(E,Z)-1,1,1,4,4,4-Hexafluorobut-2-enes: hydrofluoroolefins halogenation/dehydrohalogenation cascade to reach new fluorinated allene

• Nataliia V. Kirij,
• Andrey A. Filatov,
• Yurii L. Yagupolskii,
• Sheng Peng and
• Lee Sprague

Beilstein J. Org. Chem. 2024, 20, 452–459, doi:10.3762/bjoc.20.40

• significantly. One of the new and budding directions in recent years is the stereoselective olefin metathesis processes based on catalysis by complexes of molybdenum, tungsten and ruthenium [3][4][5]. The first publications have recently appeared that molybdenum complexes can catalyze cross-metathesis of butene

Mono or double Pd-catalyzed C–H bond functionalization for the annulative π-extension of 1,8-dibromonaphthalene: a one pot access to fluoranthene derivatives

• Nahed Ketata,
• Linhao Liu,
• Ridha Ben Salem and
• Henri Doucet

Beilstein J. Org. Chem. 2024, 20, 427–435, doi:10.3762/bjoc.20.37

• activation has also been investigated to provide a complementary method. Using the most appropriate synthetic route and substrates, it is possible to introduce the desired functional groups at positions 7–10 on fluoranthenes. Keywords: catalysis; C–H bond functionalization; direct arylation; fluoranthenes

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

• highest fungicidal activity [11]. Brønsted or Lewis acid catalysis – conventional synthetic methods The indole moiety is part of many natural products, agrochemicals, and pharmaceuticals. In medicinal chemistry, indole and its derivatives are considered important compounds, since they exhibit valuable

• of green chemistry. Organocatalysis is the acceleration of chemical reactions with the use of small organic compounds, which do not contain any amounts of enzyme or inorganic elements [37][38][39]. The benefits of solid acid catalysis render them as an appealing choice, compared to their liquid

• intriguing tool in the catalysis of various organic transformations that were previously considered unfeasible [89]. In 2003, the reaction of indoles with aldehydes and ketones under XB catalysis was reported by Bandgar and his research group utilizing I2 as the catalyst and acetonitrile as the optimum

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

• years and in the past, they were perceived as fleeting reaction intermediates. Recent progress in photoredox catalysis [6][7][8], electrochemistry [9][10], and the use of transition-metal (TM) catalysts in radical cross-coupling reactions [11] have dramatically expanded the use of radicals in synthesis

• overview of the diverse mechanisms that have been proposed for radical based transformations initiating from NHPI esters. The discussion is organized into four sections: (i) mechanisms under photochemical conditions, (ii) initiation by metal catalysis and stoichiometric reductants, (iii) N-heterocyclic

• . With this mechanistic blueprint as a backdrop, Phipps and co-workers developed an enantioselective Minisci-type addition, under dual photoredox and chiral Brønsted acid catalysis [44] (Scheme 5A). In their proposed mechanism, the activation of the NHPI ester radical precursor was proposed to occur via

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

• naphthyl substituents carrying each an alkyne moiety on the ortho position. Ring expansion of both thiophene units in 19 was then triggered by platinum catalysis to generate the corresponding thiopyrans, and finally the bromine atoms located on the latter rings were exploited for the ring closure of the

Catalytic multi-step domino and one-pot reactions

• Svetlana B. Tsogoeva

Beilstein J. Org. Chem. 2024, 20, 254–256, doi:10.3762/bjoc.20.25

• ; multi-step reactions; multicomponent reactions; one-pot synthesis; organocatalysis; tandem reactions; transition-metal-catalysis; The synthesis of pharmaceutical ingredients, natural products, agrochemicals, ligand systems, and building blocks for materials science has reached a high level of

Copper-catalyzed multicomponent reaction of β-trifluoromethyl β-diazo esters enabling the synthesis of β-trifluoromethyl N,N-diacyl-β-amino esters

• Youlong Du,
• Haibo Mei,
• Ata Makarem,
• Ramin Javahershenas,
• Vadim A. Soloshonok and
• Jianlin Han

Beilstein J. Org. Chem. 2024, 20, 212–219, doi:10.3762/bjoc.20.21

• 1 of Table 1, 54% yield product 4a was produced by this reaction in the presence of 10 mol % CuI. These results demonstrate that copper catalysis plays a crucial role in the generation of the desired product 4a. Moreover, we performed this reaction without the addition of tert-butyl nitrite (Scheme

• . Conclusion In summary, a series of new β-trifluoromethyl β-diazo esters have been designed, which are applied for the first time in a cascade reaction through an interrupted esterification with nitrile ylides as the key intermediates under copper-catalysis conditions. Varieties of unsymmetric trifluoromethyl

Chiral phosphoric acid-catalyzed transfer hydrogenation of 3,3-difluoro-3H-indoles

• Yumei Wang,
• Guangzhu Wang,
• Yanping Zhu and
• Kaiwu Dong

Beilstein J. Org. Chem. 2024, 20, 205–211, doi:10.3762/bjoc.20.20

• relatively strict reaction conditions (up to 150 bar H2). In 2022, Liu’s group reported an asymmetric hydrogenation of 3H-indoles catalyzed by a chiral Mn complex, which showed good yield and enantioselectivity [25]. In addition to metal catalysis for the enantioselective reduction, asymmetric

Copper-promoted C5-selective bromination of 8-aminoquinoline amides with alkyl bromides

• Changdong Shao,
• Chen Ma,
• Li Li,
• Jingyi Liu,
• Yanan Shen,
• Chen Chen,
• Qionglin Yang,
• Tianyi Xu,
• Zhengsong Hu,
• Yuhe Kan and
• Tingting Zhang

Beilstein J. Org. Chem. 2024, 20, 155–161, doi:10.3762/bjoc.20.14

• , employing activated and unactivated alkyl bromides as the halogenation reagents without additional external oxidants. This method features outstanding site selectivity, broad substrate scope, and excellent yields. Keywords: aminoquinolines; C–H bromination; copper catalysis; regioselectivity; Introduction

Using the phospha-Michael reaction for making phosphonium phenolate zwitterions

• Matthias R. Steiner,
• Max Schmallegger,
• Larissa Donner,
• Johann A. Hlina,
• Christoph Marschner,
• Judith Baumgartner and
• Christian Slugovc

Beilstein J. Org. Chem. 2024, 20, 41–51, doi:10.3762/bjoc.20.6

• reactive in chloroform solution, while in methanol the corresponding phosphonium phenolate is formed. Keywords: Lewis-base catalysis; Michael acceptor reactivity; phospha-Michael reaction; phosphonium phenolate zwitterion; Introduction Organocatalysis has emerged in recent years as a valuable and

Facile access to pyridinium-based bent aromatic amphiphiles: nonionic surface modification of nanocarbons in water

• Lorenzo Catti,
• Shinji Aoyama and
• Michito Yoshizawa

Beilstein J. Org. Chem. 2024, 20, 32–40, doi:10.3762/bjoc.20.5

• -doped nanocarbon g-C3N4 was achieved using aromatic micelle (PA-OCH3)n (Figure 6a). The multiple N-atoms bestow g-C3N4 with unique properties that are responsible for its widespread use in catalysis [28]. Subjecting yellow solid PA-OCH3 (1.2 mg, 1.9 μmol) and pale yellow solid g-C3N4 (1.0 mg) to the

1-Butyl-3-methylimidazolium tetrafluoroborate as suitable solvent for BF₃: the case of alkyne hydration. Chemistry vs electrochemistry

• Marta David,
• Elisa Galli,
• Richard C. D. Brown,
• Marta Feroci,
• Fabrizio Vetica and
• Martina Bortolami

Beilstein J. Org. Chem. 2023, 19, 1966–1981, doi:10.3762/bjoc.19.147

• anions could coordinate the Lewis acid BF3 through the negatively charged oxygen [107], decreasing availability of BF3 for catalysis. Otherwise, ILs possessing bis(trifluoromeylsulfonyl)imide and hexafluorophosphate anions afforded hydrated product 2a with slightly better yields (87%) compared to those

• pseudobenzylic position, as observed in Lewis acid-assisted Brønsted acid (LBA) catalysis [47][48][49][50]. Internal alkynes afforded the corresponding products in good to excellent yields (Table 4, entries 1–3). In particular, the unsymmetrical alkyl(aryl)alkynes 1b and 1c showed a higher reactivity compared to

• available for catalysis. A similar behaviour was observed with ethyl 3-(4-chlorophenyl)propiolate (1n), although with lower yield due to the deactivating effect of the chlorine substituent in the para position of the phenyl ring (Table 4, entry 14). Importantly, for the experiments involving the same alkyne

Aldiminium and 1,2,3-triazolium dithiocarboxylate zwitterions derived from cyclic (alkyl)(amino) and mesoionic carbenes

• Nedra Touj,
• François Mazars,
• Guillermo Zaragoza and
• Lionel Delaude

Beilstein J. Org. Chem. 2023, 19, 1947–1956, doi:10.3762/bjoc.19.145

• Nedra Touj Francois Mazars Guillermo Zaragoza Lionel Delaude Laboratory of Catalysis, MolSys Research Unit, Université de Liège, Institut de chimie organique (B6a), Allée du six août 13, 4000 Liège, Belgium Unidad de Difracción de Rayos X, RIAIDT, Universidade de Santiago de Compostella, Edificio

• just three decades (Figure 1) [2]. In particular, cyclic diaminocarbenes based on the imidazoline, benzimidazole, or imidazole ring system (A–C) have led to a myriad of applications in organometallic chemistry, homogeneous catalysis, and materials science, to name just a few [3][4][5]. Due to their

Anion–π catalysis on carbon allotropes

• M. Ángeles Gutiérrez López,
• Mei-Ling Tan,
• Giacomo Renno,
• Augustina Jozeliūnaitė,
• J. Jonathan Nué-Martinez,
• Javier Lopez-Andarias,
• Naomi Sakai and
• Stefan Matile

Beilstein J. Org. Chem. 2023, 19, 1881–1894, doi:10.3762/bjoc.19.140

• M. Angeles Gutierrez Lopez Mei-Ling Tan Giacomo Renno Augustina Jozeliunaite J. Jonathan Nue-Martinez Javier Lopez-Andarias Naomi Sakai Stefan Matile Department of Organic Chemistry, University of Geneva, Geneva, Switzerland 10.3762/bjoc.19.140 Abstract Anion–π catalysis, introduced in 2013

• , stands for the stabilization of anionic transition states on π-acidic aromatic surfaces. Anion–π catalysis on carbon allotropes is particularly attractive because high polarizability promises access to really strong anion–π interactions. With these expectations, anion–π catalysis on fullerenes has been

• introduced in 2017, followed by carbon nanotubes in 2019. Consistent with expectations from theory, anion–π catalysis on carbon allotropes generally increases with polarizability. Realized examples reach from enolate addition chemistry to asymmetric Diels–Alder reactions and autocatalytic ether cyclizations

N-Boc-α-diazo glutarimide as efficient reagent for assembling N-heterocycle-glutarimide diads via Rh(II)-catalyzed N–H insertion reaction

• Grigory Kantin,
• Pavel Golubev,
• Alexander Sapegin,
• Alexander Bunev and
• Dmitry Dar’in

Beilstein J. Org. Chem. 2023, 19, 1841–1848, doi:10.3762/bjoc.19.136

• , including both aromatic and saturated NH-substrates. This yields structures that are appealing for generating cereblon ubiquitin-ligase ligands and for potential use in crafting PROTAC molecules. Keywords: CRBN ligands; diazocarbonyl compounds; N–H insertion reaction; N-heterocycles; Rh(II)-catalysis

• -phenylpyrazolin-3-one, an exceptionally low conversion of the starting heterocycle was observed. In the next step, we have demonstrated the possibility of removing the protective Boc group under mild conditions without acid or base catalysis (Scheme 4). Deprotection occurs in high, near quantitative yields

• diazocarbonyl reagent is presented for the first time. The protective group is removed without acid catalysis with near quantitative yields. New benzotriazole derivatives containing functional groups capable of participating in the subsequent modification for linker attachment to assemble the PROTAC molecule

Substituent-controlled construction of A₄B₂-hexaphyrins and A₃B-porphyrins: a mechanistic evaluation

• Seda Cinar,
• Dilek Isik Tasgin and
• Canan Unaleroglu

Beilstein J. Org. Chem. 2023, 19, 1832–1840, doi:10.3762/bjoc.19.135

• of porphyrinogen and hexaphyrinogen forms. Keywords: A4B2-hexaphyrin; A3B-porphyrin; N-tosylimine; Cu(OTf)2 catalysis; HRESI–TOF analysis; Introduction Porphyrins and expanded porphyrins have found widespread applications in supramolecular chemistry [1][2][3][4]. Expanded porphyrins are utilized as

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

• , acetonitrile, with 91–100% efficiency, and the catalyst was reused in five reaction cycles without the loss of activity and selectivity. Keywords: baclofen; catalyst recovery; lipophilic cinchona squaramide; organocatalysis; stereoselective catalysis; Introduction In today’s chemical industry, catalytic

• stereoselective Michael addition reactions. Homogeneous catalysis was carried out in non-polar solvents (i.e., toluene), which allows the high performance of the lipophilic organocatalyst in terms of yield and stereoselectivity. To facilitate the pharmaceutical use of the lipophilic organocatalyst, we

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

• , limiting the reaction time to 60–90 min under these conditions allowed some of the N-hydroxy derivatives 4 to be isolated in good yield (Table 5), even though it did not entirely prevent the formation of products 5. Palladium catalysis was not appropriate for the hydrogenation of compounds 3f and 3g

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

• Tinglan Liu Yu Zhou Junhong Tang Chengming Wang Department of Chemistry, Jinan University, Guangzhou 511443, P. R. China UNITEST, Weifang 261000, P. R. China 10.3762/bjoc.19.131 Abstract Photoredox catalysis plays a crucial role in contemporary synthetic organic chemistry. Since the

• , numerous remarkable breakthroughs and notable progresses have been achieved in the realm of photoredox catalysis [1][2][3]. This domain has profoundly transformed modern organic synthesis, resulting in a considerable surge in research efforts centered on free radical reactions [4]. Presently, photoredox

• catalysis has risen to prominence as an incredibly effective methodology, establishing itself as a powerful tool for crafting various C–X (X = C, N, O, F, Cl…) bonds owing to its advantageous traits, such as sustainability, practicality, and environmental compatibility [5]. Despite its broad synthetic

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

• ; Department of Organic Chemistry, Biochemistry and Catalysis, Research Centre of Applied Organic Chemistry, 90-92 Panduri Street, RO-050663 Bucharest, Romania 10.3762/bjoc.19.130 Abstract Mechanically interlocked molecules (MIMs) have been important synthetic targets in supramolecular chemistry due to their

• in 2016. While initially obtained as chemical curiosities, rotaxanes offer now exciting opportunities for scientific advancements in supramolecular chemistry and applications in various fields ranging from molecular machines and switches [4][5][6][7][8][9] to catalysis [10][11], molecular electronics

• -functonalized stopper 3 after substitution of bromine with azide. The dialkyne-decorated pyridine 5 was prepared starting from 2,6-bis(bromomethyl)pyridine that was reacted with compound 4, under phase transfer catalysis (Scheme 1). Finally, the axle 6, as well as the reference macrocycles M1 and M2 [44], were

Selectivity control towards CO versus H₂ for photo-driven CO₂ reduction with a novel Co(II) catalyst

• Lisa-Lou Gracia,
• Philip Henkel,
• Olaf Fuhr and
• Claudia Bizzarri

Beilstein J. Org. Chem. 2023, 19, 1766–1775, doi:10.3762/bjoc.19.129

• (helping in the deprotonation of the radical cation BIH•+ formed after the reductive quenching of the PS), but also can actively assist the catalysis, by capturing CO2 [50][51][52]. On the other hand, having three hydroxy groups, TEOA is also considered a proton donor and the formation of metal hydrides is

• possible. In some cases, this metal hydride favors the production of formate [51]. However, it may induce the concomitant formation of H2. This might have been the case of the photo-driven catalysis by complex 1 in DMA/TEOA (Table 2, entries 2–4), where upon decreasing the concentration of TEOA down to

• with a TON ≈ 61 after 4 h (Table 3, entry 5). Longer irradiation times (15 h) were evaluated for the concentration of 10 μM and 5 μM of complex 1, showing that the catalysis continued beyond 4 hours and reached a TON higher than 80 and 50, for [1] of 5 and 10 μM, respectively (Table 3, entries 6 and 7

Trifluoromethylated hydrazones and acylhydrazones as potent nitrogen-containing fluorinated building blocks

• Zhang Dongxu

Beilstein J. Org. Chem. 2023, 19, 1741–1754, doi:10.3762/bjoc.19.127

• catalysis, for the synthesis of trifluoromethylated dihydropyridazines under simple reaction conditions and the chemistry displayed very good enantioselectivities and high functional group tolerance (Scheme 4) [40]. Zhan et al. reported an efficient and highly selective method for the synthesis of CF3

• Brønsted acid-assisted Lewis base catalysis. Synthesis of CF3-pyrazoles and CF3-1,6-dihydropyridazines. Asymmetric reactions of trifluoromethylimines with organometallic reagents. Mannich-type reaction of trifluoroacetaldehyde hydrazones. Synthesis of trifluoromethylated hydrazonoyl halides. Early work of

Unprecedented synthesis of a 14-membered hexaazamacrocycle

• Anastasia A. Fesenko and
• Anatoly D. Shutalev

Beilstein J. Org. Chem. 2023, 19, 1728–1740, doi:10.3762/bjoc.19.126

• agents for magnetic resonance imaging, radiopharmaceuticals, sensors, NMR shift reagents, luminescent materials, catalysis, etc. To date, a large variety of PAMs with various ring sizes, number and location of nitrogen atoms, levels of unsaturation, etc. have been prepared and studied. Nevertheless, the

Decarboxylative 1,3-dipolar cycloaddition of amino acids for the synthesis of heterocyclic compounds

• Xiaofeng Zhang,
• Xiaoming Ma and
• Wei Zhang

Beilstein J. Org. Chem. 2023, 19, 1677–1693, doi:10.3762/bjoc.19.123

• under the catalysis of AcOH at 110 °C for 6 h afforded the monocycloaddition product 19a in 93% LC yield [71]. The isolated compound 19a was used for an N-propargylation to produce compound 20a in 94% LC yield. The following Cu-catalyzed click reaction afforded triazolobenzodiazepine 21a in 88% LC yield

• ]isoquinolines. The reaction of 2-bromobenzaldehydes, 2-aminoisobutyric acid, and maleimides in MeCN under the catalysis of AcOH at 110 °C for 6 h afforded the cycloaddition products 26. The purified intermediates were used for the one-pot N-allylation with allyl bromide to afford intermediate 25 followed by a

Tying a knot between crown ethers and porphyrins

• Maksym Matviyishyn and
• Bartosz Szyszko

Beilstein J. Org. Chem. 2023, 19, 1630–1650, doi:10.3762/bjoc.19.120

• porphyrins as multitopic receptors, sensors, and supramolecular hosts, with applications in ion transport, catalysis, and polymeric materials [22][40][41][42][43][44][45]. In 1984 Lehn, Sessler and co-workers developed double-side-strapped crowned porphyrins, which served as tritopic and tetratopic receptors

• multitopic receptors capable of binding ions and ion-pairs, which have been used in ion binding and catalysis, to name a few applications [47][48][49]. A primary example of a crown ether-annulated porphyrin, i.e., β-crowned porphyrin, was established in 1996 by Murashima and co-workers [50]. The macrocycle