84646-68-4Relevant academic research and scientific papers
Rate enhancement by ethylene in the ru-catalyzed ring-closing metathesis of enynes: Evidence for an "ene-then-yne" pathway that diverts through a second catalytic cycle
Lloyd-Jones, Guy C.,Margue, Robert G.,De Vries, Johannes G.
, p. 7442 - 7447 (2005)
(Chemical Equation Presented) Mixing it: A dual-substrate/dual isotopic labeling strategy has shown that the accelerating effect of ethylene in intermolecular ring-closing metathesis of enynes is best explained by an ene-then-yne mechanism rather than the
Alkene-chelated ruthenium alkylidenes: A missing link to new catalysts
Gupta, Saswata,Sabbasani, Venkata R.,Su, Siyuan,Wink, Donald J.,Lee, Daesung
, p. 1977 - 1987 (2021)
A variety of heteroatom-chelated ruthenium alkylidenes have been developed as metathesis-active catalysts. Alkenechelated ruthenium alkylidenes, however, have not been considered as a viable alternative because alkene coordination is a necessary step in the catalytic cycle. Relying on common design principles with varying steric and electronic factors, a series of structurally diverse alkene-chelated ruthenium alkylidene complexes were prepared by trapping the intermediates of enyne ring-closing metathesis (RCM) of 1,n-enynes and diynes with a stoichiometric amount of an initiator ruthenium complex. One of the crucial structural elements that promotes the formation of 1,5-alkenechelates is the exo-Thorpe.Ingold effect, exerted by a gem-dialkyl moiety. These alkene-chelated complexes show a trans relationship between the N-heterocyclic carbene (NHC) ligand and the chelated alkene. On the other hand, η3-vinyl alkylidene complexes were generated from the RCM of ynamide-tethered 1,n-enynes. The presence of an ynamide moiety with a right connectivity is essential for the formation of these rare η3-vinyl alkylidene complexes with a cis relationship between the N-heterocyclic carbene (NHC) ligand and the chelated alkene. The stability and reactivity of these alkene-chelated ruthenium alkylidenes could be finely tuned to show characteristic behaviors in RCM, cross-metathesis (CM), and ring-opening metathesis polymerization (ROMP) reactions.
Lipase-catalyzed kinetic resolution of cyclic trans-1,2-diols bearing a diester moiety: Synthetic application to chiral seven-membered-ring α,α-disubstituted α-amino acid
Tanaka, Masakazu,Demizu, Yosuke,Nagano, Masanobu,Hama, Mariko,Yoshida, Yukio,Kurihara, Masaaki,Suemune, Hiroshi
, p. 7750 - 7756 (2007)
(Chemical Equation Presented) Chiral cycloalkane-trans-1,2-diols (±)-3 and (±)-8 having a diester moiety have been prepared from dimethyl dialkenylmalonate using olefin metathesis by Grubbs catalyst, followed by epoxidation and acidic hydrolysis. Kinetic
Synthesis, molecular modeling and preliminary biological evaluation of 1-amino-3-phosphono-3-cyclopentene-1-carboxylic acid and 1-amino-3-phosphono-2-cyclopentene-1-carboxylic acid, two novel agonists of metabotropic glutamate receptors of group III
Amori, Laura,Costantino, Gabriele,Marinozzi, Maura,Pellicciari, Roberto,Gasparini, Fabrizio,Flor, Peter J.,Kuhn, Rainer,Vranesic, Ivo
, p. 1447 - 1450 (2000)
On the basis of a pharmacophore definition of mGlu4 agonists, the two novel semi-rigid derivatives 12 and 13 were designed and synthesized. The preliminary biological evaluation demonstrated that both compounds interact with hmGlu(4a), while ineffective at group II receptor subtypes. In particular, derivative 13 is a full hmGlu(4a) agonist with an EC50=17 μM. (C) 2000 Elsevier Science Ltd. All rights reserved.
A simple oxidative procedure for the removal of ruthenium residues from metathesis reaction products
Knight, David W.,Morgan, Ian R.,Proctor, Anthony J.
, p. 638 - 640 (2010)
Ruthenium residues can be easily and rapidly removed from Grubbs metathesis products by washing with 15% aqueous hydrogen peroxide, which converts any ruthenium complexes into highly insoluble ruthenium dioxide, which then catalyzes the conversion of excess peroxide into water and oxygen. Ruthenium levels lower than 2 ppm can be routinely obtained; an additional advantage is that any phosphines are also rapidly oxidized to the corresponding, more polar phosphine oxides thereby facilitating their removal as well in many cases.
Ruthenium hydroxycarbenes as key intermediates in cycloisomerization and decarbonylative cyclization of terminal alkynals
Batuecas, Maria,Esteruelas, Miguel A.,Garcia-Yebra, Cristina,Gonzalez-Rodriguez, Carlos,Onate, Enrique,Saa, Carlos
, p. 3474 - 3480 (2014)
The complex [Ru(η5-C5H5)(CO) (κ1-OCMe2)(PiPr3)] BF 4 (1) reacts with 3,3-bis(methoxycarbonyl)-5-hexyn-1-al to give the α,β-unsaturated cyclopentenylhydroxycarbene derivative [Ru(η5-C5H5){=C(OH)C=CHCH 2C(CO2CH3)2CH2}(CO) (PiPr3)]BF4 (2), which undergoes deprotonation with Al2O3 to afford Ru(η5-C 5H5){C(O)C=CHCH2C(CO2CH 3)2CH2}(CO) (PiPr3) (3). In the presence of P2O5, the reaction of 1 with the alkynal leads to the alkenylvinylidene [Ru(η5-C5H 5){=C=C-CH=CH-C(CO2CH3)2-CH 2}(CO)(PiPr3)]BF4 (4), which yields the β,γ-unsaturated cyclopentenylhydroxycarbene [Ru(η 5-C5H5){C(OH)CHCH=CHC(CO2CH 3)2CH2}(CO)(PiPr3)] BF4 (5) by means of a 1,2-addition of water. Complex 5 slowly isomerizes into 2. The deprotonation of 5 with Al2O3 gives Ru(η5-C5H5){C(O)CHCH=CHC(CO 2CH3)2CH2}(CO)(PiPr 3) (6). Solvate Ru complex 1 and Ru hydroxycarbene 2 catalyze the cyclization of 3,3-bis(methoxycarbonyl)-5-hexyn-1-al to give mixtures of the cycloisomerized aldehyde 1,1-bis(methoxycarbonyl)-3-formylcyclopent-3-ene (7) and cycloalkene 1,1-bis(methoxycarbonyl)cyclopent-3-ene (8).
Generation and spectroscopic characterization of ruthenacyclobutane and ruthenium olefin carbene intermediates relevant to ring closing metathesis catalysis
Van Der Eide, Edwin F.,Romero, Patricio E.,Piers, Warren E.
, p. 4485 - 4491 (2008)
The reaction of phosphonium alkylidenes [(H2IMes)RuCl 2=CHPR3]+[A]- (R = C 6H11, A = OTf or B(C6F5) 4, 1-Cy; R = i-C3H7, A = CIB(C 6F5)3 or OTf, 1-iPr) with 1 equiv of ethylene at -78°C, in the presence of 2-3 equiv of a trapping olefin substrate, yields intermediates relevant to olefin metathesis catalytic cycles. Dimethyl cyclopent-3-ene-1,1-dicarboxylate gives solutions of a substituted ruthenacy-clobutane 3 of relevance to ring closing metathesis catalysis. 1H and 13C NMR data are fully consistent with its assignment as a ruthenacyclobutane, but 1JCC values of 23 Hz for the CαH2-Cβ bond and 8.5 Hz for the CαH-Cβ bond point to an unsymmetrical structure in which the latter bond is more activated than the former. In contrast, trapping with acenaphthylene leads to an olefin carbene complex (6) in which the putative ruthenacyclobutane has opened; this species was also fully characterized by NMR spectroscopy and compared to related species reported previously.
Ruthenabenzene: A Robust Precatalyst
Gupta, Saswata,Su, Siyuan,Zhang, Yu,Liu, Peng,Wink, Donald J.,Lee, Daesung
supporting information, p. 7490 - 7500 (2021/05/26)
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.
NHC (N-heterocyclic carbene) ligand, ruthenium catalyst thereof, preparation methods and application
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Paragraph 0151--0158, (2019/08/02)
The invention relates to an NHC (N-heterocyclic carbene) ligand, a ruthenium catalyst thereof, preparation methods and an application of the catalyst. The NHC ligand structures are shown in formulas Ia and Ib respectively, and the corresponding ruthenium catalyst structures are shown in formulas IIa and IIb respectively. After large steric hindrance and electron-rich groups are simultaneously introduced to the NHC ligand structures, the catalytic activity and the stability of the ruthenium complex catalyst of the NHC ligand are notably improved, and the application range of the ruthenium complex catalyst of the NHC ligand is notably enlarged.
Ruthenium dihydride complexes as enyne metathesis catalysts
Dolan, Martin A.,Dixon, Alexandre D.C.,Chisholm, John D.,Clark, Daniel A.
supporting information, p. 4471 - 4474 (2018/11/23)
Ruthenium–catalyzed enyne metathesis is a reliable and efficient method for the formation of 1,3-dienes, a common structural motif in synthetic organic chemistry. The development of new transition-metal complexes competent to catalyze enyne metathesis rea
