Thiadiazino-indole, thiadiazino-carbazole and benzothiadiazino-carbazole dioxides: synthesis, physicochemical and early ADME characterization of representatives of new tri-, tetra- and pentacyclic ring systems and their intermediates

• Gyöngyvér Pusztai,
• László Poszávácz,
• Anna Vincze,
• András Marton,
• Ahmed Qasim Abdulhussein,
• Judit Halász,
• András Dancsó,
• Gyula Simig,
• György Tibor Balogh and
• Balázs Volk

Beilstein J. Org. Chem. 2025, 21, 2220–2233, doi:10.3762/bjoc.21.169

• synthesis [18][19][20][21]. Sudhakara et al. described the advantages of using bismuth nitrate as catalyst in the synthesis of hydrazones and in the one-pot Fischer synthesis of indoles from ketones and hydrazines [22][23]. Adopting this method, hydrazone intermediates 7a–j were obtained by treatment of

• hydrazino derivatives 5a,b with ketones 6a–e in the presence of bismuth nitrate pentahydrate catalyst in refluxing methanol with good to excellent yields (method A, step 1). As regards cis–trans isomerism, compounds (E)-7a and (E)-7f were isolated in high yields (94% and 84%, respectively), however, in the

• performed using the method described in the literature [18], i.e., by heating compounds 5a,b with ketones 6a–e in the presence of bismuth nitrate pentahydrate catalyst and PPA in methanol at 110 °C in a closed vial (Scheme 1, method B). In the synthesis of asymmetric hydrazones 7a,c,f,h, the major product

C2 to C6 biobased carbonyl platforms for fine chemistry

• Jingjing Jiang,
• Muhammad Noman Haider Tariq,
• Florence Popowycz,
• Yanlong Gu and
• Yves Queneau

Beilstein J. Org. Chem. 2025, 21, 2103–2172, doi:10.3762/bjoc.21.165

• ) system can be recycled without significant loss of activity (Scheme 5) [33]. α-Bromoacetaldehyde derivatives (Scheme 6, structures a–d) and 2-phenylindoles were used to synthesize benzo[a]carbazoles. The reaction reported by the Gu research group was speeded up by bismuth trichloride (BiCl3). The Friedel

Stereoselective electrochemical intramolecular imino-pinacol reaction: a straightforward entry to enantiopure piperazines

• Margherita Gazzotti,
• Fabrizio Medici,
• Valerio Chiroli,
• Laura Raimondi,
• Sergio Rossi and
• Maurizio Benaglia

Beilstein J. Org. Chem. 2025, 21, 1897–1908, doi:10.3762/bjoc.21.147

• characteristic of the earliest versions of this transformation. Several metals from the p- and the d-blocks of the periodic table, such as aluminum [7], indium [8], bismuth [7], zinc [9][10][11][12][13][14][15][16][17], and manganese [18][19], were later studied. The use of zinc, in particular, has attracted

High-pressure activation for the solvent- and catalyst-free syntheses of heterocycles, pharmaceuticals and esters

• Kelsey Plasse,
• Valerie Wright,
• Guoshu Xie,
• R. Bernadett Vlocskó,
• Alexander Lazarev and
• Béla Török

Beilstein J. Org. Chem. 2025, 21, 1374–1387, doi:10.3762/bjoc.21.102

• all yielded the expected products to some extent, no product formation was observed at the ambient pressure control reactions. Unlike water and a few elements (silicon, bismuth, gallium, etc.) that tend to form tetrahedral crystal lattices and exhibit lower density upon freezing, most organic

Recent advances and future challenges in the bottom-up synthesis of azulene-embedded nanographenes

• Bartłomiej Pigulski

Beilstein J. Org. Chem. 2025, 21, 1272–1305, doi:10.3762/bjoc.21.99

• alkenes: A bismuth-catalysed cyclization of alkenes has been demonstrated as an efficient synthetic tool for the creation of benzenoid PAHs [89]. Murai and co-workers applied this approach to the synthesis of azulene-embedded nanographenes (Scheme 18) [90]. Vinyl ethers 133a–d were cyclized using Bi(OTf)3

Red light excitation: illuminating photocatalysis in a new spectrum

• Lucas Fortier,
• Corentin Lefebvre and
• Norbert Hoffmann

Beilstein J. Org. Chem. 2025, 21, 296–326, doi:10.3762/bjoc.21.22

• . While transition metals such as copper, palladium, cobalt, and nickel are well-established in catalyzed cross-coupling reactions, J. Cornella et al. have highlighted the reactivity of main-group elements like bismuth, which can mimic transition-metal behavior through oxidative addition. In their recent

• explores how this bismuth(I) complex undergoes oxidative addition with a variety of aryl electrophiles, including diazonium salts, iodonium salts, and challenging aryl iodides and aryl thianthrenium salts, typically requiring transition-metal catalysts (Figure 3). The reactivity of the N,C,N-bismuthinidene

• ability to operate under low-energy light conditions, opens up new avenues for main-group redox catalysis in organic synthesis. By leveraging light excitation to enhance the reducing power of the bismuth complex, the study showcases the potential of main-group photoredox systems to complement traditional

Transition-metal-free synthesis of arylboronates via thermal generation of aryl radicals from triarylbismuthines in air

• Yuki Yamamoto,
• Yuki Konakazawa,
• Kohsuke Fujiwara and
• Akiya Ogawa

Beilstein J. Org. Chem. 2024, 20, 2577–2584, doi:10.3762/bjoc.20.216

• atmosphere and in the open-air. In the absence of oxygen, the color of the reaction mixture changed only slightly. In contrast, the reaction in air resulted in the formation of black and a small amount of white insoluble solid (probably metallic bismuth or bismuth oxide) [55], and 3a was successfully

• control experiments and our previous studies, a proposed reaction pathway is shown in Scheme 5. First, thermal activation of triarylbismuthines in air forms aryl radicals together with the bismuth residues (i.e., metal bismuth and bismuth oxide). Alternatively, oxygen in air and/or boron-centered radicals

Bismuth(III) triflate: an economical and environmentally friendly catalyst for the Nazarov reaction

• Manoel T. Rodrigues Jr.,
• Aline S. B. de Oliveira,
• Ralph C. Gomes,
• Amanda Soares Hirata,
• Lucas A. Zeoly,
• Hugo Santos,
• João Arantes,
• Catarina Sofia Mateus Reis-Silva,
• João Agostinho Machado-Neto,
• Leticia Veras Costa-Lotufo and
• Fernando Coelho

Beilstein J. Org. Chem. 2024, 20, 1167–1178, doi:10.3762/bjoc.20.99

• , 13083-970 Campinas, São Paulo, Brazil Department of Pharmacology, Institute of Biomedical Sciences, University of São Paulo, 05508-000 São Paulo, Brazil 10.3762/bjoc.20.99 Abstract We describe the use of bismuth(III) triflate as an efficient and environmentally friendly catalyst for the Nazarov

• 3-aryl-1-indanones) in good to excellent yield. The reaction did not require additives and was insensitive to both air and moisture. Preliminary biological evaluation of some indanones showed a promising profile against some human cancer line cells. Keywords: bismuth; catalysis; heterocycles

• use of Lewis acids sensitive to moisture [2][27][28][30][31][33][34][36][40][41][42][43][46][47][48][49]. Despite the numerous reports on catalytic versions of the Nazarov reaction, few of them describe the use of bismuth salts as catalysts for Nazarov-type reactions [50][51] and none for the

Mechanisms for radical reactions initiating from N-hydroxyphthalimide esters

• Carlos R. Azpilcueta-Nicolas and
• Jean-Philip Lumb

Beilstein J. Org. Chem. 2024, 20, 346–378, doi:10.3762/bjoc.20.35

•  26B). A novel approach for the activation of redox-active esters was recently reported by Cornella and co-workers [32]. In this study, low valent bismuth (Bi) complex Bi-1 was found to exhibit redox properties similar to those of first row-transition metal catalysts, enabling the activation of

Clauson–Kaas pyrrole synthesis using diverse catalysts: a transition from conventional to greener approach

• Dileep Kumar Singh and
• Rajesh Kumar

Beilstein J. Org. Chem. 2023, 19, 928–955, doi:10.3762/bjoc.19.71

• pyrrole derivatives. In 2012, Bandyopadhyay et al. [77] reported the solvent-free and eco-friendly synthesis of various N-substituted pyrroles 51 in excellent 76–99% yields using bismuth nitrate as catalyst (Scheme 24). In this reaction, various aliphatic, aromatic, polyaromatic and heteropolyaromatic

• derivatives 77 in good to excellent yields using a microwave-assisted and bismuth nitrate Bi(NO3)3∙5H2O-catalyzed reaction between various amines 76 and 2,5-dimethoxytetrahydrofuran (2) in neat, H2O or THF (Scheme 37). This approach provides different pyrrole derivatives without the use of sensitive or

• -substituted pyrroles 43. Synthesis of N-substituted pyrroles 45 by using Co catalyst Co/NGr-C@SiO2-L. Zinc-catalyzed synthesis of N-arylpyrroles 47. Silica sulfuric acid-catalyzed synthesis of pyrrole derivatives 49. Bismuth nitrate-catalyzed synthesis of pyrroles 51. L-(+)-tartaric acid-choline chloride

Palladium-catalyzed enantioselective three-component synthesis of α-arylglycine derivatives from glyoxylic acid, sulfonamides and aryltrifluoroborates

• Bastian Jakob,
• Nico Schneider,
• Luca Gengenbach and
• Georg Manolikakes

Beilstein J. Org. Chem. 2023, 19, 719–726, doi:10.3762/bjoc.19.52

• situ generation of reactive imine species, we have disclosed iron- and bismuth-catalyzed three-component reactions for the synthesis of α-arylglycines [14][15][16], in which the arylboronic acid could be replaced with an electron-rich (hetero)arene as nucleophile. In parallel, we have developed

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

• benzimidoyl chloride from thioamides by desulfurization and chlorination, as well as its application to the synthesis of 2-substituted benzazoles. Keywords: benzazole; bismuth; cyclization; desulfurization; thioamide; Introduction In the production of pharmacologically active compounds, 2-substituted

• . performed the dehydrosulfurization of thioamides and thioureas that provided nitriles and cyanamides [35]. Using bismuth compounds as desulfurization reagents for synthesizing heteroazoles, this paper presents the syntheses of 2-aryl- and 2-alkylbenzoxazoles through the ring-closure reaction of 2

• proved that the reaction of 1a with 2a and Ph3BiCl2 6a in the ratio of 1:2:2 provided the best results, affording product 8a in the highest yield (99%) (Table 1, entries 1, 15, and 16). Moreover, in the presence of 30 mol % of 6a and a 1a:2a ratio of 1:2, the reaction was suppressed and the bismuth

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

• and co-workers performed a bismuth catalyst system study for the methylation and alkylation of quinone derivatives [84]. Furthermore, they also evaluated the methylation without catalysts and with the use of lanthanum(II) and copper(II) salts as additive. However, the best results were achieved with

• bismuth(III) triflate. The use of tert-butyl hydroperoxide in the presence of bismuth(III) triflate for the methylation of 1,4-naphthoquinone (1) provided 10 in 43% yield, in already optimized conditions (Scheme 3). Demethylation of 2-methyl-1,4-dimethoxynaphthalene The oxidative demethylation of 1,4

• resulted in an increase of menadione (10) conversion (40%) and also in the reaction selectivity (95%) (Scheme 22C). Another approach involving menadione acetylation was reported by Yadav and co-workers, who described a methodology for the synthesis of acetylated quinone derivatives catalyzed by bismuth(III

Transition-metal-free intramolecular Friedel–Crafts reaction by alkene activation: A method for the synthesis of some novel xanthene derivatives

• Tülay Yıldız,
• İrem Baştaş and
• Hatice Başpınar Küçük

Beilstein J. Org. Chem. 2021, 17, 2203–2208, doi:10.3762/bjoc.17.142

• gold(III) [43], iridium(III) [44][45], iron(III) [46], or bismuth(III) [47][48] were used as catalysts for the intermolecular hydroarylation of unactivated alkenes. Organic Brønsted acids were also used as catalysts in a smaller number of studies [49][50]. In this work, we searched for some organic

Recent advances in the syntheses of anthracene derivatives

• Giovanni S. Baviera and
• Paulo M. Donate

Beilstein J. Org. Chem. 2021, 17, 2028–2050, doi:10.3762/bjoc.17.131

• 2015, Lee and co-workers reported a similar approach. They published the synthesis of substituted 9-methylanthracenes 14 by cyclization of o-alkynyldiarylmethanes 13 in the presence of a bismuth catalyst. The scope of this reaction consisted of 12 examples in good yields (46–86%). They showed that the

• oxidative benzannulation reactions of 1-adamantoyl-1-naphthylamines with internal alkynes. Gold/bismuth-catalyzed cyclization of o-alkynyldiarylmethanes. [2 + 2 + 2] Cyclotrimerization reactions with alkynes/nitriles in the presence of nickel and cobalt catalysts. Cobalt-catalyzed [2 + 2 + 2

The preparation and properties of 1,1-difluorocyclopropane derivatives

• Kymbat S. Adekenova,
• Peter B. Wyatt and
• Sergazy M. Adekenov

Beilstein J. Org. Chem. 2021, 17, 245–272, doi:10.3762/bjoc.17.25

• -dimethoxyethane (Scheme 20) [60]. The difluorocarbene then added to cyclohexene (49) to form difluoronorcarane 50 with good yield. Under similar conditions tetramethylethylene afforded 1,1-difluorotetramethylcyclopropane (4). Trifluoromethyl derivatives of cadmium, bismuth, zinc, and gold: Bis(trifluoromethyl

• -difluorocyclopropane derivative 53 plus cadmium fluoride [61][62]. However, cadmium compounds are highly toxic and furthermore (CF3)2Cd is pyrophoric in air and liable to explode upon warming to room temperature. Tris(trifluoromethyl)bismuth (54) is also a source of difluorocarbene, that is generated during the

Synthesis of aryl cyclopropyl sulfides through copper-promoted S-cyclopropylation of thiophenols using cyclopropylboronic acid

• Emeline Benoit,
• Ahmed Fnaiche and
• Alexandre Gagnon

Beilstein J. Org. Chem. 2019, 15, 1162–1171, doi:10.3762/bjoc.15.113

• this method, particularly with respect to medicinal chemistry where expedient methods from easily accessible substrates are needed. Organobismuth compounds are organometallic reagents that possess a C–Bi bond and which can be synthesized from inexpensive and low-toxic bismuth salts [24][25]. Due to the

• borderline behavior of bismuth as a metal and a ligand, organobismuth species have been used as reagents and catalysts in a wide range of reactions. We reported a portfolio of methods for the construction of C–C [26][27][28][29], C–N [30] and C–O bonds [31][32][33] using triaryl- and trialkylbismuthines [34

Synthesis of acylglycerol derivatives by mechanochemistry

• Karen J. Ardila-Fierro,
• Andrij Pich,
• Marc Spehr,
• José G. Hernández and
• Carsten Bolm

Beilstein J. Org. Chem. 2019, 15, 811–817, doi:10.3762/bjoc.15.78

• catalysts such as iron(III) chloride or bismuth(III) triflate was reported. However, the implementation of these protocols in the ball mill only led to trace amounts (less than 5% yield) of the protected monoacylglycerol 4a. Finally, one of the well-established Jacobsen catalysts for the epoxide ring

Bi-mediated allylation of aldehydes in [bmim][Br]: a mechanistic investigation

• Mrunesh Koli,
• Sucheta Chatterjee,
• Subrata Chattopadhyay and
• Dibakar Goswami

Beilstein J. Org. Chem. 2018, 14, 2198–2203, doi:10.3762/bjoc.14.193

• stoichiometric/near-stoichiometric amounts of reagents. Plausibly, [bmim][Br] activates Bi metal by a charge transfer mechanism. The 1H VT-NMR studies suggested that both the allylating species, allylbismuth dibromide and diallylbismuth bromide, are generated in situ. Keywords: allylation; bismuth; [bmim][Br

• ppm. Among the possible allylbismuth intermediates I–III (Figure 2), we excluded the possibility of formation of tris(allyl)bismuth (III), as the reported [38] doublet at δ 2.33 ppm due to its allylic protons was absent in the 1H NMR spectrum of the reaction mixture. Earlier, Jadhav et al. reported

Evaluation of dispersion type metal···π arene interaction in arylbismuth compounds – an experimental and theoretical study

• Ana-Maria Preda,
• Małgorzata Krasowska,
• Lydia Wrobel,
• Philipp Kitschke,
• Phil C. Andrews,
• Jonathan G. MacLellan,
• Lutz Mertens,
• Marcus Korb,
• Tobias Rüffer,
• Heinrich Lang,
• Alexander A. Auer and
• Michael Mehring

Beilstein J. Org. Chem. 2018, 14, 2125–2145, doi:10.3762/bjoc.14.187

• the analysis of single crystal X-ray diffraction data and computational studies. First, the crystal structures of polymorphs of Ph3Bi (1) are described emphasizing on the description of London dispersion type bismuth···π arene interactions and other van der Waals interactions in the solid state and

• the effect of it on polymorphism. For comparison we have chosen the substituted arylbismuth compounds (C6H4-CH═CH2-4)3Bi (2), (C6H4-OMe-4)3Bi (3), (C6H3-t-Bu2-3,5)3Bi (4) and (C6H3-t-Bu2-3,5)2BiCl (5). The structural analyses revealed that only two of them show London dispersion type bismuth···π arene

• ), which leads to the formation of zig-zag Bi–arenecentroid ribbons formed as a result of bismuth···π arene interactions and π···π intermolecular contacts. In the crystal structures of the polymorph 2b as well as for 4 bismuth···π arene interactions are not observed, but both compounds revealed C–HPh···π

Mannich base-connected syntheses mediated by ortho-quinone methides

• Petra Barta,
• Ferenc Fülöp and
• István Szatmári

Beilstein J. Org. Chem. 2018, 14, 560–575, doi:10.3762/bjoc.14.43

• ], citric acid [54], sulfanilic acid [55], bismuth(III) nitrate pentahydrate (Bi(NO3)3·5H2O) [56], 1-hexanesulfonic acid sodium salt [57], zirconyl triflate (ZrO(OTf)2) [58], sulfonated carbon (SO3H-carbon) [59], MCM-41-N-propylsulfamic acid [60], polyphosphate ester [61] and amberlite IR-120 [62] were used

Photocatalytic formation of carbon–sulfur bonds

• Alexander Wimmer and
• Burkhard König

Beilstein J. Org. Chem. 2018, 14, 54–83, doi:10.3762/bjoc.14.4

• thiols with primary and 1,1-disubstituted alkenes. In the same year, Fadeyi et al. reported bismuth oxide (Bi2O3) as photoredox catalyst in combination with bromotrichloromethane as redox additive (Scheme 8) [38]. A series of alkyl and benzyl thiols were reacted with aliphatic alkenes and styrenes. The

CF₃SO₂X (X = Na, Cl) as reagents for trifluoromethylation, trifluoromethylsulfenyl-, -sulfinyl- and -sulfonylation and chlorination. Part 2: Use of CF₃SO₂Cl

• Hélène Chachignon,
• Hélène Guyon and
• Dominique Cahard

Beilstein J. Org. Chem. 2017, 13, 2800–2818, doi:10.3762/bjoc.13.273

• -sulfonyl amides failed to react. Interestingly, Zhang and co-workers demonstrated that this reaction could be performed as well using bismuth oxybromide (BiOBr) nanosheets instead of a ruthenium complex as the photocatalyst (Scheme 5) [12]. The reaction unfortunately suffered from the same limitations

Reagent-controlled regiodivergent intermolecular cyclization of 2-aminobenzothiazoles with β-ketoesters and β-ketoamides

• Irwan Iskandar Roslan,
• Kian-Hong Ng,
• Gaik-Khuan Chuah and
• Stephan Jaenicke

Beilstein J. Org. Chem. 2017, 13, 2739–2750, doi:10.3762/bjoc.13.270

• ]. Polyphosphoric acid has also been used to access 5a by coupling 2-aminobenzothiazole with β-ketoesters [79][91][92]. We have previously shown that bismuth salts can catalyze the intermolecular cyclization of 2-aminopyridines and β-ketoesters to pyrido[1,2-a]pyrimidin-4-ones [6]. Using Bi(OTf)3 in 1.5 mmol 2

Exploring mechanochemistry to turn organic bio-relevant molecules into metal-organic frameworks: a short review

• Vânia André,
• Sílvia Quaresma,
• João Luís Ferreira da Silva and
• M. Teresa Duarte

Beilstein J. Org. Chem. 2017, 13, 2416–2427, doi:10.3762/bjoc.13.239

• of a metallodrug, another metal-organic target The study of the chemical reactivity of bismuth and carboxylic acids, in particular salicylic acid, is quite relevant for the pharmaceutical industry, because of the large production of bismuth subsalicylate (Pepto-Bismol), an anti-acid used in the

• be more efficient but also very selective [11]. Changing the stoichiometric ratio of the reactants to 1:2 and 1:3 allowed the syntheses of another two bismuth–salicylate compounds, namely the disalicylate and the trisalicylate, respectively. The only previously known crystal structure obtained for

• bismuth salicylates was a Bi38 cluster isolated by recrystallization of the trisalicylate from acetone [148] and this was then considered a possible model for the structure of bismuth subsalicylate [11]. In 2011, André et al. performed a similar recrystallization of the disalicylate and obtained a similar