ketones [36][37] and acetolyses of α-phenoxy-α-diazoketones [38] were also employed. Recently, F. P. Cossío et al. [39] have described a method for the preparation of benzo[b]furans by thermal heating of a dispersion of α-phenoxyketones in Al2O3. We involved the

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

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

• and benzoperylene [154][155]. As for other polymers, pyrolytic methods end up to be poorly selective. In some cases, metal-catalysed depolymerisation processes of PS were described, showing significant selectivity. In an earlier example, thermal treatment of PS waste over a Fe–K@Al2O3 catalyst at 400

One-pot multicomponent green Hantzsch synthesis of 1,2-dihydropyridine derivatives with antiproliferative activity

• Giovanna Bosica,
• Kaylie Demanuele,
• José M. Padrón and
• Adrián Puerta

Beilstein J. Org. Chem. 2020, 16, 2862–2869, doi:10.3762/bjoc.16.235

• reported by Cao and collaborators [19]. Catalyst characterization and recyclability The catalyst was analyzed by X-ray fluorescence (XRF) spectroscopy in order to ascertain the PW/Al2O3-support ratio. The mass percentage ratio of tungsten, which is the main component of the catalyst, and aluminium, the

Natural dolomitic limestone-catalyzed synthesis of benzimidazoles, dihydropyrimidinones, and highly substituted pyridines under ultrasound irradiation

• Kumar Godugu,
• Venkata Divya Sri Yadala,
• Mohammad Khaja Mohinuddin Pinjari,
• Trivikram Reddy Gundala,
• Lakshmi Reddy Sanapareddy and
• Chinna Gangi Reddy Nallagondu

Beilstein J. Org. Chem. 2020, 16, 1881–1900, doi:10.3762/bjoc.16.156

• (Table 2, entry 1). To achieve the target compound 3a, the same reaction was repeated by employing various catalysts (2.5 wt %), such as Fe2O3, Al2O3, KF–alumina, dolomitic limestone, triethylamine, pyridine, and DABCO in different solvents, such as water, acetone, iPrOH, EtOH, and EtOH/H2O 1:1 (Table 2

• catalysts, Fe2O3, Al2O3, KF–alumina, triethylamine, pyridine, and DABCO, provided a moderate to low yield of the product 3a (Table 2, entries 2–4 and 6–8). The aforesaid reaction was performed under conventional stirring of the model substrates 1 and 2a in H2O in the absence of catalyst for 180 min at 45–50

One-pot synthesis of isosorbide from cellulose or lignocellulosic biomass: a challenge?

• Isaline Bonnin,
• Raphaël Mereau,
• Thierry Tassaing and
• Karine De Oliveira Vigier

Beilstein J. Org. Chem. 2020, 16, 1713–1721, doi:10.3762/bjoc.16.143

• niobium oxide hydrate, phosphoric acid-treated mesoporous and bulk niobium oxide hydrate [30]. These catalysts were compared to Ru@HZMS5, Ru@NaY, Ru@γ-Al2O3 solids. Cellulose was converted over all niobia-based catalysts with 25–43% yield of isosorbide starting from 0.6 g cellulose using 0.06 g catalyst

• (5.0 wt % Ru, Ru nanoparticles (NPs): 0.9 nm) in 30 mL H2O after 1 h of reaction at 220 °C under 60 bar of H2. Trace amounts or even no isosorbide was obtained over microporous HZSM-5, NaY, and γ-Al2O3-supported Ru catalysts. A bifunctional Ru catalyst supported on mesoporous niobium phosphate with a

Heterogeneous photocatalysis in flow chemical reactors

• Christopher G. Thomson,
• Ai-Lan Lee and
• Filipe Vilela

Beilstein J. Org. Chem. 2020, 16, 1495–1549, doi:10.3762/bjoc.16.125

Recent advances on the transition-metal-catalyzed synthesis of imidazopyridines: an updated coverage

• Gagandeep Kour Reen,
• Ashok Kumar and
• Pratibha Sharma

Beilstein J. Org. Chem. 2019, 15, 1612–1704, doi:10.3762/bjoc.15.165

• synthetic cycles without loss in activity. In addition to this, TiO2 is more stable, abundant, nontoxic, and economical [102]. Out of different supports examined like Al2O3, ZrO2, CeO2, SiO2, Al-Ti, OMS-2, C, etc., TiO2 was found to be the best for this transformation. Furthermore, a library of compounds

Olefin metathesis in multiblock copolymer synthesis

• Maria L. Gringolts,
• Yulia I. Denisova,
• Eugene Sh. Finkelshtein and
• Yaroslav V. Kudryavtsev

Beilstein J. Org. Chem. 2019, 15, 218–235, doi:10.3762/bjoc.15.21

• NMR [97]. It is curious that the resulting multiblock copolymers reveal some crystallinity, whereas the parent PNB and PCOE(OH) are fully amorphous. It can be explained if we recall that hydrogenated PNB is a semicrystalline polymer [100]. The Pd/Al2O3 catalyst was used to promote the hydrogenation of

MoO₃ on zeolites MCM-22, MCM-56 and 2D-MFI as catalysts for 1-octene metathesis

• Hynek Balcar,
• Martin Kubů,
• Naděžda Žilková and
• Mariya Shamzhy

Beilstein J. Org. Chem. 2018, 14, 2931–2939, doi:10.3762/bjoc.14.272

• of these materials have been tested as supports for MoO3 based catalysts for metathesis of higher alkenes up to now. MoOx on MCM-22 combined with γ-Al2O3 was used in cross metathesis of 2-butene and ethylene in a stream (125 °C, 1 MPa) [23]. MCM-22, and MCM-56 were also used as supports for Hoveyda

Spectroelectrochemical studies on the effect of cations in the alkaline glycerol oxidation reaction over carbon nanotube-supported Pd nanoparticles

• Dennis Hiltrop,
• Steffen Cychy,
• Karina Elumeeva,
• Wolfgang Schuhmann and
• Martin Muhler

Beilstein J. Org. Chem. 2018, 14, 1428–1435, doi:10.3762/bjoc.14.120

• , a Ag/AgCl/3 M KCl as reference and a Pt mesh as counter electrode. The working electrodes were polished to a mirror finish using grinding papers and alumina suspensions of different grain sizes. Prior to each experiment, the glassy carbon surface was repolished using a 0.05 µm Al2O3 suspension and

Bromide-assisted chemoselective Heck reaction of 3-bromoindazoles under high-speed ball-milling conditions: synthesis of axitinib

• Jingbo Yu,
• Zikun Hong,
• Xinjie Yang,
• Yu Jiang,
• Zhijiang Jiang and
• Weike Su

Beilstein J. Org. Chem. 2018, 14, 786–795, doi:10.3762/bjoc.14.66

• (Table 2, entry 4). Other solid auxiliaries such as γ-Al2O3 and sand afforded a low yield of 3aa with poor selectivity (Table 2, entries 7 and 8). Reaction pathway investigation The control experiments were further conducted to disclose the reaction pathway (Scheme 3). In the case of taking TEA as sole

Solvent-free copper-catalyzed click chemistry for the synthesis of N-heterocyclic hybrids based on quinoline and 1,2,3-triazole

• Martina Tireli,
• Silvija Maračić,
• Stipe Lukin,
• Marina Juribašić Kulcsár,
• Dijana Žilić,
• Mario Cetina,
• Ivan Halasz,
• Silvana Raić-Malić and
• Krunoslav Užarević

Beilstein J. Org. Chem. 2017, 13, 2352–2363, doi:10.3762/bjoc.13.232

• under reduced pressure and residue was purified by column chromatography on silica gel and Al2O3 with dichloromethane as eluent. We used here dichloromethane as an eluent as it is commonly used in similar systems, but it was shown that other mixtures, such as n-hexane/ethyl acetate (50:1) could also be

• temperature. The reaction mixture was stirred for 3.5 h. The solvent was removed under reduced pressure and the residue was purified by column chromatography on silica gel and Al2O3 with dichloromethane as eluent. General procedure for the mechanochemical click reactions of 1,2,3-triazole–quinoline

• to dryness under vacuo, and the closed vessel was positioned in the IST500 mill. The mixture was ground for 3.5 h at 30 Hz and then purified by column chromatography on silica gel and Al2O3 with dichloromethane as eluent. Method 2b: In one half of the reaction vessel we weighed azide (0.49 mL, 0.24

Dialkyl dicyanofumarates and dicyanomaleates as versatile building blocks for synthetic organic chemistry and mechanistic studies

• Grzegorz Mlostoń and
• Heinz Heimgartner

Beilstein J. Org. Chem. 2017, 13, 2235–2251, doi:10.3762/bjoc.13.221

• presence of Al2O3·KF in acetonitrile at room temperature (rt) [9]. Another efficient method for the preparation of dialkyl esters E-1 relies on the usage of alkyl bromo(cyano)acetates 3, which upon treatment with potassium thiocyanate in aqueous acetonitrile at room temperature are converted into the

Phosphonic acid: preparation and applications

• Charlotte M. Sevrain,
• Mathieu Berchel,
• Hélène Couthon and
• Paul-Alain Jaffrès

Beilstein J. Org. Chem. 2017, 13, 2186–2213, doi:10.3762/bjoc.13.219

• develop bone targeting which was assessed for therapy [96] and imaging [97][98]. Finally, the phosphonic acid group was also employed to immobilize organic or organometallic molecules on the surface of metal oxide [99][100] (Al2O3 [101], TiO2 [102][103], SnO2 [104], Fe3O4 [105], ZnO [106]), CdSe quantum