38511-09-0Relevant articles and documents
Highly controllable poly(N-vinylimidazole)-supported ruthenium catalysts for olefin metathesis reactions in aqueous media
?ztürk, Bengi ?zgün,Sariaslan, Begüm,Bayramgil, Nursel Pekel,?ehito?lu, Solmaz Karabulut
, p. 19 - 24 (2014)
In this study, we reported a novel poly(N-vinylimidazole) (PVI)-supported latent ruthenium catalyst for olefin metathesis applications in aqueous media. The catalysts were synthesized using direct immobilization of first- and second-generation Grubbs catalysts on poly(N-vinylimidazole). The immobilized catalysts were characterized using FT-IR, SEM and EDX. The catalysts are metathesis inactive in both organic and aqueous media but can be activated via the introduction of acid to the reaction medium. The activity of the catalysts was tested on ring closing metathesis (RCM) and ring opening metathesis polymerization (ROMP) reactions. It was shown that the molecular weight of the ROMP polymers can be controlled by initiating the reaction with varying HCl/Ru ratios. Additionally, the reusability of the catalysts for RCM of diethyldiallylmalonate was studied. In addition, the RCM reaction of diethyldiallylmalonate can be switched on and off via the introduction of acids and bases to the reaction media using PVI-supported ruthenium catalysts.
A thermally robust ruthenium phosphonium alkylidene catalyst-the effect of more bulky N -heterocyclic carbene ligands on catalyst performance in olefin metathesis reactions
Leitao, Erin M.,Piers, Warren E.,Parvez, Masood
, p. 935 - 942 (2013)
Three new ruthenium phosphonium alkylidene complexes incorporating N-heterocyclic carbene ligands with bulky N-aryl groups (2,6-diethyl, L = 1,3-bis(2,6-diethylphenyl)imidazolin-2-ylidene (H2IDEP) and 2,6-diisopropyl, L = 1,3-bis(2,6-diisopropylphenyl)imidazolin-2-ylidene (H 2ID-i-PP)) were synthesized and characterized. The H 2ID-i-PP supported complex was found to exhibit excellent thermal stabilities relative to the parent N-mesityl (N-Mes) complexes as well as the H2IDEP supported complexes. All three phosphonium alkylidenes were evaluated in comparison to the N-Mes derivative and Grubbs second generation catalyst using standard olefin metathesis reactions and conditions. The complex containing the bulky H2ID-i-PP ligand was found to have excellent activity and longevity in comparison to the other catalysts. Although initiation rates were slow for this sterically bulky precatalyst, its superior activity led to the best overall efficiency in test reactions.
Olefin-metathesis reactions using vinylideneruthenium(II) complexes as catalyst precursors
Katayama, Hiroyuki,Urushima, Hideto,Ozawa, Fumiyuki
, p. 16 - 25 (2000)
Vinylideneruthenium(II) complexes of the type RuCl2(=C=CHR)L2 (R = But, ferrocenyl; L = PPri3, PCy3), which are easily accessible from [RuCl2(p-cymene)]2 and terminal
A neutral, water-soluble olefin metathesis catalyst based on an N-heterocyclic carbene ligand
Gallivan, Justin P.,Jordan, Jason P.,Grubbs, Robert H.
, p. 2577 - 2580 (2005)
A water-soluble ruthenium-based olefin metathesis catalyst supported by a poly(ethylene glycol) conjugated N-heterocyclic carbene ligand is reported. The catalyst displays greater activity in aqueous ring-opening metathesis polymerization (ROMP) reactions
Synthesis and characterization of ruthenium(II) complexes with dendritic N-heterocyclic carbene ligands Metallodendrimers Special Issue
Fujihara, Tetsuaki,Nishida, Takeru,Terao, Jun,Tsuji, Yasushi
, p. 174 - 178 (2014)
Ru(II) complexes with a N-heterocyclic carbene ligand bearing flexible zeroth-, first-, or second-generation dendritic moieties were synthesized and characterized. The structure of the ruthenium complex with the zeroth-generation dendritic moieties was determined by X-ray crystallography. ONIOM calculations showed that the second generation dendritic moieties surrounded the ruthenium core. These complexes worked as active catalysts for the ring-closing metathesis at 25 °C.
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
supporting information, p. 4590 - 4604 (2021/08/13)
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.).
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
supporting information, (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.
Large-Scale Synthesis of a Niche Olefin Metathesis Catalyst Bearing an Unsymmetrical N-Heterocyclic Carbene (NHC) Ligand and its Application in a Green Pharmaceutical Context
Czajkowska-Szczykowska, Dorota,Czarnocki, Stefan,Grela, Karol,Kajetanowicz, Anna,Ma?ecki, Pawe?,Niena?towski, Tomasz,Paw?owska, Jolanta,Szczepanik, Pawe?
supporting information, p. 15708 - 15717 (2020/12/01)
A large-scale synthesis of known Ru olefin metathesis catalyst VII featuring an unsymmetrical N-heterocyclic carbene (NHC) ligand with one 2,5-diisopropylphenyl (DIPP) and one thiophenylmethylene N-substituent is reported. The optimised procedure does not require column chromatography in any step and allows for preparation of up to 0.5 kg batches of the catalyst from simple precursors. The application profile of the obtained catalyst was studied in environmentally friendly dimethyl carbonate (DMC). Although VII exhibited low efficiency in cross-metathesis (CM) with electron-deficient partners, good to excellent results were noted for substrates featuring easy to isomerise C?C double bonds. This includes polyfunctional substrates of medicinal chemistry interest, such as analogues of psychoactive 5F-PB-22 and NM-2201 and two PDE5 inhibitors—Sildenafil and Vardenafil. Finally, a larger scale ring-closing metathesis (RCM) of a Vardenafil derivative was conducted in DMC, allowing for straightforward isolation of the expected product (23 g) in high yield and with low Ru contamination level (7.7 ppm).
Semiheterogeneous Purification Protocol for the Removal of Ruthenium Impurities from Olefin Metathesis Reaction Products Using an Isocyanide Scavenger
Szczepaniak, Grzegorz,Noga?, Wojciech,Piatkowski, Jakub,Ruszczyńska, Anna,Bulska, Ewa,Grela, Karol
supporting information, p. 836 - 844 (2019/04/17)
A low-waste, time-economical, and scalable semiheterogeneous purification protocol for the removal of ruthenium residues from olefin metathesis (OM) reactions has been developed. It is based on the non-covalent immobilization of the commercially available
Activation of olefin metathesis complexes containing unsymmetrical unsaturated N-heterocyclic carbenes by copper and gold transmetalation
Kamal, Fadwa,Colombel-Rouen, Sophie,Dumas, Adrien,Guégan, Jean-Paul,Roisnel, Thierry,Dorcet, Vincent,Baslé, Olivier,Rouen, Mathieu,Mauduit, Marc
supporting information, p. 11583 - 11586 (2019/10/02)
The activation of ruthenium-indenylidene complexes containing two unsymmetrical unsaturated N-heterocyclic carbenes (u2-NHCs) by a transmetalation process is reported. The use of copper(i) or gold(i) chlorides promotes the rapid trapping of one NHC ligand, which releases the catalytically active Ru-species. Impressive initiation rates with full-conversions are observed within one minute. This practical protocol demonstrates excellent catalytic performances in various ring-closing metathesis (RCM) and self-metathesis (SM) reactions.
