5557-31-3Relevant articles and documents
Synthesis of Ether-Diols with Low Polarity from Long-Chained Fatty Alcohols for Use in Block Copolymers
Huber, Veronika Ramona,Riepl, Herbert Mathias
, p. 433 - 442 (2019)
Diol-terminated polyethers are important intermediates for the manufacturing of block copolymers, but only a few polyethers other than polyethylene glycols are available on a technical scale. Most of them are highly polar. Natural fatty alcohols—converted to similar polyethers—should have a grossly reduced polarity because of a large separation of the oxygen atoms in the C18 chain. A synthesis sequence of polyethers with a longer carbon chain compared to the ethylene glycol-derived ethers based on commercially available fatty alcohols was designed for a future examination of the hydrophobic properties. Palladium-catalyzed cleavage of olefinic dialkyl carbonates results in carbon dioxide elimination and subsequent formation of ethers from an allyl-palladium cation. It could be shown that this process with fatty alcohols like undec-10-en-1-ol or oleyl alcohol can be run with appreciable yield. Although carbonates were obtained here using expensive chloroformates as starting materials, transesterification of dimethylcarbonates can be used similarly. Ruthenium-catalyzed acyclic diene metathesis (ADMET) at both chain terminations then was applied to polymerize the ethers. Depending on the alkenyl chain, short oligomers with a degree of polymerization (DP) of about 5–8 seem to be formed according to gel permeation chromatography (GPC).
Tailored Ru-NHC heterogeneous catalysts for alkene metathesis
Karame, Iyad,Boualleg, Malika,Camus, Jean-Michel,Maishal, Tarun K.,Alauzun, Johan,Basset, Jean-Marie,Coperet, Christophe,Corriu, Robert J. P.,Jeanneau, Erwan,Mehdi, Ahmad,Reye, Catherine,Veyre, Laurent,Thieuleux, Chloe
, p. 11820 - 11823 (2009)
The preparation of highly active and stable Ru-NHC (ruthenium-N-heterocyclic carbene ligands) alkene metathesis catalysts through surface organometallic chemistry on hybrid mesostructured materials was reported. Two types of mesoporous hybrid materials we
Contra-thermodynamic Olefin Isomerization by Chain-Walking Hydroboration and Dehydroboration
Bloomer, Brandon,Butcher, Trevor W.,Ciccia, Nicodemo R.,Conk, Richard J.,Hanna, Steven,Hartwig, John F.
supporting information, p. 1005 - 1010 (2022/02/10)
We report a dehydroboration process that can be coupled with chain-walking hydroboration to create a one-pot, contra-thermodynamic, short-or long-range isomerization of internal olefins to terminal olefins. This dehydroboration occurs by a sequence comprising activation with a nucleophile, iodination, and base-promoted elimination. The isomerization proceeds at room temperature without the need for a fluoride base, and the substrate scope of this isomerization is expanded over those of previous isomerizations we have reported with silanes.
ACYCLIC CARBENE LIGAND FOR RUTHENIUM COMPLEX FORMATION, RUTHENIUM COMPLEX CATALYST, AND USE THEREOF
-
Paragraph 0124-0130, (2021/05/14)
Provided are a novel acyclic carbene ligand for ruthenium complex formation; a ruthenium complex catalyst using the ligand; a method of using the complex as a catalyst in an ethylene-metathesis ethenolysis reaction; a method of preparing the ruthenium complex catalyst; and a method of preparing a linear alpha-olefin, the method including the step of reacting a linear or cyclic alkene compound in the presence of the ruthenium complex catalyst. The acyclic carbene ligand of the present invention and the ruthenium complex catalyst using the same have high selectivity and turnover number for terminal olefin formation in an ethylene-metathesis ethenolysis reaction, and thus linear α-olefins may be prepared with a high yield.
Oxo 2-Adamantylidene Complexes of Mo(VI) and W(VI)
Boudjelel, Maxime,Zhai, Feng,Schrock, Richard R.,Hoveyda, Amir H.,Tsay, Charlene
supporting information, p. 838 - 842 (2021/04/09)
Molybdenum and tungsten oxo 2-adamantylidene (Adene) complexes that contain two nonafluoro-tert-butoxide (ORF9) ligands have been prepared through addition of 2-methylene-or 2-ethylideneadamantane to neophylidene or neopentylidene complexes. The isolated oxo complexes include W(O)(Adene)(ORF9)2(PPh2Me) (1W), W(O)(Adene)(ORF9)2 (2W), W(O)(Adene)(2,5-dimethylpyrrolide)2 (3W), W(O)(Adene)(2,5-dimethylpyrrolide)(2,6-dimesitylphenoxide) (4W), Mo(O)(Adene)(ORF9)2(PPhMe2) (1Mo), and Mo(O)(Adene)(ORF9)2 (2Mo). Compound 2W is a dimer that contains unsymmetrically bridging oxo ligands; it dissociates readily and reversibly into monomers, especially in the presence of a donor such as THF. In contrast, 2Mo is a monomer. Both 2W and 2Mo are remarkably stable thermally. The pale-blue complexes Mo(Adene)(ORF9)2Cl2 (5Mo) and W(Adene)(ORF9)2Cl2 (5W) are formed upon addition of PCl5 to 2Mo and 2W, respectively. The oxo complexes are reactive olefin metathesis initiators, while 5Mo and 5W are relatively poor initiators. We ascribe the thermal stability of 2Mo and 2W to resistance of the 2-adamantylidene ligands to couple bimolecularly, to the absence of an α-hydrogen in the alkylidene, or both.
Continuous Flow Z-Stereoselective Olefin Metathesis: Development and Applications in the Synthesis of Pheromones and Macrocyclic Odorant Molecules**
Browne, Duncan L.,Colombel-Rouen, Sophie,Crévisy, Christophe,Curbet, Idriss,Mauduit, Marc,McBride, Tom,Morvan, Jennifer,Roisnel, Thierry
supporting information, p. 19685 - 19690 (2021/08/06)
The first continuous flow Z-selective olefin metathesis process is reported. Key to realizing this process was the adequate choice of stereoselective catalysts combined with the design of an appropriate continuous reactor setup. The designed continuous process permits various self-, cross- and macro-ring-closing-metathesis reactions, delivering products in high selectivity and short residence times. This technique is exemplified by direct application to the preparation of a range of pheromones and macrocyclic odorant molecules and culminates in a telescoped Z-selective cross-metathesis/ Dieckmann cyclisation sequence to access (Z)-Civetone, incorporating a serial array of continually stirred tank reactors.
Synthesis and Activity of Six-Membered Cyclic Alkyl Amino Carbene-Ruthenium Olefin Metathesis Catalysts
Grubbs, Robert H.,Samkian, Adrian E.,Virgil, Scott C.,Xu, Yan,Yoon, Ki-Young
supporting information, (2020/02/27)
Ru-cyclic alkyl amino carbene (Ru-CAAC) olefin metathesis catalysts perform extraordinarily in metathesis macrocyclization and ethenolysis, but previous studies have been limited to the use of five-membered CAAC (CAAC-5) ligands. In this work, we synthesized a different group of ruthenium catalysts with more σ-donating and π-accepting six-membered CAAC (CAAC-6) ligands, and their metathesis activity was probed through initiation studies, ring-closing metathesis (RCM), cross-metathesis, and ethenolysis. These catalysts display higher initiation rates than analogous Ru-CAAC-5 complexes but demonstrate lower activity in RCM and ethenolysis.
Vortex Fluidic Ethenolysis, Integrating a Rapid Quench of Ruthenium Olefin Metathesis Catalysts
Pye, Scott J.,Chalker, Justin M.,Raston, Colin L.
, p. 1138 - 1143 (2020/08/27)
Ruthenium-catalysed ethenolysis occurs in a vortex fluidic device (VFD)-a scalable, thin-film microfluidic continuous flow process. This process takes advantage of the efficient mass transfer of gaseous reagents into the dynamic thin film of liquid. Also reported is the rapid quenching of the ruthenium-based olefin metathesis catalyst by the addition of a saturated solution of N-acetyl-l-cysteine in MeCN, as a convenient alternative to previously reported quenching methods.
In a Quest for Selectivity Paired with Activity: A Ruthenium Olefin Metathesis Catalyst Bearing an Unsymmetrical Phenanthrene-Based N-Heterocyclic Carbene
D?browski, Micha?,Grela, Karol,Trzybiński, Damian,Wo?niak, Krzysztof,Wyr?bek, Przemys?aw
, (2020/03/19)
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.
Integrating Activity with Accessibility in Olefin Metathesis: An Unprecedentedly Reactive Ruthenium-Indenylidene Catalyst
Nascimento, Daniel L.,Gawin, Anna,Gawin, Rafa?,Guńka, Piotr A.,Zachara, Janusz,Skowerski, Krzysztof,Fogg, Deryn E.
supporting information, p. 10626 - 10631 (2019/08/28)
Access to leading olefin metathesis catalysts, including the Grubbs, Hoveyda, and Grela catalysts, ultimately rests on the nonscaleable transfer of a benzylidene ligand from an unstable, impure aryldiazomethane. The indenylidene ligand can be reliably installed, but to date yields much less reactive catalysts. A fast-initiating, dimeric indenylidene complex (Ru-1) is reported, which reconciles high activity with scaleable synthesis. Each Ru center in Ru-1 is stabilized by a state-of-the-art cyclic alkyl amino carbene (CAAC, C1) and a bridging chloride donor: the lability of the latter elevates the reactivity of Ru-1 to a level previously attainable only with benzylidene derivatives. Evaluation of initiation rate constants reveals that Ru-1 initiates >250× faster than indenylidene catalyst M2 (RuCl2(H2IMes)(PCy3)(Ind)), and 65× faster than UC (RuCl2(C1)2(Ind)). The slow initiation previously regarded as characteristic of indenylidene catalysts is hence due to low ligand lability, not inherently slow cycloaddition at the Ru=CRR′ site. In macrocyclization and "ethenolysis" of methyl oleate (i.e., transformation into α-olefins via cross-metathesis with C2H4), Ru-1 is comparable or superior to the corresponding, breakthrough CAAC-benzylidene catalyst. In ethenolysis, Ru-1 is 5× more robust to standard-grade (99.9%) C2H4 than the top-performing catalyst, probably reflecting steric protection at the quaternary CAAC carbon.
