160750-61-8Relevant academic research and scientific papers
A pyridine-containing ruthenium-indenylidene complex: Synthesis and activity in ring-closing metathesis
Clavier, Hervé,Petersen, Jeffrey L.,Nolan, Steven P.
, p. 5444 - 5447 (2006)
The reaction of Cl2Ru(PCy3)2(3-phenylindenylidene) with excess pyridine leads to the new pyridine-containing ruthenium-based complex: Cl2Ru(PCy3)(Py)2(3-phenylindenylidene) in good yield. This catalyst has been fully characterized and tested in ring-closing metathesis. Its moderate activity has been examined by kinetic studies using several substrates and different reaction conditions.
Tube-in-tube reactor as a useful tool for homo- and heterogeneous olefin metathesis under continuous flow mode
Skowerski, Krzysztof,Czarnocki, Stefan J.,Knapkiewicz, Pawe?
, p. 536 - 542 (2014)
A tube-in-tube reactor was successfully applied in homo- and heterogeneous olefin metathesis reactions under continuous flow mode. It was shown that the efficient removal of ethylene facilitated by connection of the reactor with a vacuum pump significantly improves the outcome of metathesis reactions. The beneficial aspects of this approach are most apparent in reactions performed at low concentration, such as macrocyclization reactions. The established system allows achievement of both improved yield and selectivity, and is ideal for industrial applications. Copyright
The effect of silica-coating on catalyst recyclability in ionic magnetic nanoparticle-supported Grubbs-Hoveyda catalysts for ring-closing metathesis
Chen, Shu-Wei,Zhang, Zhi-Cheng,Zhai, Ning-Ning,Zhong, Chong-Min,Lee, Sang-Gi
, p. 648 - 653 (2015)
The Grubbs-Hoveyda type ruthenium-carbene complexes have been covalently immobilized on both silica coated and uncoated magnetic nanoparticles utilizing an imidazolium salt linker. These MNP-supported catalysts showed comparable catalytic activity to the
Activated Hoveyda-Grubbs Olefin Metathesis Catalysts Derived from a Large Scale Produced Pharmaceutical Intermediate – Sildenafil Aldehyde
Monsigny, Louis,Pi?tkowski, Jakub,Trzybiński, Damian,Wo?niak, Krzysztof,Niena?towski, Tomasz,Kajetanowicz, Anna,Grela, Karol
, p. 4590 - 4604 (2021)
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.).
Ethyl Lactate: A Green Solvent for Olefin Metathesis
Planer, Sebastian,Jana, Anupam,Grela, Karol
, p. 4655 - 4661 (2019)
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
Syntheses and reactivity of analogues of Grubbs' second generation metathesis catalyst with fluorous phosphines: A new phase-transfer strategy for catalyst activation
Da Costa, Rosenildo Correa,Gladysz, John A.
, p. 243 - 254 (2007)
Reactions of the bis(pyridine) complex (H2IMes)(Py) 2(Cl)2Ru(=CHPh), (H2IMes = 1,3-dimesityl-4,5- dihydroimidazol-2-ylidene) and the highly fluorophilic phosphines [R fn(CH2)m]s
Thermomorphic polyethylene-supported olefin metathesis catalysts
Hobbs, Christopher,Yang, Yun-Chin,Ling, Johnny,Nicola, Sally,Su, Haw-Lih,Bazzi, Hassan S.,Bergbreiter, David E.
, p. 3904 - 3907 (2011)
The preparation of polyethylene-oligomer (PEolig)-supported N-heterocyclic carbene ligands (NHCs) and their Ru complexes is described. These complexes are structurally analogous to their low molecular weight counterparts and can serve as thermo
Polyisobutylene-anchored n-heterocyclic carbene ligands
Hongfa, Chayanant,Su, Haw-Lih,Bazzi, Hassan S.,Bergbreiter, David E.
, p. 665 - 667 (2009)
(Figure Presented) The synthesis of polyisobutylene (PIB)-supported N-heterocyclic carbenes (NHCs) that are useful as ligands for recoverable/recyclable organometallic complexes is described. Both PIB-bound carbenes analogous to SIMes and IMes as well as
Ruthenium indenylidene "1st generation" olefin metathesis catalysts containing triisopropyl phosphite
Guidone, Stefano,Nahra, Fady,Slawin, Alexandra M. Z.,Cazin, Catherine S. J.
, p. 1520 - 1527 (2015)
The reaction of triisopropyl phosphite with phosphine-based indenylidene pre-catalysts affords "1st generation" cis-complexes. These have been used in olefin metathesis reactions. The cis-Ru species exhibit noticeable differences with the trans-Ru parent complexes in terms of structure, thermal stability and reactivity. Experimental data underline the importance of synergistic effects between phosphites and L-type ligands.
Ruthenium olefin metathesis catalysts featuring unsymmetrical N-heterocyclic carbenes
Paradiso, Veronica,Bertolasi, Valerio,Costabile, Chiara,Grisi, Fabia
, p. 561 - 571 (2016)
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.
