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

• Daniel S. Muller Olivier Basle Marc Mauduit Univ. Rennes, Ecole Nationale Supérieure de Chimie de Rennes, CNRS, ISCR – UMR 6226, F-35000 Rennes, France 10.3762/bjoc.14.279 Abstract Stereoretentive olefin metathesis based on ruthenium dithiolate complexes has become a very active field of research

• within the past years. This unique catalyst class is able to kinetically produce both Z- and E-alkenes in high stereochemical purity (typically >95:5) starting from stereochemically pure Z- or E-alkenes. The aim of this tutorial review is to organize the reported information concerning ruthenium

• dithiolate catalysts in a logic manner, thus providing an "operators handbook" for chemists who wish to apply this methodology in synthesis. Keywords: catalysis; olefin metathesis; ruthenium; stereoretentive; Review 1 Catalyst discovery and structure optimization from 2013–2018 In stereoretentive

Ring-closing-metathesis-based synthesis of annellated coumarins from 8-allylcoumarins

• Christiane Schultze and
• Bernd Schmidt

Beilstein J. Org. Chem. 2018, 14, 2991–2998, doi:10.3762/bjoc.14.278

• metathesis; ruthenium; Introduction Naturally occurring coumarins and synthetic derivatives have attracted considerable attention, because many of these compounds are pharmacologically active [1][2][3][4]. Their activity profiles are quite diverse and range from anticoagulant via anti-infective, anticancer

The activity of indenylidene derivatives in olefin metathesis catalysts

• Maria Voccia,
• Steven P. Nolan,
• Luigi Cavallo and
• Albert Poater

Beilstein J. Org. Chem. 2018, 14, 2956–2963, doi:10.3762/bjoc.14.275

• ] developed well-defined homogeneous catalysts that the area truly blossomed. Using a metal carbene complex as a catalyst, making use of the Chauvin mechanism, olefin metathesis consists of the redistribution of two carbon–carbon double bonds [9]. The metal and its ligand environment in both ruthenium and

• molybdenum systems appear to confer the right environment that allows a productive alkene metathesis [10][11]. Little productive reactivity has been uncovered using other metals [12][13][14]. Apart from the metal, ruthenium-based olefin metathesis has seen several changes during the last decades, modifying

• modification of the available catalysts has been performed in order to increase the stability of the catalyst without losing any of its activity [19][20]. Although most of the olefin metathesis catalysts are based on ruthenium [21][22], because these are more stable to oxygen and moisture [23] than their

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

• a number of challenging catalytic reactions. In ruthenium-based metathesis catalysis they are often used as ammonium tags, to provide water-soluble, environment-friendly catalysts. In this work we performed computational studies on three cationic carbenes with the formal positive charge located at

• 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

• catalysts the ammonium tag is relatively far from the carbene carbon atom chelating the ruthenium core. The reason behind such design was likely the low probability of the ammonium tag influencing the ruthenium core and therefore, having a potential negative effect on the efficiency and reaction rate of the

Olefin metathesis catalysts embedded in β-barrel proteins: creating artificial metalloproteins for olefin metathesis

• Daniel F. Sauer,
• Johannes Schiffels,
• Takashi Hayashi,
• Ulrich Schwaneberg and
• Jun Okuda

Beilstein J. Org. Chem. 2018, 14, 2861–2871, doi:10.3762/bjoc.14.265

• and challenges and opportunities in this emerging field are shown from simple small-molecule transformations over ring-opening metathesis polymerizations to in vivo olefin metathesis. Keywords: artificial metalloprotein; β-barrel protein; metathease; olefin metathesis; ruthenium; Introduction Olefin

• three-fold increase in ruthenium content as compared to cells lacking the Sav variant (80,000 Ru atoms per cell and 29,000 Ru atoms per cell, respectively) [47]. This system was subjected to directed evolution. The twenty amino acid positions closest to the active site were saturated, and the best

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

• , undergoes smooth ethenolysis only in dichloromethane as the solvent (Scheme 3). Using more sustainable solvents or no solvent at all, the reaction gave almost no turnover, regardless of the ruthenium catalyst employed. However, as a 1.1 M solution in dichloromethane, the unsaturated components of CNSL were

• 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

• insignificantly better yields (Table 1, entry 18). It is known that ruthenium metathesis catalysts can be transformed in situ into an active hydrogenation catalyst [37][38]. We, thus added charcoal and methanol to the crude reaction mixture of the cross-metathesis and stirred the reaction for additional 2 h under

Photocatalyic Appel reaction enabled by copper-based complexes in continuous flow

• Clémentine Minozzi,
• Jean-Christophe Grenier-Petel,
• Shawn Parisien-Collette and
• Shawn K. Collins

Beilstein J. Org. Chem. 2018, 14, 2730–2736, doi:10.3762/bjoc.14.251

• promote the alcohol→halide conversion using low catalyst loadings of a ruthenium-based catalyst (Ru(bpy)3Cl2, 1 mol %) in the absence of PPh3 as a reductant (Figure 1) [8]. The method possesses numerous advantages (wide functional group tolerance, no formation of oxidized phosphine byproducts [9][10][11

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

• Ritabrata Datta Subrata Ghosh School of Chemical Sciences, Indian Association for the Cultivation of Science, Jadavpur, Kolkata 700 032, India 10.3762/bjoc.14.248 Abstract The metathesis of norbornene derivatives with alkynyl side-chain with Grubbs’ ruthenium alkylidine as catalyst has been

• 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

• ether 7a in 92% yield. Two different paths can be invoked for metathesis of compound 7a. Metathesis initiation may occur by attack of the ruthenium alkylidene at the alkyne unit to produce the more substituted vinyl alkylidine intermediate 8a which may undergo concomitant ROM–RCM with the norbornene

Ring-opening metathesis of some strained bicyclic systems; stereocontrolled access to diolefinated saturated heterocycles with multiple stereogenic centers

• Zsanett Benke,
• Melinda Nonn,
• Márton Kardos,
• Santos Fustero and
• Loránd Kiss

Beilstein J. Org. Chem. 2018, 14, 2698–2707, doi:10.3762/bjoc.14.247

• Orgánica, Facultad de Farmàcia, Universidad de Valencia, Av. Vicente Andrés Estellés, s/n 46100 Valencia, Spain 10.3762/bjoc.14.247 Abstract Ring-opening metathesis (ROM) of various unsaturated, constrained bicyclic ring systems has been investigated with the use of commercial ruthenium-based catalysts

• opening of the heteroring, (Scheme 7). The process involves isomerization through olefin bond migration proceeding Z-selectively. Conclusion The ring-opening metathesis (ROM) of some ring-constrained, unsaturated bicyclic frameworks has been studied in the presence of commercially available ruthenium

Design and synthesis of C₃-symmetric molecules bearing propellane moieties via cyclotrimerization and a ring-closing metathesis sequence

• Sambasivarao Kotha,
• Saidulu Todeti and
• Vikas R. Aswar

Beilstein J. Org. Chem. 2018, 14, 2537–2544, doi:10.3762/bjoc.14.230

• considered an alternate route to synthesize compound 12. In this regard, we employed different ruthenium-based catalysts (Figure 2) and reaction conditions to obtain the ring-opening metathesis (ROM) product 13 from norbornene derivate 10. Under these conditions the starting material was not consumed

• of ruthenium-based catalysts used for ROM. Synthesis of the star-shaped norbornene derivative 11 via trimerization. Synthesis of the C3-symmetric molecule 15 bearing propellane moieties via trimerization and RCM. Synthesis of C3-symmetric molecule 21 bearing propellane moieties via trimerization and

Synthesis of dihydroquinazolines from 2-aminobenzylamine: N³-aryl derivatives with electron-withdrawing groups

• Nadia Gruber,
• Jimena E. Díaz and
• Liliana R. Orelli

Beilstein J. Org. Chem. 2018, 14, 2510–2519, doi:10.3762/bjoc.14.227

• , some ruthenium complexes bearing a 3,4-dihydroquinazoline ligand have been studied as hydrogenation-transfer catalysts, showing good to excellent activity for the reduction of ketones [17]. In the context of our research on heterocyclic amidine N-oxides [18][19][20][21][22], we recently prepared some

Synergistic approach to polycycles through Suzuki–Miyaura cross coupling and metathesis as key steps

• Sambasivarao Kotha,
• Milind Meshram and
• Chandravathi Chakkapalli

Beilstein J. Org. Chem. 2018, 14, 2468–2481, doi:10.3762/bjoc.14.223

• and ruthenium impurities in minor amounts from the reaction mixture. This aspect is also important in the pharmaceutical industry [4][55]. Biography of the Authors Sambasivarao Kotha graduated with M.Sc. degree in Chemistry from the University of Hyderabad and obtained his Ph.D. in Organic Chemistry

Bioinspired cobalt cubanes with tunable redox potentials for photocatalytic water oxidation and CO₂ reduction

• Zhishan Luo,
• Yidong Hou,
• Jinshui Zhang,
• Sibo Wang and
• Xinchen Wang

Beilstein J. Org. Chem. 2018, 14, 2331–2339, doi:10.3762/bjoc.14.208

• . Besides the CO2 reduction performance of the molecular complexes was evaluated by cooperation with a ruthenium photosensitizer Ru(bpy)32+ (bpy = 2’,2-bipyridine) with visible light irradiation [61][62][63][64][65][66][67]. As shown in Figure 5b, the activity of the CO2 reaction is reduced with the

Coordination-driven self-assembly of discrete Ru₆–Pt₆ prismatic cages

• Aderonke Ajibola Adeyemo and
• Partha Sarathi Mukherjee

Beilstein J. Org. Chem. 2018, 14, 2242–2249, doi:10.3762/bjoc.14.199

• –ruthenium(II) clips (1a(NO3)2 and 1b(NO3)2) and a tritopic platinum(II) metalloligand 2 has been performed in methanol at room temperature. The [3 + 2] hexanuclear cages 3a and 3b were isolated in good yields and characterized by well-known spectroscopic techniques including multinuclear NMR, mass

• spectrometry, UV–vis and infrared studies. Geometry optimization revealed the shapes and sizes of these hexanuclear prismatic cages. The combination of ruthenium and platinum metal center in a one-pot self-assembly reaction showcases the construction of aesthetically elegant heterometallic structures in

• supramolecular chemistry leading to the formation of a single major product. Keywords: arene–ruthenium(II); heterometallic cages; platinum metalloligand; self-assembly; supramolecular architectures; Introduction Coordination-driven self-assembly of discrete architectures has evolved as a unique protocol to

Coordination-driven self-assembly vs dynamic covalent chemistry: versatile methods for the synthesis of molecular metallarectangles

• Li-Li Ma,
• Jia-Qin Han,
• Wei-Guo Jia and
• Ying-Feng Han

Beilstein J. Org. Chem. 2018, 14, 2027–2034, doi:10.3762/bjoc.14.178

• cages based on half-sandwich ruthenium could be obtained in one-pot reactions from simple building blocks [38][39]. This finding prompted us to investigate whether condensation reactions between amines and 4-formylpyridine can be used simultaneously with coordination bond formation to construct

Graphitic carbon nitride prepared from urea as a photocatalyst for visible-light carbon dioxide reduction with the aid of a mononuclear ruthenium(II) complex

• Kazuhiko Maeda,
• Daehyeon An,
• Ryo Kuriki,
• Daling Lu and
• Osamu Ishitani

Beilstein J. Org. Chem. 2018, 14, 1806–1812, doi:10.3762/bjoc.14.153

• filtrates were collected and concentrated to a volume of 30 mL. The amount of the ruthenium complex absorbed was calculated based on the UV–vis spectrum of the filtrate, using Equation 1: where Abefore and Aafter are the absorbance of the solution before and after the adsorption procedure, respectively, and

Synthesis and photophysical studies of a multivalent photoreactive Ru^II-calix[4]arene complex bearing RGD-containing cyclopentapeptides

• Sofia Kajouj,
• Lionel Marcelis,
• Alice Mattiuzzi,
• Adrien Grassin,
• Damien Dufour,
• Pierre Van Antwerpen,
• Didier Boturyn,
• Eric Defrancq,
• Mathieu Surin,
• Julien De Winter,
• Pascal Gerbaux,
• Ivan Jabin and
• Cécile Moucheron

Beilstein J. Org. Chem. 2018, 14, 1758–1768, doi:10.3762/bjoc.14.150

• 10.3762/bjoc.14.150 Abstract Photoactive ruthenium-based complexes are actively studied for their biological applications as potential theragnostic agents against cancer. One major issue of these inorganic complexes is to penetrate inside cells in order to fulfil their function, either sensing the

• internal cell environment or exert a photocytotoxic activity. The use of lipophilic ligands allows the corresponding ruthenium complexes to passively diffuse inside cells but limits their structural and photophysical properties. Moreover, this strategy does not provide any cell selectivity. This limitation

• is also faced by complexes anchored on cell-penetrating peptides. In order to provide a selective cell targeting, we developed a multivalent system composed of a photoreactive ruthenium(II) complex tethered to a calix[4]arene platform bearing multiple RGD-containing cyclopentapeptides. Extensive

Cobalt-catalyzed C–H cyanations: Insights into the reaction mechanism and the role of London dispersion

• Eric Detmar,
• Valentin Müller,
• Daniel Zell,
• Lutz Ackermann and
• Martin Breugst

Beilstein J. Org. Chem. 2018, 14, 1537–1545, doi:10.3762/bjoc.14.130

• ][10][11], London dispersion can also play a crucial role in different transition-metal-catalyzed reactions [12][13][14][15][16][17]. The C–H-rich di-1-adamantylphosphine oxide – a typical dispersion element – was experimentally found to be an excellent preligand for ruthenium- and palladium-catalyzed

• a step-wise fashion. A similar mechanism has previously been described by McMullin, Williams, and Frost [38], as well as by Ackermann [39][40] for ruthenium-catalyzed C–H alkenylations. In the first transition state (TS1a, Figure 2), the κ2-coordination of the acetate ligand changes to a κ1

Hypervalent organoiodine compounds: from reagents to valuable building blocks in synthesis

• Gwendal Grelier,
• Benjamin Darses and
• Philippe Dauban

Beilstein J. Org. Chem. 2018, 14, 1508–1528, doi:10.3762/bjoc.14.128

• of aryl iodide. The latter is then used for a sequential ruthenium-catalyzed ortho-C–H functionalization directed by the pyrazole group (Scheme 37) [76]. Starting from non-symmetrical diaryl-λ3-iodanes, the electron-poorest or more sterically hindered aromatic group is first transferred to the 3,5

Atom-economical group-transfer reactions with hypervalent iodine compounds

• Andreas Boelke,
• Peter Finkbeiner and
• Boris J. Nachtsheim

Beilstein J. Org. Chem. 2018, 14, 1263–1280, doi:10.3762/bjoc.14.108

• atom-economical biphenylation of N-heterocycles was developed [33]. This method involved a direct N-arylation of pyrazoles or triazoles 12 under basic conditions, followed by a ruthenium-catalysed C–H arylation with the emerging aryl iodide (Scheme 8). Due to the fact that the first step of this

An overview of recent advances in duplex DNA recognition by small molecules

• Sayantan Bhaduri,
• Nihar Ranjan and
• Dev P. Arya

Beilstein J. Org. Chem. 2018, 14, 1051–1086, doi:10.3762/bjoc.14.93

Synthesis and stability of strongly acidic benzamide derivatives

• Frederik Diness,
• Niels J. Bjerrum and
• Mikael Begtrup

Beilstein J. Org. Chem. 2018, 14, 523–530, doi:10.3762/bjoc.14.38

• in a ruthenium-catalyzed C–H activation reaction [36]. Most other reported transformations pass via the imidoyl chloride intermediates (equivalent to 10) to the amidine derivatives, which have been used in rearrangement reaction studies [9][37][38][39]. By these means also N,N’-bis(triflyl

Acid-catalyzed ring-opening reactions of a cyclopropanated 3-aza-2-oxabicyclo[2.2.1]hept-5-ene with alcohols

• Katrina Tait,
• Alysia Horvath,
• Nicolas Blanchard and
• William Tam

Beilstein J. Org. Chem. 2017, 13, 2888–2894, doi:10.3762/bjoc.13.281

• includes the reduction to form alkane 8 [3], oxidative cleavage of the C=C bond to form 9 [4], ring-opening metathesis to form functionalized alkenes 10 and 11 [4], dihydroxylation to form diol 12 [5], ruthenium-catalyzed [2 + 2] cycloaddition with unsymmetrical alkynes to form regioisomers 13 and 14 [6

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

•  25). Although the regioselectivity of the reaction was overall excellent for heteroarenes, it proved to be less satisfying for substituted arenes. Further investigations allowed the authors to propose a detailed mechanism, represented in Scheme 25. After excitation of the ruthenium catalyst through

• reagent indissociable from major achievements in the field of trifluoromethylation. Indeed, early discoveries by Kamigata in the nineties using ruthenium catalysis and, more recently in 2011, by MacMillan using photoredox catalysis for the direct trifluoromethylation of the inherently reactive positions

Synthesis and supramolecular properties of regioisomers of mononaphthylallyl derivatives of γ-cyclodextrin

• Markéta Bláhová,
• Sergey K. Filippov,
• Lubomír Kováčik,
• Jiří Horský,
• Simona Hybelbauerová,
• Zdenka Syrová,
• Tomáš Křížek and
• Jindřich Jindřich

Beilstein J. Org. Chem. 2017, 13, 2509–2520, doi:10.3762/bjoc.13.248

• starting material. After the deprotection, a substantial amount of the pure γ-CD was isolated as the only byproduct containing CD. Apparently, a concurrent reaction – the cleavage of allyl ether – also took place. The use of similar ruthenium complexes as catalysts for the cleavage of allyl ethers and