C3-Alkylation of furfural derivatives by continuous flow homogeneous catalysis

• Grédy Kiala Kinkutu,
• Catherine Louis,
• Myriam Roy,
• Juliette Blanchard and
• Julie Oble

Beilstein J. Org. Chem. 2023, 19, 582–592, doi:10.3762/bjoc.19.43

• .19.43 Abstract The C3-functionalization of furfural using homogeneous ruthenium catalysts requires the preinstallation of an ortho-directing imine group, as well as high temperatures, which did not allow scaling up, at least under batch conditions. In order to design a safer process, we set out to

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

Combining enyne metathesis with long-established organic transformations: a powerful strategy for the sustainable synthesis of bioactive molecules

• Valerian Dragutan,
• Ileana Dragutan,
• Albert Demonceau and
• Lionel Delaude

Beilstein J. Org. Chem. 2020, 16, 738–755, doi:10.3762/bjoc.16.68

• account surveys the current progress on the application of intra- and intermolecular enyne metathesis as main key steps in the synthesis of challenging structural motifs and stereochemistries found in bioactive compounds. Special emphasis is placed on ruthenium catalysts as promoters of enyne metathesis

• of known, in vivo effective substances but also for designing chemically modified analogs as valid alternatives for further therapeutic agents. Keywords: bioactive compounds; enyne metathesis; ring-closing metathesis; ruthenium catalysts; tandem reactions; Introduction Alkene and alkyne metathesis

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

• organic processes and have attracted considerable interest in this regard. Ru has efficiently catalyzed C–H activation reactions for C–C bond formation, aza-Michael reactions and many more MCRs [27][76][77]. During the writing of this review, we came through the fact that ruthenium catalysts were mostly

Hoveyda–Grubbs catalysts with an N→Ru coordinate bond in a six-membered ring. Synthesis of stable, industrially scalable, highly efficient ruthenium metathesis catalysts and 2-vinylbenzylamine ligands as their precursors

• Kirill B. Polyanskii,
• Kseniia A. Alekseeva,
• Pavel V. Raspertov,
• Pavel A. Kumandin,
• Eugeniya V. Nikitina,
• Atash V. Gurbanov and
• Fedor I. Zubkov

Beilstein J. Org. Chem. 2019, 15, 769–779, doi:10.3762/bjoc.15.73

• -containing ruthenium catalysts required preliminary synthesis of the imidazolium ligand and o-vinylbenzylamines (Figure 2). Whereas numerous methods for the preparation of the carbene precursor are known, no satisfactory suitable approach for the synthesis of ortho-substituted styrenes was found. Several

• , almost all steps of ligands’ and catalysts’ synthesis were accomplished in preparative and multigram scales. Commercially available ruthenium catalysts for metathesis reactions. Retrosynthesis of the ruthenium catalysts. Selected X-ray data for ruthenium complexes 11a–c. All hydrogen atoms were deleted

Aqueous olefin metathesis: recent developments and applications

• Valerio Sabatino and
• Thomas R. Ward

Beilstein J. Org. Chem. 2019, 15, 445–468, doi:10.3762/bjoc.15.39

• exploit biocompatible conditions. This review focuses on the progress made in aqueous olefin metatheses and their applications in chemical biology. Keywords: aqueous catalysis; artificial metalloenzymes; chemical biology; green chemistry; olefin metathesis; ruthenium catalysts; stapled peptides

• Raines both performed RCM reactions with the benchmark substrate 21 in mixtures of water/organic solvent at room temperature in air (Table 2). Table 2 summarizes the activities of the different ruthenium catalysts in protic media. The ratio water/co-solvent affects the RCM of substrate 21 catalyzed by G

• -metathesis of allyl alcohol (59) and the cis–trans isomerization of cis-butenedienol (Z-58). Metathesis catalysts bearing quaternary ammonium groups provide an attractive alternative to classical ruthenium catalysts. Although they do not represent a great improvement in terms of catalytic activity, they

Application of olefin metathesis in the synthesis of functionalized polyhedral oligomeric silsesquioxanes (POSS) and POSS-containing polymeric materials

• Patrycja Żak and
• Cezary Pietraszuk

Beilstein J. Org. Chem. 2019, 15, 310–332, doi:10.3762/bjoc.15.28

• -2-ene as model olefins (Scheme 16). For the majority of the ruthenium catalysts tested, despite the mild reaction conditions, high yields were observed. No reaction or lower yields of the test reaction products were observed for first generation catalysts and indenylidene complexes. For further

Synthesis of 1,2-divinylcyclopropanes by metal-catalyzed cyclopropanation of 1,3-dienes with cyclopropenes as vinyl carbene precursors

• Jesús González,
• Alba de la Fuente,
• María J. González,
• Laura Díez de Tejada,
• Luis A. López and
• Rubén Vicente

Beilstein J. Org. Chem. 2019, 15, 285–290, doi:10.3762/bjoc.15.25

• importantly, with complete endo (syn) selectivity. The use of gold, platinum or ruthenium catalysts showed poorer results with respect to reaction yield and endo/exo (syn/anti) selectivity, as indicated in Scheme 2. Considering these results, the scope of the reaction with unbiased 1,3-dienes was next

Ruthenium-based olefin metathesis catalysts with monodentate unsymmetrical NHC ligands

• Veronica Paradiso,
• Chiara Costabile and
• Fabia Grisi

Beilstein J. Org. Chem. 2018, 14, 3122–3149, doi:10.3762/bjoc.14.292

• to the current state of research are discussed. Keywords: ligand design; olefin metathesis; ruthenium catalysts; selectivity; unsymmetrical N-heterocyclic carbenes; Introduction The transition metal-catalyzed olefin metathesis reaction is an indispensable synthetic tool for the construction of new

• heteroatoms, such as thiazol-2-ylidene ligands [10], or those containing one nitrogen substituent, such as the series of cyclic (alkyl) (amino) carbenes (CAACs) introduced by Bertrand et al. [11], are not included in this survey. Review Ruthenium catalysts coordinated with N-aryl, N’-aryl NHCs The first

• development of this new concept for enantioinduction are still ongoing [18]. Ruthenium catalysts coordinated with N-alkyl, N’-aryl NHCs N-Alkyl-substituents possessing no functionalities or heteroatoms Unsymmetrical N-alkyl, N’-aryl NHC frameworks were initially developed in order to improve the catalytic

A tutorial review of stereoretentive olefin metathesis based on ruthenium dithiolate catalysts

• Daniel S. Müller,
• Olivier Baslé and
• Marc Mauduit

Beilstein J. Org. Chem. 2018, 14, 2999–3010, doi:10.3762/bjoc.14.279

• , mercaptophenolate and catecholthiolate catalysts (e.g., Ru-10) [8][9][10]. Variation of sterically demanding catecholthiolate ligands was reported by Grubbs in 2017 (e.g., Ru-11) [11]. In 2018 our group reported a series of electronically and sterically activated dithiolate ruthenium catalysts (e.g., Ru-12) [12

• commercially available and very inexpensive (≈40 €/500 mL) [20]. Catalyst loadings of 3 to 5 mol % are typically required to obtain useful yields of the corresponding allylic alcohols. The cross metathesis with carboxylic acid 15 is particularly noteworthy as cyclometallated Z-selective ruthenium catalysts are

The influence of the cationic carbenes on the initiation kinetics of ruthenium-based metathesis catalysts; a DFT study

• Magdalena Jawiczuk,
• Angelika Janaszkiewicz and
• Bartosz Trzaskowski

Beilstein J. Org. Chem. 2018, 14, 2872–2880, doi:10.3762/bjoc.14.266

• of metathesis results from the high stabilities and efficiencies of Ruthenium catalysts stabilised by NHC moieties. In this class of compounds NHC ligands, with the poor π-acceptor and strong σ-donor properties, stabilize the 14-electron ruthenium active species during the catalytic cycle [11][12

• assess the need to use the D3 correction we have performed additional benchmark calculations for selected ruthenium catalysts and compared them with the experimental data. Based on these results we decided to use the D3 correction in the estimation of all Gibbs free energies apart from the Grubbs-like

Synthesis of a tyrosinase inhibitor by consecutive ethenolysis and cross-metathesis of crude cashew nutshell liquid

• Jacqueline Pollini,
• Valentina Bragoni and
• Lukas J. Gooßen

Beilstein J. Org. Chem. 2018, 14, 2737–2744, doi:10.3762/bjoc.14.252

• Supporting Information File 1). In principle, these internal olefins can still undergo metathesis albeit with less activity, depending on the catalyst. It was possible to reduce the time of the reaction to 6 h with almost the same yield (Table 1, entry 11). We investigated various ruthenium catalysts in

Domino ring-opening–ring-closing enyne metathesis vs enyne metathesis of norbornene derivatives with alkynyl side chains. Construction of condensed polycarbocycles

• Ritabrata Datta and
• Subrata Ghosh

Beilstein J. Org. Chem. 2018, 14, 2708–2714, doi:10.3762/bjoc.14.248

• metathesis; natural products; polycarbocycles; Introduction The metathesis of norbornene derivatives having an alkene side-chain on the norbornene nucleus with Grubbs’ ruthenium catalysts has been extensively investigated. Generally the reaction proceeds through a domino process involving a ring opening of

Oxidative dehydrogenation of C–C and C–N bonds: A convenient approach to access diverse (dihydro)heteroaromatic compounds

• Santanu Hati,
• Ulrike Holzgrabe and
• Subhabrata Sen

Beilstein J. Org. Chem. 2017, 13, 1670–1692, doi:10.3762/bjoc.13.162

• (Scheme 24). Ruthenium catalysts have also been used under aerobic conditions for oxidative dehydrogenation of heterocycles. For example Lingayya et al. demonstrated that ruthenium chloride (p-cumene)2 [RuCl2(p-cumene)2] catalyzed tandem reaction involving oxidative dehydrogenation, cross coupling and

Chemoselective synthesis of diaryl disulfides via a visible light-mediated coupling of arenediazonium tetrafluoroborates and CS₂

• Jing Leng,
• Shi-Meng Wang and
• Hua-Li Qin

Beilstein J. Org. Chem. 2017, 13, 903–909, doi:10.3762/bjoc.13.91

• -2,2’-bipyridine) [25][26] were used, the product yield of diphenyl disulfide (3a) was much lower compared to reactions performed in the presence of ruthenium catalysts (Table 3, entries 9–11). A plausible reaction mechanism has been proposed and is depicted in Scheme 2. We envision that the phenyl

Synthesis of 1-indanones with a broad range of biological activity

• Marika Turek,
• Dorota Szczęsna,
• Marek Koprowski and
• Piotr Bałczewski

Beilstein J. Org. Chem. 2017, 13, 451–494, doi:10.3762/bjoc.13.48

Palladium-catalyzed ring-opening reactions of cyclopropanated 7-oxabenzonorbornadiene with alcohols

• Katrina Tait,
• Oday Alrifai,
• Rebecca Boutin,
• Jamie Haner and
• William Tam

Beilstein J. Org. Chem. 2016, 12, 2189–2196, doi:10.3762/bjoc.12.209

• heteroatomic nucleophiles [23][24], or when ruthenium catalysts are used with alcohol nucleophiles [25]. Furthermore, unsubstituted dihydronaphthalenols 7 can be obtained through the reductive ring opening of oxabicyclic alkene 1 with hydride nucleophiles [26]. These intermediates find synthetic uses in the

NeoPHOX – a structurally tunable ligand system for asymmetric catalysis

• Jaroslav Padevět,
• Marcus G. Schrems,
• Robin Scheil and
• Andreas Pfaltz

Beilstein J. Org. Chem. 2016, 12, 1185–1195, doi:10.3762/bjoc.12.114

• as a widely used privileged ligand class [4][5][6][7][8][9][10][11][12]. One of the major areas of application of PHOX and related N,P ligands is the iridium-catalyzed asymmetric hydrogenation [13][14][15][16]. Compared to rhodium and ruthenium catalysts, iridium complexes derived from chiral N,P

Effective immobilisation of a metathesis catalyst bearing an ammonium-tagged NHC ligand on various solid supports

• Krzysztof Skowerski,
• Jacek Białecki,
• Stefan J. Czarnocki,
• Karolina Żukowska and
• Karol Grela

Beilstein J. Org. Chem. 2016, 12, 5–15, doi:10.3762/bjoc.12.2

• the need for sophisticated linkers and tags, is significantly more complicated. Several protocols were developed for heterogenisation of ruthenium catalysts and this topic has been thoroughly reviewed [8][9][10][11][12][13][14][15][16][17][18]. The implementation of such concepts requires the presence

New metathesis catalyst bearing chromanyl moieties at the N-heterocyclic carbene ligand

• Agnieszka Hryniewicka,
• Szymon Suchodolski,
• Agnieszka Wojtkielewicz,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 2795–2804, doi:10.3762/bjoc.11.300

• ruthenium catalysts. Selected ruthenium metathesis catalyst bearing chromanyl moieties. π-Complex and rutenacyclobutane intermediate with a five-membered ring chelate. Numbering of carbon atoms in the chromanyl moiety. Synthesis of the new NHC precursor. Reagents and conditions: a) HNO3, CH2Cl2, 0 °C, 58

Beyond catalyst deactivation: cross-metathesis involving olefins containing N-heteroaromatics

• Kevin Lafaye,
• Cyril Bosset,
• Lionel Nicolas,
• Amandine Guérinot and
• Janine Cossy

Beilstein J. Org. Chem. 2015, 11, 2223–2241, doi:10.3762/bjoc.11.241

• especially as a simple chlorine substituent is sufficient to allow the metathesis to proceed (Table 5). Conclusion N-Heteroaromatics are known to have a deleterious impact on metathesis by inducing ruthenium catalysts deactivation. Based on NMR and kinetic mechanistic studies, Lewis and/or Brønsted basicity

• , particularly for industrial purposes. Some ruthenium catalysts for metathesis reactions. Decomposition of methylidenes 1 and 2. Deactivation of G-HII in the presence of ethylene. Reaction between GI/GII and n-BuNH2. Reaction of GII with amines a–d. Amine-induced decomposition of GII methylidene 2. Amine

Olefin metathesis in air

• Lorenzo Piola,
• Fady Nahra and
• Steven P. Nolan

Beilstein J. Org. Chem. 2015, 11, 2038–2056, doi:10.3762/bjoc.11.221

• hopefully raise the awareness of the significant tolerance of standard metathesis catalysts to these conditions. Review Well-defined ruthenium catalysts Although well-defined early transition metal-based catalysts formed the basis of early metathesis reactions and can be thought of as the forefathers of

Stereochemistry of ring-opening/cross metathesis reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-ene-2-carbonitriles with allyl alcohol and allyl acetate

• Piotr Wałejko,
• Michał Dąbrowski,
• Lech Szczepaniak,
• Jacek W. Morzycki and
• Stanisław Witkowski

Beilstein J. Org. Chem. 2015, 11, 1893–1901, doi:10.3762/bjoc.11.204

• ROCM reactions of exo- and endo-7-oxabicyclo[2.2.1]hept-5-en-2-carbonitrile (1 and 2, respectively) with allyl acetate (3) or allyl alcohol (4) catalyzed by several commercially available ruthenium catalysts ([Ru]1–6, Figure 1). To the best of our knowledge there is no example of a ROCM reaction of 7

• . Furthermore, less complex mixtures of products were formed and they were easier to separate from the ROMP products. 7-Oxanorbornenes 1 and 2 were treated with olefin 3 or 4 in the presence of ruthenium catalysts [Ru]1–6 (Figure 1) to afford mixtures of tetrahydrofurans 5–12 (Scheme 2). The mixtures were

Cross metathesis of unsaturated epoxides for the synthesis of polyfunctional building blocks

• Meriem K. Abderrezak,
• Kristýna Šichová,
• Nancy Dominguez-Boblett,
• Antoine Dupé,
• Zahia Kabouche,
• Christian Bruneau and
• Cédric Fischmeister

Beilstein J. Org. Chem. 2015, 11, 1876–1880, doi:10.3762/bjoc.11.201

• cross metathesis of 1 with methyl acrylate was transformed by means of nucleophilic ring-opening of the epoxide to furnish a diol, an alkoxy alcohol and an amino alcohol in high yields. Keywords: cross metathesis; epoxide; ruthenium catalysts; tandem reactions; Introduction Catalytic carbon–carbon

A comprehensive study of olefin metathesis catalyzed by Ru-based catalysts

• Albert Poater and
• Luigi Cavallo

Beilstein J. Org. Chem. 2015, 11, 1767–1780, doi:10.3762/bjoc.11.192

• . Possible side or bottom mechanism of the insertion of the olefin. Ruthenium catalysts, bottom-bound (a) or side-bound (b and c). Studied systems. Binding energy, in kcal/mol, of the first, E1, and of the second, E2, pyridine/PMe3 molecule to the naked 14e species 1–13. Energies (E) in kcal/mol, of the