- Synthesis and Application of Stereoretentive Ruthenium Catalysts on the Basis of the M7 and the Ru-Benzylidene-Oxazinone Design
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A series of new stereoretentive ruthenium catalysts bearing the dithiocatecholate ligand was synthesiszed on the basis of the M7 and Ru-benzylidene-oxazinone design. The activity of the catalysts was tested in ring-opening cross-metathesis reactions, ring
- Dumas, Adrien,Müller, Daniel S.,Curbet, Idriss,Toupet, Lo?c,Rouen, Mathieu,Baslé, Olivier,Mauduit, Marc
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- Ruthenabenzene: A Robust Precatalyst
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Metallaaromatics constitute a unique class of aromatic compounds where one or more transition metal elements are incorporated into the aromatic system, the parent of which is metallabenzene. One of the main concerns about metallabenzenes generally deals with the structural characterization related to their relative aromaticity compared to the carbon archetype. Transition metal-containing metallabenzenes are also implicated in certain catalytic processes such as alkyne metathesis polymerization; however, these transition metal-based metallaaromatic compounds have not been developed as a catalyst. Herein, we describe an effective strategy to generate diverse arrays of ruthenabenzenes and demonstrated them as an aromatic equivalent of the Grubbs-type ruthenium alkylidene catalysts. These ruthenabenzenes can be prepared via an enyne metathesis and metallotropic [1,3]-shift cascade process to form alkyne-chelated ruthenium alkylidene intermediates followed by spontaneous cycloaromatization. The aromatic nature of these complexes was confirmed by spectroscopic and X-ray crystallographic data, and the mechanistic pathways for the cycloaromatization process were studied by DFT calculations. These ruthenabenzenes display robust catalytic activity for metathesis and other transformations, which illustrates that metallabenzenes are not only compounds of structural and theoretical interests but also are a novel platform for new catalyst development.
- Gupta, Saswata,Su, Siyuan,Zhang, Yu,Liu, Peng,Wink, Donald J.,Lee, Daesung
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supporting information
p. 7490 - 7500
(2021/05/26)
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- Activated Hoveyda-Grubbs Olefin Metathesis Catalysts Derived from a Large Scale Produced Pharmaceutical Intermediate – Sildenafil Aldehyde
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Two EWG-activated Hoveyda-Grubbs-type ruthenium complexes (Sil-II and Sil-II’) were obtained, characterized, and screened in a set of olefin metathesis reactions. These catalysts were conveniently synthesized from a commercially available pharmaceutical building block – Sildenafil aldehyde – in two steps only. Stability and catalytic activity tests disclosed that the bulkier NHC-ligand bearing catalyst Sil-II’ is visibly more stable and productive than its smaller NHC-analogue Sil-II. Good application profile of catalyst Sil-II’ was confirmed in a set of diverse metathesis reactions including ring-closing metathesis (RCM) and cross-metathesis (CM) of complex polyfunctional substrates of medicinal chemistry interest, including a challenging macrocyclization of the Pacritinib precursor. Compatibility of the new catalyst with various green solvents was checked and metathesis of Sildenafil and Tadalafil-based substrates was successfully conducted in acetone. The mechanism of Sil-II’ initiation has been investigated through kinetic experiments unveiling that the decrease of the steric hindrance of the chelating alkoxy moiety (from iPrO to EtO) favors the interchange initiation pathway over the typical dissociation pathway for other popular 2nd generation Hoveyda-Grubbs catalysts. (Figure presented.).
- Monsigny, Louis,Pi?tkowski, Jakub,Trzybiński, Damian,Wo?niak, Krzysztof,Niena?towski, Tomasz,Kajetanowicz, Anna,Grela, Karol
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supporting information
p. 4590 - 4604
(2021/08/13)
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- Stable CAAC-based Ruthenium Complexes for Dynamic Olefin Metathesis Under Mild Conditions
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A series of olefin metathesis catalysts bearing cyclic (alkyl)(amino)carbene (CAAC) ligands of varying size and steric demand has been synthesized and evaluated in ring-closing-, self-, and cross-metathesis reactions at room temperature. The catalysts were also probed for potential applications in dynamic covalent chemistry. The majority of the catalysts showed high stability, and remained active in the reaction mixtures for several days, including in methanol-based solutions. Higher temperatures could be used to control the reactivity towards sterically challenging substrates, enabling formation of tetrasubstituted olefins. The CAAC complexes exhibited remarkable functional group tolerance towards heteroaromatic and nucleophilic additives, making them potentially useful in the screening of biologically active compounds.
- Biedermann, Maurice,Inge, A. Ken,Kravchenko, Alexander,Ramstr?m, Olof,Timmer, Brian J. J.
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p. 4841 - 4847
(2021/10/14)
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- A Fluorescence-Based High-Throughput Screening Method for Olefin Metathesis Using a Ratiometric Fluorescent Probe
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(Z)-1,8-Di(pyren-1-yl)oct-4-ene (1) was prepared as a probe for olefin metathesis. The conversions of substrate by olefin metathesis under various conditions were calculated using the ratiometric fluorescence intensity change of 1. The conversions calcula
- Noh, Hyeongju,Lim, Taeho,Park, Byoung Yong,Han, Min Su
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supporting information
p. 1703 - 1708
(2020/01/02)
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- In a Quest for Selectivity Paired with Activity: A Ruthenium Olefin Metathesis Catalyst Bearing an Unsymmetrical Phenanthrene-Based N-Heterocyclic Carbene
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Robust, selective, and stable in the presence of ethylene, ruthenium olefin metathesis pre-catalyst, {[3-benzyl-1-(10-phenyl-9-phenanthryl)]-2-imidazolidinylidene}dichloro(o-isopropoxyphenylmethylene)ruthenium(II), Ru-3, bearing an unsymetrical N-heterocyclic carbene (uNHC) ligand, has been synthesized. The initiation rate of Ru-3 was examined by ring-closing metathesis and cross-metathesis reactions with a broad spectrum of olefins, showing an unprecendented selectivity. It was also tested in industrially relevant ethenolysis reactions of olefinic substrates from renewable feedstock with very good yields and selectivities.
- D?browski, Micha?,Grela, Karol,Trzybiński, Damian,Wo?niak, Krzysztof,Wyr?bek, Przemys?aw
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supporting information
(2020/03/19)
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- Compositions And Methods For Visible-Light-Controlled Ruthenium-Catalyzed Olefin Metathesis
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The present disclosure provides compositions and methods for metathesizing a first alkenyl or alkynyl group with a second alkenyl or alkynyl group, the composition comprising a ruthenium metathesis catalyst and a photoredox catalyst that is activated by v
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Paragraph 0172-0173; 0222-0223; 0235; 0238
(2020/04/29)
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- High-throughput screening method of olefin metathesis reaction using pyrene derivatives
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The present invention relates to a novel pyrene derivative, a screening composition for olefin metathesis reaction comprising the pyrene derivative, a screening method for olefin metathesis reaction using the pyrene derivative, and a catalyst sorting meth
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Paragraph 0173-0206
(2020/03/24)
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- Specialized ruthenium olefin metathesis catalysts bearing bulky unsymmetrical NHC Ligands: Computations, synthesis, and application
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Second-generation ruthenium olefin metathesis catalysts were investigated with systematic variation of the unsymmetrical uNHC ligands. Depending on the uNHC steric bulk, the catalysts exhibited different activity and selectivity in metathesis reactions. DFT calculations and X-ray crystallographic data were used to understand the influence of uNHC ligand structure on the catalyst properties. Furthermore, the catalysts were examined in the context of reactions that are problematic for general-purpose Ru catalysts, including industrially important self-cross metathesis of α-olefins and ethenolysis of ethyl oleate.
- Ma?ecki, Pawe?,Gajda, Katarzyna,Gajda, Roman,Wo?niak, Krzysztof,Trzaskowski, Bartosz,Kajetanowicz, Anna,Grela, Karol
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p. 587 - 598
(2019/01/08)
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- Visible-Light-Controlled Ruthenium-Catalyzed Olefin Metathesis
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Olefin metathesis is now one of the most efficient ways to create new carbon-carbon bonds. While most efforts focused on the development of ever-more efficient catalysts, a particular attention has recently been devoted to developing latent metathesis cat
- Theunissen, Cédric,Ashley, Melissa A.,Rovis, Tomislav
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supporting information
(2019/05/08)
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- New olefin metathesis catalyst bearing N-mesitylimidazole and nitrate ligands – Synthesis, activity, and performance in aqueous media
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A new 18-electron ruthenium complex, where ruthenium catalytic center is coordinated with the N-mesitylimidazole and nitrate ligands, as well as o-isopropoxystyrene moiety, is reported. The synthesis and detailed characterization of the Ru complex, togeth
- Malinowska, Marta,Kozlowska, Mariana,Hryniewicka, Agnieszka,Morzycki, Jacek W.
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p. 154 - 161
(2019/06/24)
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- Visible-Light-Controlled Ruthenium-Catalyzed Olefin Metathesis
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Olefin metathesis is now one of the most efficient ways to create new carbon-carbon bonds. While most efforts focused on the development of ever-more efficient catalysts, a particular attention has recently been devoted to developing latent metathesis cat
- Theunissen, Cédric,Ashley, Melissa A.,Rovis, Tomislav
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supporting information
p. 6791 - 6796
(2019/05/10)
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- Ethyl Lactate: A Green Solvent for Olefin Metathesis
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Compatibility of selected, commercially available ruthenium olefin metathesis catalysts with ethyl lactate as solvent was evaluated using a range of substrates and conditions. In addition, the preparation of a metathesis catalyst in simplified manner by u
- Planer, Sebastian,Jana, Anupam,Grela, Karol
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p. 4655 - 4661
(2019/10/28)
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- Light-and Thermal-Activated Olefin Metathesis of Hindered Substrates
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Efficient light-and thermal-Activated metathesis reactions of tetra-substituted olefins were obtained by the S-chelated ruthenium precatalyst Tol-SCF3. Its reactivity in a series of benchmark olefin metathesis reactions was compared to previous
- Ivry, Elisa,Frenklah, Alexander,Ginzburg, Yakov,Levin, Efrat,Goldberg, Israel,Kozuch, Sebastian,Lemcoff, N. Gabriel,Tzur, Eyal
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p. 176 - 181
(2018/02/06)
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- A versatile and highly Z -Selective olefin metathesis ruthenium catalyst based on a readily accessible N -heterocyclic carbene
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A ruthenium catalyst for Z-selective olefin metathesis has been synthesized from a readily accessible N-heterocyclic carbene (NHC) ligand that is prepared using an efficient, practical, and scalable multicomponent synthesis. The desired ruthenium complex
- Dumas, Adrien,Tarrieu, Robert,Vives, Thomas,Roisnel, Thierry,Dorcet, Vincent,Baslé, Olivier,Mauduit, Marc
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p. 3257 - 3262
(2018/04/14)
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- Stereoretentive Olefin Metathesis Made Easy: In Situ Generation of Highly Selective Ruthenium Catalysts from Commercial Starting Materials
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The in situ preparation of highly stereoretentive ruthenium-based metathesis catalysts is reported. This approach completely avoids the isolation of intermediates and air-sensitive catalysts, thus allowing for the rapid access and evaluation of numerous dithiolate Ru catalysts. A procedure was established to perform cross-metathesis reactions without the use of a glovebox, and on a small scale even Schlenk techniques are not required. Consequently, the chemistry displayed in this report is available to every practicing organic chemist and presents a powerful approach for the identification of new stereoretentive catalysts.
- Müller, Daniel S.,Curbet, Idriss,Raoul, Yann,Le N?tre, Jér?me,Baslé, Olivier,Mauduit, Marc
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supporting information
p. 6822 - 6826
(2018/10/31)
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- RUTHENIUM COMPLEXES USEFUL FOR CATALYZING METATHESIS REACTIONS
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Compound of formula (4) or formula (5), wherein L is a neutral ligand, preferably a nitrogen-containing heterocyclic carbene (NHC) such as carbene containing at least two nitrogen atoms, a cyclic aminoalkyl carbene (CAAC) or a bicyclic aminoalkyl carbene (BICAAC); R1, R3, R4, R5, R6, R7, R8, R9, R10 and R11 are, independently, H, unbranched or branched C1-20 alkyl, C5-9 cycloalkyl, unbranched or branched C1-20 alkoxy, optionally bearing one or more halogen atoms, respectively; or aryl, optionally substituted with one or more of unbranched or branched C1-20 alkyl, C5-9 cycloalkyl, unbranched or branched C1-20 alkoxy, aryl, aryloxy, unbranched or branched C1-20 alkylcarbonyl, arylcarbonyl, unbranched or branched C1-20 alkoxycarbonyl, aryloxycarbonyl, heteroaryl, carboxyl, cyano, nitro, amido, aminosulfonyl, N-heteroarylsulfonyl, unbranched or branched C1-20 alkylsulfonyl, arylsulfonyl, unbranched or branched C1-20 alkylsulfinyl, arylsulfinyl, unbranched or branched C1-20 alkylthio, arylthio, sulfonamide, halogen or N(Ry)(Rz), wherein Ry and Rz are independently selected from H and C1-20 alkyl: R2 is H, unbranched or branched C1-20 alkyl.
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Paragraph 0098-00100
(2018/05/27)
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- Stable ruthenium olefin metathesis catalysts bearing symmetrical NHC ligands with primary and secondary: N -alkyl groups
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Four novel stable Hoveyda-Grubbs-type catalysts containing N,N′-dineopentyl- and N,N′-dicyclohexyl-substituted N-heterocyclic carbene (NHC) ligands with syn and anti phenyl groups on the ring backbone were synthesized and fully characterized. The catalytic potential of these complexes was investigated in metathesis reactions of both standard and renewable substrates. Compared to the Hoveyda-Grubbs second generation catalyst (HGII), all of the new catalysts showed high performances in most of the examined metathesis transformations. In particular, N,N′-dicyclohexyl catalysts gave improved results in the challenging ring-closing metathesis (RCM) reaction to form tetrasubstituted olefins, while catalysts with neopentyl N-groups were found to be more active and Z-selective in cross-metathesis (CM) reactions. Modest enantioselectivities in the asymmetric ring-closing metathesis (ARCM) of achiral trienes with different steric hindrance were observed in the presence of catalysts bearing chiral C2-symmetric NHC ligands.
- Ambrosio, Chiara,Paradiso, Veronica,Costabile, Chiara,Bertolasi, Valerio,Caruso, Tonino,Grisi, Fabia
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supporting information
p. 6615 - 6627
(2018/05/23)
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- NOVEL RUTHENIUM COMPLEX, METHOD OF ITS PRODUCTION AND ITS USE IN REACTION OF OLEFINE METATHESIS
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The invention relates to novel ruthenium complexes of formula (9). The invention also relates to the method for preparation of novel metal complexes of formula (9) and their use in olefin metathesis reactions.
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Page/Page column 25
(2018/06/22)
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- Helicenes as Chirality-Inducing Groups in Transition-Metal Catalysis: The First Helically Chiral Olefin Metathesis Catalyst
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Helical chirality is a novel enantioselectivity-inducing property in transition-metal-catalyzed transformations. The principle is illustrated herein for the example of asymmetric olefin metathesis. This work reports the synthesis of the first helically chiral Ru-NHC alkylidene complex from an aminohelicene-derived imidazolium salt, which was ligated to the first generation Hoveyda–Grubbs catalyst. Kinetic data were acquired for benchmark test reactions and compared to an achiral catalyst. The helically chiral Ru-catalyst was evaluated in asymmetric ring-closing metathesis (RCM) and ring-opening metathesis–cross-metathesis (ROM/CM) reactions, which proceeded with promising levels of enantioselectivity. Extensive NMR-spectroscopic investigations and a DFT geometry optimization were performed. These results led to a topographic steric map and calculation of percent-buried-volume values for each quadrant around the metal center.
- Karras, Manfred,D?browski, Micha?,Pohl, Radek,Rybá?ek, Ji?í,Vacek, Jaroslav,Bednárová, Lucie,Grela, Karol,Stary, Ivo,Stará, Irena G.,Schmidt, Bernd
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supporting information
p. 10994 - 10998
(2018/07/31)
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- Carbamato-benzylidene ruthenium chelates – Synthesis, structure and catalytic activity in olefin metathesis
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New carbamato-κN-benzylidene ruthenium chelates were synthesized from the first [RuCl2(PCy3)2(=CHPh)] and second [RuCl2(SIMes)(PCy3)(=CHPh)] generation Grubbs catalysts by metathetic exchange of benzylidene ligand for tert-butyl (2-vinylphenyl)carbamates bearing benzylidene ligand substituted in the position para to carbamato functionality with methyl or trifluoromethyl group. In all metathetical transformations tested, i.e. in ROMP of cycloocta-1,5-diene, RCM of diethyl diallylmalonate and diethyl 2-allyl-2-(2-methylallyl)malonate and cross-metathesis of allylbenzene with Z-1,4-diacetoxybut-2-ene, the complexes behave like latent catalysts. Complexes remain completely inactive until they are activated by the addition of ethereal solution of HCl. The presence of the electron-withdrawing group results in a slight increase in the catalytic activity of the activated form of the catalyst relative to a similar form of the unsubstituted complex or the least active complex carrying the electron donating group.
- Rogalski, Szymon,?ak, Patrycja,Pawlu?, Piotr,Kubicki, Maciej,Pietraszuk, Cezary
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- Mild Functionalization of Tetraoxane Derivatives via Olefin Metathesis: Compatibility of Ruthenium Alkylidene Catalysts with Peroxides
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An easy and mild functionalization method of tetraoxane derivatives via olefin metathesis is reported. This reaction offers a new method to afford fully functionalized tetraoxanes in high yields. This method is also utilized in the functionalization of bioactive compounds.
- Jana, Anupam,Grela, Karol
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p. 520 - 523
(2017/02/10)
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- The mechanism of activation of amidobenzylidene ruthenium chelates-latent catalysts of olefin metathesis
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Amidobenzylidene ruthenium chelates-latent catalysts of olefin metathesis can be easily activated by the addition of Br?nsted or Lewis acids. Their activation in the presence of hydrogen chloride involves the formation of catalytically active trans-dichlo
- Rogalski, Szymon,Zak, Patrycja,Tadeuszyk, Natalia,Pyta, Krystian,Przybylski, Piotr,Pietraszuk, Cezary
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supporting information
p. 1277 - 1282
(2017/02/05)
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- Ruthenium Catalysts Supported by Amino-Substituted N-Heterocyclic Carbene Ligands for Olefin Metathesis of Challenging Substrates
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N-Heterocyclic carbene (NHC) ligands IMes (Formula presented.) and IMes (Formula presented.) derived from the well-known IMes ligand by substituting the carbenic heterocycle with one and two dimethylamino groups, respectively, were employed for the synthesis of second-generation Grubbs- and Grubbs–Hoveyda-type ruthenium metathesis precatalysts. Whereas the stability of the complexes was found to depend on the degree of dimethylamino-substitution and on the type of complex, the backbone-substitution was shown to have a positive impact on their catalytic activity in ring-closing metathesis, with a more pronounced effect in the second-generation Grubbs-type series. The new complexes were successfully implemented in a number of challenging olefin metathesis reactions leading to the formation of tetra-substituted C=C double bonds and/or functionalized compounds.
- César, Vincent,Zhang, Yin,Ko?nik, Wioletta,Zieliński, Adam,Rajkiewicz, Adam A.,Ruamps, Mirko,Bastin, Stéphanie,Lugan, No?l,Lavigne, Guy,Grela, Karol
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supporting information
p. 1950 - 1955
(2017/02/15)
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- Hoveyda-Type Quinone-Containing Complexes – Catalysts to Prevent Migration of the Double Bond under Metathesis Conditions
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Three new quinone-containing Hoveyda-type complexes have been synthesised and fully characterised. Their ability to suppress undesired double-bond migration along the carbon chain during metathesis reactions was examined. It was proved that these catalysts decrease the amounts of undesired side-products with a shifted double bond in the reaction mixture.
- Kajetanowicz, Anna,Milewski, Mariusz,Rogińska, Joanna,Gajda, Roman,Wo?niak, Krzysztof
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p. 626 - 638
(2017/02/05)
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- Hoveyda-grubbs-type precatalysts with unsymmetrical N-Heterocyclic carbenes as effective catalysts in olefin metathesis
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In our search for more-selective olefin metathesis catalysts, a series of Hoveyda-Grubbs-type second-generation complexes bearing unsymmetrical N-heterocyclic carbene (NHC) ligands were synthesized and tested in model reactions. It was found that the N-benzyl substituent in NHC has a positive influence on the selectivity of the newly obtained catalysts in the self-metathesis reaction of α-olefins. As expected, a typical relationship between activity and selectivity with respect to the N-aryl substituent used was observed. Dipp-containing complexes exhibited higher stability at elevated temperature, while Mes-bearing complexes typically gave better yields than their Dipp analogues.
- Ma?ecki, Pawe?,Gajda, Katarzyna,Ablialimov, Osman,Malińska, Maura,Gajda, Roman,Wo?niak, Krzysztof,Kajetanowicz, Anna,Grela, Karol
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p. 2153 - 2166
(2017/06/19)
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- Hoveyda-Grubbs catalyst analogues bearing the derivatives of: N -phenylpyrrol in the carbene ligand-structure, stability, activity and unique ruthenium-phenyl interactions
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We have synthesized a series of N-phenylpyrrole and N-phenylindole carbenes and used them as ruthenium-ligating moieties in the synthesis of Hoveyda-Grubbs catalyst derivatives. We show that most of these complexes are difficult to synthesize and unstable apart from the N-phenylpyrrole-2,6-diisopropylphenyl ruthenium complex and its perbrominated derivative. These two systems are almost completely inactive in ring-closing metathesis at room temperature and become active only at 80 °C. DFT, SAPT0 and DLPNO-CCSD(T) calculations suggest that the rarely occurring phenyl-ruthenium interactions are responsible for the very slow initiation of these precatalysts at low temperatures.
- Grudzień,Trzaskowski,Smoleń,Gajda,Wo?niak,Grela
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p. 11790 - 11799
(2017/09/18)
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- Expanding the Family of Hoveyda-Grubbs Catalysts Containing Unsymmetrical NHC Ligands
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A series of Hoveyda-Grubbs second-generation catalysts containing N-alkyl/N′-aryl N-heterocyclic carbene (NHC) ligands were synthesized and investigated in representative olefin metathesis reactions. Steric perturbations of unsymmetrical NHCs were achieved through modulation of the hindrance of alkyl (neopentyl, neophyl, cyclohexyl) and aryl (2-isopropylphenyl, mesityl) substituents at the nitrogen atoms in combination with different backbone configurations (syn and anti). The NHC substitution patterns strongly influence the stability and reactivity of the corresponding complexes. In general, complexes bearing an anti NHC backbone are more stable and more active than their corresponding syn isomers. In both the series, the presence of bulky, highly branched N-alkyl groups tends to give reduced catalytic differences between syn and anti isomers, whereas the nature of the N′-aryl substituent (2-isopropylphenyl or mesityl) gives rise to different activity and/or selectivity. Of note, an N′-mesityl catalyst with anti backbone was found to be highly competent in the ethenolysis of ethyl oleate, achieving up to 90% selectivity for the formation of terminal olefins.
- Paradiso, Veronica,Bertolasi, Valerio,Costabile, Chiara,Caruso, Tonino,D?browski, Micha?,Grela, Karol,Grisi, Fabia
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p. 3692 - 3708
(2017/10/13)
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- Novel olefin metathetis catalysts with fluorinated N-alkyl-N′-arylimidazolin-2-ylidene ligands
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Novel ruthenium carbene complexes bearing unsymmetrical NHC-ligands based on N-alkyl-N′-arylimidazoline with hexafluoroisopropylmethoxy group in para-position of N-aryl moiety have been synthesized. Catalytic activity of complexes obtained was investigate
- Masoud,Akmalov,Artyushin,Bruneau,Osipov
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p. 1601 - 1606
(2018/01/01)
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- Synthesis of metathesis catalysts with fluorinated unsymmetrical N,N’-diaryl imidazoline-based NHC ligands
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New olefin metathesis catalysts bearing unsymmetrical fluorinated NHC ligands with hexafluoroisopropylmethoxy group in ortho-positions of N-aryl-substituent have been synthesized. The effects of mono-ortho-arylsubstitution and the replacement of para-meth
- Masoud, Salekh M.,Topchiy, Maxim A.,Peregudov, Alexander S.,Roisnel, Thierry,Dixneuf, Pierre H.,Bruneau, Christian,Osipov, Sergey N.
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- Cationic ruthenium alkylidene catalysts bearing phosphine ligands
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The discovery of highly active catalysts and the success of ionic liquid immobilized systems have accelerated attention to a new class of cationic metathesis catalysts. We herein report the facile syntheses of cationic ruthenium catalysts bearing bulky phosphine ligands. Simple ligand exchange using silver(i) salts of non-coordinating or weakly coordinating anions provided either PPh3 or chelating Ph2P(CH2)nPPh2 (n = 2 or 3) ligated cationic catalysts. The structures of these newly reported catalysts feature unique geometries caused by ligation of the bulky phosphine ligands. Their activities and selectivities in standard metathesis reactions were also investigated. These cationic ruthenium alkylidene catalysts reported here showed moderate activity and very similar stereoselectivity when compared to the second generation ruthenium dichloride catalyst in ring-closing metathesis, cross metathesis, and ring-opening metathesis polymerization assays.
- Endo, Koji,Grubbs, Robert H.
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supporting information
p. 3627 - 3634
(2016/03/05)
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- RUTHENIUM COMPLEXES, METHOD OF PRODUCING THEM, AND THEIR USE
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The subject of the present invention are novel ruthenium complexes defined by the general Formula 1. The present invention also relates to method of manufacturing of a novel metal complexes defined by the general Formula 1 as well as their use in olefin metathesis reactions.
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Page/Page column 35
(2016/07/05)
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- Ruthenium olefin metathesis catalysts featuring unsymmetrical N-heterocyclic carbenes
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New ruthenium Grubbs' and Hoveyda-Grubbs' second generation catalysts bearing N-alkyl/N-isopropylphenyl N-heterocyclic carbene (NHC) ligands with syn or anti backbone configuration were obtained and compared in model olefin metathesis reactions. Different catalytic efficiencies were observed depending on the size of the N-alkyl group (methyl or cyclohexyl) and on the backbone configuration. The presence of an N-cyclohexyl substituent determined the most significant reactivity differences between catalysts with syn or anti phenyl groups on the backbone. In particular, anti catalysts proved highly efficient, especially in the ring-closing metathesis (RCM) of encumbered diolefins, while syn catalysts showed low efficiency in the RCM of less hindered diolefins. This peculiar behavior, rationalized through DFT studies, was found to be related to the high propensity of these catalysts to give nonproductive metathesis events. Enantiopure anti catalysts were also tested in asymmetric metathesis reactions, where moderate enantioselectivities were observed. The steric and electronic properties of unsymmetrical NHCs with the N-cyclohexyl group were then evaluated using the corresponding rhodium complexes. While steric factors proved unimportant for both syn and anti NHCs, a major electron-donating character was found for the unsymmetrical NHC with anti phenyl substituents on the backbone.
- Paradiso, Veronica,Bertolasi, Valerio,Costabile, Chiara,Grisi, Fabia
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supporting information
p. 561 - 571
(2016/01/09)
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- A Ruthenium Catalyst for Olefin Metathesis Featuring an Anti-Bredt N-Heterocyclic Carbene Ligand
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A ruthenium complex bearing an "anti-Bredt" N-heterocyclic carbene was synthesized, characterized and evaluated as a catalyst for olefin metathesis. Good conversions were observed at room temperature for the formation of di- A nd tri-substituted olefins b
- Martin, David,Marx, Vanessa M.,Grubbs, Robert H.,Bertrand, Guy
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p. 965 - 969
(2016/04/05)
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- N-Trifluoromethyl NHC Ligands Provide Selective Ruthenium Metathesis Catalysts
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We report the synthesis of ruthenium metathesis catalysts containing unsymmetrical N-trifluoromethyl NHC ligands. These complexes have been fully characterized, and a Ru-F interaction has been identified in the solid state by X-ray crystallographic analysis for three catalysts with Ru-F distances between 2.629(2) and 2.652(2) ?. The influence of the N-trifluoromethyl NHC ligands on the initiation rates and activation parameters was studied. The activity of these catalysts was evaluated in benchmark olefin metathesis reactions and compared to the standard second-generation Grubbs catalyst. Remarkably, N-trifluoromethyl catalysts display an unusually high selectivity for the formation of terminal olefins (up to 90%) in the ethenolysis of ethyl oleate. Much improved selectivity is demonstrated for alternating copolymerization of cyclooctene and norbornene as well. These results underline the importance of electronic effects exerted by the NHC ligand.
- Engl, Pascal S.,Fedorov, Alexey,Copéret, Christophe,Togni, Antonio
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p. 887 - 893
(2016/04/19)
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- Cross-metathesis reaction of functionalized and substituted olefins using group 8 transition metal carbene complexes as metathesis catalysts
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The invention pertains to the use of Group 8 transition metal carbene complexes as catalysts for olefin cross-metathesis reactions. In particular, ruthenium and osmium alkylidene complexes substituted with an N-heterocyclic carbene ligand are used to catalyze cross-metathesis reactions to provide a variety of substituted and functionalized olefins, including phosphonate-substituted olefins, directly halogenated olefins, 1,1,2-trisubstituted olefins, and quaternary allylic olefins. The invention further provides a method for creating functional diversity using the aforementioned complexes to catalyze cross-metathesis reactions of a first olefinic reactant, which may or may not be substituted with a functional group, with each of a plurality of different olefinic reactants, which may or may not be substituted with functional groups, to give a plurality of structurally distinct olefinic products. The methodology of the invention is also useful in facilitating the stereoselective synthesis of 1,2-disubstituted olefins in the cis configuration.
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Page/Page column 47; 48
(2016/08/29)
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- New indenylidene-type metathesis catalysts bearing unsymmetrical N-heterocyclic ligands with mesityl and nitrobenzyl substituents
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New indenylidene-type second generation catalysts bearing modified unsymmetrically substituted N- heterocyclic carbene ligands were synthesized. The com- plexes contain an N-mesityl and N?-nitrobenzyl substituted NHC ligand. The precursors of free carbenes—imidazolinium salts—were obtained in an easy and environment- friendly way (under aqueous or neat conditions). The new catalysts were prepared by reaction of in situ generated carbenes with a 1st generation indenylidene catalyst, containing pyridine ligands instead of tricyclohexylphosphine. The complexes were tested in RCM, CM, and ene-yne metathesis model reactions in commercial-grade solvents in air. Their activities were compared with that of commercially available indenylidene catalyst. The structures of complexes and their stability were investigated using static DFT calculations with mixed basis set.
- Malinowska, Marta,Kozlowska, Mariana,Hryniewicka, Agnieszka,Witkowski, Stanis?aw,Morzycki, Jacek W.
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p. 1091 - 1100
(2017/01/11)
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- New fluorinated catalysts for olefin metathesis
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New olefin metathesis catalysts, analogues of Grubbs II ones, bearing hexafluoroisopropylmethoxy groups in NHC ligand, provide high conversions in model ring closing metathesis of diallylmalonate and cross metathesis of allylbenzene with 1,3-diacetoxybut-
- Masoud, Salekh M.,Mailyan, Artur K.,Peregudov, Alexander S.,Bruneau, Christian,Osipov, Sergey N.
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p. 474 - 476
(2016/11/30)
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- Divergent Approach to a Family of Tyrosine-Derived Ru-Alkylidene Olefin Metathesis Catalysts
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A simple and generic approach to access a new family of Ru-alkylidene olefin metathesis catalysts with specialized properties is reported. This strategy utilizes a late stage, utilitarian Hoveyda-type ligand derived from tyrosine, which can be accessed via a multigram-scale synthesis. Further functionalization allows the catalyst properties to be tuned, giving access to modified second-generation Hoveyda-Grubbs-type catalysts. This divergent synthetic approach can be used to access solid-supported catalysts and catalysts that function under solvent-free and aqueous conditions.
- Gleeson, Ellen C.,Wang, Zhen J.,Jackson, W. Roy,Robinson, Andrea J.
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p. 7205 - 7211
(2015/07/28)
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- Ruthenium indenylidene complexes bearing N-alkyl/N-mesityl-substituted N-heterocyclic carbene ligands
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We report on the synthesis and characterization of second generation ruthenium indenylidene catalysts bearing unsymmetrical N-heterocyclic carbene (NHC) ligands denoted as RuCl2(3-phenyl-1-indenylidene)(1-mesityl-3-R-4,5-dihydroimidazol-2-ylidene)(PCy3), in which R is methyl 8a, octyl 8b or cyclohexyl 8c. The characterization of 8a-c was performed by NMR spectroscopy, elemental analysis, IR, HRMS and single-crystal X-ray diffraction analysis. In addition, the catalytic activity of the obtained initiators was evaluated in various representative metathesis reactions. The results reveal that the complexes 8a-c, bearing an N-alkyl side on the NHC, show a faster catalytic initiation than the reference complex 2. Complex 8a, which performs the best among the investigated indenylidene complexes, exhibits slower initiation but better overall efficiency than its benzylidene analogue 1c, especially in a low catalyst loading.
- Yu, Baoyi,Hamad, Fatma B.,Sels, Bert,Van Hecke, Kristof,Verpoort, Francis
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supporting information
p. 11835 - 11842
(2015/06/30)
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- NOVEL RUTHENIUM COMPLEXES, THEIR USE IN THE METATHESIS REACTIONS, AND A PROCESS FOR CARRYING OUT THE METATHESIS REACTION
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The invention is related to the metal complexes of the general formula (1). The invention is related also to the use of metal complexes of the formula 1 as (pre)catalysts for the olefin metathesis reactions, as well as to the process for carrying out the
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Paragraph 0093-0094
(2015/06/17)
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- High-Performance Isocyanide Scavengers for Use in Low-Waste Purification of Olefin Metathesis Products
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Three isocyanides containing a tertiary nitrogen atom were investigated for use as small-molecule ruthenium scavenging agents in the workup of olefin metathesis reactions. The proposed compounds are odorless, easy to obtain, and highly effective in removi
- Szczepaniak, Grzegorz,Urbaniak, Katarzyna,Wierzbicka, Celina,Kosiński, Krzysztof,Skowerski, Krzysztof,Grela, Karol
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p. 4139 - 4148
(2015/12/30)
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- 2-Methyltetrahydrofuran: Sustainable solvent for ruthenium-catalyzed olefin metathesis
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Applicability of 2-methyltetrahydrofuran for olefin metathesis was examined with a set of ruthenium Hoveyda-type second generation catalysts. Influence of temperature was studied and the results were compared with those obtained in classical solvents for metathesis: dichloromethane and toluene.
- Smoleń, Micha?,K?dziorek, Mariusz,Grela, Karol
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- Synthesis, structure, and catalytic activity of new ruthenium(II) indenylidene complexes bearing unsymmetrical N - heterocyclic carbenes
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New robust and air-stable ruthenium(II) indenylidene type second-generation precatalysts with unsymmetrical N-heterocyclic carbene (NHC) ligands were synthesized. The reaction profiles of these complexes were studied in commercial-grade solvents in air with model substrates leading to the di-, tri-, and tetrasubstituted olefins. In addition, application of selected precatalysts for olefin metathesis reactions on a broad spectrum of substrates with different functional groups was examined. Studies of solvent effects for the selected precatalysts as well as thermal activation of the corresponding complexes showed significant differences in their activities. Observed relationships in connection with single-crystal X-ray analysis revealed the influence of the unsymmetrical NHC ligands on the initiation rate of precatalysts. Dissociation of the phosphine ligand, the rate-determining step for our most active precatalysts, is accelerated by the steric repulsion of the dangling benzyl arm and the tricyclohexylphosphine ligand. A precatalyst with a hemilabile benzyl arm evinced decreased activity, probably due to coordination of the heteroatom to the ruthenium core taking place after dissociation of the phosphine ligand.
- Ablialimov, Osman,Kedziorek, Mariusz,Malinska, Maura,Wozniak, Krzysztof,Grela, Karol
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supporting information
p. 2160 - 2171
(2014/06/09)
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- Ruthenium olefin metathesis catalysts with frozen NHC ligand conformations
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The catalytic behavior of Grubbs and Hoveyda-Grubbs II type ruthenium complexes bearing N-heterocyclic carbene (NHC) ligands with syn-phenyl groups on the backbone and syn- or anti-oriented o-tolyl N-substituents was evaluated in a series of olefin metath
- Perfetto, Alessandra,Costabile, Chiara,Longo, Pasquale,Grisi, Fabia
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supporting information
p. 2747 - 2759
(2014/06/24)
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- Novel olefin metathesis ruthenium catalysts bearing backbone-substituted unsymmetrical NHC ligands
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Stable Ru-based catalysts containing unsymmetrical N-heterocyclic carbene (NHC) ligands with phenyl substituents on the backbone in syn and anti stereochemical relationships have been easily prepared and fully characterized. Preliminary investigation reve
- Paradiso, Veronica,Bertolasi, Valerio,Grisi, Fabia
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supporting information
p. 5932 - 5935
(2015/02/19)
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- Chelating Ruthenium Phenolate Complexes: Synthesis, General Catalytic Activity, and Applications in Olefin Metathesis Polymerization
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Cyclic Ru-phenolates were synthesized, and these compounds were used as olefin metathesis catalysts. Investigation of their catalytic activity pointed out that, after activation with chemical agents, these catalysts promote ring-closing metathesis (RCM), enyne and cross-metathesis (CM) reactions, including butenolysis, with good results. Importantly, these latent catalysts are soluble in neat dicyclopentadiene (DCPD) and show good applicability in ring-opening metathesis polymeriyation (ROMP) of this monomer. Olefin metathesis catalysis: Investigation of the catalytic activity of Ru phenolate catalysts pointed out that, after activation with chemical agents, these catalysts promote ring-closing metathesis (RCM), enyne, and cross-metathesis (CM) reactions, including butenolysis, with good results (see scheme, Mes=2,4,6-trimethylphenyl, Cy=cyclohexyl). The phenolanate catalysts, well soluble in dicyclopentadiene (DCPD), also show good applicability in ring-opening metathesis polymerization (ROMP) of this monomer.
- Koz?owska, Anna,Dranka, Maciej,Zachara, Janusz,Pump, Eva,Slugovc, Christian,Skowerski, Krzysztof,Grela, Karol
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supporting information
p. 14120 - 14125
(2016/02/18)
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- NOVEL RUTHENIUM COMPLEXES, THEIR USE IN THE METATHESIS REACTIONS, AND A PROCESS FOR CARRYING OUT THE METATHESIS REACTION
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The invention is related to the metal complexes of the general formula (1). The invention is related also to the use of metal complexes of the formula 1 as (pre)catalysts for the olefin metathesis reactions, as well as to the process for carrying out the olefin metathesis reaction.
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Page/Page column 16
(2014/02/16)
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- Investigations into ruthenium metathesis catalysts with six-membered chelating NHC ligands: Relationship between catalyst structure and stereoselectivity
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A series of ruthenium catalysts bearing five-membered chelating NHC architectures that exhibit very high Z-selectivity in a variety of metathesis reactions have recently been reported. It was envisioned that catalysts possessing six-membered chelates could similarly exhibit high Z-selectivity and address limitations of this methodology. We thus prepared a number of new catalysts and systematically investigated the impact of the NHC and anionic ligand on their stereoselectivity. In standard metathesis assays, only catalysts containing six-membered chelated NHC structures and η2-bound anionic ligands favored the Z-olefin products. In addition, substitution with bulkier N-aryl groups led to improved Z-selectivity. The effect of ligand structure on stereoselectivity discovered in this study will be useful in the future design of highly active and Z-selective ruthenium catalysts.
- Endo, Koji,Herbert, Myles B.,Grubbs, Robert H.
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supporting information
p. 5128 - 5135
(2013/10/08)
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- Ruthenium nitronate complexes as tunable catalysts for olefin metathesis and other transformations
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Novel ruthenium(ii) complexes were obtained as a result of a stoichiometric reaction of Grubbs' benzylidene second generation catalysts with 3-nitropropene. These stable complexes, formally ruthenaisoxazole N-oxide derivatives, display activity in both me
- Wdowik, Tomasz,Samojlowicz, Cezary,Jawiczuk, Magdalena,Malinska, Maura,Wozniak, Krzysztof,Grela, Karol
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supporting information
p. 674 - 676
(2013/02/25)
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